case study on environmental challenges

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Seven case studies in carbon and climate

Every part of the mosaic of Earth's surface — ocean and land, Arctic and tropics, forest and grassland — absorbs and releases carbon in a different way. Wild-card events such as massive wildfires and drought complicate the global picture even more. To better predict future climate, we need to understand how Earth's ecosystems will change as the climate warms and how extreme events will shape and interact with the future environment. Here are seven pressing concerns.

The Far North is warming twice as fast as the rest of Earth, on average. With a 5-year Arctic airborne observing campaign just wrapping up and a 10-year campaign just starting that will integrate airborne, satellite and surface measurements, NASA is using unprecedented resources to discover how the drastic changes in Arctic carbon are likely to influence our climatic future.

Wildfires have become common in the North. Because firefighting is so difficult in remote areas, many of these fires burn unchecked for months, throwing huge plumes of carbon into the atmosphere. A recent report found a nearly 10-fold increase in the number of large fires in the Arctic region over the last 50 years, and the total area burned by fires is increasing annually.

Organic carbon from plant and animal remains is preserved for millennia in frozen Arctic soil, too cold to decompose. Arctic soils known as permafrost contain more carbon than there is in Earth's atmosphere today. As the frozen landscape continues to thaw, the likelihood increases that not only fires but decomposition will create Arctic atmospheric emissions rivaling those of fossil fuels. The chemical form these emissions take — carbon dioxide or methane — will make a big difference in how much greenhouse warming they create.

Initial results from NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) airborne campaign have allayed concerns that large bursts of methane, a more potent greenhouse gas, are already being released from thawing Arctic soils. CARVE principal investigator Charles Miller of NASA's Jet Propulsion Laboratory (JPL), Pasadena, California, is looking forward to NASA's ABoVE field campaign (Arctic Boreal Vulnerability Experiment) to gain more insight. "CARVE just scratched the surface, compared to what ABoVE will do," Miller said.

Methane is the Billy the Kid of carbon-containing greenhouse gases: it does a lot of damage in a short life. There's much less of it in Earth's atmosphere than there is carbon dioxide, but molecule for molecule, it causes far more greenhouse warming than CO 2 does over its average 10-year life span in the atmosphere.

Methane is produced by bacteria that decompose organic material in damp places with little or no oxygen, such as freshwater marshes and the stomachs of cows. Currently, over half of atmospheric methane comes from human-related sources, such as livestock, rice farming, landfills and leaks of natural gas. Natural sources include termites and wetlands. Because of increasing human sources, the atmospheric concentration of methane has doubled in the last 200 years to a level not seen on our planet for 650,000 years.

Locating and measuring human emissions of methane are significant challenges. NASA's Carbon Monitoring System is funding several projects testing new technologies and techniques to improve our ability to monitor the colorless gas and help decision makers pinpoint sources of emissions. One project, led by Daniel Jacob of Harvard University, used satellite observations of methane to infer emissions over North America. The research found that human methane emissions in eastern Texas were 50 to 100 percent higher than previous estimates. "This study shows the potential of satellite observations to assess how methane emissions are changing," said Kevin Bowman, a JPL research scientist who was a coauthor of the study.

Tropical forests

Tropical forests are carbon storage heavyweights. The Amazon in South America alone absorbs a quarter of all carbon dioxide that ends up on land. Forests in Asia and Africa also do their part in "breathing in" as much carbon dioxide as possible and using it to grow.

However, there is evidence that tropical forests may be reaching some kind of limit to growth. While growth rates in temperate and boreal forests continue to increase, trees in the Amazon have been growing more slowly in recent years. They've also been dying sooner. That's partly because the forest was stressed by two severe droughts in 2005 and 2010 — so severe that the Amazon emitted more carbon overall than it absorbed during those years, due to increased fires and reduced growth. Those unprecedented droughts may have been only a foretaste of what is ahead, because models predict that droughts will increase in frequency and severity in the future.

In the past 40-50 years, the greatest threat to tropical rainforests has been not climate but humans, and here the news from the Amazon is better. Brazil has reduced Amazon deforestation in its territory by 60 to 70 percent since 2004, despite troubling increases in the last three years. According to Doug Morton, a scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, further reductions may not make a marked difference in the global carbon budget. "No one wants to abandon efforts to preserve and protect the tropical forests," he said. "But doing that with the expectation that [it] is a meaningful way to address global greenhouse gas emissions has become less defensible."

In the last few years, Brazil's progress has left Indonesia the distinction of being the nation with the highest deforestation rate and also with the largest overall area of forest cleared in the world. Although Indonesia's forests are only a quarter to a fifth the extent of the Amazon, fires there emit massive amounts of carbon, because about half of the Indonesian forests grow on carbon-rich peat. A recent study estimated that this fall, daily greenhouse gas emissions from recent Indonesian fires regularly surpassed daily emissions from the entire United States.

Wildfires are natural and necessary for some forest ecosystems, keeping them healthy by fertilizing soil, clearing ground for young plants, and allowing species to germinate and reproduce. Like the carbon cycle itself, fires are being pushed out of their normal roles by climate change. Shorter winters and higher temperatures during the other seasons lead to drier vegetation and soils. Globally, fire seasons are almost 20 percent longer today, on average, than they were 35 years ago.

Currently, wildfires are estimated to spew 2 to 4 billion tons of carbon into the atmosphere each year on average — about half as much as is emitted by fossil fuel burning. Large as that number is, it's just the beginning of the impact of fires on the carbon cycle. As a burned forest regrows, decades will pass before it reaches its former levels of carbon absorption. If the area is cleared for agriculture, the croplands will never absorb as much carbon as the forest did.

As atmospheric carbon dioxide continues to increase and global temperatures warm, climate models show the threat of wildfires increasing throughout this century. In Earth's more arid regions like the U.S. West, rising temperatures will continue to dry out vegetation so fires start and burn more easily. In Arctic and boreal ecosystems, intense wildfires are burning not just the trees, but also the carbon-rich soil itself, accelerating the thaw of permafrost, and dumping even more carbon dioxide and methane into the atmosphere.

North American forests

With decades of Landsat satellite imagery at their fingertips, researchers can track changes to North American forests since the mid-1980s. A warming climate is making its presence known.

Through the North American Forest Dynamics project, and a dataset based on Landsat imagery released this earlier this month, researchers can track where tree cover is disappearing through logging, wildfires, windstorms, insect outbreaks, drought, mountaintop mining, and people clearing land for development and agriculture. Equally, they can see where forests are growing back over past logging projects, abandoned croplands and other previously disturbed areas.

"One takeaway from the project is how active U.S. forests are, and how young American forests are," said Jeff Masek of Goddard, one of the project’s principal investigators along with researchers from the University of Maryland and the U.S. Forest Service. In the Southeast, fast-growing tree farms illustrate a human influence on the forest life cycle. In the West, however, much of the forest disturbance is directly or indirectly tied to climate. Wildfires stretched across more acres in Alaska this year than they have in any other year in the satellite record. Insects and drought have turned green forests brown in the Rocky Mountains. In the Southwest, pinyon-juniper forests have died back due to drought.

Scientists are studying North American forests and the carbon they store with other remote sensing instruments. With radars and lidars, which measure height of vegetation from satellite or airborne platforms, they can calculate how much biomass — the total amount of plant material, like trunks, stems and leaves — these forests contain. Then, models looking at how fast forests are growing or shrinking can calculate carbon uptake and release into the atmosphere. An instrument planned to fly on the International Space Station (ISS), called the Global Ecosystem Dynamics Investigation (GEDI) lidar, will measure tree height from orbit, and a second ISS mission called the Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) will monitor how forests are using water, an indicator of their carbon uptake during growth. Two other upcoming radar satellite missions (the NASA-ISRO SAR radar, or NISAR, and the European Space Agency’s BIOMASS radar) will provide even more complementary, comprehensive information on vegetation.

Ocean carbon absorption

When carbon-dioxide-rich air meets seawater containing less carbon dioxide, the greenhouse gas diffuses from the atmosphere into the ocean as irresistibly as a ball rolls downhill. Today, about a quarter of human-produced carbon dioxide emissions get absorbed into the ocean. Once the carbon is in the water, it can stay there for hundreds of years.

Warm, CO 2 -rich surface water flows in ocean currents to colder parts of the globe, releasing its heat along the way. In the polar regions, the now-cool water sinks several miles deep, carrying its carbon burden to the depths. Eventually, that same water wells up far away and returns carbon to the surface; but the entire trip is thought to take about a thousand years. In other words, water upwelling today dates from the Middle Ages – long before fossil fuel emissions.

That's good for the atmosphere, but the ocean pays a heavy price for absorbing so much carbon: acidification. Carbon dioxide reacts chemically with seawater to make the water more acidic. This fundamental change threatens many marine creatures. The chain of chemical reactions ends up reducing the amount of a particular form of carbon — the carbonate ion — that these organisms need to make shells and skeletons. Dubbed the “other carbon dioxide problem,” ocean acidification has potential impacts on millions of people who depend on the ocean for food and resources.

Phytoplankton

Microscopic, aquatic plants called phytoplankton are another way that ocean ecosystems absorb carbon dioxide emissions. Phytoplankton float with currents, consuming carbon dioxide as they grow. They are at the base of the ocean's food chain, eaten by tiny animals called zooplankton that are then consumed by larger species. When phytoplankton and zooplankton die, they may sink to the ocean floor, taking the carbon stored in their bodies with them.

Satellite instruments like the Moderate resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua let us observe ocean color, which researchers can use to estimate abundance — more green equals more phytoplankton. But not all phytoplankton are equal. Some bigger species, like diatoms, need more nutrients in the surface waters. The bigger species also are generally heavier so more readily sink to the ocean floor.

As ocean currents change, however, the layers of surface water that have the right mix of sunlight, temperature and nutrients for phytoplankton to thrive are changing as well. “In the Northern Hemisphere, there’s a declining trend in phytoplankton,” said Cecile Rousseaux, an oceanographer with the Global Modeling and Assimilation Office at Goddard. She used models to determine that the decline at the highest latitudes was due to a decrease in abundance of diatoms. One future mission, the Pre-Aerosol, Clouds, and ocean Ecosystem (PACE) satellite, will use instruments designed to see shades of color in the ocean — and through that, allow scientists to better quantify different phytoplankton species.

In the Arctic, however, phytoplankton may be increasing due to climate change. The NASA-sponsored Impacts of Climate on the Eco-Systems and Chemistry of the Arctic Pacific Environment (ICESCAPE) expedition on a U.S. Coast Guard icebreaker in 2010 and 2011 found unprecedented phytoplankton blooms under about three feet (a meter) of sea ice off Alaska. Scientists think this unusually thin ice allows sunlight to filter down to the water, catalyzing plant blooms where they had never been observed before.

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Editor’s pick: 7 case studies on environmental cooperation

We know environmental changes and dwindling resources can lead to conflicts and inflame grievances among societal groups or even states dependant on nature. But how often do we speak about the role of environment as a catalyst for cooperation? In honour of this year’s World Environment Day, we bring to you 7 case studies in which the need to share a common environment and its resources has led adversaries to – despite hostilities and even ongoing conflict, and with the help of several resolution mechanisms – work in cooperation.

Turkey-Armenia: Water Cooperation Despite Tensions

Armenia and Turkey have been sharing the water of the Arpacay River – which forms the border between them – equitably, despite their lack of bilateral diplomatic relations. Before Armenia became independent in 1991, the former USSR had signed a number of treaties with Turkey over the Arpacay (or Akhourian) River. Although relations between Turkey and Armenia have been at an impasse since the 1990s, both countries have continued to implement the old treaties brokered before the collapse of the USSR and share the Arpacay River equitably to this day. 

DISCOVER THE CASE STUDY

Jordan and Israel: Tensions and Water Cooperation in the Middle-East

The rivers of the Jordan system all have a transboundary nature, a configuration which requires cooperation amongst all co-riparians to achieve sustainable water management. Yet the tensions which have prevailed between Israel and its Arab neighbours since 1948 have limited cooperation until today and at times escalated to war. However, one country, Jordan, distanced itself from the other Arab countries in the region and signed a peace agreement with Israel in which cooperation over water played an important role.

Transnational Conflict and Cooperation in the Lake Chad Basin

Since the beginning of the 2000s, growing claims of an urgent need to protect and restore Lake Chad have led the riparian states and the Lake Chad Basin Commission to engage in a number of joint water management initiatives with the support of a number of international organisations. These include a major project to transfer the waters of the Congo Basin (Oubangui) to Lake Chad in order to replenish the lake – the “Transaqua” project and a sustainable development programme for Lake Chad, which was launched in 2009. The Lake Chad Water Charter adopted in 2012 seeks to define water management and wetland management objectives based on shared concerns.

EU Influence on the Euphrates-Tigris Conflict

From the 1960s to the 1990s, tensions among the co-riparian states of the Euphrates-Tigris Basin hampered cooperation over the rivers. Since 1999, when Turkey was granted the status of candidate country for membership to the EU, the country started transposing and implementing the EU body of legislation, including the EU Water Framework Directive (WFD). The renewed cooperation which was observed among the three co-riparians in the 2000s reflects the influence of the WFD.

Lower Mekong Basin: Challenges and opportunities for early cooperation

To promote peace, regional cooperation, and development in the Lower Mekong Basin, the United Nations (UN) encouraged the creation of an intergovernmental agency for joint water management. In 1957, the Mekong Committee was created. After an initial period of enthusiasm, momentum began to subside during the 1970s. Nevertheless, the Mekong’s early institutional architecture provided a forum for dialogue that was sustained even in times of regional hostilities. It also laid the groundwork for contemporary Mekong governance in times of rapid development.

Transboundary Water Disagreements between South Africa and Namibia

Following the independence of Namibia in 1990, a number of water-related disagreements have emerged between the Orange River riparians South Africa and Namibia. These revolve around the demarcation of a common border, water allocation and water pricing, and the Lesotho Highlands Water Project (LHWP). Existing water scarcity in the lower Orange River Basin is likely to be further aggravated by the impacts of climate change. Despite the conflict potential harboured by existing disagreements, the basin’s high level of institutionalised cooperation and the possibilities for intra- and inter-basin water transfers could help alleviate water stress and resolve bilateral disagreement over shared water resources.

Iraq-Iran: from Water Dispute to War

The Shatt al-Arab River forms the boundaries between Iran and Iraq before flowing into the Persian Gulf. Due to its strategic importance for both Iraq and Iran, for centuries both countries have defended their sovereignty rights over the river. The Shatt al-Arab dispute was an important cause which led to the outbreak of the 1980-1988 war between Iraq and Iran. In recent years – and particularly since the beginning of the war in Syria –, relations between Iraq and Iran have majorly improved. This has been reflected on the Shatt-al Arab issue. In 2014, Iraq and Iran’s Prime Minister met to discuss how to delimit the river in a mutually acceptable way and to put an end to the status quo. Water-protection aspects took also a major space in the talks. Today both countries have restored bilateral diplomatic relations and reached agreements on a mutually satisfying delimitation of the river. They are also jointly working towards the protection of the river. 

130+ case studies on environment, conflict and cooperation

The Factbook is a knowledge platform that provides an overview of environmental conflict and cooperation from around the world. It does so by offering a select number of case studies that reflect instances of conflict, resolution and peacebuilding processes that are related to environmental change.

The Factbook seeks to help policy-makers, experts, researchers and any interested members of the public to better understand and compare the drivers behind environmental conflict and cooperation. The ultimate goal of this project is to contribute to the prevention and sustainable transformation of such conflicts using lessons learned from earlier (non-) interventions.

                Discover the ECC Factbook

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• Published: 07 July 2022

A global horizon scan of issues impacting marine and coastal biodiversity conservation

• James E. Herbert-Read   ORCID: orcid.org/0000-0003-0243-4518 1   na1 ,
• Ann Thornton   ORCID: orcid.org/0000-0002-7448-8497 2   na1 ,
• Diva J. Amon   ORCID: orcid.org/0000-0003-3044-107X 3 , 4 ,
• Silvana N. R. Birchenough   ORCID: orcid.org/0000-0001-5321-8108 5 ,
• Isabelle M. Côté   ORCID: orcid.org/0000-0001-5368-4061 6 ,
• Maria P. Dias   ORCID: orcid.org/0000-0002-7281-4391 7 , 8 ,
• Brendan J. Godley 9 ,
• Sally A. Keith   ORCID: orcid.org/0000-0002-9634-2763 10 ,
• Emma McKinley   ORCID: orcid.org/0000-0002-8250-2842 11 ,
• Lloyd S. Peck   ORCID: orcid.org/0000-0003-3479-6791 12 ,
• Ricardo Calado 13 ,
• Omar Defeo   ORCID: orcid.org/0000-0001-8318-528X 14 ,
• Steven Degraer   ORCID: orcid.org/0000-0002-3159-5751 15 ,
• Emma L. Johnston   ORCID: orcid.org/0000-0002-2117-366X 16 ,
• Hermanni Kaartokallio 17 ,
• Peter I. Macreadie   ORCID: orcid.org/0000-0001-7362-0882 18 ,
• Anna Metaxas   ORCID: orcid.org/0000-0002-1935-6213 19 ,
• Agnes W. N. Muthumbi 20 ,
• David O. Obura   ORCID: orcid.org/0000-0003-2256-6649 21 , 22 ,
• David M. Paterson 23 ,
• Alberto R. Piola   ORCID: orcid.org/0000-0002-5003-8926 24 , 25 ,
• Anthony J. Richardson   ORCID: orcid.org/0000-0002-9289-7366 26 , 27 ,
• Irene R. Schloss   ORCID: orcid.org/0000-0002-5917-8925 28 , 29 , 30 ,
• Paul V. R. Snelgrove   ORCID: orcid.org/0000-0002-6725-0472 31 ,
• Bryce D. Stewart 32 ,
• Paul M. Thompson   ORCID: orcid.org/0000-0001-6195-3284 33 ,
• Gordon J. Watson   ORCID: orcid.org/0000-0001-8274-7658 34 ,
• Thomas A. Worthington   ORCID: orcid.org/0000-0002-8138-9075 2 ,
• Moriaki Yasuhara   ORCID: orcid.org/0000-0003-0990-1764 35 &
• William J. Sutherland 2 , 36  

Nature Ecology & Evolution volume  6 ,  pages 1262–1270 ( 2022 ) Cite this article

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The biodiversity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal biodiversity over the next 5–10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for example the impact of wildfires and the effect of poleward migration on equatorial biodiversity; resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens; and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal biodiversity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems.

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The fifteenth Conference of the Parties (COP) to the United Nations Convention on Biological Diversity will conclude negotiations on a global biodiversity framework in late-2022 that will aim to slow and reverse the loss of biodiversity and establish goals for positive outcomes by 2050 1 . Currently recognized drivers of declines in marine and coastal ecosystems include overexploitation of resources (for example, fishes, oil and gas), expansion of anthropogenic activities leading to cumulative impacts on the marine and coastal environment (for example, habitat loss, introduction of contaminants and pollution) and effects of climate change (for example, ocean warming, freshening and acidification). Within these broad categories, marine and coastal ecosystems face a wide range of emerging issues that are poorly recognized or understood, each having the potential to impact biodiversity. Researchers, conservation practitioners and marine resource managers must identify, understand and raise awareness of these relatively ‘unknown’ issues to catalyse further research into their underlying processes and impacts. Moreover, informing the public and policymakers of these issues can mitigate potentially negative impacts through precautionary principles before those effects become realized: horizon scans provide a platform to do this.

Horizon scans bring together experts from diverse disciplines to discuss issues that are (1) likely to have a positive or negative impact on biodiversity and conservation within the coming years and (2) not well known to the public or wider scientific community or face a substantial ‘step-change’ in their importance or application 2 . Horizon scans are an effective approach for pre-emptively identifying issues facing global conservation 3 . Indeed, marine issues previously identified through this approach include microplastics 4 , invasive lionfish 4 and electric pulse trawling 5 . To date, however, no horizon scan of this type has focused solely on issues related to marine and coastal biodiversity, although a scan on coastal shorebirds in 2012 identified potential threats to coastal ecosystems 6 . This horizon scan aims to benefit our ocean and human society by stimulating research and policy development that will underpin appropriate scientific advice on prevention, mitigation, management and conservation approaches in marine and coastal ecosystems.

We present the final 15 issues below in thematic groups identified post-scoring, rather than rank order (Fig. 1 ).

Numbers refer to the order presented in this article, rather than final ranking. Image of brine pool courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico 2014. Image of biodegradable bag courtesy of Katie Dunkley.

Ecosystem impacts

Wildfire impacts on coastal and marine ecosystems.

The frequency and severity of wildfires are increasing with climate change 7 . Since 2017, there have been fires of unprecedented scale and duration in Australia, Brazil, Portugal, Russia and along the Pacific coast of North America. In addition to threatening human life and releasing stored carbon, wildfires release aerosols, particles and large volumes of materials containing soluble forms of nutrients including nitrogen, phosphorus and trace metals such as copper, lead and iron. Winds and rains can transport these materials over long distances to reach coastal and marine ecosystems. Australian wildfires, for example, triggered widespread phytoplankton blooms in the Southern Ocean 8 along with fish and invertebrate kills in estuaries 9 . Predicting the magnitude and effects of these acute inputs is difficult because they vary with the size and duration of wildfires, the burning vegetation type, rainfall patterns, riparian vegetation buffers, dispersal by aerosols and currents, seasonal timing and nutrient limitation in the recipient ecosystem. Wildfires might therefore lead to beneficial, albeit temporary, increases in primary productivity, produce no effect or have deleterious consequences, such as the mortality of benthic invertebrates, including corals, from sedimentation, coastal darkening (see below), eutrophication or algal blooms 10 .

Coastal darkening

Coastal ecosystems depend on the penetration of light for primary production by planktonic and attached algae and seagrass. However, climate change and human activities increase light attenuation through changes in dissolved materials modifying water colour and suspended particles. Increased precipitation, storms, permafrost thawing and coastal erosion have led to the ‘browning’ of freshwater ecosystems by elevated organic carbon, iron and particles, all of which are eventually discharged into the ocean 11 . Coastal eutrophication leading to algal blooms compounds this darkening by further blocking light penetration. Additionally, land-use change, dredging and bottom fishing can increase seafloor disturbance, resuspending sediments and increasing turbidity. Such changes could affect ocean chemistry, including photochemical degradation of dissolved organic carbon and generation of toxic chemicals. At moderate intensities, limited spatial scales and during heatwaves, coastal darkening may have some positive impacts such as limiting coral bleaching on shallow reefs 12 but, at high intensities and prolonged spatial and temporal extents, lower light-regimes can contribute to cumulative stressor effects thereby profoundly altering ecosystems. This darkening may result in shifts in species composition, distribution, behaviour and phenology, as well as declines in coastal habitats and their functions (for example, carbon sequestration) 13 .

Increased toxicity of metal pollution due to ocean acidification

Concerns about metal toxicity in the marine environment are increasing as we learn more about the complex interactions between metals and global climate change 14 . Despite tight regulation of polluters and remediation efforts in some countries, the high persistence of metals in contaminated sediments results in the ongoing remobilization of existing metal pollutants by storms, trawling and coastal development, augmented by continuing release of additional contaminants into coastal waters, particularly in urban and industrial areas across the globe 14 . Ocean acidification increases the bioavailability, uptake and toxicity of metals in seawater and sediments, with direct toxicity effects on some marine organisms 15 . Not all biogeochemical changes will result in increased toxicity; in pelagic and deep-sea ecosystems, where trace metals are often deficient, increasing acidity may increase bioavailability and, in shallow waters, stimulate productivity for non-calcifying phytoplankton 16 . However, increased uptake of metals in wild-caught and farmed bivalves linked to ocean acidification could also affect human health, especially given that these species provide 25% of the world’s seafood. The combined effects of ocean acidification and metals could not only increase the levels of contamination in these organisms but could also impact their populations in the future 14 .

Equatorial marine communities are becoming depauperate due to climate migration

Climate change is causing ocean warming, resulting in a poleward shift of existing thermal zones. In response, species are tracking the changing ocean environmental conditions globally, with range shifts moving five times faster than on land 17 . In mid-latitudes and higher latitudes, as some species move away from current distribution ranges, other species from warmer regions can replace them 18 . However, the hottest climatic zones already host the most thermally tolerant species, which cannot be replaced due to their geographical position. Thus, climate change reduces equatorial species richness and has caused the formerly unimodal latitudinal diversity gradient in many communities to now become bimodal. This bimodality (dip in equatorial diversity) is projected to increase within the next 100 years if carbon dioxide emissions are not reduced 19 . The ecological consequences of this decline in equatorial zones are unclear, especially when combined with impacts of increasing human extraction and pollution 20 . Nevertheless, emerging ecological communities in equatorial systems are likely to have reduced resilience and capacity to support ecosystem services and human livelihoods.

Effects of altered nutritional content of fish due to climate change

Essential fatty acids (EFAs) are critical to maintaining human and animal health and fish consumption provides the primary source of EFAs for billions of people. In aquatic ecosystems, phytoplankton synthesize EFAs, such as docosahexaenoic acid (DHA) 21 , with pelagic fishes then consuming phytoplankton. However, concentrations of EFAs in fishes vary, with generally higher concentrations of omega-3 fatty acids in slower-growing species from colder waters 22 . Ongoing effects of climate change are impacting the production of EFAs by phytoplankton, with warming waters predicted to reduce the availability of DHA by about 10–58% by 2100 23 ; a 27.8% reduction in available DHA is associated with a 2.5 °C rise in water temperature 21 . Combined with geographical range shifts in response to environmental change affecting the abundance and distribution of fishes, this could lead to a reduction in sufficient quantities of EFAs for fishes, particularly in the tropics 24 . Changes to EFA production by phytoplankton in response to climate change, as shown for Antarctic waters 25 , could have cascading effects on the nutrient content of species further up the food web, with consequences for marine predators and human health 26 .

Resource exploitation

The untapped potential of marine collagens and their impacts on marine ecosystems.

Collagens are structural proteins increasingly used in cosmetics, pharmaceuticals, nutraceuticals and biomedical applications. Growing demand for collagen has fuelled recent efforts to find new sources that avoid religious constraints and alleviate risks associated with disease transmission from conventional bovine and porcine sources 27 . The search for alternative sources has revealed an untapped opportunity in marine organisms, such as from fisheries bycatch 28 . However, this new source may discourage efforts to reduce the capture of non-target species. Sponges and jellyfish offer a premium source of marine collagens. While the commercial-scale harvesting of sponges is unlikely to be widely sustainable, there may be some opportunity in sponge aquaculture and jellyfish harvesting, especially in areas where nuisance jellyfish species bloom regularly (for example, Mediterranean and Japan Seas). The use of sharks and other cartilaginous fish to supply marine collagens is of concern given the unprecedented pressure on these species. However, the use of coproducts derived from the fish-processing industry (for example, skin, bones and trims) offers a more sustainable approach to marine collagen production and could actively contribute to the blue bio-economy agenda and foster circularity 29 .

Impacts of expanding trade for fish swim bladders on target and non-target species

In addition to better-known luxury dried seafoods, such as shark fins, abalone and sea cucumbers, there is an increasing demand for fish swim bladders, also known as fish maw 30 . This demand may trigger an expansion of unsustainable harvests of target fish populations, with additional impacts on marine biodiversity through bycatch 30 , 31 . The fish swim-bladder trade has gained a high profile because the overexploitation of totoaba ( Totoaba macdonaldi) has driven both the target population and the vaquita ( Phocoena sinus) (which is bycaught in the Gulf of Mexico fishery) to near extinction 32 . By 2018, totoaba swim bladders were being sold for US$46,000 kg −1 . This extremely lucrative trade disrupts efforts to encourage sustainable fisheries. However, increased demand on the totoaba was itself caused by overexploitation over the last century of the closely related traditional species of choice, the Chinese bahaba ( Bahaba taipingensis) . We now risk both repeating this pattern and increasing its scale of impact, where depletion of a target species causes markets to switch to species across broader taxonomic and biogeographical ranges 31 . Not only does this cascading effect threaten other croakers and target species, such as catfish and pufferfish but maw nets set in more diverse marine habitats are likely to create bycatch of sharks, rays, turtles and other species of conservation concern.

Impacts of fishing for mesopelagic species on the biological ocean carbon pump

Growing concerns about food security have generated interest in harvesting largely unexploited mesopelagic fishes that live at depths of 200–1,000 m (ref. 33 ). Small lanternfishes (Myctophidae) dominate this potentially 10 billion ton community, exceeding the mass of all other marine fishes combined 34 and spanning millions of square kilometres of the open ocean. Mesopelagic fish are generally unsuitable for human consumption but could potentially provide fishmeal for aquaculture 34 or be used for fertilizers. Although we know little of their biology, their diel vertical migration transfers carbon, obtained by feeding in surface waters at night, to deeper waters during the day across many hundreds and even thousands of metres depth where it is released by excretion, egestion and death. This globally important carbon transport pathway contributes to the biological pump 35 and sequesters carbon to the deep sea 36 . Recent estimates put the contribution of all fishes to the biological ocean pump at 16.1% (± s.d. 13%) (ref. 37 ). The potential large-scale removal of mesopelagic fishes could disrupt a major pathway of carbon transport into the ocean depths.

Extraction of lithium from deep-sea brine pools

Global groups, such as the Deep-Ocean Stewardship Initiative, emphasize increasing concern about the ecosystem impacts from deep-sea resource extraction 38 . The demand for batteries, including for electric vehicles, will probably lead to a demand for lithium that is more than five times its current level by 2030 39 . While concentrations are relatively low in seawater, some deep-sea brines and cold seeps offer higher concentrations of lithium. Furthermore, new technologies, such as solid-state electrolyte membranes, can enrich the concentration of lithium from seawater sources by 43,000 times, increasing the energy efficiency and profitability of lithium extraction from the sea 39 . These factors could divert extraction of lithium resources away from terrestrial to marine mining, with the potential for significant impacts to localized deep-sea brine ecosystems. These brine pools probably host many endemic and genetically distinct species that are largely undiscovered or awaiting formal description. Moreover, the extremophilic species in these environments offer potential sources of marine genetic resources that could be used in new biomedical applications including pharmaceuticals, industrial agents and biomaterials 40 . These concerns point to the need to better quantify and monitor biodiversity in these extreme environments to establish baselines and aid management.

New technologies

Colocation of marine activities.

Climate change, energy needs and food security have moved to the top of global policy agendas 41 . Increasing energy needs, alongside the demands of fisheries and transport infrastructure, have led to the proposal of colocated and multifunctional structures to deliver economic benefits, optimize spatial planning and minimize the environmental impacts of marine activities 42 . These designs often bring technical, social, economic and environmental challenges. Some studies have begun to explore these multipurpose projects (for example, offshore windfarms colocated with aquaculture developments and/or Marine Protected Areas) and how to adapt these concepts to ensure they are ‘fit for purpose’, economically viable and reliable. However, environmental and ecosystem assessment, management and regulatory frameworks for colocated and multi-use structures need to be established to prevent these activities from compounding rather than mitigating the environmental impacts from climate change 43 .

Floating marine cities

In April 2019, the UN-HABITAT programme convened a meeting of scientists, architects, designers and entrepreneurs to discuss how floating cities might be a solution to urban challenges such as climate change and lack of housing associated with a rising human population ( https://unhabitat.org/roundtable-on-floating-cities-at-unhq-calls-for-innovation-to-benefit-all ). The concept of floating marine cities—hubs of floating structures placed at sea—was born in the middle of the twentieth century and updated designs now aim to translate this vision into reality 44 . Oceanic locations provide benefits from wave and tidal renewable energy and food production supported by hydroponic agriculture 45 . Modular designs also offer greater flexibility than traditional static terrestrial cities, whereby accommodation and facilities could be incorporated or removed in response to changes in population or specific events. The cost of construction in harsh offshore environments, rather than technology, currently limits the development of marine cities and potential designs will need to consider the consequences of more frequent and extreme climate events. Although the artificial hard substrates created for these floating cities could act as stepping stones, facilitating species movement in response to climate change 46 , this could also increase the spread of invasive species. Finally, the development of offshore living will raise issues in relation to governance and land ownership that must be addressed for marine cities to be viable 47 .

Trace-element contamination compounded by the global transition to green technologies

The persistent environmental impacts of metal and metalloid trace-element contamination in coastal sediments are now increasing after a long decline 48 . However, the complex sources of contamination challenge their management. The acceleration of the global transition to green technologies, including electric vehicles, will increase demand for batteries by over 10% annually in the coming years 49 . Electric vehicle batteries currently depend almost exclusively on lithium-ion chemistries, with potential trace-element emissions across their life cycle from raw material extraction to recycling or end-of-life disposal. Few jurisdictions treat lithium-ion batteries as harmful waste, enabling landfill disposal with minimal recycling 49 . Cobalt and nickel are the primary ecotoxic elements in next-generation lithium-ion batteries 50 , although there is a drive to develop a cobalt-free alternative likely to contain higher nickel content 50 . Some battery binder and electrolyte chemicals are toxic to aquatic life or form persistent organic pollutants during incomplete burning. Increasing pollution from battery production, recycling and disposal in the next decade could substantially increase the potentially toxic trace-element contamination in marine and coastal systems worldwide.

New underwater tracking systems to study non-surfacing marine animals

The use of tracking data in science and conservation has grown exponentially in recent decades. Most trajectory data collected on marine species to date, however, has been restricted to large and near-surface species, limited by the size of the devices and reliance on radio signals that do not propagate well underwater. New battery-free technology based on acoustic telemetry, named ‘underwater backscatter localization’ (UBL), may allow high-accuracy (<1 m) tracking of animals travelling at any depth and over large distances 51 . Still in the early stages of development, UBL technology has significant potential to help fill knowledge gaps in the distribution and spatial ecology of small, non-surfacing marine species, as well as the early life-history stages of many species 52 , over the next decades. However, the potential negative impacts of this methodology on the behaviour of animals are still to be determined. Ultimately, UBL may inform spatial management both in coastal and offshore regions, as well as in the high seas and address a currently biased perspective of how marine animals use ocean space, which is largely based on near-surface or aerial marine megafauna (for example, ref. 53 ).

Soft robotics for marine research

The application and utility of soft robotics in marine environments is expected to accelerate in the next decade. Soft robotics, using compliant materials inspired by living organisms, could eventually offer increased flexibility at depth because they do not face the same constraints as rigid robots that need pressurized systems to function 54 . This technology could increase our ability to monitor and map the deep sea, with both positive and negative consequences for deep-sea fauna. Soft-grab robots could facilitate collection of delicate samples for biodiversity monitoring but, without careful management, could also add pollutants and waste to these previously unexplored and poorly understood environments 55 . With advancing technology, potential deployment of swarms of small robots could collect basic environmental data to facilitate mapping of the seabed. Currently limited by power supply, energy-harvesting modules are in development that enable soft robots to ‘swallow’ organic material and convert it into power 56 , although this could result in inadvertently harvesting rare deep-sea organisms. Soft robots themselves may also be ingested by predatory species mistaking them for prey. Deployment of soft robotics will require careful monitoring of both its benefits and risks to marine biodiversity.

The effects of new biodegradable materials in the marine environment

Mounting public pressure to address marine plastic pollution has prompted the replacement of some fossil fuel-based plastics with bio-based biodegradable polymers. This consumer pressure is creating an economic incentive to adopt such products rapidly and some companies are promoting their environmental benefits without rigorous toxicity testing and/or life-cycle assessments. Materials such as polybutylene succinate (PBS), polylactic acid (PLA) or cellulose and starch-based materials may become marine litter and cause harmful effects akin to conventional plastics 57 . The long-term and large-scale effect of the use of biodegradable polymers in products (for example, clothing) and the unintended release of byproducts, such as microfibres, into the environment remain unknown. However, some natural microfibres have greater toxicity than plastic microfibres when consumed by aquatic invertebrates 58 . Jurisdictions should enact and enforce suitable regulations to require the individual assessment of all new materials intended to biodegrade in a full range of marine environmental conditions. In addition, testing should include studies on the toxicity of major transition chemicals created during the breakdown process 59 , ideally considering the different trophic levels of marine food webs.

This scan identified three categories of horizon issues: impacts on, and alterations to, ecosystems; changes to resource use and extraction; and the emergence of technologies. While some of the issues discussed, such as improved monitoring of species (underwater tracking and soft robotics) and more sustainable resource use (marine collagens), may have some positive outcomes for marine and coastal biodiversity, most identified issues are expected to have substantial negative impacts if not managed or mitigated appropriately. This imbalance highlights the considerable emerging pressures facing marine ecosystems that are often a byproduct of human activities.

Four issues identified in this scan related to ongoing large-scale (hundreds to many thousands of square kilometres) alterations to marine ecosystems (wildfires, coastal darkening, depauperate equatorial communities and altered nutritional fish content), either through the impacts of global climate change or other human activities. There are already clear impacts of climate change, for example, on stores of blue carbon (for example, ref. 60 ) and small-scale fisheries (for example, ref. 61 ) but the identification of these issues highlights the need for global action that reverses such trends. The United Nations Decade of Ocean Science for Sustainable Development (2021–2030) is now underway, aligning with other decadal policy priorities, including the Sustainable Development Goals ( https://sdgs.un.org/ ), the 2030 targets for biodiversity to be agreed in 2022, the conclusion of the ongoing negotiations on biodiversity beyond national jurisdictions (BBNJ) ( https://www.un.org/bbnj/ ), the UN Conference on Biodiversity (COP15) ( https://www.unep.org/events/conference/un-biodiversity-conference-cop-15 ) and the UN Climate Change Conference 2021 (COP26) ( https://ukcop26.org/ ). While some campaigns to allocate 30% of the ocean to Marine Protected Areas by 2030 are prominently aired 62 , the unintended future consequences of such protection and how to monitor and manage these areas, remain unclear 63 , 64 , 65 .

Another set of issues related to anticipated increases in marine resource use and extraction (swim bladders, marine collagens, lithium extraction and mesopelagic fisheries). The complex issue of mitigating the impacts on marine conservation and biodiversity of exploiting and using newly discovered resources must consider public perceptions of the ocean 66 , 67 , market forces and the sustainable blue economy 68 , 69 .

The final set of issues related to new technological advancements, with many offering more sustainable opportunities, albeit some having potentially unintended negative consequences on marine and coastal biodiversity. For example, trace-element contamination from green technologies and harmful effects of biodegradable products highlights the need to assess the step-changes in impacts from their increased use and avoid the paradox of technologies designed to mitigate the damaging effects of climate change on biodiversity themselves damaging biodiversity. Indeed, the impacts on marine and coastal biodiversity from emerging technologies currently in development (such as underwater tracking or soft robotics) need to be assessed before deployment at scale.

There are limitations to any horizon scanning process that aims to identify global issues and a different group of experts may have identified a different set of issues. By inviting participants from a range of subject backgrounds and global regions and asking them to canvass their network of colleagues and collaborators, we aimed to identify as broad a set of issues as possible. We acknowledge, however, that only about one-quarter of the participants were from non-academic organizations, which may have skewed the submitted issues and how they were voted on. However, others 3 reported no significant correlation between participants’ areas of research expertise and the top issues selected in the horizon scan conducted in 2009. Therefore, horizon scans do not necessarily simply represent issues that reflect the expertise of participants. We also sought to achieve diversity by inviting participants from 22 countries and actively seeking representatives from the global south. However, the final panel of 30 participants spanned only 11 countries, most in the global north. We were forced by the COVID-19 pandemic to hold the scan online and while we hoped that this would enable participants to engage from around the world alleviating broader global inequalities in science 63 , digital inequality was in fact enhanced during the pandemic 70 . Our experience highlights the need for other mechanisms that can promote global representation in these scans.

This Marine and Coastal Horizon Scan seeks to raise awareness of issues that may impact marine and coastal biodiversity conservation in the next 5–10 years. Our aim is to bring these issues to the attention of scientists, policymakers, practitioners and the wider community, either directly, through social networks or the mainstream media. Whilst it is almost impossible to determine whether issues gained prominence as a direct result of a horizon scan, some issues featured in previous scans have seen growth in reporting and awareness. Others 3 found that 71% of topics identified in the Horizon Scan in 2009 had seen an increase in their importance over the next 10 years. Issues such as microplastics and invasive lionfish had received increased research and investment from scientists, funders, managers and policymakers to understand their impacts and the horizon scans may have helped motivate this increase. Horizon scans, therefore, should primarily act as signposts, putting focus onto particular issues and providing support for researchers and practitioners to seek investment in these areas.

Whilst recognizing that marine and coastal environments are complex social-ecological systems, the role of governance, policy and litigation on all areas of marine science needs to be developed, as it is yet to be established to the same extent as in terrestrial ecosystems 71 . Indeed, tackling many of the issues presented in this scan will require an understanding of the human dimensions relating to these issues, through fields of research including but not limited to ocean literacy 72 , 73 , social justice, equity 74 and human health 75 . Importantly, however, horizon scanning has proved an efficient tool in identifying issues that have subsequently come to the forefront of public knowledge and policy decisions, while also helping to focus future research. The scale of the issues facing marine and coastal areas emphasizes the need to identify and prioritize, at an early stage, those issues specifically facing marine ecosystems, especially within this UN Decade of Ocean Science for Sustainable Development.

Identification of issues

In March 2021, we brought together a core team of 11 participants from a broad range of marine and coastal disciplines. The core team suggested names of individuals outside their subject area who were also invited to participate in the horizon scan. To ensure we included as many different subject areas as possible within marine and coastal conservation, we selected one individual from each discipline. Our panel of experts comprised 30 (37% female) marine and coastal scientists, policymakers and practitioners (27% from non-academic institutions), with cross-disciplinary expertise in ecology (including tropical, temperate, polar and deep-sea ecosystems), palaeoecology, conservation, oceanography, climate change, ecotoxicology, technology, engineering and marine social sciences (including governance, blue economy and ocean literacy). Participants were invited from 22 countries across six continents, resulting in a final panel of 30 experts from 11 countries (Europe n  = 17 (including the three organizers); North America and Caribbean n  = 4; South America n  = 3; Australasia n  = 3; Asia n  = 1; Africa n  = 2). All experts co-authored this paper.

To reduce the potential for bias in the identification of suitable issues, each participant was invited to consult their own network and required to submit two to five issues that they considered new and likely to have a positive or negative impact on marine and coastal biodiversity conservation in the next 5–10 years ( Supplementary Information text describes instructions given to participants). Each issue was described in paragraphs of ~200 words (plus references). Due to the COVID-19 pandemic, participants relied mainly on virtual meetings and online communication using email, social-media platforms, online conferences and networking events. Through these channels ~680 people were canvassed by the participants, counting all direct in-person or online discussions as individual contacts but treating social-media posts or generic emails as a single contact. This process resulted in a long list of 75 issues that were considered in the first round of scoring (see Supplementary Table 1 for the full list of initially submitted issues).

Round 1 scoring

The initial list of proposed issues was then shortened through a scoring process. We used a modified Delphi-style 76 voting process, which has been consistently applied in horizon scans since 2009 (refs. 4 , 77 ) (see Fig. 2 for the stepwise process). This process ensured that consideration and selection of issues remained repeatable, transparent and inclusive. Panel members were asked to confidentially and independently score the long list of 75 issues from 1 (low) to 1,000 (high) on the basis of the following criteria:

Whether the issue is new (with ‘new’ issues scoring higher) or is a well-known issue likely to exhibit a significant step-change in impact

Whether the issue is likely to be important and impactful over the next 5–10 years

Whether the issue specifically impacts marine and coastal biodiversity

Left and right columns show the process for the first and second rounds of scoring, respectively.

Participants were also asked whether they had heard of the issue or not.

‘Voter fatigue’ can result in issues at the end of a lengthy list not receiving the same consideration as those at the beginning 76 . We counteracted this potential bias by randomly assigning participants to one of three differently ordered long-lists of issues. Participants’ scores were converted to ranks (1–75). We had aimed to retain the top 30 issues with the highest median ranks for the second round of assessment at the workshop but kept 31 issues because two issues achieved equal median ranks. In addition, we identified one issue that had been incorrectly grouped with three others and presented this as a separate issue. The subsequent online workshop to discuss this shortlist, therefore, considered the top-ranked 32 issues (Fig. 3a ) (see Supplementary Table 2 for the full list).

a , Round 1. Each point represents an individual issue. For all issue titles, see Supplementary Table 1 . Issues in dark blue were retained for the second round. Issues that were ranked higher were generally those that participants had not heard of (Spearman rank correlation = 0.38, P  < 0.001). b , Round 2. Scores as in round 1. For titles of the second round of 32 issues, see Supplementary Table 2 . The 15 final issues (marked in red) achieved the top ranks (horizontal dashed line) and had only been heard of by 50% of participants (vertical dashed line). Red circles, squares and triangles denote issues relating to ecosystem impacts, resource exploitation and new technologies, respectively. The two grey issues marked with crosses were discounted during final discussions because participants could not identify the horizon component of these issues.

Source data

Workshop and round 2 scoring.

Before the workshop, each participant was assigned up to four of the 32 issues to research in more detail and contribute further information to the discussion. We convened a one-day workshop online in September 2021. The geographic spread of participants meant that time zones spanned 17 h. Despite these constraints, discussions remained detailed, focused, varied and lively. In addition, participants made use of the chat function on the platform to add notes, links to articles and comments to the discussion. After discussing each issue, participants re-scored the topic (1–1,000, low to high) based on novelty and the issue’s importance for, and probable impact on, marine and coastal biodiversity (3 participants out of 30 did not score all issues and therefore their scores were discounted). At the end of the selection process, scores were again converted to ranks and collated. Highest-ranked issues were then discussed by correspondence focusing on the same three criteria as outlined above, after which the top 15 horizon issues were selected (Fig. 3b ).

Reporting summary

Further information on research design is available in the Nature Research Reporting Summary linked to this article.

Data availability

The datasets generated during and/or analysed during the current study are available from figshare https://doi.org/10.6084/m9.figshare.19703485.v1 . Source data are provided with this paper.

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Acknowledgements

This Marine and Coastal Horizon Scan was funded by Oceankind. S.N.R.B. is supported by EcoStar (DM048) and Cefas (My time). R.C. acknowledges FCT/MCTES for the financial support to CESAM (UIDP/50017/2020, UIDB/50017/2020, LA/P/0094/2020) through national funds. O.D. is supported by CSIC Uruguay and Inter-American Institute for Global Change Research. J.E.H.-R. is supported by the Whitten Lectureship in Marine Biology. S.A.K. is supported by a Natural Environment Research Council grant (NE/S00050X/1). P.I.M. is supported by an Australian Research Council Discovery Grant (DP200100575). D.M.P. is supported by the Marine Alliance for Science and Technology for Scotland (MASTS). A.R.P. is supported by the Inter-American Institute for Global Change Research. W.J.S. is funded by Arcadia. A.T. is supported by Oceankind. M.Y. is supported by the Deep Ocean Stewardship Initiative and bioDISCOVERY. We are grateful to everyone who submitted ideas to the exercise and the following who are not authors but who suggested a topic that made the final list: R. Brown (colocation of marine activities), N. Graham and C. Hicks (altered nutritional content of fish), A. Thornton (soft robotics), A. Vincent (fish swim bladders) and T. Webb (mesopelagic fisheries).

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These authors contributed equally: James E. Herbert-Read, Ann Thornton.

Authors and Affiliations

Department of Zoology, University of Cambridge, Cambridge, UK

James E. Herbert-Read

Conservation Science Group, Department of Zoology, Cambridge University, Cambridge, UK

Ann Thornton, Thomas A. Worthington & William J. Sutherland

SpeSeas, D’Abadie, Trinidad and Tobago

Diva J. Amon

Marine Science Institute, University of California, Santa Barbara, CA, USA

The Centre for Environment, Fisheries and Aquaculture Science (Cefas), Lowestoft, UK

Silvana N. R. Birchenough

Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada

Isabelle M. Côté

Centre for Ecology, Evolution and Environmental Changes (cE3c), Department of Animal Biology, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal

Maria P. Dias

BirdLife International, The David Attenborough Building, Cambridge, UK

Centre for Ecology and Conservation, University of Exeter, Penryn, UK

Brendan J. Godley

Lancaster Environment Centre, Lancaster University, Lancaster, UK

Sally A. Keith

School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK

Emma McKinley

British Antarctic Survey, Natural Environment Research Council, Cambridge, UK

Lloyd S. Peck

ECOMARE, CESAM—Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Santiago University Campus, Aveiro, Portugal

Ricardo Calado

Laboratory of Marine Sciences (UNDECIMAR), Faculty of Sciences, University of the Republic, Montevideo, Uruguay

Royal Belgian Institute of Natural Sciences, Operational Directorate Natural Environment, Marine Ecology and Management, Brussels, Belgium

Steven Degraer

School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia

Emma L. Johnston

Finnish Environment Institute, Helsinki, Finland

Hermanni Kaartokallio

Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood Campus, Burwood, Victoria, Australia

Peter I. Macreadie

Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada

Anna Metaxas

Department of Biology, University of Nairobi, Nairobi, Kenya

Agnes W. N. Muthumbi

Coastal Oceans Research and Development in the Indian Ocean, Mombasa, Kenya

David O. Obura

School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Queensland, Australia

Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, UK

David M. Paterson

Servício de Hidrografía Naval, Buenos Aires, Argentina

Alberto R. Piola

Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos, CONICET/CNRS, Universidad de Buenos Aires, Buenos Aires, Argentina

School of Mathematics and Physics, The University of Queensland, St Lucia, Brisbane, Queensland, Australia

Anthony J. Richardson

Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere, Queensland Biosciences Precinct, St Lucia, Brisbane, Queensland, Australia

Instituto Antártico Argentino, Buenos Aires, Argentina

Irene R. Schloss

Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina

Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur, Ushuaia, Argentina

Department of Ocean Sciences and Biology Department, Memorial University, St John’s, Newfoundland and Labrador, Canada

Paul V. R. Snelgrove

Department of Environment and Geography, University of York, York, UK

Bryce D. Stewart

Lighthouse Field Station, School of Biological Sciences, University of Aberdeen, Cromarty, UK

Paul M. Thompson

Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth, UK

Gordon J. Watson

School of Biological Sciences, Area of Ecology and Biodiversity, Swire Institute of Marine Science, Institute for Climate and Carbon Neutrality, Musketeers Foundation Institute of Data Science, and State Key Laboratory of Marine Pollution, The University of Hong Kong, Kadoorie Biological Sciences Building, Hong Kong, China

Moriaki Yasuhara

Biosecurity Research Initiative at St Catharine’s (BioRISC), St Catharine’s College, University of Cambridge, Cambridge, UK

William J. Sutherland

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Contributions

J.E.H.-R. and A.T. contributed equally to the manuscript. J.E.H.-R., A.T. and W.J.S. devised, organized and led the Marine and Coastal Horizon Scan. D.J.A., S.N.R.B., I.M.C., M.P.D., B.J.G., S.A.K., E.M. and L.S.P. formed the core team and are listed alphabetically in the author list. All other authors, R.C., O.D., S.D., E.L.J., H.K., P.I.M., A.M., A.W.N.M., D.O.O., D.M.P., A.R.P., A.J.R., I.R.S., P.V.R.S., B.D.S., P.M.T., G.J.W., T.A.W. and M.Y. are listed alphabetically. All authors contributed to and participated in the process and all were involved in writing and editing the manuscript.

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Correspondence to James E. Herbert-Read or Ann Thornton .

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Herbert-Read, J.E., Thornton, A., Amon, D.J. et al. A global horizon scan of issues impacting marine and coastal biodiversity conservation. Nat Ecol Evol 6 , 1262–1270 (2022). https://doi.org/10.1038/s41559-022-01812-0

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Issue Date : September 2022

DOI : https://doi.org/10.1038/s41559-022-01812-0

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A Case Study of Environmental Injustice: The Failure in Flint

Carla campbell.

1 Department of Public Health Sciences, Room 408, College of Health Sciences, University of Texas at El Paso, 500 W. University Ave, El Paso, TX 79968, USA

Rachael Greenberg

2 National Nurse-led Care Consortium (NNCC), Philadelphia, PA 19102, USA; su.ccnn@grebneergr

Deepa Mankikar

3 Research and Evaluation Group, Public Health Management Corporation, Philadelphia, PA 19102, USA; gro.cmhp@rakiknamd

Ronald D. Ross

4 Occupational and Environmental Medicine Consultant, Las Cruces, NM 88001, USA; [email protected]

The failure by the city of Flint, Michigan to properly treat its municipal water system after a change in the source of water, has resulted in elevated lead levels in the city’s water and an increase in city children’s blood lead levels. Lead exposure in young children can lead to decrements in intelligence, development, behavior, attention and other neurological functions. This lack of ability to provide safe drinking water represents a failure to protect the public’s health at various governmental levels. This article describes how the tragedy happened, how low-income and minority populations are at particularly high risk for lead exposure and environmental injustice, and ways that we can move forward to prevent childhood lead exposure and lead poisoning, as well as prevent future Flint-like exposure events from occurring. Control of the manufacture and use of toxic chemicals to prevent adverse exposure to these substances is also discussed. Environmental injustice occurred throughout the Flint water contamination incident and there are lessons we can all learn from this debacle to move forward in promoting environmental justice.

1. Description of the Flint Water Crisis

At this point, most Americans have heard of the avoidable and abject failure of government on the local, state and federal level; environmental authorities; and water company officials to prevent the mass poisoning of hundreds of children and adults in Flint, Michigan from April 2014 to December 2015 [ 1 , 2 , 3 ]. One tends to imagine chemical poisoning as a victim dropping dead in a murder mystery, or the immediate casualties in an industrial accident or a chemical warfare attack. Unlike the release of methyl isocyanate gas in Bhopal, India in 1984 or the release of radiation with the radiation accident in Chernobyl, Ukraine in 1986, the poisoning of the population in Flint was an insidious one. People drinking the contaminated water would never have known they had elevated blood lead levels (BLLs) without specific medical testing for blood lead levels. In fact, if the water contamination had not been made public, most exposed children and their families would have never suspected they were being exposed over a 20-month period of time, and it would be expected that the water contamination and lead exposure would have continued up until today.

Lead can cause immediate acute poisoning but the subacute, moderate, long-term exposure impact of concern in Flint is more common, and much more insidious. Any resulting behavioral disturbance or loss of intellectual function would probably not been have linked by their physicians or families to lead poisoning, and instead accepted as something that had just occurred. Additionally, the adverse effects from this event may take years to surface as most negative health effects from low-level lead exposure develop slowly [ 4 ]. Hypertension and kidney damage may not present until long after the exposure. Any resulting behavioral disturbance or loss of intellectual function would probably have not been linked by their physicians or families to lead poisoning, and instead accepted as something that had just occurred.

The Flint disaster was due to the switch in water supply from Lake Huron to the Flint River, which was then not treated with an anti-corrosion chemical to prevent lead particles and solubilized lead from being released from the interior of water pipes, particularly those from lead service lines or those with lead solder. This water was known to be very corrosive, so corrosive that, in fact, it was not used by the nearby auto industry [ 2 ]. The General Motors plant switched to water from the neighboring Flint Township when General Motors noticed rust spots on newly machined parts [ 2 ]. This corrosive new water supply was then not treated with the anti-corrosion treatment, in noncompliance with the Environmental Protection Agency’s (EPA) Lead and Copper Rule, which calls for action when a water supply is found to be corrosive to prevent the potential release of metals from water service lines [ 5 ].

A national water expert, Dr. Marc Edwards, a professor of civil and environmental engineering at Virginia Tech University, has stated that the published instructions by EPA for collection of water samples for lead analysis were biased in the direction of underestimating the lead content of the water samples. He had spent years communicating this problem to EPA without a subsequent change in these instructions [ 6 ]. Dr. Edwards testified before Congress in spring 2016 that the Regional EPA Administrator was not alert to what was happening in Flint. Dr. Edwards also published papers previously bringing to the public attention the lead contamination of drinking water in Washington, DC. After Washington, DC made a change in its water disinfectant from chlorine to chloramine, residents were exposed to water with high levels of lead (140 ppb and above) from 2001 to 2004 [ 7 , 8 ]. This resulted in an increase of blood lead levels in young children (many from high-risk neighborhoods) of four times the amount that it was prior to the change in water disinfectant [ 7 , 8 ]. Dr. Edwards was a key player in ensuring that this issue was brought to light and those responsible parties were held accountable [ 9 ]. For comparison, the EPA standard for maximum contaminant level for lead in water is 15 ppb [ 5 ].

Regarding the Flint, Michigan water contamination incident, Dr. Mona Hanna-Attisha, a local pediatrician, performed a study looking at blood lead levels (BLLs) from Flint children from 2013 (before the water change) to 2015 (after the water change), assessing the percentage of BLLs over the Centers for Disease Control and Prevention (CDC) reference level of 5 µg/dL, reviewing water levels in Flint, and identifying geographical locations of blood and water levels using geospatial analysis. Her study demonstrated that the level of elevated blood lead levels (above 5 µg/dL) in a group of Flint children almost doubled between levels collected prior to the change in water source and afterwards; among children living in the area with highest water lead levels the percentage with elevated BLLs was approximately three times higher when compared to pre-diversion levels (4% versus 10.6%) [ 10 ]. These are extraordinary changes! (The specific blood lead levels or even range of BLLs was not reported in the article.) Unfortunately, many children in Flint already had multiple risk factors for lead poisoning, including “poor nutrition, concentrated poverty, and older housing stock” [ 10 ].

2. Elevated Blood Lead Levels in US Children and the Adverse Health Impacts and Costs of Exposure

Lead exposure in young children can lead to decrements in intelligence, development, behavior, attention, and other neurological functions. Two giants in childhood lead poisoning research and advocacy, Dr. Philip Landrigan and Dr. David Bellinger, summarize the adverse effects of lead very completely, yet succinctly: “Lead is a devastating poison. It damages children’s brains, erodes intelligence, diminishes creativity and the ability to weigh consequences and make good decisions, impairs language skills, shortens attention span, and predisposes to hyperactive and aggressive behavior. Lead exposure in early childhood is linked to later increased risk for dyslexia and school failure.” [ 11 ] Other articles and reports have also confirmed these adverse effects [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ].

Therefore, it is important to determine the extent of the problem of elevated blood lead levels in U.S. children. Currently, based on data from the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2012, 3.24% of children overall aged 1–5 years had a BLL > 5 µg/dL, compared with 7.8% of non-Hispanic Black (NHB) children [ 21 ]. Males had higher adjusted BLLs than females, and a higher poverty income ratio was associated with lower adjusted blood lead levels. Adjusted BLLs increased in renter-occupied (as opposed to owner-occupied) homes and with an increase in the numbers of smokers inside the home [ 21 ]. A previous analysis by Dixon et al. [ 22 ] of NHANES data from 1999 to 2004 found that BLLs were affected by the levels of lead in the floor and the condition of and surface type of the floor; that non-Hispanic Black children had higher BLLs than non-Hispanic white (NHW) children; that Mexican-born children had higher BLLs than those born in the U.S.; that houses built before 1940 were associated with children with higher BLLs; that children living in houses with a smoker had higher BLLs than those living with non-smokers; and that the odds of NHB children having BLLs > 5 µg/dL and > 10 µg/dL were more than double that of NHW children [ 21 , 22 ]. A recent report suggested that many children requiring blood lead testing due to Medicaid insurance status or state or city requirements for testing are not getting tested, and/or the results are not being properly followed up on [ 23 ].

The costs from lead poisoning are considerable, as are the cost savings for prevention of childhood lead poisoning. Attina and Trasande state that in the United States and Europe the lead-attributable economic costs have been estimated at $50.9 and $55 billion dollars, respectively [ 24 ]. Interestingly, they estimate a total cost of $977 billion of international dollars in low- and middle-income countries, with economic losses equal to $134.7 billion in Africa, $142.3 billion in Latin American and the Caribbean, and $699.9 billion in Asia, giving a total economic loss for these countries in the range of $728.6–$1,162.5 billion [ 24 ]. A previous analysis showed that each dollar invested in lead paint hazard control results in a return of $17–$221 or a net savings of $181–$269 billion for a specific cohort of children under six years of age as the benefits of BLL reduction would include categories such as health care, lifetime earnings, tax revenue, special education, attention deficit-hyperactivity disorder, and the direct costs of crime [ 25 ]. Another prior analysis estimated the economic benefits resulting from an historic lowering of children’s BLLs as measured by data from the National Health and Nutrition Examination Survey (NHANES) to be $110–$319 billion for each year’s cohort of 3.8 million two-year-old children, using a discounted lifetime earnings of $723,300 for each two-year-old child in 2000 dollars [ 26 ]. These estimated benefits were due to projected improvements in worker productivity due to increased intelligence quotient (I.Q.) points.

3. How the Flint Case and Other Examples Exhibit Environmental Injustice

Most affected by this egregious environmental disaster was a mostly poor and African-American population [ 27 ]. Some have speculated whether such an error in judgment might have occurred if a different population had been involved, and The New York Times uses the term racism in its editorial [ 27 ]. Another New York Times article talks of an analysis of emails from Governor Rick Snyder’s office that did not mention race but talked of costs involving Flint’s water supply, questioned scientific data regarding water contamination with lead, and mentioned uncertainties about the duties of state and local health officials [ 28 ]. It also mentions that some civil rights advocates were indicating that the Flint water crisis appeared to represent environmental racism [ 28 ]. The article goes on to discuss that the switch in water source was explicitly decided in favor of saving money for the financially unstable city of Flint, and that an emergency manager appointed by Gov. Snyder to carry out the running of the city was himself African-American [ 28 ]. One of Gov. Snyder’s key staff people sounded an alarm about the concern for lead in water, but the state health department responded back that the Flint water was safe [ 28 ].

The Flint Water Advisory Task Force, comprised of five experts in public health and water policy and convened by Governor Snyder, repeatedly stated in its findings that the Michigan Department of Environmental Quality (MDEQ) improperly and inaccurately described the Flint water as being safe, which unfortunately was then interpreted as accurate by other state agencies and city and county agencies [ 29 ]. The Task Force report also described the Flint water crisis as “a story of government failure, intransigence, unpreparedness, delay, inaction and environmental injustice”, and adds that the MDEQ failed in its responsibility to properly enforce drinking water regulations, while the Michigan Department of Health and Human Services (MDHHD) failed its mission to protect public health [ 29 ]. A recent article suggests these two agencies produced sampling data that were flawed, failed to provide accurate information to the Governor’s office, the EPA and the public, and did not respond appropriately when given information by environmental health and medical professionals [ 30 ]. The Task Force report also explains that state-appointed emergency managers replaced local decision-makers in Flint, thus removing “the checks and balances and public accountability that come with public decision-making” [ 29 ]. The group also credits the public and engaged Flint citizens with continuing to question government leadership (although the Task Force noted “callous and dismissive responses to citizens’ expressed concerns”), and the media for its investigative journalism of the crisis [ 29 ]. The Task Force’s conclusion was that “Flint water customers were needlessly and tragically exposed to toxic levels of lead and other hazards through mismanagement of their drinking water supply” [ 29 ]. The Flint Water Advisory Task Force suggests that the Michigan governor should issue an executive order to mandate training and guidance on environmental justice across all state agencies, with acknowledgement that the Flint crisis of water contamination is an example of environmental injustice which has fallen on a predominantly African-American community [ 29 ]. The Task Force issued 44 recommendations to remedy the results of the failure of proper governance and resultant lead poisoning [ 29 , 30 ].

Many have spoken out about this environmental injustice, including research scientists and clinicians [ 11 , 31 , 32 , 33 ] and public health professionals [ 34 ]. Even the EPA administrator, Gina McCarthy, is speaking about how Michigan evaded the EPA regarding the Flint water crisis and how this type of disaster cannot happen elsewhere [ 34 , 35 ]. Dr. Robert Bullard, dean of the School of Public Health at Texas Southern University, calls the Flint water crisis—leading to lead exposure and poisoning with long delays in addressing the problem—a classic case of environmental racism [ 36 ]. “Environmental racism is real…so real that even having the facts, having the documentation and having the information has never been enough to provide equal protection for people of color and poor people” [ 37 ]. He continues, “It takes longer for the response and it takes longer for the recovery in communities of color and low-income communities.” [ 37 ] He explains that regional EPA officials and state officials in Michigan responded first with a cover-up, “and then defensively—either trying to avoid responsibility or minimizing the extent of the damage”, as contrasted with handling of other environmental problems in predominantly white communities [ 37 ]. An example is then given of government officials on all levels helping to clean up a spill of coal ash in Roane County, Tennessee, in a mostly white community [ 37 ]. A Democrat who represents Flint, Michigan, Representative Dan Kildee, called race “the single greatest determinant of what happened in Flint” [ 28 ]. What is the solution? Dr. Bullard suggests that real solutions will result when communities previously left out of decision-making are offered a seat at the table [ 31 ]. In order to stop unequal protection from environmental hazards, Dr. Bullard has come up with five principles he suggests government adopt to further environmental justice: “guaranteeing the right to environmental protection, preventing harm before it occurs, shifting the burden of proof to the polluters, obviating proof of intent to discriminate, and redressing existing inequities” [ 37 ]. Charles Lee, another author writing about environmental justice who worked in the Office of Environmental Justice at EPA, quotes a definition of the environment as “the place where we live, where we work, and where we play” [ 38 ]. He goes on to state that “environmental justice must be the starting point for achieving healthy people, homes, and communities” [ 38 ]. Lastly, the Flint Water Task Force elaborates on its finding of environmental injustice in the Flint case. “Environmental justice or injustice, therefore, is not about intent. Rather, it is about process and results—fair treatment, equal protection, and meaningful participation in neutral forums that honor human dignity…The facts of the Flint water crisis lead us to the inescapable conclusion that this is a case of environmental injustice. Flint residents, who are majority Black or African American and among the most impoverished of any metropolitan area in the United States, did not enjoy the same degree of protection from environmental and health hazards as that provided to other communities” [ 29 ].

The reader is referred to several references [ 1 , 2 , 3 ] for a more detailed timeline of the specific events and actions that occurred in Flint. The Flint Water Task Force report also provides a summary of its findings and recommendations, giving greater details on the specific events and actions during the switch in water supply [ 29 ]. Regardless of the motivations behind the water supply mismanagement, we must improve governmental safeguards and public health surveillance to strive to avoid such needless exposures to environmental toxicants in the future.

Another recent disaster, involving contamination of local water supplies, was that of the contamination of the Animas River in southern Colorado and northern New Mexico by mine waste from the Gold King Mine, leading to excessively high levels of some toxic elements metals including lead, arsenic and cadmium (all of these being toxic metals) [ 39 , 40 , 41 ]. The river water was subsequently off limits for agricultural use and closed for recreational use [ 39 , 42 ]. The Navajo Nation has recently expressed how difficult and problematic this poisoning of their drinking water source has been to this tribe, and that they have not been adequately reimbursed for the adverse impacts to their water source and way of life [ 43 , 44 ]. The Native American Rights Fund states that a source of clean and abundant water is hard to come by for many Native tribes and peoples and that many face health and developmental risks from environmental problems such as surface and groundwater contamination, hazardous waste disposal, illegal dumping, and mining wastes, all of which can contribute to poor quality of water [ 45 ]. As the Flint, the Navajo Nation, and the Native American Rights group exposures highlight, poor and minority communities are unfortunately too often exposed to poisonous chemicals in their neighborhoods and on their tribal lands, leading to environmental injustice [ 44 ].

Not only has the incident in Flint brought to light the contamination of Flint’s water system, it raises issues about local water supplies to towns and cities, and particularly to child care centers and school systems, around the nation [ 46 , 47 , 48 ]. This has caused our nation to focus on investigating for lead contamination in water supplies in other cities, particularly in school systems, child care centers and other places occupied by children [ 49 , 50 ]. A Huffington Post article states that the Flint water crisis has provided a wake-up call to the country with the “discovery” of poisoned water in many communities in the U.S., and that our water infrastructure is outdated and deteriorating, and that water sampling procedures for lead are also “dangerously” outdated, as they allow for 10% of the population to be exposed to levels over the EPA maximum contaminant level [ 51 ]. Some cities have been cited for their exemplary actions in keeping their city water supplies free from lead contamination [ 52 ].

Historically, the scientists in the companies that put lead in gasoline and lead in paint became aware of the dangers of those specific lead exposures, but it took much time to finally remove lead from these products; many counties banned the use of lead-based paint in residential housing before the U.S. did [ 53 , 54 ]. One author states, “Flint’s tragedy is shedding light on a health issue that’s been lurking in U.S. households for what seems like forever. But that demands the question: Why has lead poisoning never really been treated like what it is—the longest-lasting childhood-health epidemic in U.S. history?” [ 55 ]. Bliss then goes on to describe how when in the 1950s, when “millions of children had had been chronically or acutely exposed (to lead)” and this had been linked to health problems, that “If the lead industry had stepped up then (or if it had been forced to by government)”, maybe lead poisoning would have been treated like any other major childhood disease—polio, for example. In the 1950s, “Fewer than sixty thousand new cases of polio per year created a near-panic among American parents and a national mobilization that led to vaccination campaigns that virtually wiped out the disease within a decade”, write Rosner and Markowitz [ 56 ]. “With lead poisoning, the industry and federal government could have mobilized together to systemically detoxify the nation’s lead-infested housing stock, and end the epidemic right there” [ 55 ]. Bliss then goes on to describe how “the industry’s powerful leaders diverted the attention of health officials away from their products, and toward class and race” by associating childhood lead poisoning with that of a child “with ‘ignorant’ parents living in ‘slums’” [ 55 ]. Bliss goes on to state that “lead poisoning in children can be eradicated…Today the cost of detoxifying the entire nation hovers around $1 trillion, says Rosner. Any federal effort to systematically identify and remove lead from infested households would be complex, decades-long, and require ongoing policy reform. ‘But it’s also saving a next generation of children,’ Rosner says. ‘You’re actually going to stop these kids from being poisoned. And isn’t that worth something?’” [ 56 ]. “And Rosner is a tiny bit hopeful. Amid national conversation about economic inequality, a housing crisis, and the value of black and Latino lives, the attention that Flint has brought to lead might usher in the country’s first comprehensive lead-poisoning prevention program” [ 56 ].

With the information about lead contamination in Flint and many cities around the country, one might wonder whether there is a dearth of information or recommendations about how to prevent and manage childhood lead poisoning. There is not. Many authors have weighed in on this question recently [ 11 , 12 , 13 , 15 , 17 , 19 , 57 , 58 , 59 , 60 , 61 , 62 ], some with very specific plans and ideas. Primary prevention of lead exposure has been particularly emphasized in almost all of them. Landrigan and Bellinger compel us to “map the sources of lead, get the lead out, and make sure there is no new lead” [ 11 ]. Jacobs and colleagues at the National Center for Healthy Housing have started a campaign for lead exposure detection and lead poisoning prevention based on these three principles: “find it, fix it, and fund it” [ 33 ]. Some call for revised standards for lead in air, house dust, soil and water [ 12 , 61 , 62 , 63 ]. The chief causes of lead exposure are nicely summarized by Levin and colleagues [ 64 ]. Unfortunately, childhood lead poisoning prevention is often deemed to be not important enough to work on, with other pressing medical and public health problems intervening; it is also complicated, complex and involves many stakeholders. Thus, the clinicians, government officials, and public health officials looking for a quick fix and a one-prescription answer to this medical problem are often disappointed and discouraged.

Concern about the neurotoxic effects of lead has been expanded now to include the neurotoxic effects of many more new chemicals out in use by the American public, including children. Children are exposed to chemicals in their everyday lives, as these are found in toys, children’s products, personal care items such as shampoos and skin creams, on foods in the form of pesticide residues, and in the air in the form of air pollutants. Some authors have weighed in on the need for more control of the manufacture and use of these toxicants and for more research into adverse health effects [ 31 , 65 , 66 ]. In 2015, a unique group of research scientists, clinicians, government representatives, and health care advocates met to form the Project TENDR (Targeting Environmental Neurodevelopmental Risks) which focuses on engendering action to prevent exposure of fetuses, infants and children to environmental toxicants [ 67 ]. The group has created a list of five chemical classes of neurotoxins which have adverse effects on brain development. The list includes lead, specific air pollutants, organophosphate pesticides, phthalates, and polybrominated diphenyl ethers (PBDEs), which are flame retardants. These were selected based on the degree of evidence for their adverse effects and the ability of this group and other scientists, clinicians, government officials, and advocates to work effectively to prevent exposures to these toxicants. Project TENDR has recently released a consensus statement with many signatures of both individuals and groups [ 67 , 68 , 69 ], as well as other articles on the project’s work [ 70 ]. Later this year, the group will release specific recommendations for prevention of exposure to the five chemical groups. The recent passage of the Frank R. Lautenberg Chemical Safety for the 21st Century Act has been a welcome revision and updating of the Toxic Substances Control Act promulgated by EPA in 1976 [ 71 , 72 , 73 ]. This is a step in right direction for better control of exposures to lead and other toxic chemicals in our environment.

4. Future Directions: How to Move Toward Environmental Justice

How do we remedy the situation in Flint, Michigan, and prevent future episodes similar to the Flint and Navajo Nation disasters? The Flint Water Task Force recommends that the MDHHS establish a Flint Toxic Exposure Registry to follow-up on the children and adults who were residing in Flint from April 2014 until the present, and carry out more aggressive clinical and public health follow-up for all children with elevated BLLs in the state [ 29 ]. It also recommends that routine lead screening and appropriate follow-up occur in the children’s medical homes (with the primary care provider) [ 29 ]. Additionally, the Task Force recommends that the Genesee County Health Department improve follow-up of health concerns in cooperation with the MDHHS and City of Flint “to effect timely, comprehensive, and coordinated activity and ensure the best health outcomes for children and adults affected” [ 29 ]. Dr. Hanna-Attisha has established the Flint Child Health and Development Fund which will support children and their families to obtain the optimum health and development outcomes, early childhood education, access to a pediatric medical home, improved nutrition and integrated social services [ 6 ]. The Michigan State University (MSU)/Hurley Pediatric Public Health Initiative will assess, monitor, and intervene to increase children’s readiness to succeed in school by providing the above services, along with stimulating environments and parenting education [ 6 ]. This type of close follow-up has been recommended under the Flint Recovery and Remediation section of the Flint Water Task Force, as well as a recommendation to establish a dedicated subsidiary fund in the Michigan Health Endowment Fund for funding health-related services for Flint residents [ 29 ]. Therefore, local efforts will be taken to counteract the negative consequences of exposure to lead for Flint’s children. Several recent publications support the positive effects that enriched home environments can have on cognition and behavior in both human and animal studies [ 74 , 75 , 76 ].

Secondly, government agencies at the federal, state and local level and municipal authorities will need to improve their performance to ensure environmental justice, rather than contribute toward environmental injustice. This was mandated in an Executive Order by President William Clinton which requires all federal agencies to take action to ensure environmental justice [ 77 ]. The American Academy of Pediatrics provides a good starting point regarding childhood lead exposure prevention with their recommendation that “The US EPA and HUD should review their protocols for identifying and mitigating residential lead hazards (e.g., lead-based paint, dust, and soil) and lead-contaminated water from lead service lines or lead solder and revise downward the allowable levels of lead in house dust, soil, paint, and water to conform with the recognition that there are no safe levels of lead” [ 12 ]. They also give many other recommendations for government, as well as for pediatricians and other health care providers, for reducing and preventing children’s exposure to lead. Other groups, authors and reports have weighed in on what needs to be fixed and carried out, as indicated earlier in this article. As Bellinger puts it, “We know where the lead is, how people are exposed, and how it damages health. What we lack is the political will to do what should be done” [ 32 ].

Looking at the Flint case specifically, why was the water supply switched in Flint? The evidence seems to point to financial reasons for this. In Flint, state officials decided to save money without concern for providing environmental protections for a community at well-established increased risk. This is clear injustice in environmental protection to a low income and minority community. Why weren’t the corrosion control measures implemented? The Flint Water Task Force implicates various leadership groups, including the MDEQ, MDHHS, Michigan’s Governor’s Office, State-appointed Emergency Managers, the EPA, and City of Flint, although the MDEQ and EPA seem to share most culpability [ 29 ].

5. Conclusions

In short, this crisis was the result of failures on every level. We have presented various comments about how environmental racism and injustice played into this situation. Why were the concerns and complaints about water quality from a mostly African-American community not addressed? The facts presented demonstrate that environmental injustice is the major and underlying factor involved in the events in Flint. Having a state-appointed emergency manager in charge took away the normal communication the City of Flint might have had with its residents and constituents. The Flint Water Task Force has a list of 44 recommendations, mostly directed at the various agencies and offices involved, for improving the situation and preventing further problems [ 29 ]. Much of this involves recommending that these entities seek and follow expert advice, whether on water treatment techniques or protecting the public’s health [ 29 ]. It is also imperative to rebuild relationships with Flint’s community and respond to community needs in order to make real and lasting change. Perhaps putting the Flint situation under a microscopic analysis may prevent future episodes of such environmental injustice.

We must do a better job at moving forward and preventing environmental injustice; our future work is cut out for us.

Author Contributions

The concept of the paper was developed by all of the authors. Carla Campbell performed the lead writing. Rachael Greenberg, Deepa Mankikar and Ronald Ross contributed references, edited the paper, and contributed to the revisions. All authors reviewed the article and approved the final content.

Conflicts of Interest

The authors declare no conflict of interest.

Top 10 Sustainability Case Studies & Success Stories in 2024

Cem is the principal analyst at AIMultiple since 2017. AIMultiple informs hundreds of thousands of businesses (as per Similarweb) including 60% of Fortune 500 every month.

Cem's work focuses on how enterprises can leverage new technologies in AI, automation, cybersecurity(including network security, application security), data collection including web data collection and process intelligence.

Environmental and social practices have a significant impact on the long-term success of businesses. Some businesses outperform others in this area, giving them a competitive advantage. We will present ten sustainability success stories to executives searching for methods to close the sustainability gap between themselves and outperformers. 

We take a holistic approach to sustainability when presenting these case studies, seeing environmental and social challenges as a part of maintaining a sustainable business (see Figure 1). We also recognize that, while technology can aid in the improvement of corporate sustainability, changing business processes can be just as successful. As a result, we will provide a variety of scenarios that fully demonstrate the ESG framework .

1. UPS ORION: Improve transportation efficiency

Transportation activities accounted for almost 30% of US greenhouse gas (GHG) emissions. (See Figure 2). For a company like UPS, which distributes goods across regions, transportation activities make up the bulk of GHG emissions. As a result, enhancing transportation efficiency is crucial for organizations like UPS to remain sustainable.

As a solution, UPS adopted an AI system called ORION which is a route optimizer that aims to minimize the number of turns during the delivery. Initiation began in 2012 and up today UPS has been working on developing it.

ORION saves UPS 10 million gallons of fuel per year, which means that in addition to the financial benefits, it decreases UPS’s carbon footprint by 100,000 metric tonnes per year, or the equivalent to removing more than 20,000 cars from the roads.

There are public cloud route optimizer systems which businesses can deploy without building hardware. These tools help firms to use their software as a service by paying a subscription cost.

To learn more about ensuring supply chain sustainability with technology you can read our Top 5 Technologies Improving Supply Chain Sustainability article.

Figure 2: US GHG emissions.

2. IKEA IWAY: Make business with ESG oriented corporations

Supplier code of conducts are established guidelines that require other businesses to demonstrate their operations’ social and environmental impacts. The objective is to reward companies that meet strong ESG standards. It is also one of the positive governance indications for organizations, as we highlighted in our ESG metrics article .

IWAY is the supplier code of conduct of IKEA forcing suppliers to meet certain environmental and humanitarian qualities to work with. The initiative has been in place for over 20 years, and over that time, IKEA has refined it based on their prior experiences. IWAY six is the most recent version of IKEA’s supplier code of conduct, which evaluates:

• Core worker rights.
• Safety of the working place.
• Life-work balance of employees.
• Water and waste management of potential suppliers.
• Prevention of child labour. 

3. General Electric digital wind farm: Produce green energy efficiently

Wind turbine productivity varies greatly depending on the design, weather conditions, and geography of the location it is deployed. Using IoT and digital twins to collect data on each wind turbine and simulate possible modifications such as adjusting the direction of the wind turbine can assist corporations in locating their wind turbines in a wind farm more effectively (see Figure 3).

Furthermore, the performance of wind turbines declines with time and may require maintenance; employing sensors and digital twins can assist in determining the appropriate time for repair.

Figure 3: How digital twins can optimize wind turbine productivity.

The General Electric’s (GE) digital wind farms are based on these two elements. GE optimized over 15,000 turbines using sensors and digital twins technologies. Each wind farm can create up to 10% more green energy as a result of the digital wind farm initiative, which helps to enhance our worldwide green energy mix.

4. Swire Properties green building: Minimize GHG emissions

Swire Properties is a construction company that operates in China and especially in the Hong Kong area. In 2018, the company built One Taikoo Place which is a green building that aims to reduce GHG emissions of Swire Properties in order to align with sustainability goals of the company’s stakeholders.

Swire properties use 3D modeling techniques to optimize the building’s energy efficiency. Reduce electricity consumption by using smart lighting systems with sunshine and motion sensors. A biodiesel generation system has been installed in the building, which converts waste food oil into biodiesel. Swire Properties additionally uses low carbon embedded materials and a lot of recycled materials in their construction.

Swire Properties was able to cut GHG emissions intensity throughout their portfolio by nearly 20% because of the usage of digital technologies and low carbon integrated materials.

5. H&M Let’s Close the Gap: Deposit scheme for gathering raw material

In 2021, we consumed 1.7 times more resources than Earth generates annually because our economic outlook is based on production, use and disposal. Such an economy is not sustainable and that is the reason why the concept of circular economy (CE) is trending nowadays.

The most basic principles of CE is to use trash as a raw material for production through innovation, recycling, or repairing and reusing existing products.

H&M’s “Let’s Close the Gap” project began in 2013 as a CE best practice that collects and categorizes discarded clothing from customers. If the garment is in decent condition, they will restore it and find a new owner for it. If a garment reaches the end of its useful life, H&M will recycle it and reuse the material in new goods.

Customers who bring in their old clothes are rewarded with tokens that can be used to get a discount at H&M shops. Incentivizing customers creates a complete CE loop.

In 2019, 57% of H&M’s raw materials were sustainable, according to Forbes. By 2030, the company hopes to improve it 100 percent.

6. Gusto: Hiring female engineers to close gender inequality gap

Gender inequality remains a major social issue despite all the improvements. There are two common types of gender disparity in the workplace. The first is gender pay disparity, which occurs when companies pay male employees more and provide better working conditions than female employees in the same position. 

The second is occupational segregation, in which women are hired for non-technical jobs while men hold the majority of leadership roles. This was the situation at software firm Gusto, where female engineers made up slightly more than 5% of the engineering team at the beginning of 2015. 

Julia Lee , one of Gusto’s first female engineers, claimed that other engineers did not accept her ideas because she was a “female engineer.” Gusto initiated an HR drive to reduce gender inequality by prioritizing the recruitment of female engineers, prohibiting female workers from scrolling, and deleting masculine job ads like “ninja rockstar coder.”

Gusto was able to improve its female engineer ratio to roughly 20% by the end of 2015 thanks to the campaign. The average ratio among software businesses’ engineering teams was 12% in 2013, therefore this was a significant improvement in a short period of time.  

7. HSBC: ESG concerned green finance

Finance companies can help speed up the transition to sustainable business practices by supporting initiatives run by responsible businesses. By the end of 2025, HSBC has committed to investing $100 billion in sustainability projects. HSBC already has funded sustainability projects that require more than $50 billion in investment as of 2019, indicating that the corporation is on track to meet its objective.

HSBC created an ESG risk evaluation framework to assure funding for green projects in 2019. Since then, the framework has been improved. In 2021, HSBC’s ESG practices were rewarded with an AA rating by MSCI.

HSBC is also working toward a goal of using 100% renewable energy as their source of electricity by 2030. Company reduces its consumption of paper, and single used plastics for coffee and beverages.

For more information about best ESG practices you can read our Top 6 ESG Reporting Best Practices article.

8. Signify light-as-a-Service: Enhance production stewardship

The product-service system ( PSS ) is a business model in which producers acquire a product over its lifetime and rent or lease it to the users. PSS ensures product stewardship since the product always becomes the asset of the company. It encourages producers to provide high-quality, repairable items in order to extend the product’s useful life. As a result, it helps to close the circularity gap by ensuring better use of natural resources.

Signify, a luminaire producer, adopts such a business strategy where it demands a subscription fee according to usage period of their lightning systems. PSS allows Signify claims that PSS allows them to produce 0 luminaire waste and drops maintenance costs around 60%.

9. Airbus additive manufacturing: Manufacture lighter planes with 3D printing

AIMultiple expects that additive manufacturing will disruptive for the airplane manufacturing since:

• It speeds up the manufacturing of parts compared to traditional molding techniques.
• It is cheaper due to effective use of raw materials and time reduction of production.
• It enables the manufacturing of lighter parts by up to 45% , resulting in lighter planes that burn less fuel. According to Airbus, additive manufacturing technology can reduce an A320 plane’s annual GHG emissions by around 465,000 metric tons, which is roughly the same as eliminating 100,000 automobiles from the road for a year. (An average car emits 4.6 tonnes of GHG per year). 

To effectively use 3D printers Airbus partnered with Materialise , a Belgium-based technology company  that specialize in additive manufacturing.

For more information regarding improving corporate sustainability by digital transformation you can read our Top 4 Digital Technologies that Improve Corporate Sustainability article.

10. Tata Power: Solar plants on the roofs

Rooftops offer a lot of empty space that can be used to install solar panels. Such initiatives have been taken in various parts of the world. Tata Power does it in India and generates green electricity by using idle places of buildings.

In 2021, Tata Power was able to spread their program throughout 90 Indian cities, producing 421 million watts of electricity, which is equivalent to nearly 40 thousand homes’ yearly electricity use in the US. (The average annual power usage for a residential utility customer in the US was 10,715 kWh in 2020, according to the EIA .).

We expect that in the near future the cooperation between energy and construction companies will enhance the use of idle places in buildings in a more effective way. Such an industrial symbiosis reduces both sectors’ ESG risk.

For more information on the top carbon footprint calculators, check our article, Top 7 Carbon Footprint Calculator Software/Tools for Businesses .

To learn more about corporate sustainability you can contact with us:

This article was drafted by former AIMultiple industry analyst Görkem Gençer.

Cem's work has been cited by leading global publications including Business Insider, Forbes, Washington Post, global firms like Deloitte, HPE, NGOs like World Economic Forum and supranational organizations like European Commission. You can see more reputable companies and media that referenced AIMultiple.

Cem's hands-on enterprise software experience contributes to the insights that he generates. He oversees AIMultiple benchmarks in dynamic application security testing (DAST), data loss prevention (DLP), email marketing and web data collection. Other AIMultiple industry analysts and tech team support Cem in designing, running and evaluating benchmarks.

Throughout his career, Cem served as a tech consultant, tech buyer and tech entrepreneur. He advised enterprises on their technology decisions at McKinsey & Company and Altman Solon for more than a decade. He also published a McKinsey report on digitalization.

He led technology strategy and procurement of a telco while reporting to the CEO. He has also led commercial growth of deep tech company Hypatos that reached a 7 digit annual recurring revenue and a 9 digit valuation from 0 within 2 years. Cem's work in Hypatos was covered by leading technology publications like TechCrunch and Business Insider.

Cem regularly speaks at international technology conferences. He graduated from Bogazici University as a computer engineer and holds an MBA from Columbia Business School.

AIMultiple.com Traffic Analytics, Ranking & Audience , Similarweb. Why Microsoft, IBM, and Google Are Ramping up Efforts on AI Ethics , Business Insider. Microsoft invests $1 billion in OpenAI to pursue artificial intelligence that’s smarter than we are , Washington Post. Data management barriers to AI success , Deloitte. Empowering AI Leadership: AI C-Suite Toolkit , World Economic Forum. Science, Research and Innovation Performance of the EU , European Commission. Public-sector digitization: The trillion-dollar challenge , McKinsey & Company. Hypatos gets $11.8M for a deep learning approach to document processing , TechCrunch. We got an exclusive look at the pitch deck AI startup Hypatos used to raise $11 million , Business Insider.

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A wonderful collection of case studies on corporate sustainability. I enjoyed the read. I am convicted to delve into promoting sustainability in Africa.

Hello, James! Thank you for your feedback. Awesome! That’s a great cause to pursue.

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Twenty Key Challenges in Environmental and Resource Economics

• Open access
• Published: 16 October 2020
• Volume 77 , pages 725–750, ( 2020 )

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• Lucas Bretschger 1 &
• Karen Pittel 2  

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Economic and ecological systems are closely interlinked at a global and a regional level, offering a broad variety of important research topics in environmental and resource economics. The successful identification of key challenges for current and future research supports development of novel theories, empirical applications, and appropriate policy designs. It allows establishing a future-oriented research agenda whose ultimate goal is an efficient, equitable, and sustainable use of natural resources. Based on a normative foundation, the paper aims to identify fundamental topics, current trends, and major research gaps to motivate further development of academic work in the field.

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1 Introduction

1.1 research frontier.

The research agenda in environmental and resource economics has always been very broad and dynamic, reflecting the ways our economies interact with the natural environment. While in classical economics of the eighteenth century the factor land played a dominant role, the effects of pollution externalities, resource scarcities, ecosystem services, and sustainability became important in subsequent time periods. These issues have triggered different waves of research with very prominent results, specifically on optimal policies in the presence of externalities (Pigou 1920 ), optimal extraction of non-renewable resources (Hotelling 1931 ), optimal capital accumulation in the presence of resource scarcities (Dasgupta and Heal 1974 ), and sustainable development (Hartwick 1977 ; Pearce et al. 1994 ). Of course, the list of topics has already been very diverse in the past but has increasingly become so with recent global environmental problems challenging the functioning of a world economy which is growing at a high rate and heavily relies on an international division of labour and trade.

In the past, new research challenges emerged and manifested in different ways: Some topical fields became increasingly relevant due to new technological developments, new ecological or societal challenges or new political agendas. Others arose in fields that were already well researched but rose in importance. Not all challenges were of a topical nature. In some fields, we found our methodological tool-kit not equipped to deal with new problems or in need of extension to find new (and better) answers to old questions. At the same time, it has become increasingly clear that we have to reach out to other disciplines to meet new and often immense challenges. In environmental economics it is key to seek a good balance between disciplinary excellence, interdisciplinary collaboration, and political impact.

Environmental and resource economics is a dynamic field, in which new key topics emerge frequently. So, while the topical and methodological challenges that the paper identifies will be important for some time to come, they will and should also be subject to further development over the next years and decades. The paper aims to identify and address the variety of new complex problems generated by humans when they exploit natural resources and the environment. We specifically identify Twenty Challenges that we feel will be important for environmental and resource economists to address. We are aware that such a list will never be unanimously agreed upon and we do not even lay claim on the list being complete; the next section provides a background to the compilation of the list. Nevertheless, we feel it to be important to (at best) point researchers in directions important to work in in the future or (at least) to launch a new—controversial but productive—discussion on the development of our field. In any case, the paper should support the profession to operate at the research frontier generating novel theories, empirical designs, and workable policies. But, before we turn to the Twenty Challenges , we aim to motivate the framing of research in our field—past, present and future.

1.2 Identification of Research Challenges

To provide a normative foundation for our research agenda we characterize our underlying assumptions and generalized views on the nature of research in the field. This set of basic assumptions motivates the criteria of importance, activeness, and distinction of the selected topics as well as our choices with respect to design, methodology and research methods. Identifying the relevant issues, i.e. the mere choice of what to study in environmental economics imposes specific values on the subjects. In our view, the guiding principle in the normative framework is that environmental economics differs from general economics by its ontology, i.e. the system of belief that reflects the interpretation of what constitutes an important fact. It is a deep and serious concern about the state of the natural environment that drives the economic analysis of ecological processes. Nature is not simply part of the economic system but a different system with its own very complex regularities and dynamics; ecosystem values are not reducible to market exchange values. The task to integrate the ecological and economic systems to a holistic framework in an appropriate manner and to derive valid guidelines for the economy under the restrictions imposed by the environment lies at the heart of our research. Central parts of the ontology are the valuation of ecosystems, the increasing scarcities in natural resources and sinks, the effects of environmental externalities, the long-term orientation of planning, an important role of uncertainty, and the existence of irreversible processes. The anthropocentric view and the use of utilitarianism do not imply that individuals are purely self-centered and narrowly selfish. It highlights the indistinguishable role of human decision making for the future of the planet and aims at decision making that cares for efficiency, equity, and posterity. Based on a broad utilitarian setup, growth is not valued in terms of material consumption but in terms of wellbeing, which includes elements like social preferences, work-life balance, appreciation of nature etc. Posterity reflects our care for future generations, whose welfare should not be harmed by the activities of current generations. Fundamental changes of the economy e.g. the phase-out of fossil fuels, includes policy-induced decrease of activities, a role for technology, substitutability in production and consumption, a decoupling from natural resource use, and internalizing cost to correct market failures. Substantive transitions are very difficult to implement, as important lock-in mechanisms such as habit persistence, built infrastructure, and supporting policies such as subsidies stabilize current practices. To achieve a change of mindset in politics to achieve a transition to a green economy is a difficult task. A fundamental systems change, as discussed by many these days, is undoubtedly much more complex to accomplish; its impacts are uncertain and may delay the necessary steps which are important to rapidly improve the state of our ecosystems.

We acknowledge that one can always challenge an ontological position because it reflects ethical principles. In our research agenda there is no external reality, independent of what we may think or understand it to be. We reduce economic and ecological complexity through our personal system of belief to design our preferred map, which by definition is not the territory. In his survey of ecological research issues for the economists, Ehrlich ( 2008 ) refers to his ”own mental meta-analysis” to motivate his choices and to alert us to the importance of research on big issues like the meaning of life, mortality, and death. At the same time, he acknowledges that the emergence of pervasive new environmental problems, such as climate change and biodiversity loss, requires to flexibly adjust research programs to societal demand. Adjustments of the agenda may also be supply driven, when new methods allow for more effective engagement with important issues like risk and uncertainty or assessment of empirical regularities with superior estimation methods.

1.3 Forming a Research Agenda

Environmental economics is closely linked to general economics in its epistemology, i.e. the validity, scope and methods of acquiring knowledge by using models, distinguishing between positive and normative models, and testing hypotheses with empirical methods and experiments. An important cornerstone for economic research has always been the analysis of economic efficiency. Since the early days of environmental economics research, this has also held for our field whether it concerned the efficiency in the use of natural resources or the design of policies. Although research in our field has become much more interdisciplinary and policy-oriented, this still constitutes common ground. It is still a prime duty of the economist to point at the potentially vast allocative inefficiencies of the use of natural resources in pure market economies. Efficiency is a necessary condition for optimal states of the economic-ecological system and the foundation for policies maximizing social welfare.

The pursuit of optimality has to be complemented by a requirement to take care of equity and posterity enabling sustainability of development. In this long-run perspective, economics has to highlight the substitution effect as a powerful mechanism establishing consistency between humanity and its natural environment. Substitution comes in many guises, e.g. as substitution between clean and dirty production, renewable and exhaustible resources, extractive and conservationist attitude, pollution intensive and extensive consumption, etc. This dynamic analysis is crucial in many respects. It has recently been included at all levels of research in the fields. The same holds for the issue of risk and uncertainty, a pervasive topic when dealing with the environment.

In many cases, there has been a significant discrepancy between the theoretical derivation of social optima in academia and the attempts to foster their implementation under realistic policy conditions. As a consequence, policies dealing with environmental issues have been of very different quality and effectiveness. The reduction of acid rains, the protection of the ozone layer, and cutbacks of particulate matter emissions in many world regions were among the prominent successes. Global warming, extraction of rare earth elements, and loss of biodiversity are not yet addressed in a comprehensive manner. Political resistance against the protection of nature often refers to the economic costs of policies, including the concerns of growth reduction, employment loss, and adverse effect on income distribution. The lack of success in many policy areas has led to reformulation and extension of the research agenda. In the future, research should focus more on strengthening the links between theory and policy.

Our selection of the Twenty Challenges is also based on the potential of research in these areas to contribute and leverage social welfare and sustainable development. We specifically look for areas that are either inherently new to the research agenda in environmental and resource economics or in which research stagnates. We present the challenges in a specific order and like to highlight the links between them before we enter into the details. The aim of net zero carbon emission by the mid of the century dominates current policy debates and unites basically all important elements of our discipline; it thus constitutes a good starting point. Decarbonization necessarily involves a deep understanding of systems dynamics and of risk and resilience, which are presented next. An important and not sufficiently addressed research issue is the emergence of disruptive development during a substantive transition, the next challenge for our research. Extending the scope, we then address human and government behaviour. In the context of environmental policy, the popular and sometimes underrated request of an equitable use of the environment has emerged as a dominant topic, a next issue for further research. As natural capital involves many more elements than the climate, biodiversity and general ecosystem services are included in the sequence. Broadening the scope to the big problems of human behaviour with natural resources we then turn to political conflicts, population development and conflicting land use. Shifting the focus on induced movements of the labour force we go on by dealing with environmental migration and urbanization. These affect welfare of the individuals in a major way, like health and the epidemiological environment as a next research challenge. In terms of the reorganization of the transition to a green economy we highlight the central role of finance and the implementation of new measures in the dominant energy sector. The final three research challenges are motivated by advances in the methodology. Big data and machine learning offer new perspectives in sustainability research, refined methods and increasing experience improve our simulation models and structural assessment modelling, which forms the last three challenges of our list.

1.4 Links to Current Research

In order to put our agenda into a broader perspective and to concretize the selected challenges, we believe it is important to show the relationship between our research agenda and the priorities in current literature and policy debates. We have considered three main links. First, we conducted a quantitative and qualitative literature review and analyzed current research as presented at international conferences (World Conference of Environmental and Resource Economics in 2018, the SURED conference in 2018, Meetings of the American, European, and Asian Associations of Environmental and Resource Economics in 2019). The aim of this analysis was to see where our profession moves and which of the currently hotly debated topics offers a high potential for future research. Second, we took the discussions in interdisciplinary research fora into consideration to identify further fields that are of high importance for future resource use, sustainable development and environmental outcomes but have so far not been adequately addressed from an economics perspective. Information on this research was gained through interdisciplinary research initiatives (for example The Belmont Forum, Future Earth and National Research Funding Activities). Involvement in interdisciplinary and globally oriented research councils provided further access to the discussions in other disciplines. Third, we draw conclusions from current policies and news as well as our involvement in the policy arena. The authors are involved in a number of institutionalized policy-oriented activities on the regional, national and international level (Regional Climate Councils, National Climate Policy Platforms as well as the UN climate negotiations).

The paper relates to similar contributions in recent literature. Based on citation data Auffhammer ( 2009 ) identifies important topics and scholars and provides a brief historical overview of the discipline from exhaustible and renewable resources to sustainability, pollution control, development, international trade, climate change, international agreements, and non-market valuation. Polyakov et al. ( 2018 ) analyze authorship patterns using text analysis for classification of articles in Environmental and Resource Economics. Based on 1630 articles published in the Journal from 1991 to 2015 they document the importance of applied and policy-oriented content in the field. They identify non-market valuation, recreation and amenity, and conservation, as popular topics and growing when measured by both number of articles and citations. Costanza et al. ( 2016 ) investigate the most influential publications of Ecological Economics in terms of citation counts both within the journal itself and elsewhere. Important topics turn out to be social aspects of environmental economics and policy, valuation of environmental policy, governance, technical change, happiness and poverty, and ecosystem services. A contemporary analysis of how research issues have developed in the Journal of Environmental Economics and Management in the time of its existence is provided by Kubea et al. ( 2018 ). These authors show that the sample of topics has broadened from the core issues of non-market valuation, cost-benefit analysis, natural resource economics, and environmental policy instruments to a more diversified array of research areas, with climate change and energy issues finding their way into the journal. In addition, increasing methodological plurality becomes apparent. They conclude that energy, development, and health are on the rise and that natural resources, instrument choice, and non-market valuation will endure; multidisciplinary work will be increasingly important. An excellent survey on research in the central field of sustainable development is provided in Polasky et al. ( 2019 ), which explicitly shows where the collaboration between economists and the other disciplines is currently insufficient and how it should be intensified in the future.

Regarding the literature that we connect our Twenty Challenges to, we naturally face the problem that some challenges have so far not been addressed adequately in the (economics) literature. In these cases we also reference papers from other disciplines. We, however, also take basic literature and recent research in environmental and resource economics into account. As we often deal with emerging topics, we cite some of this work even when not yet published. In other cases, where future research can build on or learn from past research, we also go back in time and reference older papers. Ultimately, neither our list of challenges nor the literature we base our analysis on will be satisfying to everybody. Our selection cannot be comprehensive and does not claim to be. But the specific task to identify future-oriented topics ultimately lasts on a subjective individual assessment of the authors. Nevertheless, hopefully it imparts impulses for future research in the different subfields of environmental and resource economics.

2 Twenty Challenges

The ordering of the following challenges should not be understood to perfectly reflect their individual importance (beyond what we explained in the previous sections). Also, many of the fields discussed are inherently related, creating some unavoidable overlap. We feel that efforts to bring the challenges into some complete ’natural order’ are not only doomed to fail but also would not do them justice as they relate to very different areas and can/should not be weighed against each other. Also, attempting to show their interrelations would result in a 20-by-20 matrix that would not provide more clarity.

Deep decarbonization and climate neutrality To limit global warming to a maximum of 1.5 degrees Celsius, a state of net zero greenhouse gas emissions—i.e. climate neutrality—should be reached by the mid of the century (IPCC 2018 ). The directly following and unprecedented challenge is to decarbonize the global economy in very a narrow time window (Hainsch et al. 2018 ). This holds especially as the threshold for 1.5 degrees is expected to be passed around 2040 (IPCC 2018 ). Countries must increase their NDC ambitions of the Paris Agreement more than fivefold to achieve the 1.5 degree goal (UN - United Nations 2019 ). The time window for necessary decisions is closing fast. Infrastructure that is installed today often has a life span that reaches until and beyond 2050. Decisions on investments today therefore affect the ability to reach climate targets not only in 2030 but also 2050 and beyond. And while the necessity of reaching net zero emissions by mid century is reflected by, e.g., the European Commission’ Green Deal, much uncertainty remains regarding its implementation. This holds to an even larger extent with respect to other countries and regions. The fundamental challenge is to better understand economically viable deep decarbonization paths and then to implement incentives for input substitution, technology development, and structural change. More specifically, the vision of these policies has to be long-term and reach beyond phasing out coal and increasing energy efficiency. However, despite recent research efforts in climate economics, many issues around decarbonization, negative emissions and economic development are still controversial or insufficiently understood by economists. Specifically, industry applications for which alternative technologies are not available yet as well as agricultural emissions will have to be addressed. Also, the later greenhouse gas emissions start to fall, the faster their decline will have to ultimately be in order not to overshoot temperature targets (Agliardi and Xepapadeas 2018 ), leading to an increased need for negative emissions. However, potential trade-offs and synergies in the use of land for negative emission technologies, food production and biodiversity are still underresearched. Identifying technologies today that are the most promising in the very long run is subject to high uncertainty. Yet, while investing too early might be costly, delaying investment might cost even more or might lead to a weakening of future climate targets (Gerlagh and Michielsen 2015 ). Also, transition processes may involve strong scale effects implying nonlinear development of abatement cost. Once certain thresholds are reached, lower abatement cost or even disruptive development completely altering the production process could emerge in a later phase of decarbonization. Given the dramatic increase needed in mitigation efforts to reach the 1.5 or even 2 degree target, more attention also has to be devoted to the question of adaptation. Until today, the focus of research as well as policy has been primarily on mitigation rather than adaptation, partially because of expected substitution effects between mitigation and adaptation and partially because adaptation was taken to be automatic (Fankhauser 2017 ). However, as Fankhauser lays out “knowledge gaps, behavioral barriers, and market failures that hold back effective adaptation and require policy intervention”. All of these topics present a wide scope for substantial further research.

Dynamics of the economic-ecological system Depletion of exhaustible resources, harvesting of renewable resources, recycling of raw materials, and accumulation of pollution stocks require basic societal decisions which are of an inherently dynamic nature. Whether the world society will be able to enjoy constant or increasing living standards under such dynamic natural constraints depends on another dynamic process, which is the accumulation of man-made capital. To derive the precise laws of motion in all the stock variables is challenging because general solutions of dynamic systems with several states are usually hard to obtain. An adequate procedure to obtain closed-form solutions may be to link several stocks in a reasonable way, e.g. when simultaneously dealing with resource, pollution, and capital stocks (Peretto 2017 ; Bretschger 2017b ). The specific challenge is then to find the best possible economic justification to motivate the links. One may also focus on a few stocks which are considered the main drivers of economic development and sustainable growth on a global scale (Marin and Vona 2019 ; Borissov et al. 2019 ). When resorting to numerical simulation methods it is a main challenge to provide basic economic results which are sufficiently robust and supported by ample economic intuition. Social-ecological systems are increasingly understood as complex adaptive systems. Essential features of these systems - such as nonlinear feedbacks, strategic interactions, individual and spatial heterogeneity, and varying time scales—pose another set of substantial challenges for modeling in a dynamic framework. A main challenge is the characterization and selection of dynamic paths with multiple equilibria and the overall tractablility of the models, given the diversity of interlinkages and nonlinear relationships. The complexity of economic-ecological systems lead to a main challenge for designing effective policies is taking account of network effects, strategic interaction, sectoral change, path dependencies, varying time lags, and nonlinear feedbacks have to be considered as well as different regional and temporal scales, interdependencies between ecosystems, institutional restrictions and distributional implications (see, e.g., Engel et al. 2008 ; Levin et al. 2013 ; Vatn 2010 ). Optimal policies should also acknowledge the balance between the preservation of the ecology and the development of the economy especially for countries growing out of poverty. Setting a price for ecosystem services and natural capital via policy is important for preventing innovation incentives from being skewed against maintaining natural capital and ecosystem services.

Risk, uncertainty, and resilience The vast majority of contributions in environmental economics use models with a purely deterministic structure. However, large negative environmental events require a completely different framework, which poses specific challenges for modelling. Heatwaves, floods, droughts, and hurricanes are shocks that are very uncertain, arriving at irregular times and with varying intensity. Also, risk and uncertainty about socio-economic impacts and technological development affect the optimal design of policies (see, e.g., Jensen and Traeger 2014 ). Moreover, uncertainty changes the political economy of climate policy and, finally, regulatory and policy uncertainty might create obstacles to reach climate targets through, for example, distortions of investment decisions (Pommeret and Schubert 2018 ; Bretschger and Soretz 2018 ). Stern ( 2016 ) argued forcefully that climate economics research needs to better integrate risk and uncertainty. Bigger disasters or so-called ”tipping points” such as the melting of the Greenland ice sheet, the collapse of Atlantic thermohaline circulation, and the dieback of Amazon rainforest involve an even higher level of uncertainty (Lenton and Ciscar 2013 ) with implications for optimal policy design and capital accumulation (Van der Ploeg and de Zeeuw 2018 ). Understanding the implications of tipping points is further complicated as the different tipping points are not independent of each other (Cai et al. 2016 ). The Economy and the Earth system both form non-deterministic systems; combining the two in an overarching framework and adding institutions for decision making multiplies the degree of complexity for adequate modelling and methods (Athanassoglou and Xepapadeas 2012 ). It is thus a main challenge for further research to provide analytic foundations and policy rules for rational societal decision-making under the conditions of risk and uncertainty up to deep uncertainty (Brock and Xepapadeas 1903 ; Baumgärtner and Engler 2018 ). Future work on policy design under deep uncertainty can build on a wide range of literature ranging from the assessment of the precautionary principle in this context to the fundamental contributions by Hansen and Sargent ( 2001 ) and Klibanoff et al. ( 2005 ) as well as on more recent analyses in the context of environmental and resource economics, e.g. Manoussi et al. ( 2018 ). An important challenge of the environmental discipline is to provide a framework for the global economy providing the conditions for resilience against major shocks and negative environmental events (Bretschger and Vinogradova 2018 ). With deep uncertainty one has to generate rules for deep resilience. Including uncertainty is especially important when environmental events do not occur constantly but cause the crossing of tipping points involving large and sudden shifts. Economic modeling needs to increasingly incorporate tipping points and the value of resilience in theory and to generate and use data supporting the empirical validity. The combination of uncertainty and potential irreversible outcomes (e.g., species extinction) is another big challenge for research.

Disruptive development and path dependencies Substantial and sometimes disruptive changes in behavioral patterns, economic structure and technologies will be required if net zero GHG emissions and the UN sustainable development goals are to be reached. On the bright side, development may exhibit favorable disruptions. Consumers’ preferences and political pressure coupled with new technology achievements may alter certain sectors in a short period of time. Similar to the communication industry which has completely changed, transportation and heat generation could and mst probably will undergo fundamental changes in the near future. The research challenge here is to provide adequate models predicting and adequately analyzing such important transitions and to highlight resisting forces at the same time. In fact, the change of trajectories in development is often hampered by technological, economic and behavioral lock-ins, resulting in path dependencies and inertia. In such situations, history influences current development through, for example, past investment in R&D, the size of established markets, increasing returns or habits acquired (Aghion et al. 2016 ; Barnes et al. 2004 ; Arthur 1989 ). Behavioral path dependencies affect acceptance and adoption of new technologies, hinder social innovation and might render policies aimed at marginal changes ineffective. They can thus postpone the transition to a low-carbon economy, harm efforts in biodiversity conservation and prolong unsustainable resource use patterns and lifestyles, even if they are welfare enhancing in the long-run (e.g. Acemoglu et al. 2012 ; Kalkuhl et al. 2012 ). Inertia and lock-ins may also be policy driven with, for example, political or economics elites trying to block change (Acemoglu and Robinson 2006 ) or clean energy support schemes fostering new technology lock-ins. Whether disruption or a lock-in emerges depends, for example, on expectations determining the steady state of an economy (Bretschger and Schaefer 2017 ). This requires nonlinearities e.g. in capital return, generating overlap regions in which the growth path is indeterminate and could be either driven by history or by expectations. The challenge is to add more substantial research into system dynamics and the political economy of change, to gain a better understanding of the different mechanisms responsible for inertia and disruptive change. So far, the role of path dependencies has often been neglected in empirical as well as theoretical analyses (Calel and Dechezlepretre 2016 ). Also, understanding the triggers or tipping points for disruptive change can help to identify policies that have a big environmental impact with moderate costs in terms of environmental policy.

Behavioral environmental economics Traditionally, economics focuses predominantly on the supply side when analyzing potentials and challenges for environmental policies. Preferences of individuals are mostly assumed to be given with economic analysis confining itself to studying the effects of changing incentives and altering constraints. The change and development of preferences over time plays only a comparative minor role for economic research. Also, the follow-up question whether policies should be allowed to tamper with preferences is rarely discussed with nudging being one big exception to this rule (e.g. Strassheim and Beck 2019 ). While the traditional, supply-side oriented analysis has provided powerful results in positive analysis, it proves to be limited in a field which inherently includes normative conclusions like environmental economics. The path toward sustainable development requires behavioral changes and political actions changing our relationship to the environment. Ultimately, environmental policies have to be decided by the same people overusing the environment in the absence of a policy. In situations where outcomes are inefficient because individuals and political actors follow their own self-interest and ignore external costs and benefits of their actions, it is clearly not sufficient for economists to advocate the implementation of environmental policies. It is crucial to understand under what conditions preferences change and agents support green policies (Casari and Luini 2009 ). So, the challenge to economic research is to better understand the evolution of green attitudes, the emergence of preferences for a clean environment, and expectations in the case of multiple equilibria (Cerda Planas 2018 ). The formation and development of preferences is also not independent from cultural, regional and community aspects. Research that ignores heterogeneity among actors or the role of social and group dynamics and only relies on the traditional, isolated analysis of individual preferences is likely to lead to an incomplete understanding of preference dynamics. As the example of discounting shows, the social context has an impact on myopic attitudes and the motivation to undertake sacrifices for a cleaner future (Galor and Özak 2016 ). Also, attention to behavioral details, that economists might find rather uninteresting from a research perspective, might influence effectiveness of policies tremendously (Duflo 2017 ). Especially with the natural environment, the choice and guise of policy instruments should take these mechanisms into account.

Institutional analysis of environmental policy Virtually every contribution to the environmental and resource economics literature culminates in one or several policy conclusions. However, these results are often received with skepticism from industry and public. Therefore, a continuing key challenge for our profession is a thorough understanding of environmental policy institutions, processes and decision-making; this task has become even more important given the enormous scale and global nature of future policies. Research in this area has, however, the advantage of already looking back on a long tradition (see e.g. the body of work by Daniel Bromley, e.g. Bromley 1989 ). Well-designed institutions support and create incentives to drive development toward a welfare-improving state. Absent, weak, inefficient, or even corrupt governments and institutions are detrimental to successful environmental policy (Pellegrini and Gerlagh 2008 ; Dasgupta and De Cian 2016 ) or might lead to detrimental effects of resource wealth (see Badeeb et al. 2017 for an overview of the related literature). To effectively increase social welfare by, for example, conservation of ecological services, one has to design policies in a way that allow implementation under realistic policy conditions (Rodrik 2008 ). Pure reference to the construct of a social planner is not sufficient. For increasing efficiency in problem solving, the ex-post evaluation of policies has to be expanded and improved. Policy evaluation should not only analyze if regulatory objectives have been reached but also which side-effects arise (OECD 2017 ). Moreover, the comparison with alternative measures and a continuous international exchange of best practices have to be supported by science. A proactive environmental policy analysis should furthermore include studying vested interests, lobbying, political power, policy communication, and voting behavior. Especially insights from behavioral economics may add to our understanding of a proper design of environmental institutions. On the international level, the adequate institutional design for global environmental policy still poses great challenges. Beyond traditional research fields like international environmental agreements in specific areas like climate change, the multi-dimensionality of the sustainable development goals (SDGs) and potential trade-offs between different goals need to be explored further. This holds especially given the vast differences in income, vulnerability, and resilience between countries, as well as the need for unanimity and voluntary contributions on the UN level. Relating national to international policies has the potential to be especially rewarding in this context given the SDGs relevance for and acceptance in national as well as international politics. Insights from the analysis of institutions in traditional economic sectors (e.g. on the efficiency of capital markets) should be transferred and applied to the global level (e.g. with respect to investment in the world’s natural capital stock).

Equitable use of the environment We place equity and fairness in dealing with the natural environment on the priority list of our challenges because first and foremost equity is a central requirement for sustainability of development. By definition, sustainable development seeks an equitable treatment across different generations as well as agents living today. We also believe that for successful environmental policies, equity and fairness are crucial complements to the dominant efficiency requirement (Sterner 2011 ). It is a specific challenge of our field to study equity in an economic context and to demonstrate its importance for sustainability to mainstream economics and the public. The first aspect of the problem is the aforementioned unequal vulnerability of countries to environmental changes such as global warming. If vulnerability is higher in less developed countries, the equity perspective is especially striking. As a matter of fact, most of the climate vulnerable countries have a low average income. Global environmental policy is then motivated not only by efficiency but also by the aim of preventing increasing inequalities (Bretschger 2017a ). Global efforts are also indicated to avoid adverse feedback effects of induced inequalities like environmental migration. The second aspect is that acceptance of public policies sharply increases with the perceived fairness of the measure (Pittel and Rübbelke 2011 ; IPCC 2018 ). In the past, economists have often underestimated political resistance against efficient environmental protection, which was mostly related to negative impacts on income distribution. Take carbon pricing and emission regulation as a current example. Although evidence from cross-country studies suggests that regressivity of carbon pricing is much less frequent than often assumed in the public (Parry 2015 ), the perceived distributional impact is often very different (Beck et al. 2016 ). Therefore the impact of environmental policies on income groups, regions, and countries should be better integrated in our analysis and policy recommendations. Where efficient policies are regressive, economists have to evaluate and propose alternative or complementary policy designs. Benefits and costs need to be disaggregated by group (country) with a special attention on the poorest members of society (countries). Internationally, equity concerns need to be addressed especially in situations where the entire world benefits from the protection of natural capital and ecosystem services in poor countries (e.g., of carbon sinks and biodiversity hubs like tropical rain forests). The experience with the REDD+ process shows the complexity of designing such international approaches to incentivize and enable developing countries to protect these global public goods. More economic analysis is needed on all of the above aspects, giving rise to a rich research agenda in theory and applied work.

Loss of biodiversity and natural capital The rate of species extinction today is estimated to be up to 1000 times higher than without human interference (Rockstrom 2009 ). Human activities impact biodiversity through land use change, pollution, habit fragmentation and the introduction of non-native species but also increasingly through climate change and its interaction with already existing drivers of biodiversity change (IPCC 2002 ). In view of this, biodiversity conservation has long been a focus of politics. In 1992, the United Nations Convention on Biological Diversity main objectives were stated as ”the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources” (UN - United Nations 1992 ). Yet, although economists have developed conceptual and theoretical frameworks addressing the valuation of biodiversity (Weitzman 1998 ; Brock and Xepapadeas 2003 ) and despite data on valuation having become increasingly available (see, e.g. TEEB 2020 ), Weitzman ( 2014 ) points out, that an objective or even widely agreed measure of biodiversity and its value is still missing. The same holds for an underlying theory framework and a comprehensive measure of natural capital that not only includes biodiversity but also its links to regulating services (e.g., pollution abatement, land protection), material provisioning services (e.g., food, energy, materials), and nonmaterial services (e.g., aesthetics, experience, learning, physical and mental health, recreation). How biodiversity and natural capital should be measured, which societal, political and economic values underlie different measures and valuation and how ecological and economical trade-offs should be dealt with are big challenges left for future research. In order to address these issues, not only do we need to develop appropriate assessment methods, but we also need to disclose the theoretical basics of this assessment and which trade-offs go hand in hand with different assessments (Brei et al. 2020 ; Antoci et al. 2019 ; Drupp 2018 ). Completely new issues for the valuation of biodiversity and natural capital arise with the development of new technologies. Take DSI (digital sequence information), for example. DSI are digital images of genetic resources (DNA) that can be stored in databases. This gives rise not only to new challenges regarding their valuation but also about the fair and equitable sharing of the benefits arising out of the utilization of these resources.

Valuing and paying for ecosystem services Related to the question of biodiversity valuation is the market and non-market valuation of ecosystem services in general and the adequate design of payment for ecosystem services (PES). Overall, research on ecosystem services valuation has made significant progress in the last decades. Nevertheless, challenges remain even in traditional valuation fields (for example, valuation of non-use or interconnected ecosystems). Other, so far underresearched areas that constitute promising fields for future research are health-related valuation aspects (Bratman et al. 2019 ) and nonmaterial ecosystem services, such as amenities of landscapes or cultural ecosystem services (Small et al. 2017 ; James 2015 ). Also, data availability remains a problem in many valuation areas. Although digitized observation and information systems offer large potentials for previously unknown data access, they also raise a whole slew of new ethical, privacy as well as economic questions, especially in areas like health. While a lot of progress has been made in the valuation of ecosystem services, their impact on decision making still lags behind. One factor contributing to this disconnect are prevalent mismatches between regional and temporal scales of economic, institutional and ecological systems that make valuation and policy design complex (Schirpke et al. 2019 ). The challenge is to develop combined natural science-economic models that allow better insights into how changes in economic systems lead to changes in the flows of ecosystem services and vice versa (Verburg et al. 2016 ). This requires a deep understanding of ecological and economic systems as well as other aspects like technologies, regional heterogeneity and system boundaries, i.e. catastrophic events. It also raises classic economic problems, such as choosing an appropriate discount rate and degree of risk aversion. Regarding tools to include ecosystem services in economic decision making, PES are a, by now, well-established (Salzman et al. 2018 ) and also quite well-researched approach for promoting environmental outcomes. Still, the literature has identified a number of aspects to be addressed in the design of PES to make them more effective as well as efficient and to simultaneously improve social outcomes (Wunder et al. 2018 ; Chan et al. 2017 ). A promising area of research rarely addressed are PES to preserve transboundary or global ecosystem services through international payment schemes (for example, in tropical forest preservation). While some work has been done on the conceptual level (e.g. Harstad 2012 ), the REDD+ process (Maniatis et al. 2019 ) and the failure of the Yasuni initiative (Sovacool and Scarpaci 2016 ) show the complexity of such approaches for which a thorough economics analysis is still missing.

Conflicts over natural resources Climate change and decarbonization transform regional and global geopolitical landscapes and might give rise to future domestic as well as international conflicts (Mach et al. 2019 ; Carleton and Hsiang 2016 ). First, decarbonization changes the role of resources and of resource- and energy-related infrastructures. Climate policies affect the rent allocation between different fossil fuels like, for example, coal and natural gas, but might also change the overall rent level (Kalkuhl and Brecha 2013 ). Asset stranding can endanger stability in resource (rent) dependent countries. Conflicts may also arise over materials critical to new, low-carbon energy technologies like rare earth elements but also over access to sustainable energy (Goldthau et al. 2019 ; O’Sullivan et al. 2017 ). Further research is needed to design policies that are better equipped to reduce the vulnerability of economies to changes in resource availability and resource rents. This opens up challenges for future research, especially as restrictions from very diverse institutional capacities have to be considered to render policies efficient and effective. Second, climate change will affect the ability to meet basic human needs through food, land and water. Sulemanaa et al. ( 2019 ) find a positive effect of the occurrence of temperature extremes on conflict incidence. They stress the need for more advanced spatial econometric models to identify effects that are transmitted across space. More research is also needed on the role of institutions and interaction with other phenomena like population dynamics, migration, and environmental degradation. Currently, the role of climate for conflict is still small compared to other causes, many linkages between conflicts and climate change as well as other factors promoting conflict are still uncertain (Mach et al. 2019 ). The challenge to economic research is to get early insights into the nexus of historical and cultural factors, vested interests, population dynamics and climate change in order to help to prevent resource-related conflicts.

Population development and use of the environment Already since antiquity, demographic analysis has been a central topic of human thinking. With the Malthusian predictions of catastrophes caused by population growth, the topic is firmly related to the natural environment and the limits of planet Earth. While limited food production was the dominant topic in the 18th century, the impact of world population on global commons, availability of renewable and exhaustible resources, and ecosystem services have been dominant topics in the last decades. Still, while it is often argued in the public and in natural sciences that world population size should be a concern because of ecological constraints, economics has largely left the topic on the side; the few exceptions (Peretto and Valente 2015 ) and (Bretschger 2013 , 2020 ) point in a different direction, namely the compatibility of population growth and sustainable development under very general conditions. Current trends of demographic transition show significant signs of population degrowth for leading economies while trends for developing countries vary substantially (UN - United Nations 2019 ). Population is forecasted to expand especially in Africa, accounting for more than half of the world’s population growth over the coming decades, raising questions about the effect of this population increase on fragile ecosystems, resource use and ultimately the potential for sustainable growth (African Development Bank 2015 ). Population growth will also promote further urbanization and migration triggered by environmental and resource depletion but also giving rise to new environmental problems (Awumbila 2017 ). Challenges from population development and environment are thus closely linked to the other research topics highlighted in this article. However, population growth is not exogenously given but determined by economic, social as well as environmental factors. Education and income or economic development have long been established as crucial for fertility (see e.g. the reviews of the literature provided by Kan and Lee 2018 ; Fox et al. 2019 ). To integrate these findings into a holistic approach is a mediating challenge for future research. Climate change might affect these channels in different ways, potentially exacerbating global inequality (Casey et al. 2019 ). However, population development, fertility, and mortality are not only affected by climate change but also by other environmental stresses like air pollution (Conforti et al. 2018 ). A successful combination of endogenous fertility and mortality with natural resource scarcity, agricultural production, and pollution accumulation as well as capital and knowledge build-up in a comprehensive framework is a respectable challenge for an economic modeller; we suggest that in the future it should be considered by economists more intensively.

Land use and soil degradation The terrestrial biosphere with its products, functions and ecosystem services is the foundation of human existence, not only for food security but far beyond. Currently, about a quarter of ice-free land area is degraded by human impacts (IPCC 2019 ). The optimal use of scarce land resources becomes an even more urgent topic in the face of the biodiversity crisis and the onset of climate change. This holds especially as the physical and economic access to sufficient, safe and nutritious food is the basic precondition for human existence. Climate change challenges this access on different levels. On the one hand, climate change increases the pressure on productive land areas (due to extreme weather events such as droughts, floods, forest fires or the shifting of climatic zones). On the other hand, land plays a major role in many climate protection scenarios by reducing emissions from land use and land use change, protecting carbon stocks in soils and ecosystems, and conserving and expanding natural carbon sinks. Also, the capture and storage of CO 2 through carbon dioxide removal technologies plays an increasing role for reaching the Paris climate goals (IPCC 2018 ). The induced increase in the demand for the different services from land inevitably implies trade-offs. However, neither the trade-offs nor the potentials for synergic uses are, as of now, comprehensively understood from an economic point of view and thus pose a challenge for future research. While there is a growing literature on negative emission technologies, their costs, potentials and side effects (Fuss et al. 2019 and references within) as well as on the interaction between climate goals and other SGDs on the global level (von Stechow et al. 2016 ), many research questions still remain to be addressed (Minx et al. 2018 ). This concerns especially a better understanding of opportunity costs, governance requirements, regional and distributional effects as well as of acceptance and ethical considerations. With respect to land degradation and land use for food production, changing climate and weather conditions as well as regional population pressure may raise the rate of land degradation (Fezzi and Bateman 2015 ), hurting food security and calling for preservation policies (Brausmann and Bretschger 2018 ). The overuse of ecosystems like forests and water, which protect and complement land, can accelerate the risk of adverse shocks and thus lower soil fertility, which reveals the close link between the different research subjects. However, much of the agricultural research in this field is still quite distant from mainstream environmental economics which can harm research productivity substantially. It remains a challenge to integrate agricultural and environmental research better, for example by bringing together food production, population, and the environment into a macrodynamic framework (Lanz et al. 2017 ).

Environmental migration Migration in times of climate change is an extraordinarily complex, multicausal and controversial challenge (Adger et al. 2014 ). Heatwaves, droughts, hurricanes, and rising sea levels are likely to motivate or even force a growing number of people to leave their homes moving to presumably safer places. Climate-related migration can take a variety of different forms (Warner 2011) from voluntary to involuntary, from short- to long-distance and from temporary to permanent. Migration decisions are usually based on different motives and personal circumstances (climatically, politically, economically, socially), leading to heterogeneous reactions to climate events and making it often problematic to identify and delineate climate-induced migration. Due to these and other methodological difficulties and the small number of studies so far, no globally reliable forecasts for climate induced migration exist (WBGU - German Advisory Council on Global Change 2018a , b ). At present, the forecasted magnitude of the phenomenon ranges from 25 million up to 1 billion people by 2050 (Ionesco et al. 2017 ). Much of this migration can be expected to take place within countries, for example, from rural to urban areas or from drylands to coastal zones (Henderson et al. 2014 ) with environmental migration being one possible adaptation and survivor strategy in the face of climate change (Millock 2015 ). Given the uncertainty in future migration projections, the challenge is to improve migration models (Cattaneo et al. 2019 ) which includes a better understanding and integration of the microfoundation of agents’ migration decisions. Migration, and especially mass-migration, can have a profound impact on the environment of the new as well as the old settlement location and on their economic structure. Labor and commodities markets will be affected the most, with challenges arising also for education and health systems, government budgets and public spending. By affecting public institutions and the skill-mix of the labor force, migration alters economic development both in the sending and in the receiving countries or regions. More research is needed on these impacts. The influx of environmental migrants to new settlement locations may also trigger hostile attitudes and lead to clashes and even armed conflicts. The migrants may be perceived as rivals for scarce resources (land, clean water) or jobs. The situation may be aggravated by lack of political stability and poor-quality political institutions. Dealing with these aspects gives rise to new challenges in environment and resource economics. Traditional analysis of economic costs and benefits of migration have to be complemented by behavioral economic and political economy analyses.

Urbanization as a key for environmental development In the last 70 years, the urban population has increased fivefold with more than half of the world’s population living in cities today and forecasts projecting the share of urban population to rise to almost 70% in 2050 (UN - United Nations 2018 ). Cities are responsible for about 70% of the world energy use and global CO \(_{2}\) -emissions (Seto et al. 2014 ) and ecological footprints are positively correlated to the degree of urbanization (WBGU - German Advisory Council on Global Change 2016 ). In 2014, about 880 million people were living in slums (UN - United Nations 2016 ) elucidating the problems to make urban development environmentally as well as economically and socially sustainable. The speed of urbanization is projected to be the fastest in low and middle income countries, especially in Africa and Asia (UN - United Nations 2018 ), leading to new challenges for the provision of infrastructure, housing, energy supply, transport and even health care. Climate change can be expected to not only foster urbanization trends (Henderson et al. 2017 ) but also increase the magnitude of urbanization-related challenges. Urban areas are often located close to the coast or rivers basins, making them susceptible to rising sea levels and impacts of extreme weather events. Risks can be expected to be higher for poor households due to settlement in less safe areas and poorer housing (Barata et al. 2011 ), potentially perpetuating existing inequalities. On the other hand, cities might offer more efficient adaptation potentials. To date the consequences of climate change for cities and urbanization are still to be determined in detail but depend heavily on factors like location, size and level of development as well as governance capacities. Making cities, their population and their infrastructure resilient to climate change will be decisive for future development. The main challenge here is to better connect the research fields of environmental and urban economics to understand the drivers and dynamic effects of climate change on urbanization and resulting economic development, on adaptation costs and benefits and on the role of institutions. Insights from regional, political and behavioral economics can help shape effective governance to enhance resilience of cities to climate change.

Health and epidemiological environment Environmental degradation can have profound implications for human health. These implications lead to direct as well as indirect challenges for economic decision making, economic development and thus economic research. While many of these challenges might not be new per se, they can be severely exacerbated by, for example, climate change. Economic implications of long-term increases in vector-borne diseases and heat stress as well as pandemics like the COVID-19 and ozone formation still remain to be analyzed in depth, as do the costs and benefits of adaptation measures dedicated to mitigating these effects (Mendelsohn 2012 ). Climate change also affects human health indirectly through impacts on economic development, land use, and biodiversity - and vice versa. Failed emission reductions and bad environmental management especially impact developing countries negatively through direct effects on health but also through health effects of delayed poverty reduction (Fankhauser and Stern 2020 ). Exposure to diseases or epidemics can increase the risk of civil conflicts and violence (Cervellati et al. 2016 , 2018 ). While research has addressed effects of life-expectancy, diseases and premature mortality on long-run economic development (e.g. Ebenstein et al. 2015 ; Acemoglu and Johnson 2007 ), a thorough analysis of the climate-health-development nexus is still missing. Overall, most research carried out on the interaction between environment, climate and human health has focused on physical health and mortality. The effects of air pollution from the burning of fossil fuels or agriculture on premature deaths, cardiac conditions and respiratory diseases, for example, received not only renewed interest in the wake of recent scandals (see e.g. Alexander and Schwandt 2019 ) but have been an active field of research for a number of years (Schlenker and Walker 2016 ; Tschofen et al. 2019 ). Mental health implications like stress, anxiety or depression on the other hand have received much less attention although, for example, Chen et al. ( 2018 ) in a study on air pollution in China estimate these effects to be on a similar scale to costs arising from impacts on physical health. Also, Danzer and Danzer ( 2016 ) find substantial effects of a large energy-related disaster (the Chernobyl catastrophe) on subjective well-being and mental health. Economic research should take up the challenge and put more effort into the economic evaluation of mental health related effects of climate change and environmental degradation in general. Potential to analyze these and other health-related questions have risen substantially in the last years, method-wise as well as topical, with new large data sets becoming available. Big data from insurance companies, satellite imagery on pollution dispersion and effects of draughts, for example, can provide new insights into the dynamics between environmental changes and health. But digital technologies themselves also generate new research questions addressing, for example, risks, costs and benefits of these new technologies.

Carbon exposure and green finance The impact of climate change and of climate policy on the financial system is a topic of increasing public concern. The transition to a low-carbon economy poses a lot of challenges not only from physical risks and damages but also from transition risks. These accrue in such different areas as climate-related policy making, altered market behavior, changes in international trade patterns, technology development, and consumer behavior. To support a safe and gradual transition to a low-carbon economy, the financial sector needs to evaluate and eventually address the new risks associated with climate change and decarbonization in an efficient manner. There is widespread concern that financial markets currently lack sufficient information about the carbon exposure of assets, resulting in risks from climate change and climate policy for investments (Karydas and Xepapadeas 2018 ). If not anticipated by the markets, climate shocks also cause asset stranding, i.e. unanticipated and premature capital write-offs, downward revaluations, and conversion of assets to liabilities (Rozenberg et al. 2020 ; Bretschger and Soretz 2018 ). The same holds true for climate policies which are not or cannot be correctly anticipated by investors (Dietz et al. 2016 ; Stolbova et al. 2018 ; Sen and von Schickfus 2020 ). The growing awareness of these risks is reflected in the attention that policy makers have devoted to the development of transparency improving information systems and indicators in recent years. However, challenges related the design of these systems and indicators, e.g. with respect to an accurate and encompassing risk assessment, still remain. The importance of addressing these challenges is excerbated by prevalent network effects and counterparty risks that transmit climate-induced financial shocks from individual firms to the broad public holding their capital in stocks of fossil-fuel-related firms, investment funds, and pension funds, which all could suffer from stranded assets (Battiston et al. 2017 ). Divestment campaigns, shareholder engagement, and mandatory disclosure of climate-relevant financial information by companies and investors warrant further theoretical and empirical analysis. Also, a better understanding of the economics behind financing instruments like green bonds is only recently emerging (Agliardi and Agliardi 2019 ). Despite some early studies there is a knowledge gap with respect to the extent of climate and policy risks for central banks and regarding the potential significance of different channels connecting the risks in the real economy with monetary policy. Given the environmental and international policy perspective of the climate problem, the specific contribution of the financial sector and the central banks in the architecture of global climate policy has to be subject to further investigation.

Energy system transformation The transition from a fossil-based to a green economy is needed to combat climate change but requires a thorough transformation of energy systems (Pommeret and Schubert 2019 ) in developed as well as in developing countries. In industrialized countries, challenges arise from the structural transformation of highly complex energy systems and their linkage with other economic sectors. While one hundred years ago, it was the rapid dissemination of fossil-based industrial processes, transportation, and heating that resulted in wide-spread sectoral change, similar adjustments can be expected with the increasing importance of electricity for decarbonization. However, changing the use of energy technologies in practice involves decisions on different levels and constitutes a highly nonlinear process. Future power generation in many countries will increasingly rely on renewable energies like wind and solar energy. To offset intermittent power generation, more and better storage capacities of batteries or pumped hydropower will be needed (Ambec and Crampes 2019 ). Synthetic fuels, heat pumps, fuel cells and e-mobility will increasingly use electricity to replace fossil fuels not only in the power sector but also in traffic and heat generation. While the adoption of renewable technologies like wind and solar was often much faster than predicted in the past, the critical mass of market penetration has still to be reached in other areas to benefit from potential scale effects and cost decreases. Shape and speed of the energy transition are, however, highly dependent on a political process which is hard to predict for market participants. Policy and ecological risks, together with the long-run character of the energy and related infrastructure investments, pose a big challenge for research and practice. In this context, it is especially the economic potential of green hydrogen and/or synthetic fuels that is controversially discussed at present. As production costs are expected to fall (Glenk and Reichelstein 2019 ), interest in hydrogen is increasing sharply (IEA 2019 ) and new research questions arise. For developing countries, clean and decentralized renewable energy technologies offer big potentials for electrification and economic development. However, despite the potential for decarbonization and the reduction of other externalities and health hazards and despite the fact that more than 90% of the annual increase in power generation comes from emerging economies, research on the development and adoption of clean energy technologies still focuses mainly on the developed world. More research on the barriers and challenges for adoption in developing countries is needed, including sustainable financing, institutional framing and the design of regionally tailored policies.

Sustainability perspective on digitalization Digitalization and artificial intelligence are often seen as opportunities for enhancing the efficiency of energy and resource use. They offer new opportunities for circular economy, agriculture, monitoring of ecosystems and biodiversity, sustainable finance and decarbonization (see WBGU 2019 and literature within). However, they may also accelerate energy and resource use, increase inequality between regions and income groups and endanger sustainable development. Digitalization offers new access to markets, impacts market forms and shapes consumer behavior all of which can have extensive implications for the ecological, social and economic dimensions of sustainable development. Digitalization is a cross-cutting theme that reaches across spatial scales (from regional development to globalization) as well as temporal scales (from short-run impacts on energy systems to long-run adaptation to climate change). So far, the potentials and challenges for sustainable development that are associated with digital technologies have mostly been addressed outside of environmental and resource economics. The focus has been on topics such as data security and privacy or, for example, on the implications of the ”fourth industrial revolution” on employment and labor markets. Costs and benefits of digitization, the design and effectiveness of policies in industrialized as well as developing countries have garnered much less attention in the context of environmental, resource, energy and climate economics. Also, impacts of digitization on the behavior of economic agents resulting in, for example, rebound effects or changes in consumption patterns and environmental awareness, have not been addressed comprehensively (Gossar 2015 ). In all of these areas, our limited knowledge base creates opportunities and challenges for future research in the field. But, digitalization not only creates new research questions, it also provides new means to answer them. It has led to new developments in data science, big data analysis, machine learning and artificial intelligence that allow new insights into, for example, material flows, emission patterns and technology diffusion as well as the optimal design, implementation and effectiveness of regulation (Fowlie et al. 2019 ; Weersink et al. 2018 ; Graziano and Gillingham 2015 ).

Quantitative analysis of environmental use Recently, there has been a significant shift in the empirical methods used in economics from traditional regression analysis to random assignment and quasi-experiments. Arguably this can improve the capturing of causal relationships and reduce the biases of traditional study designs. In environmental economics, experimental and quasi-experimental approaches have been applied mainly for capturing individuals’ or firms’ decisions on the use of land, water, resources, and energy (e.g. Allcott 2011 ; Duflo et al. 2013 ; Deschenes et al. 2017 ). Wider applications of these rigorous methods in environmental economics and well-suited empirical designs are desirable but certainly challenging e.g. when assessing aggregate environmental costs from climate change or biodiversity loss. An important but underrated field in applied environmental economics is the ex-post empirical assessment of environmental policies. The challenge is not only to identify environmental externalities, causalities, and impact intensities but also to provide an accurate valuation of the cost of policies, because they vary widely especially in environmental economics. The traditional empirical methods remain to be important and are not simply replaced. The same holds true for empirical designs in a time, cross-country, or panel structure. The increasing availability of large or very large datasets with observations varying widely across time and space offers a different set of options to provide evidence on the impact of environmental damages or policies to abate them (e.g. Currie and Walker 2011 ; Martin et al. 2014 ; Zhang et al. 2018 ). Fast-growing computational power and machine learning provide even more avenues for fruitful applications in environmental economics (see e.g. Abrell et al. 2019 ) but the challenge to use computer power wisely and to derive results which are sufficiently robust remains demanding .

Structural assessment modelling and modelling transparency In an effort to better understand the ramifications of political decisions and technological developments on climate change, energy supply and resource extraction (to name but a few examples), increasingly sophisticated numerical models have been developed in recent decades. It is evident that quantitative economics analysis is important for policy advice. Yet despite their complexity, these models usually still adopt some very simplifying and sometimes ad-hoc assumptions. In particular assumptions used in integrated valuation models have come under heavy criticism in recent years (Stern 2013 ; Pindyck 2013 ). Simplifications concern market structures and market failures, the integration of risk and uncertainty as well as societal, institutional and cultural detail. Also, manifestations of climate change and damages come at very different regional and temporal scales, making a truly integrated assessment of the climate-ecosystem-economy nexus next to impossible. We see it as a major challenge for future research to provide more accurate foundations for integrated assessment models. While simplifications are needed to reduce computational complexity, they raise the question to which extent the results obtained render reliable insights into future developments. Asking for models that are detailed in every dimension and can answer every question resembles of course the search for the holy grail. However, the need for a better understanding of the model dynamics has already led to the development of a new generation of models which have a stronger foundation in theory (Golosov et al. 2014 , Bretschger and Karydas 2019 ). A better understanding of the limits of models and of the questions specific models can and cannot address is still needed as well as transparency in model development. More applied studies, assessments of global environmental trends under different economic assumptions often use ”scenarios” to describe future trajectories. The scenarios are mostly based on expert opinion and do not rely on estimates about the likelihood that such a trajectory will occur. It is also critical that the economics behind the scenarios is often neglected. Prominently, per capita income can be projected using endogenous growth theory, while population development can be evaluated using state-of-the-art theories on fertility and morbidity.

3 Conclusions

This article set out to highlight a number of challenges that are highly relevant for future research in the field of environmental and resource economics. The focus was mainly, although not exclusively, on topical issues. We only briefly touched upon on some methodological advancements that might have the power to further parts of our field. Big data, machine learning and artificial intelligence hold high promise in this regard but their limits and potentials for environment, climate and resource economics have yet to be fully understood.

It should have become clear, that a number of the challenges presented can only be addressed adequately by interdisciplinary research teams with relevant disciplines ranging from climate science, (computer) engineering, sociology, virology to soil sciences. In many cases, economists’ analysis and the derivation of sound policy recommendations require the knowledge available in these fields. However, such research cooperations are by no means one-way streets: Other disciplines need the input of economists in order to assess future development scenarios and implementability of solutions. The knowledge and data required for economics analysis does not always exist yet, but interdisciplinary cooperation can help to identify and close these gaps. Overall, the less economists have already worked on specific challenges, the harder it is to assess best research strategies and the potential for success. Take the digitization-sustainable-development-nexus as an example: best research strategies and success are extremely difficult to predict as not only is the related economics research still in its infancy but also the field itself is extremely dynamic.

As already pointed out in the beginning: We are aware that our selection is bound to create discontent and disagreement. Having said this, it should also be stated that we expect some of our challenges to be more or less universally agreed upon. This holds especially for the broader topics: for example, how to accomplish deep decarbonization; how to deal with risk and uncertainty; or how to assess the role of disruptive development. One reason for this lies in the encompassing nature of these topics. They are relevant for many of the other fields that we have pointed out: For behavioral analyses, the capacity to deal with disruptive change in the face of risk and uncertainty are essential. Loss of biodiversity and natural capital, land degradation, conflicts over resources and migration are exacerbated by climate change. The potential of digitization for sustainable development constitutes disruptive change in itself. Yet, all of these fields are not merely subfields of the more overarching themes, they raise important research questions in their own right.

Nevertheless, it is to be expected that it will be the more specific fields over which disagreement will arise: Are ‘land use and soil degradation’ more important than ‘fisheries’? Is the ‘institutional analysis of environmental policies’ of higher relevance than the ‘development of alternative welfare concepts’ (to pick out some random examples). Of course, there are more fields that could have been included and also, of course, there is no objective criterion for the inclusion or exclusion of fields. The selection of the challenges is based on the analysis and criteria presented in the first section but it is ultimately ours; we are happy if this paper contributes to a lively and constructive discussion about the future of our field.

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Alaska Case Study

Explore the opportunities and challenges of Alaska, a case study of a cold environment.

Alaska is the most northern state in the USA, covering 2 million square kilometres. The southern half experiences relatively mild conditions, whereas a tundra environment overlaying permafrost is found to the north.

Alaska is one of the most sparsely populated places on Earth. Nearly half its 750,000 residents live in the city of Anchorage.

Alaska’s indigenous people include the Inupiat and Yup’ik tribes. Since the 1800s, approximately 100,000 Inuit have been joined by permanent settlers.

A wealth of ecosystems span the vast and varied landscapes of Alaska from temperate rainforests to tundra.

How has migration brought different groups to Alaska?

The US state of Alaska borders Canada and the Arctic Ocean. Alaska has been home to people for thousands of years despite being one of the coldest regions on Earth.  The indigenous people of Alaska include the Inupiat and Yup’ik tribes, each part of a larger ethnic group called the Inuit. The ancestors of the Inuit spread throughout the Arctic into Scandinavia, Alaska, Russia and Canada during the last ice age . During this time, Russia and the USA were joined by a land bridge.

Since the 19th century, mainly European temperament settlers joined the 100,000 Inuit bringing the total population to nearly 750,000. In addition, temporary economic migrants have travelled north to work for mining and oil companies.

Opportunities for development in Alaska

Alaska has a range of development opportunities.

Mineral Extraction 

Alaska has abundant mineral resources, including coal, copper, silver, gold and zinc. During the 1800s, there was a gold rush to the state. Twenty per cent of Alaska’s mineral wealth lies in gold. Alaska’s second most valuable non-energy commodity is gravel, with more than a billion tons mined, worth $2.1 billion at today’s prices.

There are vast reserves of oil and gas in the north of Alaska. One-third of the state’s income comes from the industry, which employs over 100,000 people. Oil is transported from Prudhoe Bay in the north to Valdez in the south by the trans-Alaskan pipeline. The oil is heated as it travels along the pipe to stop it from freezing. In addition, the pipeline is raised above the land to avoid melting the permafrost, which could cause the pipeline to break.

Trans Alaskan pipeline

From Valdez, the oil is transported by tanker.

Fishing 

The fishing industry employs eighty thousand people in Alaska. Alaska’s 3,000 rivers, three million lakes and 10,686 kilometres of coastline are rich in fish, including salmon, trout and several species of white fish. The industry is worth $8 billion to the economy. In addition, indigenous people use fish to provide food, clothing, and oil as part of their subsistence lifestyle.

Alaska’s fisheries are a successful example of sustainable management.

Alaska’s spectacular environments with mountains and glaciers attract over 2 million tourists every year. In addition, cruises are popular, with 60% of summer tourists arriving this way.

A cruise ship approaching Alaska

Adventure tourism is a growth industry in Alaska.

Development challenges in Alaska

Extreme Temperature 

Winter temperatures can drop below -30°C in the north of Alaska. This, along with limited sunlight in the winter, makes working outside very challenging. In addition, in the winter the sea freezes and roads become very dangerous.

Buildings and Infrastructure

Permafrost in Alaska creates considerable challenges for building and constructing infrastructure. For example, roads are built on raised gravel beds to reduce heat transfer which can thaw the permafrost.

An Alaskan road

Many domestic services such as freshwater and sanitation have to be provided above ground in insulated utilidors to minimise the risk of freezing pipes and thawing the permafrost. In addition, runways are painted white to reflect the energy and reduce heat transfer from the sun.

Inaccessibility 

Alaska is a very remote region, relying on transport such as planes and ships for access. In addition, some roads depend on crossing frozen rivers in the winter, which is very dangerous. As a result, locals rely on snowmobiles and 4x4s in the winter.

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Global benefits challenges: SLB case study

Energy technology company has “four big items of work” as it looks to the future of a decarbonised world

Investment in sustainable wellbeing and in technology, maximising impact and return on investment, and adopting a benefits team structure that is “effective in the current environment” are energy technology company SLB’s priorities. 

Its head of benefits and mobility Delphine Boyer told the Multinational benefits strategies that will mitigate business risk REBA webinar on 15 May 2024 that it could see new risks coming.

The company – formerly Schlumberger – works to accelerate decarbonisation and develop innovative technology for the oil and gas industry. It faces myriad global people challenges – attraction and retention, the safety of its employees, many of whom work in hazardous environments, and how to manage a mobile workforce in a decarbonised world.

“SLB has worked in a very volatile and high-risk environment for decades. We also see that risks that are coming are new, and the pace of [economic] cycles is getting shorter,” Boyer said. “Today the concept of safety has taken on a much broader meaning. We are changing and evolving the culture to have more [focus on] psychological safety.”

A poll conducted during the webinar found that 15% of attendees assess the health and resilience of their people in all regions as part of overall business risk, 40% partly do but need to improve, 18% don’t but intend to, and 26% have no current plans to.

Another challenge for SLB is maintaining the balance between benefits centralisation and localisation, and aligning compliance and governance with its global strategy. “[We also need to] provide the right level of flexibility and customisation, because we don’t have the same kind of employees everywhere in various regions,” Boyer added.

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Green Orgs’ New Study Challenges Rationale Behind One Of Biden’s Biggest Crackdowns On Major Energy Sector

A new study published by two green organizations stands at odds with the stated reasoning behind one of President Joe Biden’s most aggressive moves against the fossil fuel industry.

Ceres , a green consultancy, and an environmental group called Clean Air Task Force (CATF) recently released a study using Environmental Protection Agency (EPA) data that found methane emissions from natural gas activity decreased while production increased between 2015 and 2022.

The Biden administration paused approvals for new liquified natural gas (LNG) export terminals in January in large part because of its “evolving understanding” of “the perilous impacts of methane” and concerns that continuing as normal could inflict major damage on the climate.

Read: Liberty Justice Center Claims Victory Against Illinois Election Law Changes

Notably, both Ceres and CATF support major government action to decarbonize the American economy, a goal that Biden has also pursued through his first term as president. Ceres is a leading force in the environmental, social and corporate governance (ESG) investing push, while CATF aims to “accelerate the development and deployment of zero-carbon fuels” and also to “catalyze deep, global reductions in methane emissions.”

Specifically, the study found that, between 2015 and 2022, U.S. natural gas production increased by 40% while methane emissions from that production fell by 37%, according to the study. The study and its results indicate that “when energy companies want to, they can effectively reduce emissions of methane,” according to Canary Media, an independent nonprofit news outlet launched by the Rocky Mountain Institute that focuses on green energy and climate change.

“The fact is that the major portion of greenhouse gas emissions in the western world for the last three decades has come about thanks to natural gas — made up mainly of the constantly demonized methane — displacing coal in power generation. All of the central planning efforts by the activists and their water carriers in the public policy realm pale in comparison,” David Blackmon, a 40-year veteran of the oil and gas business who now writes and consults on the energy industry, told the Daily Caller News Foundation. “I’d like to send a personal word of thanks to Ceres and CATF for conducting this revealing study, even if they are reluctant to talk about its key results.”

Read: Florida Rep. Matt Gaetz Leads Intro Of GAZA Act, “Guarding American Zones Against Palestinian Immigration Act”

The study’s authors used data from the EPA’s Greenhouse Gas Reporting Program (GHGRP) and calculations based on the agency’s Greenhouse Gas Inventory to inform their findings, as opposed to a direct measure of emissions. The study concedes that GHGRP data is not perfect because it can be prone to underestimating emissions, but the program “currently represents the most robust and comprehensive inventory of company-level [greenhouse gas] emissions from the oil and gas industry.”

Notably, both Ceres and CATF support major government action to decarbonize the American economy, a goal that Biden has also pursued through his first term as president.

“From 2015 to 2022, U.S. natural gas production increased by 40 percent, while methane emissions from gas extraction declined by 37 percent,” Steve Everley, a senior managing director for FTI Consulting’s energy and natural resources practice, wrote in a post to X about the Ceres and CATF study. “Remember that the central justification for the LNG export pause was alleged uncertainty about the climate advantage of U.S. natural gas, with methane emissions being a key element.”

Read: U.S. House Approves Florida Rep. Steube’s Measure To Prohibit VA From Using Resources On Illegal Immigrants

One of the reasons for the decrease in emissions is technological advancement, which has allowed operators to more accurately monitor possible methane leaks, for example, according to ARUSI, an engineering firm based in Phoenix, Arizona.

Concerns about methane pollution and climate change factored into the administration’s decision to halt new LNG export terminal approvals in January, according to the White House. Numerous environmental groups have applauded the decision, with some specifically citing methane emissions as a key concern addressed by the decision.

However, Biden’s pause is unlikely to bring down global emissions because would-be buyers of natural gas will likely look to other countries who produce gas less cleanly to meet their needs, energy sector experts previously explained to the DCNF.

Two previous Department of Energy (DOE) analyses — conducted in 2014 and 2019 , respectively — have found that American LNG exports are cleaner than coal that is mined and used domestically. While the Biden administration apparently is not swayed by those studies, White House officials were reportedly “influenced” by a questionable paper authored by an expressly anti-fossil fuel Ivy League professor that arrived at the exact opposite conclusion.

Read: Texas Sen. John Cornyn Condemns Biden’s Immigration Order As Political Ploy

Robert Howarth of Cornell University, the paper’s author, released it into the public domain before passing through peer review specifically so that it could impact political discussions about gas exports, and the paper’s topline finding has been revised several times since its initial release. Howarth has battled against the fossil fuel industry for years while openly favoring a societal shift away from their use, and an anti-fracking environmental group partially funded the study.

Critics of the administration’s LNG pause have asserted that the decision was political rather than scientific, viewing the move as one meant to appease the younger, climate-focused voters and well-funded environmental organizations that Biden figures to lean on as he seeks a second term in November.

The White House, Ceres and CATF did not respond immediately to requests for comment.

First published by the Daily Caller News Foundation .

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