The study shows that more than 90% of global “blue” food production, in both capture fisheries and aquaculture, faces substantial risks from environmental change, with several leading countries in Asia and the United States set to face the greatest threats to production.

The authors behind the new paper produced the first-ever global analysis of environmental stressors impacting the production quantity and safety of blue foods around the world, ranking countries for the first time according to their exposure from key stressors. A total of 17 stressors were surveyed, including algal blooms, sea level rise, changing temperatures and pesticide exposure.

“Environmental stressors do not care about national borders,” noted Ben Halpern, co-lead author and professor at UC Santa Barbara and director of the National Center for Ecological Analysis and Synthesis. “Stressors get moved by air, water, species, and humans, connecting land to sea and ecosystem to ecosystem.”

The research published by Nature Sustainability, titled “Vulnerability of Blue Foods to Human-induced Environmental Change” is one of seven scientific papers published by the Blue Food Assessment (BFA) as part of a global effort to inform future aquatic food sustainability.

Alongside climate change, the report highlights that highly vulnerable blue food production systems are found across all continents, including some of the world’s largest blue food producers such as Norway, China, and the United States, yet also argues there is too often a lack of understanding around the complexity of stressors causing environmental change.

“We have only scratched the surface in our understanding of how environmental stressors are connected, and how they can both negatively impact the production and safety of the resulting blue foods,” said Ling Cao, co-lead author and professor at the State Key Laboratory of Marine Environmental Science at Xiamen University.

“Understanding the complexity of these stressors, and their cascading impacts, will be essential in developing successful adaptation and mitigation strategies,” she said.

Species invasion, inland eutrophication or algal blooms, ocean warming and sea level rise were cited by the paper as the main threats to blue food production in the U.S., with freshwater and marine fisheries facing disproportionately large risks.

As the largest blue food producer, China’s freshwater aquaculture is also highly exposed to inland eutrophication and severe weather events, the research shows.

The authors also argue that special attention should be paid to countries facing high exposure to environmental change yet not possessing adequate capacity for adaptation, including Bangladesh, Eswatini, Guatemala, Honduras and Uganda.

In terms of production systems, the paper finds that marine fisheries were generally more vulnerable to climate-related stressors, particularly rising temperatures and acidification, whilst aquaculture was more susceptible to the effects of diseases and hypoxia, or low oxygen levels.

“Although we have made some progress with climate change, our adaptation strategies for blue food systems facing environmental change are still underdeveloped and need urgent attention,” said Rebecca Short, co-lead author and researcher at the Stockholm Resilience Centre.

Among the report’s key recommendations is a call for more transboundary collaboration and adaptation strategies which recognize that the ecosystems that blue food production rely upon are highly interconnected, with environmental change in one area having potential knock-on effects elsewhere.

The authors also call for a diversification of blue food production in high-risk countries to cope with the impact of environmental change unless sufficient mitigation and adaptation strategies are adopted.

Likewise, the paper highlights the urgent need for greater stakeholder engagement in understanding, monitoring and mitigating pressures on blue food production systems. Indigenous knowledge will be critical for strategic planning and policies to mitigate and adapt to environmental change, particularly for artisanal fisheries and heavy marine fisheries-dependent countries, such as Small Island Developing States (SIDS).

The research also includes an extended dataset which ranks countries around the world based on the exposure of their blue food production systems to the various environmental stressors.

Man-made climate change is one of the greatest challenges facing us today, but uncertainty in the exact magnitude of global change hampers effective policy responses.

A significant source of uncertainty relates to future changes to water vapour in the stratosphere, an extremely dry region of the atmosphere 15-50 km above the Earth’s surface.

Future increases in water vapour here risk amplifying climate change and slowing down the recovery of the ozone layer, which protects life on Earth from harmful solar ultraviolet radiation.

Now an international team led by Peer Nowack, until recently a member of the Climatic Research Unit at UEA, has developed a new statistical learning approach that combines information from satellite observations with state-of-the-art climate model data to narrow the range of likely future stratospheric water vapour amounts.

One of the key results, published today in the journal Nature Geoscience, effectively rules out the most extreme scenarios, which imply that water vapour concentrations could increase by more than 25% per degree of global warming. The new approach represents a 50% reduction in the 95th percentile of climate model responses.

“Man-made climate change affects Earth’s atmosphere in many important and often surprising ways,” said Prof Nowack, now at the Institute of Theoretical Informatics at the Karlsruhe Institute of Technology, Germany.

“In our paper, we look at changes in stratospheric water vapour under global warming, an effect that is still poorly understood. Since water vapour is central to the physics and chemistry of the stratosphere, I felt that we crucially need a new approach to address this longstanding uncertainty factor.

“With our new data-driven approach, which exploits machine learning ideas, we were able to make highly effective use of Earth observations to reduce this uncertainty. This required us to develop a framework in which we could combine scientific understanding and mathematical relationships learned from satellite data in innovative ways.”

“With this approach, we were able to show that many climate model projections of very large stratospheric water vapour changes are now inconsistent with observational evidence,” said co-author Dr Sean Davis, a Research Scientist at the National Oceanic and Atmospheric Administration in the US, specializing in satellite measurements of stratospheric water vapour.

Quantifying stratospheric water vapour trends under global warming is a longstanding research challenge. The complexity of the underlying processes that control stratospheric water vapour and the relatively short record of high-quality satellite observations has made this task difficult.

The presence of so-called climate feedbacks presents an additional challenge, as these can act to further amplify or dampen global warming, therefore leading to a wider range of possible future temperature increases.

The amount of water vapour that the stratosphere holds is an example of one such feedback, which climate models have predicted to increase, but the range of modelled increases has remained very wide for decades.

This is important, because large climate-driven increases in stratospheric water vapour, like those projected by many climate models, could delay the recovery of the ozone layer and of the Antarctic ozone hole over the course of this century.

However, Manoj Joshi, Professor of Climate Dynamics at UEA and a co-author on the paper, said: “Our research implies that while stratospheric water vapour concentrations are still likely to increase with global warming, the large changes that could substantially delay ozone recovery are highly unlikely.”

The research was funded by the UK Natural Environment Research Council (NERC) through the ML4CLOUDS project.

This finding may explain why many animals besides turtles have temperature-dependent sex determination and why the system persists, despite seeming like a risky strategy. It may also provide a troubling glimpse of what could lie ahead in a warming world.

What the researchers found, as published June 23 the journal Current Biology, is that the number of “germ cells” — pre-eggs — that an embryo carries is increased by higher incubation temperatures. In fact, they found that those germ cells themselves play a role in the embryo becoming female.

“Sex determination by temperature isn’t just one mechanism,” said senior author Blanche Capel, the James B. Duke Distinguished Professor of Cell Biology in the Duke School of Medicine. “Higher temperatures seem to affect sex determination in incremental ways through multiple cell types in the embryo.”

The more abundant germ cells themselves seem to drive feminization, said Boris Tezak, a postdoctoral researcher in the Capel lab who led this project. “The temperatures that produce females are also the temperatures that increase germ cell number,” he said.

Higher numbers of germ cells are known to control female development in fish as well, Capel said. But to prove the point that more germ cells lead to female turtles, they removed some germ cells from red-eared slider embryos raised at an intermediate temperature that should have yielded 50-50 proportions, and saw more males than expected.

Scientists have known about temperature-dependent sex development for decades and have found it in many different parts of the tree of life, apparently because it evolved multiple times in multiple ways.

“It popped up everywhere,” Tezak said. “It seems like a really risky strategy, especially in the context of weather variations and climate change, so why would this system persist?”

They think it’s because temperature-dependent sex development creates a reproductive advantage.

“A female that hatches with more germ cells is presumably more reproductively fit — it increases her reproductive potential to carry more eggs,” Tezak said. “We’ve linked the female pathway to the increased number of germ cells, and if that does make her more reproductively fit, that would go a long way toward explaining why temperature-dependent sex development persists.”

As global temperatures continue to rise, the question becomes: what will happen to the turtles and other temperature-sensitive breeders? “We’ll be looking at how further increases in temperature will affect the pool of germ cells,” Tezak said. “Will it produce less-fit females?”

To answer these questions, Tezak carefully nurtures clutches of red-eared slider eggs obtained from a Louisiana breeder in plastic boxes filled with moist medium and kept at a constant temperature in the lab. One incubator runs at 26 degrees Celsius, producing more males. Another is at 31 degrees, the optimum temperature for producing more females.

When he takes out one of each to check on their progress with a very bright light, the embryo that was incubated warmer is markedly larger and more active inside the egg.

“We are hypothesizing that there’s a temperature ‘sweet-spot,'” Capel said. “There is a short range where you get a large number of germ cells, and beyond that you start to see declines,” Capel said.

“We have incubated some eggs at 33.5 degrees, only two and a half degrees higher than the optimal temperature for females,” Tezak said. “It created some really wonky embryos — there were cyclops and two-headed embryos. We haven’t counted their germ cells yet.”

The lab is also about to take delivery on some alligator eggs to continue the temperature experiments. Alligators are known to produce females at low temperatures and males at high temperatures, the opposite pattern from the red-eared slider turtle. However, the low temperature in alligators is the same as the high temperature in turtles, so both species produce females at 31 degrees Celsius. “The interesting question is whether we see more germ cells in both species at this temperature,” Tezak said.

Funding for this study was provided by the U.S. National Science Foundation (1854642) and the Czech Science Foundation (23-07658S).

Meeting the 1.5°C goal of the Paris Agreement will require ambitious climate action this decade. Difficult questions remain as to how warming can be limited within technical realities while respecting the common but differentiated responsibilities and respective capabilities of nations on the way to a sustainable future. Meeting this challenge requires substantial emissions reductions to reach net-zero emissions globally.

Among the new options being studied in scientific literature, engineered Carbon Dioxide Removal (CDR) like Direct Air Capture of CO₂ with Carbon Capture and Storage (DACCS), is a potentially promising technology to help bridge this gap. DACCS captures carbon by passing ambient air over chemical solvents, which can be considered a form of CDR if the captured carbon is stored permanently underground. But whether these novel technologies can help make ambitious goals more attainable, or whether they can help reach them more equitably remains an open question.

In their study published in Environmental Research Letters, an interdisciplinary research group led by IIASA scientists developed new scenarios exploring fairness and feasibility in deep mitigation pathways, including novel CDR technologies. For the first time, the team implemented DACCS in a well-established integrated assessment model called MESSAGEix-GLOBIOM, and studied how this technology could impact global mitigation pathways under different scenarios of environmental policy effectiveness based on country-level governance indicators.

“In current policy debates, concerns about the political feasibility and fairness of the current generation of climate mitigation scenarios are raised, and DACCS is often proposed as a possible solution. In our study we quantified under what conditions and how DACCS might address those concerns,” explains Elina Brutschin, a study coauthor and researcher in the Transformative Institutional and Social Solutions Research Group of the IIASA Energy, Climate, and Environment Program.

The researchers emphasize that the goal of limiting warming to 1.5°C does not change when considering novel forms of CDR. For a broader perspective on pathways to limit warming, the research team investigated how novel CDR interacts under different assumptions of technoeconomic progress and the evolution of regional institutional capacity. The researchers highlight the risks of dependency on unproven carbon removal while also discussing the role novel CDR and similar technologies could play in the future for developing countries.

The results indicate that novel CDR can keep pre-Paris climate targets within reach when accounting for such risks, but that increasing institutional capacity beyond historical trends is necessary for limiting warming to the Paris Agreement’s 1.5°C goal, even with novel CDR processes. The study also suggests that substantially improving institutional capacity to implement environmental policies, regulations, and legislation is critical to keep warming below 2°C if new forms of CDR fail to emerge in the near future.

The authors further point out that, when accounting for the possible future evolution of novel CDR technologies combined with inherent risks, the ‘fairness’ of overall outcomes did not meaningfully improve. DACCS did not impact near-term required global mitigation ambition, and additional carbon removal in developed economies accounted for only a small component of the mitigation necessary to achieve stringent climate targets. This is because the removal of carbon dioxide in these areas does not compensate sufficiently for their historical emissions by mid-century.

The inability of DACCS to enhance the fairness of outcomes, like cumulative carbon emissions, in 1.5°C scenarios, emphasizes the notion that meeting global climate targets is a global effort requiring an ‘all-of-the-above’ mitigation strategy. There is no room for flexibility when it comes to reaching climate goals.

The results, however, show that engineered removals can play a role in making the post-peak temperature stabilization (or decline) phase more equitable. This means that the full timeframe under which accounting takes place is critical for exploring fair outcomes that are agreeable by most Parties to the United Nations Framework Convention on Climate Change (UNFCCC).

“Our results show that new technologies for removing carbon from the atmosphere can play a role in ambitious climate policy, but they won’t be a silver bullet for solving the climate crisis. Developed countries especially need to cut emissions by more than half this decade, primarily by reducing existing sources of emissions while scaling up CDR technologies to be in line with the Paris Agreement,” says study lead author Matthew Gidden, a researcher in the IIASA Energy, Climate, and Environment Program.

The researchers emphasize that there is a clear need for the modeling community to assess the role of novel CDR in a structured way to better understand robust outcomes and insights versus observations related to a given model framework or approach. Looking forward, these issues can be explicitly included in scenario design to arrive at more equitable outcomes while incorporating political realities of the capabilities of governments and institutions to enact strong climate policy.

Turn World Refugee Day into positive action. Join a very special conversation with actor-activist Ger Duany, who escaped from life as a child soldier during the civil war in Sudan to become a model, actor, and international advocate for refugees and environmental responsibility. Ger points out that we are entering an “Era of Displacement.” This phrase succinctly captures the dire planetary predicament we face due to climate change. We also talk with two of Ger’s partners in his advocacy work on behalf of refugees, Newday Impact Investing CEO and our frequent guest Doug Heske and Bernice Romero, executive director of the Norwegian Refugee Council USA, a humanitarian organization that helps people forced to flee from disaster, war, and climate change build a new future for themselves. 

Ger’s life journey started in South Sudan, where a generation of youth known as “the Lost Boys” endured Sudan’s brutal civil wars. After escaping and finding refuge in the United States, Ger was catapulted to prominence in the entertainment industry with notable roles in the films “I Heart Huckabees,” “The Good Lie,” and the recent, Cannes-debuted “Goodbye Julia.” He also wrote about his experiences and journey in the book, “Walk Toward the Rising Sun.” 

True to his roots, Ger used his newfound fame to become an ardent advocate for refugees, mental health support for displaced individuals, and African environmental responsibility. Having served as a Goodwill Ambassador for the United Nations High Commissioner for Refugees, he recently took on the leadership of the Advocacy, Corporate Engagement, and Stewardship program at Newday Impact Investing, which is devoted to corporate education and outreach to support individuals displaced by the climate crisis. We’ll explore how private and nonprofit organizations are preparing for the Era of Displacement and what we, collectively and individually, can do to alleviate the suffering of millions displaced from their homes and communities. Tune in to an enlightening and sobering discussion — it’s an episode not to be missed on World Refugee Day.

You can learn more about Ger Duany and how to support his work at gerduany.com. The Norwegian Refugee Council USA’s website is at nrc.no and follow them at @nrc_norway on Instagram and Twitter. For more information about Newday Impact Investing and its environmental and socially responsible portfolio programs, visit newdayimpact.com. 

Promoting national security and economic competitiveness will require America’s researchers to find new ways to obtain the materials that we need for many technologies. These include batteries, magnets in electric motors, catalysts, nuclear reactors and other essential carbon-free energy technologies.

Water represents one underexplored avenue of acquiring these materials. Scientists at the U.S. Department of Energy’s Argonne National Laboratory have recently published a comprehensive review detailing the various mechanisms by which critical materials can be extracted from diverse water streams.

Different types of water offer different kinds of material resources, said Seth Darling, chief science and technology officer for Argonne’s Advanced Energy Technologies directorate. ​”The oceans are such a tremendous resource because the total quantities of many valuable and important materials are vast, but they are also highly dilute,” he said. ​”Wastewater has also been in need of reframing — we want people to see that wastewater is not truly waste, rather, it’s rich with all sorts of valuable stuff.”

Darling also pointed to groundwater aquifers and geothermal brines as other possible sources of valuable materials. These materials include lithium, which is increasingly in demand for electric vehicle batteries and could be used to help decarbonize our economy. ​”Lithium is in the ocean and in geothermal brines; you’d extract it differently from these two sources but it’s important to understand which is cheapest, has the smallest environmental impact, and enables secure supply chains,” Darling said. ​”For many other materials, water is underexplored as a source, and that’s something we’re paying increasingly more attention to.”

The technologies that Darling and his colleagues are exploring to extract critical materials from different types of water range from the traditional (like membranes) to the innovative (like interfacial solar steam generators).

Omar Kazi, a Ph.D. student in molecular engineering at the University of Chicago working with Darling, is studying methods to concentrate wastewater streams to recover valuable materials. ​”Getting rid of the water through evaporation is an energy-intensive and slow process,” Kazi said. ​”In geothermal brines, it can take years for water to evaporate to be able to recover the lithium that’s contained in them, which creates a huge bottleneck. The question we are asking is ​’how we can make the water evaporate faster?'”

One way to do that could be through the use of porous photothermal materials, which convert light to heat efficiently. These light absorbers act like a black T-shirt that heats up on a sunny day. That heat is transferred to the water directly at the interface with the surrounding air, significantly accelerating evaporation.

Overall, Darling noted, Argonne has rich capabilities in supply chain, life cycle and technoeconomic analyses. In addition, the laboratory specializes in the materials, chemistry and process engineering relevant to critical material extraction. This uniquely positions the lab to help achieve a more secure and circular economy of materials, especially when it comes to getting more out of water streams.

A paper based on the study, ​”Material design strategies for recovery of critical resources from water,” appeared online in Advanced Materials on March 31.

In addition to Darling and Kazi, other authors of the study include Argonne’s Wen Chen, Jamila Eatman, Feng Gao, Yining Liu, Yuqin Wang, and Zijing Xia.

This work was supported as part of the Advanced Materials for Energy-Water Systems (AMEWS) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at Argonne National Laboratory.

Based on climate models, scientists previously estimated humans pumped 2,150 gigatons of groundwater, equivalent to more than 6 millimeters (0.24 inches) of sea level rise, from 1993 to 2010. But validating that estimate is difficult.

One approach lies with the Earth’s rotational pole, which is the point around which the planet rotates. It moves during a process called polar motion, which is when the position of the Earth’s rotational pole varies relative to the crust. The distribution of water on the planet affects how mass is distributed. Like adding a tiny bit of weight to a spinning top, the Earth spins a little differently as water is moved around.

“Earth’s rotational pole actually changes a lot,” said Ki-Weon Seo, a geophysicist at Seoul National University who led the study. “Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole.”

Water’s ability to change the Earth’s rotation was discovered in 2016, and until now, the specific contribution of groundwater to these rotational changes was unexplored. In the new study, researchers modeled the observed changes in the drift of Earth’s rotational pole and the movement of water — first, with only ice sheets and glaciers considered, and then adding in different scenarios of groundwater redistribution.

The model only matched the observed polar drift once the researchers included 2150 gigatons of groundwater redistribution. Without it, the model was off by 78.5 centimeters (31 inches), or 4.3 centimeters (1.7 inches) of drift per year.

“I’m very glad to find the unexplained cause of the rotation pole drift,” Seo said. “On the other hand, as a resident of Earth and a father, I’m concerned and surprised to see that pumping groundwater is another source of sea-level rise.”

“This is a nice contribution and an important documentation for sure,” said Surendra Adhikari, a research scientist at the Jet Propulsion Laboratory who was not involved in this study. Adhikari published the 2016 paper on water redistribution impacting rotational drift. “They’ve quantified the role of groundwater pumping on polar motion, and it’s pretty significant.”

The location of the groundwater matters for how much it could change polar drift; redistributing water from the midlatitudes has a larger impact on the rotational pole. During the study period, the most water was redistributed in western North America and northwestern India, both at midlatitudes.

Countries’ attempts to slow groundwater depletion rates, especially in those sensitive regions, could theoretically alter the change in drift, but only if such conservation approaches are sustained for decades, Seo said.

The rotational pole normally changes by several meters within about a year, so changes due to groundwater pumping don’t run the risk of shifting seasons. But on geologic time scales, polar drift can have an impact on climate, Adhikari said.

The next step for this research could be looking to the past.

“Observing changes in Earth’s rotational pole is useful for understanding continent-scale water storage variations,” Seo said. “Polar motion data are available from as early as the late 19^th century. So, we can potentially use those data to understand continental water storage variations during the last 100 years. Were there any hydrological regime changes resulting from the warming climate? Polar motion could hold the answer.”

A possible ice-free Arctic in the 2030-2050s was projected regardless of humanity’s efforts to reduce its greenhouse gas emissions by Professor Seung-Ki Min and Research Professor Yeon-Hee Kim from the Division of Environmental Science and Engineering at Pohang University of Science and Technology (POSTECH) and a joint team of researchers from the Environment Climate Change Canada and Universität Hamburg, Germany. The research was published in the international journal, Nature Communications.

The term global warming has become a household name since it was first used by a climate scientist at NASA in 1988. The Earth has seen a rapid decline in the Arctic sea ice area as its temperature has increased over the past several decades. This reduction in Arctic sea ice has induced the acceleration of Arctic warming, which is suggested to contribute to the increased frequency of extreme weather events in mid-latitude regions.

To predict the timing of Arctic sea ice depletion, the research team analyzed 41 years of data from 1979 to 2019. By comparing the results of multiple model simulations with three satellite observational datasets, it was confirmed that the primary cause of the decline is attributed to ‘human-made greenhouse gas emissions’. Greenhouse gas emissions resulting from human fossil fuel combustion and deforestation have been the primary drivers of Arctic sea ice decline over the past 41 years, while the influence of aerosols, solar and volcanic activities has been found to be minimal. Monthly analysis found that increased greenhouse gas emissions were reducing Arctic sea ice all year round, regardless of season or timing, although September exhibited the smallest extent of sea ice reduction.

Furthermore, it was revealed that climate models used in previous IPCC predictions generally underestimated the declining trend of sea ice area, which was taken into account to adjust the simulation values for future predictions. The results showed accelerated decline rates across all scenarios, most importantly confirming that Arctic sea ice could completely disappear by the 2050s even with reductions in greenhouse gas emissions. This finding highlights for the first time that the extinction of Arctic sea ice is possible irrespective of achieving ‘carbon neutrality.’

The accelerated decline of Arctic sea ice, faster than previously anticipated, is expected to have significant impacts not only on the Arctic region but also on human societies and ecosystems worldwide. The reduction of sea ice can result in more frequent occurrences of extreme weather events such as severe cold waves, heat waves, and heavy rainfalls all across the globe, with the thawing of the Siberian permafrost in the Arctic region possibly intensifying global warming further. We may witness terrifying scenarios, which we have seen only in disaster movies, unfold right before our eyes.

Professor Seung-Ki Min, who led the study, explained, “We have confirmed an even faster timing of Arctic sea ice depletion than previous IPCC predictions after scaling model simulations based on observational data.” He added, “We need to be vigilant about the potential disappearance of Arctic sea ice, regardless of carbon neutrality policies.” He also expressed the importance of “evaluating the various climate change impacts resulting from the disappearance of Arctic sea ice and developing adaptation measures alongside carbon emission reduction policies.”

The study was funded by the National Research Foundation of Korea (Mid-Career Researcher program).