Trends, Impacts and Policies to Adapt to a Drier World
Introduction
Droughts are becoming more frequent, prolonged and severe with climate change, threatening water security and placing growing pressure on people, ecosystems and economies. From reduced crop yields and strained power supply and river trade to degraded landscapes and disrupted livelihoods, the impacts of droughts are on the rise – and so are their costs.
The OECD’s Global Drought Outlook assesses how countries can strengthen drought management to adapt to a changing climate. It provides new insights into the rising human, environmental, and economic impacts of droughts and offers practical policy solutions to minimise losses, build long-term resilience, and support adaptation to a drier future.
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The world’s most productive agricultural regions face the greatest losses from climate change, with major farming areas in wealthy nations potentially losing as much as 40% of their maize and wheat production this century, a comprehensive new study has found.
In their analysis of more than 12,000 regions across 55 countries, a team of researchers from top U.S. and international institutions found that for every 1°C increase in global temperature, global food production could decline by approximately 120 calories per person per day—equivalent to 4.4% of current daily consumption.
The study, published in Nature, reveals that even when so-called climate adaptation strategies are undertaken, “breadbasket” regions are particularly vulnerable, and will face substantial reductions in the production of most key food crops, presenting a concerning outlook for global food security.
"It's almost like in this context, those with the most to lose, lose the most," said Andrew Hultgren, assistant professor at the University of Illinois and a lead author of the study. "In the U.S., we often think of the impacts of climate change being more heavily felt in poorer regions of the world. Here we find the opposite, where it is U.S. farmers in the heartland that actually face some of the largest risks to their future yields."
The study comes hot on the heels of research showing global warming has caused an unprecedented increase in drought severity around the world. That paper, from researchers in Europe and the U.K. and also published by Nature, indicates that a record 30% of Earth's land area experienced moderate to extreme drought in 2022, 42% of which was attributed to atmospheric evaporative demand, a phenomenon caused by higher average temperatures.
The food production study reveals a counterintuitive pattern: modern-day breadbasket regions with favorable climates are particularly vulnerable precisely because of their current advantages. "Wealthy 'breadbasket’ regions benefit from the very favorable climates they currently enjoy,” Hultgren explained. “They are not exposed to as much extreme heat now, and so are not as adapted to it.”
In contrast, farmers in hotter, lower-income regions have already developed more climate-adaptive practices. "These lower-income regions tend to be located in hotter parts of the world,” Hultgren explained. “They already have to grapple with exposure to heat extremes now, and so have adapted to those heat extremes already."
The impact on specific crops reveals how current agricultural powerhouses could be transformed. Maize production faces some of the most significant projected losses, with yields potentially declining by up to 40% in several key growing regions, including the U.S. grain belt, eastern China and Central Asia. Wheat production in today's major producing regions could see losses reaching 30-40% across the United States, Canada, China and Russia.
The study breaks new ground by examining how farmers actually adapt to changing conditions, rather than relying on theoretical models. "For a long time, it's been an open question how much producers will adapt to future climate change," Hultgren said. "We find that adaptation is protective, but only partially so—it mitigates about one-third of future yield losses."
While rice appears to be the only major staple crop that might avoid significant losses, the outlook for other crops remains concerning; the implications for global food security are complex and far-reaching. "Because the most agriculturally productive regions of the world face the highest yield losses, those losses drive down overall global production in a high warming future," Hultgren noted. "This could result in higher food prices in general and concerns around food security globally."
While lower-income regions may be better adapted to heat, they still face significant challenges. Cassava, a crucial subsistence crop in many low-income countries, could see losses of around 40% in Sub-Saharan Africa. Because the poorest populations globally often engage in subsistence farming—meaning they farm to grow food for their families rather than to sell it on the market—such communities might be less able to weather such losses.
The researchers went beyond crop projections to calculate how these agricultural losses could influence climate policy through what's known as the "social cost of carbon"—an attempt to put a dollar value on the damage caused by each ton of carbon dioxide emissions. By calculating how much future crop losses would cost society in economic terms, the team found that agricultural impacts alone could add between $0.99 and $49.48 to the social cost of each ton of CO2, depending on various economic assumptions.
Richard Waite, director of agriculture initiatives at the World Resources Institute, told me why the findings are significant.
"Reduced crop yields, in our world of growing food demand, mean even higher pressure on the world's remaining forests and other natural ecosystems," Waite said. "This creates a vicious cycle of additional climate change that then in turn increases the threat to agriculture."
In Waite’s view, the study’s findings suggest that current adaptation strategies must evolve beyond traditional approaches. "Going forward, the world needs to breed staple crops not only for increasing yield but also for thriving in a changing climate, such as the ability to withstand higher temperatures or increased rainfall variability," he said.
The new research underscores the urgent need for both more aggressive reductions of emissions, and enhanced support for agricultural adaptation—with failure on either count threatening widespread hunger and unrest.
"Looking beyond our immediate findings, this should raise concerns around global food security and international political stability in a high warming future," Hultgren concluded.
Abstract
Ambitious international commitments have been made to preserve biodiversity, with the goal of preventing extinctions and maintaining ecosystem resilience, yet the efficacy of large-scale protection for preventing near-term extinctions remains unclear. Here, we used a trait-based approach to show that global actions—such as the immediate abatement of all threats across at least half of species ranges for ~10,000 bird species—will only prevent half of the projected species extinctions and functional diversity loss attributable to current and future threats in the next 100 years. Nonetheless, targeted recovery programmes prioritizing the protection of the 100 most functionally unique threatened birds could avoid 68% of projected functional diversity loss. Actions targeting ‘habitat loss and degradation’ will prevent the greatest number of species extinctions and proportion of functional diversity loss relative to other drivers of extinction, whereas control of ‘hunting and collection’ and ‘disturbance and accidental mortality’ would save fewer species but disproportionately boost functional richness. These findings show that conservation of avian diversity requires action partitioned across all drivers of decline and highlight the importance of understanding and mitigating the ecological impacts of species extinctions that are predicted to occur even under optimistic levels of conservation action.
A new report by the United Nations says the world is facing some of the most damaging and widespread droughts in recorded history.
The report said the event is driven by climate change and environmental degradation.
The report was published by the UN Convention to Combat Desertification (UNCCD), the US National Drought Mitigation Center (NDMC) and the International Drought Resilience Alliance (IDRA).
It examined global drought impacts from 2023 to 2025, highlighting how the crisis devastates lives and ecosystems while deepening poverty, hunger, energy insecurity, and economic damage.
According to the report, 90 million people across eastern and southern Africa are facing acute hunger, with some regions experiencing their worst drought in history.
In Ethiopia, Zimbabwe, Zambia and Malawi, maize and wheat crops have failed repeatedly.
The report said in Zimbabwe, the 2024 corn harvest dropped by 70 percent year-on-year, maize prices doubled, and 9,000 cattle died due to thirst and starvation.
In Somalia, 43,000 people died in 2022 alone due to hunger linked to drought. As of early 2025, one in four Somalis was experiencing crisis-level food insecurity.
It noted that the effects have also disrupted energy systems.
In Zambia, drought has led to one of the world’s worst energy crises. In April 2025, the Zambezi River fell to just 20 percent of its long-term average, pushing the Kariba Dam, the country’s largest hydroelectric plant, to only 7 percent generation capacity.
The UN report said the resulting 21-hour daily blackouts forced the closure of hospitals, bakeries, and factories.
The report also stressed that the impacts extend beyond Africa. In Spain, two years of drought and record heat caused a 50 percent drop in olive production by September 2023, doubling the price of olive oil.
In Türkiye, groundwater depletion driven by drought is triggering sinkholes, endangering infrastructure and reducing aquifer storage capacity.
In the Amazon Basin, the report said low river levels in 2023 and 2024 caused mass fish and dolphin deaths, disrupted water supply, and made transportation difficult for hundreds of thousands of residents.
It added that ongoing deforestation and fires have raised fears that the Amazon could shift from being a vital carbon sink to a carbon source.
According to the report, global trade has also been affected. The Panama Canal saw transit drop by more than one-third due to low water levels, resulting in soybean export decline in the US and product shortages in UK supermarkets.
‘DROUGHT IS A SILENT KILLER’
Ibrahim Thiaw, UNCCD executive secretary, described the climate crisis as a “silent killer”.
“Drought is a silent killer. It creeps in, drains resources, and devastates lives in slow motion. Its scars run deep,” Thiaw said.
“Drought is no longer a distant threat. It is here, escalating, and demands urgent global cooperation. When energy, food, and water all go at once, societies start to unravel. That’s the new normal we need to be ready for.”
Mark Svoboda, report co-author and director of the NDMC, said: “This is a slow-moving global catastrophe, the worst I’ve ever seen.”
“This is not a dry spell. This report underscores the need for systematic monitoring of how drought affects lives, livelihoods, and the health of the ecosystems that we all depend on.
“The struggles experienced by Spain, Morocco and Türkiye to secure water, food, and energy under persistent drought offer a preview of water futures under unchecked global warming. No country, regardless of wealth or capacity, can afford to be complacent.”
To address the crisis, the report recommends improving early warning systems, monitoring real-time drought impacts, and investing in nature-based solutions such as watershed restoration and the use of indigenous crops.
It also called for more resilient infrastructure such as off-grid energy and alternative water sources, as well as international cooperation, especially around shared water basins and trade routes.
New findings from studying over two decades of satellite observations reveal that Earth's continents have experienced unprecedented freshwater loss since 2002, driven by climate change, unsustainable groundwater use and extreme droughts. The study, led by Arizona State University and published today in Science Advances, highlights the emergence of four continental-scale "mega-drying" regions, all located in the northern hemisphere, and warns of severe consequences for water security, agriculture, sea level rise and global stability.
The research team reports that drying areas on land are expanding at a rate roughly twice the size of California every year. And, the rate at which dry areas are getting drier now outpaces the rate at which wet areas are getting wetter, reversing long-standing hydrological patterns.
The negative implications of this for available freshwater are staggering. 75% of the world's population lives in 101 countries that have been losing freshwater for the past 22 years. According to the United Nations, the world's population is expected to continue to grow for the next 50 to 60 years—at the same time the availability of freshwater is dramatically shrinking.
The researchers identified the type of water loss on land, and for the first time, found that 68% came from groundwater alone—contributing more to sea level rise than the Greenland and Antarctic ice sheets combined.
"These findings send perhaps the most alarming message yet about the impact of climate change on our water resources," said Jay Famiglietti, the study's principal investigator and a Global Futures Professor with the ASU School of Sustainability. "Continents are drying, freshwater availability is shrinking, and sea level rise is accelerating. The consequences of continued groundwater overuse could undermine food and water security for billions of people around the world. This is an 'all-hands-on-deck' moment—we need immediate action on global water security."
The researchers evaluated more than two decades of data from the US-German Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow On (GRACE-FO) missions, looking at how and why terrestrial water storage has changed since 2002. Terrestrial water storage includes all of Earth's surface and vegetation water, soil moisture, ice, snow, and groundwater stored on land.
"It is striking how much non-renewable water we are losing," said Hrishikesh A. Chandanpurkar, lead author of the study and a research scientist for ASU. "Glaciers and deep groundwater are sort of ancient trust funds. Instead of using them only in times of need such as a prolonged drought, we are taking them for granted. Also, we are not trying to replenish the groundwater systems during wet years and thus edging towards an imminent freshwater bankruptcy."
Tipping point and worsening continental drying
The study identified what seems to be a tipping point around 2014-15 during a time considered "mega El-Niño" years. Climate extremes began accelerating and in response, groundwater use increased and continental drying exceeded the rates of glacier and ice sheet melting.
Additionally, the study revealed a previously unreported oscillation where after 2014, drying regions flipped from being located mostly in the southern hemisphere to mostly in the north, and vice versa for wet regions.
One of the key drivers contributing to continental drying is the increasing extremes of drought in the mid-latitudes of the northern hemisphere, for example, in Europe. Additionally, in Canada and Russia, snow, ice, and permafrost melting increased over the last decade, and the continued depletion of groundwater globally is a major factor.
This figure shows the long-term terrestrial water storage trends from GRACE/FO averaged for every country (2/2003-4/2024).
In a previous study, members of the team studied terrestrial water storage from satellite data spanning 2002—2016. In the new study, the team looked at more than 20 years of data and discovered a critical, major development in continental drying. Several regional drying patterns and previously identified localized 'hotspots' for terrestrial water storage loss are now interconnected—forming the four continental-scale mega drying regions.
These include:
• Southwestern North America and Central America: this region includes major food-producing regions across the American Southwest, along with major desert cities such as Phoenix, Tucson, Las Vegas, and major metropolitan areas such as Los Angeles and Mexico City.
• Alaska and Northern Canada: this region includes melting alpine glaciers in Alaska and British Columbia, snow and permafrost melting across the Canadian high latitudes, and drying in major agricultural regions such as British Columbia and Saskatchewan
• Northern Russia: this region is experiencing major snow and permafrost melting across the high latitudes
• Middle East-North Africa (MENA) Pan-Eurasia: this region includes major desert cities including Dubai, Casablanca, Cairo, Baghdad and Tehran; major food producing regions including Ukraine, northwest India, and China's North China Plain region; the shrinking Caspian and Aral Seas; and major cities such as Barcelona, Paris, Berlin, Dhaka and Beijing.
In fact, the study showed that since 2002, only the tropics have continued to get wetter on average by latitude, something not predicted by IPCC (Intergovernmental Panel on Climate Change) climate models—sophisticated computer programs used to project future climate scenarios. Continuous records are critical in understanding the long-term changes in the water cycle.
"This study really shows how important it is to have continuous observations of a variable such as terrestrial water storage," said Chandanpurkar. "GRACE records are really getting to the length where we are able to robustly see long-term trends from climate variability. More in-situ observations and data sharing would further support in making this separation and inform water management."
A planetary wake-up call
The unprecedented scale of continental drying threatens agriculture and food security, biodiversity, freshwater supplies and global stability. The current study highlights the need for ongoing research at scale to inform policymakers and communities about worsening water challenges and opportunities to create meaningful change.
"This research matters. It clearly shows that we urgently need new policies and groundwater management strategies on a global scale," said Famiglietti, who is also with the Julie Ann Wrigley Global Futures Laboratory and a former Senior Water Scientist at NASA's Jet Propulsion Laboratory. "While efforts to mitigate climate change are facing challenges, we can address continental drying by implementing new policies around regional and international groundwater sustainability. In turn, this will slow the rate of sea level rise and help preserve water for future generations."
The study calls for immediate action to slow and reverse groundwater depletion, protect remaining freshwater resources, and adapt to the growing risk of water scarcity and coastal flooding. The research team goes on to say that strategic water management, international cooperation, and sustainable policies are essential to preserving water for future generations and mitigating further damage to planetary systems.
The research will also support an upcoming World Bank Group flagship report that will delve deeper into these findings, including the human and economic implications of continental drying, and present actionable solutions for countries to address the growing freshwater crisis.
The findings are based on over 22 years of terrestrial water storage data from US-German GRACE and GRACE-FO satellite missions. The full report details the scientific analyses and regional breakdowns of the drying trends, which have proven robust and persistent despite climate variability.
The research team includes scientists from Arizona State University; Hrishikesh A. Chandanpurkar, FLAME University; John T. Reager and David N. Wiese, JPL; Kaushik Gopalan and Yoshihide Wada, King Abdullah University of Science and Technology; Kauru Kakinuma, Korea Advanced Institute of Science and Technology; and Fan Zhang, The World Bank.