Soaring Temperatures Threaten Crops, So Scientists Are Looking to Alter the Plants. Genetically altering crops may be key to helping them adapt to extreme temperatures. But shrinking funds and social acceptance stand in the way.

Photosynthesis, the process through which plants get energy, stops working at higher temperatures, which are becoming more common in many of the world’s agricultural regions.Credit...Thomas Lohnes/Getty Images

 

 

By Rebecca Dzombak

 

 

The world’s bread baskets are heating up, threatening the global food supply. Climate change has already shrunk yields for major crops like wheat and maize, and crop losses are likely to worsen in the coming decades.

But researchers are trying to avoid that future by helping plants deal with heat.

“There’s a lot of excitement in identifying why it is that some crops that are grown in the most extreme conditions are able to survive,” said Carl Bernacchi, a crop researcher at the University of Illinois Urbana-Champaign and the author of one of a trio of papers on crop modification that were published Thursday in the journal Science.

Farmers can help crops beat the heat with water-based cooling, but that method has limitations. Modifying crops, either through traditional crossbreeding, artificially sped-up mutation or direct genetic editing, offers control over how plants respond to heat.

Photosynthesis, the process through which plants get energy, grinds to a halt between 40 and 45 degrees Celsius, or 104 to 113 degrees Fahrenheit, temperatures that are becoming more common in many of the world’s agricultural regions.

 

“Photosynthesis really dictates the currency plants have to use,” Dr. Bernacchi said. “If photosynthesis falters, plants run out of energy and die.”

Dr. Bernacchi and his co-authors reviewed the potential of editing rubisco, the key enzyme that transforms carbon into sugar, and its partner, rubisco activase. In plants that grow in warm climates, rubisco activase seems to work better at helping rubisco function. Transferring that molecule from hot-climate plants to cool-climate plants can help cool-climate plants adapt to heat. Simply boosting its activity could help, too.

Altering photosynthesis is still a distant goal, said Walid Sadok, a crop physiologist at the University of Minnesota who was not involved with the paper.

“It’s a complex endeavor,” he said. “It’s still in its infancy, but it’s an interesting idea.”

A plant’s genome can also be altered to change its leaf architecture, spacing leaves out and setting them at just the right angle to ensure a balance of sun and shade that can help maintain temperature and productivity. Editing a leaf’s reflectivity and the amount of chlorophyll, or green pigment, that it contains can help, too.

Plants’ temperature-sensing system could also be modified. In a second Science paper, researchers propose a new way of understanding the network of proteins that control plants’ responses to heat. Instead of plants having discrete “thermometers,” temperature sensing could be spread out in many plant systems and proteins, the researchers say. That could provide many targets for editing for heat tolerance.

 

“We could develop designer crops tailored to future climates,” said Suresh Balasubramanian, a plant geneticist at Monash University in Australia who led the study.

Selective crossbreeding of plants is still a reliable option and should be continued while researchers work toward more complicated genetic editing goals, Dr. Sadok said.

But as temperatures climb beyond levels that modern crops can withstand, genetic editing may be more crucial, Dr. Bernacchi said.

“We may get to a point where existing crops don’t have the genetic diversity we need to adapt crops to the growth conditions that we’re going to see in the near future,” he said. “In that situation, we might need to be creative.”

Wild plants hold a vast pool of genetic diversity that could inspire new ways to keep crops cool. Plants can thrive in the hottest and driest places on Earth, such as Death Valley in California, the Atacama Desert in South America and the Namib Desert in southern Africa, where temperatures regularly soar above the threshold for photosynthesis.

 

Exploring these plants’ genomes could give scientists genes to transfer into staple crops such as soybeans, wheat and rice, bringing along heat tolerance. Scientists can also work backward, starting with a highly heat-tolerant plant and using genetic editing to add other desirable traits, like taste and size.

“We’re trying to cast our net more broadly,” said Sam Yeaman, an evolutionary biologist at the University of Calgary who wrote a third paper. “If we limit ourselves to only looking at crops, we’re going to have a tiny slice of the picture.”

Some complex genetic editing projects, such as photosynthesis or the temperature-sensing system, are years away from hitting farmers’ fields. Other genetic editing tools for heat tolerance, like changes to leaf architecture, could be available sooner, if they could get field tested and permitted, an expensive and time-consuming process.

“Funding right now in the United States doesn’t look particularly promising for the future of this research,” Dr. Bernacchi said.

And acceptance of genetically modified foods has been shrinking over the past decade or so, said Dominique Brossard, who studies the communication of controversial topics at the University of Wisconsin. The Trump administration’s movement toward “natural” foods could further stymie willingness to adopt genetically modified foods, she said.

 

 

Bank unveils green loans plan to unlock trillions for climate finance. IADB’s proposals involve lenders using public money to buy up renewable energy loans in poor countries

 

A street in San Pedro Sula, Honduras, devastated by a hurricane. IADB says the green loans proposal could be an ‘engine’ for growth. Photograph: Delmer Martínez/AP

 

Fiona Harvey Environment editor

 

 

An innovative plan to use public money to back renewable energy loans in the developing world could liberate cash from the private sector for urgently needed climate finance.

Avinash Persaud, a special adviser on climate change to the president of the Inter-American Development Bank (IADB), who developed the proposals, believes the plan could drive tens of billions of new investment in the fledgling green economy in poorer countries within a few years, and could provide the bulk of the $1.3tn in annual climate finance promised to the developing world by 2035.

“This could be an engine for green growth, and produce the trillions needed for climate finance in the future,” he told the Guardian. “It could be a transformation.”

 

His ideas will be set out in detail at a UN meeting in Germany this week, kicking off negotiations for the Cop30 climate summit that will take place in Brazil this November against a worrying global background for the discussions.

Having missed a deadline in February, the world’s largest economies still need to submit plans for their greenhouse gas emissionsbefore the Brazil summit, but so far only a few have done do so.

But research seen by the Guardian, carried out by the campaign group Oil Change International, shows that many developed countries are still planning to expand their extraction of oil and gas, despite promising at Cop28 in 2023 to “transition away from fossil fuels”.

The analysis found that the US, Canada, Norway and Australia were responsible for 70% of projected new oil and gas expansion in 2025-35.

Romain Ioualalen, the global policy lead at Oil Change International, said: “It is sickening that countries with the highest incomes and outsized historical responsibility for causing the climate crisis are planning massive oil and gas expansion with no regard for the lives and livelihoods at stake.”

At the two-week meeting in Bonn, which ends on 26 June, the vital issue of finance for developing countries – which they need in order to cut their emissions and cope with the impacts of extreme weather – will also come to the fore.

The proposals by Persaud and others to buy up loans to renewable energy projects in the developing world could allow billions of dollars of private sector cash to flood the sector, in a big boost to global climate finance.

The plan, which is being pioneered by the IADB, would involve getting taxpayer-funded development banks to buy existing loans to green projects in poor countries, which would free up investment from private sector lenders.

Such loans are relatively low risk because they are already performing – but because they are in developing countries, with credit ratings lower than those of rich states – mainstream private sector investors such as pension funds are often forbidden from touching them because of their strict rules on credit worthiness.

But if those loans are backed instead by development banks, which can provide guarantees against default, and which themselves have impeccable credit ratings, the “repackaged” loan finance can meet private sector criteria.

 

The Barbados PM, Mia Mottley, who launched a blistering attack on rich countries at Cop27 climate talks. Photograph: Independent Photo Agency Srl/Alamy

 

“The lightbulb moment was realising there was $50bn in performing green loans in Latin America,” said Persaud, a former adviser to Barbados’s prime minister, Mia Mottley, who has championed climate finance. “Why not buy that to enable new projects to be created?”

Key to the concept is that when the loans are bought up by the development banks, which pay a small premium to the current private sector creditors that own the loans, the originators of the renewable energy projects must agree to use the finance they gain access to in new projects.

This creates a “virtuous circle”, by which when the loans are bought up, developers – who already have expertise in setting up successful renewable energy schemes – seek new opportunities, which leads to further investment.

IADB is working on launching the programme now, and is expected to send a request for proposals within the next few months, before Cop30. The initial portfolio of loans is likely to be about $500m to £1bn.

Several private and public sector experts said Persaud’s ideas could have a big impact.

Mattia Romani, a senior partner at Systemiq, a consultancy that is working with Cop30 on climate finance, said: “It is a very powerful initiative, both pragmatic and innovative. Given the constraints we will inevitably face in the coming years, securitisation is one of the few realistic tools to reach [the sums needed].

“This initiative is designed to unlock institutional capital by leveraging the balance sheets of domestic commercial banks – securitising their loans so that they can meet the fiduciary needs of institutional investors, and turning them into engines for transition finance. What’s new is the direct engagement with local banks – we are starting with a pilot in Latin America.”

Deadly algal bloom in South Australia’s Coorong an environmental ‘eye opener’, ecologist says

 

 

Dead and dying polychaete worms at the southern end of Coorong’s North Lagoon. Photograph: Glen Hill

by Petra Stock

 Among the dead in the internationally significant wetland are estuarine snails, shore crabs, baby flounder and ‘a thick stew of polychaete worms’

 

When South Australia’s algal bloom arrived in the Coorong, it stained the water like strong tea before turning it into a slurry of dead worms.

Many had hoped the storm in late May would break up the bloom of Karenia mikimotoi algae, which has killed more than 200 different marine species. Instead, high tides swept the algae into the Coorong, an internationally significant Ramsar wetland at the mouth of the Murray River.

Once there, the algae began “reproducing madly” in the nutrient rich waters of the North Lagoon, according to estuarine ecologist Faith Coleman.

Among the dead were mostly benthic species – estuarine snails, shore crabs, baby flounder and “a thick stew of dead polychaete worms” – a crucial food source for shorebirds and fish.

 

Levels had declined from their peak but the smell of rotting fish remained, along with algal spores buried in the sediment. “As soon as it warms up again, the likelihood is [the algal bloom will] be back,” Coleman said.

The marine heatwave, a contributing factor to the bloom, persisted off the coast of SA, according to an 11 June update, which showed increases in chlorophyll – an indicator of algae concentrations – along the Coorong coast and western Gulf Saint Vincent.

Fourth generation fisherman Gary Hera-Singh was one of the first to notice the lagoon’s colour turn a “dark, orangey-brown”.

“We had a big storm event, a lot of seawater got pushed around, and this algal bloom found its way into the Coorong and has just created havoc since,” he said, and there were still “massive patches – 100 acres at a time” where the bloom was flourishing.

Hera-Singh has witnessed the health of the Coorong decline in his lifetime, but said in 41 years of fishing the impact of the algal bloom was the worst event he had seen.

The Coorong, a 120km narrow band of water separated by sand dunes from the Southern Ocean, together with lakes Alexandrina and Albert, is considered a wetland of international significance, providing critical habitat for fish, water birds and many threatened species. The North Lagoon – the area affected – is an important nursery for fish such as mulloway and bream.

 Prof Peter Gell, an expert in Ramsar listed wetlands, said the wetlands had degraded over a long period of time, with barrages (structures that control water flow) added in the 1950s, higher nutrient loads and extended periods of reduced flow from the Murray.

 

Algal blooms were symptoms of broader changes, he said. “Because of this we’re seeing – both offshore and within the Coorong – substantial changes in the food web.”

As a wetland of international significance, the Australian government was obliged to report environmental changes to the Coorong under the Ramsar convention, Gell said, a process that usually triggered restoration efforts.

Federal and state governments were liaising about the situation, including any long-term impacts likely to affect the ecological character of the Coorong, a federal environment department spokesperson said.

“We understand that, given the dynamics of the North Lagoon, it is difficult to dissipate the bloom and it might remain for some time.”

Fresh water may help the situation, Coleman said, given the algae thrived at salinity levels of 18-37 grams per litre. Restoration efforts would help build the resilience of the Coorong and marine areas, she said.

The system was already under pressure, said Dr Nick Whiterod, an ecologist and science program manager at the Coorong Lower Lakes Murray Mouth Research Centre. But the recent drought and unusual algal blooms had been “eye openers” to many people, he said.

Last year, a tropical species of blue-green algal bloomed in Lake Alexandrina for the first time, and had persisted, Whiterod said. Now that karenia mikimotoi had got into the Coorong, there was concern it too would bloom again.

The Coorong was vulnerable to the impacts of climate change, like sea level rise and reduced river flows, he said.

“Ocean temperatures are heating up. It’s creating conditions that are conducive to algal blooms all around the world,” he said. “Our ecosystems are really stressed, we are getting to a period of time where some may not have the capacity to recover.”

 

World Bank Ends Its Ban on Funding Nuclear Power Projects

 

Construction of Bangladesh’s first nuclear plant in 2023.Credit...Abdul Goni/Agence France-Presse — Getty Image

 

By Max Bearak

 

 The decision, a major reversal, could help poorer nations industrialize, cut planet-warming emissions and boost U.S. competitiveness on next-generation reactors.

 

 

The world’s largest and most influential development bank said on Wednesday it would lift its longstanding ban on funding nuclear power projects.

The decision by the board of the World Bank could have profound implications for the ability of developing countries to industrialize without burning planet-warming fuels such as coal and oil.

The ban has been formally in place since 2013, but the last time the bank funded a nuclear power project was 1959 in Italy. In the decades since, a few of the bank’s major funders, particularly Germany, have opposed its involvement in nuclear energy, on the grounds that the risk of catastrophic accidents in poor countries with less expertise in nuclear technology was unacceptably high.

The bank’s policy shift, described in an email to employees late on Wednesday, comes as nuclear power is experiencing a global surge in support.

Casting nuclear power as an essential replacement for fossil fuels, more than 20 countries — including the United States, Canada, France and Ghana — signed a pledge to triple nuclear power by 2050 at the United Nations’ flagship climate conference two years ago.

The Trump administration, while far less concerned about climate change than it is with competing against the Russian and Chinese nuclear industries, is trying to expand the fleet of American reactors and quadruple their contribution to the country’s electric grids. Cabinet officials have emphasized support for a new generation of smaller reactors that offer the promise of faster deployment but have yet to be proven.

The United States is the World Bank’s single largest shareholder and holds significant sway over its policies. In April, Treasury Secretary Scott Bessent urged the bank to lift its ban, saying in a speech that doing so would “revolutionize energy supply for many emerging markets.”

A new government in Germany, led by the Christian Democratic Union, has voiced support for nuclear power, particularly the smaller next-generation reactors. Germany decided to phase out its own reactors after the Fukushima disaster in 2011 and shuttered its last reactor in 2023.

Even the Union of Concerned Scientists, long a voice of caution on nuclear proliferation, has softened its stance in recent years, saying that while it doesn’t support building new reactors, “the low-carbon electricity provided by existing nuclear power plants is increasingly valuable in the fight against climate change.”

 

The bank’s move was welcomed by proponents of nuclear power as an alternative to fossil fuels, the burning of which is the leading cause of global warming.

“If you care about getting the world off coal, then this is potentially massive, especially in Southeast Asia,” said Todd Moss, executive director of the Energy for Growth Hub. Countries like Vietnam and Indonesia are heavily coal dependent and have sought loans to help them retire coal plants early by replacing them with cleaner alternatives.

The bank stopped funding oil and gas drilling projects in 2017, but continues to work on some gas-related infrastructure in developing countries. In Wednesday’s email to staff members, the bank’s president, Ajay Banga, also raised the possibility that a ban on funding oil and gas drilling could be lifted in the future, but no agreement had been reached.

Over the past decade, the bank has ramped up the proportion of its funding that goes to projects that either help reduce greenhouse gas emissions or help poor countries adapt to climate change. That has led to criticism from the Trump administration. But Mr. Banga has vowed to keep his climate commitments while expanding energy access to hundreds of millions of people in Africa who still lack it. Much of that effort relies on small-scale solar power.

 

“I’m not a climate evangelist,” Mr. Banga said in an interview this year. “I’m just the guy getting the stuff done.”

Russia, China, the United States and European countries are at varying stages of developing small modular reactors and World Bank financing could help spur their development by opening up new markets in the developing world.

Currently, developing countries largely look to Russia and China for nuclear technology and financing. Because those countries have nuclear energy companies that are partly or wholly state-owned, and which control everything from fuel to financing to construction, developing countries are able to approach them as easy one-stop shops.

“The Russian and Chinese deals come with 30- to 40-year fuel-lockup agreements,” Mr. Moss said. His organization estimates that 20 countries that do not have access to nuclear energy either already have the technical expertise to begin construction or would by 2030.

Ghana, for instance, has urged the World Bank to change its nuclear policy because it wants to build its own reactors without having to throw its lot into one geopolitical corner. It has been trying since the 1960s.

“Things have been slow for us because of global politics around nuclear, but we have been preparing, setting up an institutional structure, identifying sites,” said Ishmael Ackah, a technical adviser to Ghana’s Energy Ministry. “We want a 24-hour economy, industrial production to be happening day and night,” Mr. Ackah said.

 

 

‘Ticking timebomb’: sea acidity has reached critical levels, threatening entire ecosystems – study. Ocean acidification has already crossed a crucial threshold for planetary health, scientists say in unexpected finding.

As scientists looked deeper into the ocean, they found worse levels of acidification. Photograph: DrPixel/Getty Images

 Lisa Bachelor

The world’s oceans are in worse health than realised, scientists have said today, as they warn that a key measurement shows we are “running out of time” to protect marine ecosystems.

Ocean acidification, often called the “evil twin” of the climate crisis, is caused when carbon dioxide is rapidly absorbed by the ocean, where it reacts with water molecules leading to a fall in the pH level of the seawater. It damages coral reefs and other ocean habitats and, in extreme cases, can dissolve the shells of marine creatures.

Until now, ocean acidification had not been deemed to have crossed its “planetary boundary”. The planetary boundaries are the natural limits of key global systems – such as climate, water and wildlife diversity – beyond which their ability to maintain a healthy planet is in danger of failing. Six of the nine had been crossed already, scientists said last year.

 

However, a new study by the UK’s Plymouth Marine Laboratory (PML), the Washington-based National Oceanic and Atmospheric Administration and Oregon State University’s Co-operative Institute for Marine Resources Studies found that ocean acidification’s “boundary” was also reached about five years ago.

“Ocean acidification isn’t just an environmental crisis – it’s a ticking timebomb for marine ecosystems and coastal economies,” said PML’s Prof Steve Widdicombe, who is also co-chair of the Global Ocean Acidification Observing Network.

The study drew on new and historical physical and chemical measurements from ice cores, combined with advanced computer models and studies of marine life, which gave the scientists an overall assessment of the past 150 years.

It found that by 2020 the average ocean condition worldwide was already very close to – and in some regions beyond – the planetary boundary for ocean acidification. This is defined as when the concentration of calcium carbonate in seawater is more than 20% below preindustrial levels.

The deeper in the ocean they looked, the worse the findings were, the scientists said. At 200 metres below the surface, 60% of global waters had breached the “safe” limit for acidification.

“Most ocean life doesn’t just live at the surface,” said PML’s Prof Helen Findlay. “The waters below are home to many more different types of plants and animals. Since these deeper waters are changing so much, the impacts of ocean acidification could be far worse than we thought.”

This had, she added, huge implications for important underwater ecosystems such as tropical and even deep-sea coral reefs that provided essential habitats and nursery grounds for the young of many species.

As pH levels drop, calcifying species such as corals, oysters, mussels and tiny molluscs known as sea butterflies struggle to maintain their protective structures, leading to weaker shells, slower growth, reduced reproduction and decreased survival rates.

 

The authors underlined that decreasing CO₂ emissions was the only way to deal with acidification globally, but that conservation measures could and should focus on the regions and species that were most vulnerable.

Jessie Turner, director of the International Alliance to Combat Ocean Acidification, who was not involved in the study, said: “This report makes it clear: we are running out of time and what we do – or fail to do – now is already determining our future.

“We are coming to terms with an existential threat while grappling with the difficult reality that much suitable habitat for key species has already been lost. It’s clear that governments can no longer afford to overlook acidification in mainstream policy agendas,” she said.

 

See How Marine Heat Waves Are Spreading Across the Globe
 

Today’s newsletter focuses on Britain’s hot, stinking water mess — from water shortages to sewage problems.

 

The bed of Woodhead Reservoir partially revealed by a falling water level, near Glossop, northern England in May. Photographer: Oli Scarff/AFP/Getty Images

 

The messy details

By Joe Wertz and Priscila Azevedo Rocha While England is often associated with rain, the country has managed to end up with short supply of water thanks in part to climate change. The problem was on full display this week: Reservoir levels across England fell far below the norm during the driest spring in more than a century. Reservoirs were 77% full at the end of May compared with the long-term average of 93%, the UK’s Environment Agency said. This spring was the UK’s sunniest and warmest on record, and England’s driest March-May period since 1893, the agency said. While wetter conditions have since provided some relief, it’s unlikely to plug the deficit as extreme heat and more dry weather looms.

The hot, dry spring has been fueled by an unusual rise in high-pressure patterns that scientists say have amplified long-term global warming. The news comes at time when water mismanagement was already grabbing headlines across Britain.  Things have been particularly bad at Thames Water, which supplies about a quarter of the UK population, and has been on a long downward financial slope. It came close to running out of money several times before finally unlocking an emergency loan in March. There was hope for a turnaround when alternative asset manager KKR & Co. made a bid to invest £4 billion ($5.4 billion) in Thames Water earlier this year. Only this week the US infrastructure giant realized there was little upside to a deal and withdrew its offer, according to people familiar with the deliberations. Read More: KKR Quit Thames Bid After It Saw Little Upside to a Rescue The crisis follows decades of poor regulatory oversight that allowed water company owners to pay themselves billions of pounds in dividends instead of using the money to maintain the infrastructure.  Meanwhile, regulator Ofwat flexed new powers today when it banned six water companies from paying bonuses to senior executives who haven’t done enough to tackle pollution.   Water companies are facing widespread public anger over sewage leaks into rivers and lakes throughout Britain. Photographer: Carl Court/Getty Images   Ofwat’s authority to stop “unjustified” payments for poor environmental and customer performance is part of new legislation that comes into come into force today. Bosses at Thames Water, Yorkshire Water, Anglian Water, Wessex Water, United Utilities and Southern Water are not permitted to receive bonuses with immediate effect, the Department for Environment, Food and Rural Affairs said.  Stopping bonuses is meant to address the public perception that company bosses are rewarded even if a firm is pumping waste into waterways illegally. Public anger has been further fueled by bill increases of as much as 47% in April while water companies have awarded over £112 million in bonuses and incentives over the last decade, according to government figures. --With assistance from Claire Ruckin and Giulia Morpurgo

It’s Not Just Poor Rains Causing Drought. The Atmosphere Is ‘Thirstier.’

Center-pivot irrigation in Eureka County, Nev.Credit...Kim Raff for The New York Times

 

 Higher temperatures caused by climate change are driving complex processes that make droughts bigger and more severe, new research shows.

 

 By Rebecca Dzombak

 

 

Look down from a plane at farms in the Great Plains and the West and you’ll see green circles dotting the countryside, a kind of agricultural pointillism.

They’re from center-pivot irrigation systems. But some farmers are finding older versions, many built 10, 15 or even 20 years ago, aren’t keeping up with today’s hotter reality, said Meetpal Kukal, an agricultural hydrologist at the University of Idaho. “There’s a gap between how much water you can apply and what the crop demands are,” he said.

By the time the sprinkler’s arm swings back around to its starting point, the soil has nearly dried out. The main culprit? Atmospheric thirst.

“A hotter world is a thirstier one,” said Solomon Gebrechorkos, a hydroclimatologist at the University of Oxford. He led a new study, published on Wednesday in the journal Nature, which found that atmospheric thirst, a factor that fills in some of the blanks in our understanding of drought, over the last four decades has made droughts more frequent, more intense and has caused them cover larger areas.

 

In general, droughts happen when there’s an imbalance between water supply and demand.

Rain delivers water to the surface. The atmosphere removes water from the surface through evaporation, with temperature, wind, humidity and radiation from the sun controlling how much water is evaporated. It’s a complicated physical process that is hard to capture in models and, for a long time, studies of global droughts only focused on precipitation.

“It just really wasn’t detailed enough,” Dr. Gebrechorkos said, likening it to trying to balance a checkbook while only looking at income and leaving out expenses.

 

The new study aimed to figure out how atmospheric thirst has changed over more than one hundred years, including how to best model it and how it can improve monitoring and predictions of drought.

Dr. Gebrechorkos and his co-authors used multiple precipitation data sets, climate models and ways of calculating drought from 1901 to 2022 to assess how to capture atmospheric thirst and how it has been affecting droughts.

They found that it played an even bigger role than previously thought, drying out historically arid and wet regions alike.

 

Drought has been spreading and getting more intense since the 1980s almost everywhere around the world except for southeastern Asia, the study found. Atmospheric thirst, a direct result of global warming, made those droughts about 40 percent more severe, the study found.

The Western United States, large areas of Africa and South America, Australia and Central Asia are particularly prone to drought because of increased atmospheric thirst, the study found.

“We were very much shocked when we saw the results,” Dr. Gebrechorkos said. A sharp increase in drought activity in the last five years of the study, from 2018 to 2022, particularly alarmed him.

The area affected by droughts during that time was on average 74 percent larger than in the previous four decades. The drought area in the Western United States more than doubled during this time, as well as in Australia and southern South America. Atmospheric thirst was to blame.

And 2022 was striking. About one-third of the world experienced moderate or extreme drought at some point. Lake Mead, an important reservoir on the Colorado River, nearly dried up. Europe saw a record-breaking combination of drought and extreme heat that led to limits on water use. Millions of people faced food insecurity in the Horn of Africa.

 

Mike Hobbins, a hydrologist at the University of Colorado Cooperative Institute for Research in Environmental Sciences who was not involved in the study, said the findings were in line with his expectations.

“But I think it’s very important to quantify,” Dr. Hobbins said. “The demand side of drought has been ignored for so long, and we don’t have to ignore it any more. We can get it right.”

This year, Dr. Hobbins and Dr. Kukal added a new term to the weather dictionary: thirstwaves, for when evaporative demand is exceptionally high for at least three days, putting crops at risk.

The study’s broader results matched up with Dr. Kukal’s experience working with farmers in the West, as well as national patterns in irrigation.

“There’s a huge shift,” Dr. Kukal said. Some farmers in the west are giving up on irrigation, while more farmers in the upper Midwest and eastern United States are beginning to invest in expensive irrigation systems as atmospheric thirst causes more and more flash droughts.

 

“All this, we see because of warming,” Dr. Gebrechorkos said. “Looking ahead, unfortunately, the trend is set to continue.”

The study ends in 2022, but the following years brought record heat. The summer of 2024 was the warmest on record in the Northern Hemisphere; 2023 was second. And as warming continues, atmospheric thirst will grow, as will droughts. Landscapes that experience droughts again and again struggle to recover, creating a vicious cycle of desiccation.

Better models of atmospheric thirst should improve predictions for drinking water, irrigation and hydropower, allowing better adaptation to an increasingly drought-stricken world. The study used a six-month average; future work could focus on shorter time scales that are more helpful for farmers and water managers, Dr. Kukal said.