Global warming-fuelled heat and drought is聽already hitting yields of maize, wheat and soybeans to the tune of $20 billion a year, a study has estimated. This could rise eightfold, to more than $160 billion by 2100, unless we slash emissions.

While the financial losses will be greatest for big producers such as the US, the impacts will be felt most in the lowest-income countries, where ,听蝉补测蝉 at the International Institute for Applied Systems Analysis (IIASA) in Austria. 鈥淚f you look at the least-developed countries in Africa, the impact is much bigger.鈥� This could lead to social unrest and increased migration, she warns.

There is great uncertainty about these kinds of projections, not least because so much depends on how farmers respond and adapt to a continually changing climate, for instance, by switching to different crops or adopting irrigation where it is possible. In fact, the whole point of this study is to raise awareness and encourage adaptation, to help ensure these projections turn out to be overestimates, says team member , also at IIASA. 鈥淭his is the entire mission of climate scientists: we make these cases for people to react, so our projections turn out to be wrong.鈥�

The researchers started by gathering data on the yields per country of maize, wheat and soya from the UN Food and Agriculture Organization (FAO). Next, they took past climate data and calculated the drought level, using a standard approach that estimates soil moisture levels from rainfall and evaporation levels.

Past heat extremes and drought levels were then compared with the yields from 1974 to 2004 to estimate the impact of heat and drought. They then used these statistical correlations to estimate crop losses from 2007 to 2019. Their results suggest that increases in heat extremes and drought have caused a 3.5 per cent decline in yields relative to the 1974 to 2004 baseline. 鈥淭hree per cent or so might not sound like much, but this is a major impact [on] the global food market, which regionally can trigger a severe crisis,鈥� says Kornhuber.

The researchers then calculated the economic losses, based on FAO data showing how much farmers would have been paid for their produce at the time. Finally, they used the same approach to project future losses in several different emissions scenarios, assuming that some adaptation takes place.

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In a high-emissions scenario, known as SSP3-7.0, global yields will fall by around 35 per cent by 2100, with annual losses rising to more than $161 billion. 鈥淭he production losses caused by heat and drought are around 855 million tonnes a year,鈥� says Hwong, who presented the results at a meeting of the European Geosciences Union in Vienna in May. 鈥淚 think that is equivalent to what around 2 billion people consume over a year.鈥�

This could be an underestimate of the full impact of climate change for a number of reasons: it鈥檚 just three crops, and it doesn鈥檛 include flood, storm or rain damage, or the possibility that shortages could lead to big price increases, as is already happening with some other crops such as coffee and cacao.

A key solution to climate change isn鈥檛 happening 鈥� and that鈥檚 good

Removing CO2 from the atmosphere by capturing the carbon from burning biomass is supposed to save the planet, but it looks like the flagship project will never happen

at Columbia University in New York says the study鈥檚 reliance on the statistical relationships between yield losses and extreme heat and drought could result in it overestimating the impacts by 2100. 鈥淪tatistical yield models are great for explaining what鈥檚 happening now, and in the near past [or] future, but they are inherently unreliable when pushed into vastly different environmental regimes, such as high-emission climate scenarios by the end of the century.鈥� Computer models of how plants are affected by rising CO2 and temperatures are better for projecting what will happen by the end of the century, he says.

at the University of Queensland, Australia, makes the same point. 鈥淎lthough models are not perfect, they are better suited for this type of extrapolation.鈥� However, her team recently released a , which hasn鈥檛 been peer-reviewed, showing that two widely used models for wheat make large errors and are especially poor at forecasting the combined effects of extreme heat and drought.

But Kornhuber has defended his team鈥檚 use of statistical methods. 鈥淭he models are remarkable tools, but some of the validation papers have suggested that they might not be super responsive to extremes,鈥� he says. 鈥淚n our project, extremes were the main focus, so we decided to establish these relationships directly through statistics.鈥�

Short-term geoengineering to brighten clouds over the eastern Pacific Ocean could limit the damage caused by El Ni帽o and save the global economy trillions of dollars, although there could be winners and losers from the disruption of natural cycles.

The El Ni帽o climate phase occurs when easterly winds weaken, allowing warm water built up in the western Pacific to slosh back across the central and eastern parts of the ocean. That heats the atmosphere and raises global temperatures, with losses to economic growth estimated in the trillions of dollars.

What could become a very strong or 鈥渟uper鈥� El Ni帽o is now developing in the eastern Pacific. But climate modelling has suggested that, in the future, a geoengineering method called marine cloud brightening might be able to cut this warming short.

The technique involves spraying tiny droplets of seawater into the air below low-lying stratocumulus clouds, where moisture condenses onto them. The clouds become whiter thanks to the increase in the number of droplets, reflecting more sunlight back to space.

Shading part of the eastern Pacific called the Ni帽o 3.4 region via cloud brightening could interrupt the feedback loops that cause an El Ni帽o to develop. Cooler sea surface temperatures would strengthen the trade winds to again blow warm water back into the western Pacific. More cool water would then well up from the depths of the eastern Pacific, further cooling surface temperatures, and so on.

鈥淵ou can basically stop the dominoes from falling early when you do marine cloud brightening,鈥� says at the University of California, San Diego, who worked on the study. 鈥淲e鈥檙e kicking the cycle in the other direction.鈥�

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Wan and her colleagues got the idea from the 鈥渂lack summer鈥� of catastrophic bush fires in Australia in 2019-2020, which were followed by La Ni帽a, the opposite phase of El Ni帽o that lowers global temperatures. Research has that drifting smoke particles brightened clouds and cooled the eastern Pacific, intensifying and prolonging the 鈥渢riple dip鈥� La Ni帽a that began in 2020 and persisted through three winters, rather than just one or two.

The study modelled what cloud brightening could have done to the super El Ni帽o events of 1997-1998 and 2015-2016. It found that nine months of spraying seawater would have nearly halved warming of the Ni帽o 3.4 region, from 2掳C or more to a little over 1掳C. It would have ended the El Ni帽o by January, shaving several months off the events.

The hypothetical cloud-brightening mission would have been massive, involving an estimated 2400 ships and delivering an amount of seawater spray that isn鈥檛 possible with current nozzle technology. But it would have turned a super El Ni帽o into a moderate one.

Wan says she was surprised how well it seemed to work, given that it could only be started in June, once El Ni帽o had clearly begun developing.

at the University of Exeter, UK, warns that these results might not translate to the real world, where warming seas typically start dissipating low-level clouds, leading to further warming and dissipation through a feedback loop.

鈥淚n a model with a stronger cloud feedback, you would have to do more aerosol injection,鈥� he says. 鈥淭he experiments seem to be at the limit of what can be done.鈥�

Wan admits this approach could have unexpected consequences, since the model only projected the impact over two-year periods. In both simulations, La Ni帽a started earlier after El Ni帽o subsided, and in the 2015-2016 case, this subsequent cooler phase became stronger. That could be bad news for regions like the Horn of Africa, where strong La Ni帽as have, in the past, disrupted rainfall and .

But she says the idea is worth further research. Unlike geoengineering aimed at reducing global temperatures for the long term, short-term geoengineering like this could avoid the risk of 鈥�termination shock鈥�, where any disruption to the spraying of low-level seawater or stratospheric aerosols could allow years of pent-up warming to come roaring back.

鈥淭his study is opening up doors for a completely new target for geoengineering research, which is climate variability and things like El Ni帽o,鈥� says Wan. 鈥淚t鈥檚 potentially very powerful, because you鈥檙e not locked into these long-term risks.鈥�

贰耻谤辞辫别鈥檚 most extreme heatwave so far may have killed between 17,000 and 25,000 people, according to an early estimate based on past deaths from heat in the region.

鈥淭hese numbers are preliminary,鈥� says at Indiana University. 鈥淏ut they highlight the need for rapid adaptation investments to avoid these impacts in the future.鈥�

Callahan鈥檚 estimate is based on . 鈥淲e鈥檙e taking data on temperature and mortality across Europe, and we are correlating how high temperatures relate to excess mortality rates,鈥� says Callahan. 鈥淲e then use that relationship to infer how a given heatwave affects mortality over a region like Europe.鈥�

Callahan鈥檚 conclusion is that the heatwave in Europe from 22 to 28 June 2026 killed approximately 20,390 people, including 5210 in France, 4543 in Germany, 3163 in Spain, 2709 in Italy and 862 in the UK. These numbers are much higher than the direct counts announced so far, but this isn鈥檛 surprising because it takes time for data on deaths to be collected and analysed.

鈥淭his figure is a modelled estimate rather than a final count, and it will be some months before the true toll is confirmed, in part because heat rarely appears on a death certificate,鈥� says at the University of Warwick in the UK.

For instance, on 28 June, the head of the World Health Organization, Tedros Adhanom Ghebreyesus, said so far. This number is largely based on reporting around 1000 more deaths in the country than expected from 24 to 26 June.

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However, that statement made it clear that this number is based on a computerised death certificate system that is far from complete. It records 80 per cent of hospital deaths, 45 per cent of deaths in long-term care facilities and 25 per cent of deaths at home. 鈥淢ortality will consequently be higher than these initial figures suggest,鈥� the statement said.

Even so, other experts think Callahan may have overestimated the numbers. 鈥淭wenty-thousand for a single week seems very large,鈥� says at the University of Bristol in the UK. 鈥淲e鈥檇 have to look into details of the modelling to be more sure.鈥�

While Callahan鈥檚 method is sound, the main issue is that he used data from 2015 to 2019 to calculate the relationship between heat and deaths, says at Pozna艅 University of Medical Sciences in Poland. People may now be less vulnerable due to ongoing adaptations, such as increased access to air conditioning, . Walkowiak鈥檚 back-of-the-envelope calculation is that if this is taken into account, the actual number of deaths would be around 15,000.

Callahan is sticking to his guns. 鈥淲e don鈥檛 have very strong evidence that the relationship between temperature and mortality dramatically changed over time,鈥� he says. 鈥淪o it鈥檚 not obvious it鈥檚 different now than it was 10 years ago.鈥�

鈥淚n general, we find that our sort of broader statistical estimates give higher numbers than direct reporting on the ground, because that direct reporting can often miss people who die from heat where it鈥檚 not obvious that heat was the cause,鈥� he says.

On the flip side, Walkowiak says that Callahan hasn鈥檛 taken into account the fact that heatwaves of the same temperature are more deadly in early summer than in late summer. 鈥淚n late summer, part of the especially vulnerable population is already long gone,鈥� he says.

Mitchell also says the kind of approach used by Callahan also counts only the immediate deaths. There can be longer-term impacts, such as more deaths from domestic violence, suicides and kidney failure. 鈥淭he impacts of heat on health vary a lot across timescales,鈥� he says.

What matters most is avoiding further deaths as the planet warms further and heat becomes more extreme, says Nunes. 鈥淭he signal is clear: heat is now the deadliest weather hazard we face, and the majority of these deaths are preventable,鈥� she says. 鈥淲e can now forecast these events with considerable accuracy; what we have not done is build the systems, across health, housing, social care and transport, for example, that translate an accurate forecast into actual protection. Adaptation is not keeping pace with the risk.鈥�

In the winter of 2013-2014, the strong winds of the jet stream shifted north, allowing a mass of warm water dubbed 鈥渢he blob鈥� to across more than 1500 kilometres of the north Pacific Ocean.

Floating instruments moored to the seabed off Alaska, Washington and Oregon alerted scientists and the fishing industry to the arrival of this water, which was up to 4掳C hotter than normal.

They were part of the Ocean Observatories Initiative (OOI), five mooring off the US west and east coasts and Greenland. Announcing $220 million in funding for the programme in 2023, the US National Science Foundation (NSF) the OOI was needed to monitor 鈥渃ritical organs of the Earth鈥�. But last month the NSF from the water following funding cuts by the administration of US President Donald Trump.

As a planet-warming El Ni帽o climate phase warmed the water further in 2015-2016, sensors running up and down OOI mooring wires revealed the blob was into the deep sea below 250 metres. The mooring data helped show the blob, which repeated in 2019 and may be happening more frequently due to climate change, spurred toxic algal blooms that California鈥檚 $60 million Dungeness crab fishery for the season.

The removal of most OOI moorings will diminish the accuracy of weather forecasting, including precipitation patterns influencing the record drought in the western US. It will also hinder efforts to monitor a possible weakening in the Atlantic Meridional Overturning Circulation (AMOC) that keeps Europe temperate, as well as the effects of an imminent El Ni帽o.

鈥淲e鈥檙e flying blind, and it will end up costing us more,鈥� says at the University of St. Thomas in Minnesota.

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While the OOI costs $56 million a year to run, the US commercial fishing industry, which relies in part on OOI data, billions of dollars each year. Weather and climate disasters did $183 billion of in 2024. (The US government discontinued this tally in 2025.)

Without the OOI, fleets won鈥檛 know which fishing areas might be less impacted by the coming El Ni帽o, which some models say could be the strongest on record, says at Oregon State University. Oyster, clam and shellfish farms won鈥檛 be able to prepare for heating and reduced nutrients the El Ni帽o could bring, and scientists will lose their view of harms to marine ecosystems. In the past, the OOI has also alerted scientists to the formation of low-oxygen 鈥渄ead zones鈥� on the seafloor.

鈥淭hat is going to be lost at exactly the worst time,鈥� says at Boston College in Massachussetts.

Because satellites can鈥檛 see beneath the surface of the sea, measurements by underwater floats, gliders and moorings are crucial to understand what鈥檚 happening in the 70 per cent of the planet covered by ocean.

While these mostly measure temperature, salinity and flow rate, the OOI moorings also have sensors for parameters like pH, oxygen and CO2 for understanding the biology and chemistry of the ocean. And they do so in remote, little-monitored places where the movement of water masses affects the climate.

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The loss of these sensors will impact the rest of the world, especially by reducing observations of the AMOC. The OOI array in the Irminger Sea, east of Greenland, is part of OSNAP, a line of moorings, gliders and floats stretching from Canada to Greenland to Scotland. It monitors warm, salty water flowing from the tropics to the north Atlantic, where it cools and sinks, driving the AMOC. A collapse in this system could plunge Europe into 鈥渋ce age鈥� winters and disrupt monsoon rains critical for agriculture in Africa and Asia.

鈥淥SNAP has taught us that most of the actual overturning takes place east of Greenland and that the Irminger Sea is key in understanding the overturning variability,鈥� says at the Royal Netherlands Institute for Sea Research.

Removing OOI will create a data gap that will limit understanding of the AMOC, even if it鈥檚 someday replaced, Palevsky adds.

女生小视频s fear the dismantling of OOI is the start of a massive rollback of US ocean research funding that could see the discontinuation of OSNAP. Some worry it could even undercut Argo, a vital network of almost 4000 descending instrument floats across the global ocean, of which are provided by the US.

In a statement to New 女生小视频, the NSF said the OOI removal was to 鈥減rioritize support for evolving scientific priorities鈥�. But it comes as the Trump administration wages what at the Union of Concerned 女生小视频s calls an 鈥渁ttack on science鈥�. The administration has or suspended thousands of research grants, and it has proposed slashing the NSF鈥檚 budget by 55 per cent in 2027.

This week, the administration proposed a rule that would cancel peer review of research grant applications, allowing political appointees rather than independent experts to decide the fate of federally funded research. It would also ban international collaborations and research on gender and diversity.

The looming El Ni帽o could be bad 鈥� but much worse is to come

Global warming will amplify the impacts of El Ni帽o events, and could also make them much stronger and more far-reaching

at the Oregon State University, who manages the OOI array off the coast of Washington and Oregon, says the dismantling of OOI and the proposed grant rule are both part of sweeping changes that would 鈥渨eaken peer review and politicise NSF-funded science鈥�.

A last month found that dismantling even one-fifth of the Global Ocean Observing System, a network of instruments that includes the OOI arrays and the Argo floats, would increase the error in the annual rate of ocean heating by 33 per cent. That would be like going from predicting an unemployment rate of 3 per cent this year to only being able to give a range of 2 to 4 per cent, says Abraham, who was part of the team behind the research.

鈥淭his is purposeful to try and remove our eyes and ears in the ocean,鈥� he says of the OOI dismantling. 鈥淏ecause if we don鈥檛 measure something, how do we know we have a problem?鈥�

A line that runs through Africa, Europe, Alaska and both poles divides Earth into two halves that reflect the same amount of light 鈥� and this newly discovered symmetry may play a critical role in the planet鈥檚 climate.

It was previously known that the northern and southern hemispheres have almost equal reflectivity, or albedo, but at the National Oceanic and Atmospheric Administration in the US and his colleagues have now uncovered a second line of symmetry along the 27掳 east and 153掳 west meridians.

The hemispheres separated by this line are nearly equal in three respects: their albedo in clear skies, the reflectivity of clouds and the fractions covered by ice-free oceans. This symmetry has persisted throughout 25 years of satellite observations analysed by Zhang and his colleagues.

At first, Zhang thought it must be a coincidence. 鈥淲hat convinced me that the east-west symmetry is not trivial are three features: its uniqueness, its persistence and what we call the triple symmetry feature,鈥� he says. 鈥淔inding one division with equal total reflection might be expected. But finding a persistent, unique east-west division that also balances land-ocean distribution, clear-sky reflection and cloudy-sky reflection is much less trivial 鈥� especially given how variable and dynamic clouds are.鈥�

While the east-west symmetry is centred near 27掳 east when averaged over the 25-year satellite record, in any individual year, the exact line of symmetry shifts slightly. The team found that these small year-to-year shifts are strongly related to the phase of the El Ni帽o-Southern Oscillation (ENSO), a global climate phenomenon related to fluctuations in sea-surface temperatures in the Pacific Ocean.

鈥淚n other words, the symmetry may not simply be a geometric accident,鈥� says Zhang. 鈥淚t may be connected to one of the most important modes of climate variability on Earth. ENSO may act as a large-scale adjustment mechanism that helps keep the long-term east-west symmetry centred near 27掳 east.鈥�

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at the Centre for International Climate Research in Oslo, Norway, who wasn鈥檛 involved in the study, says he doubted the discovery at first.

鈥淚 was a bit sceptical of an east-west symmetry separated at around 27 degrees east, which intuitively seems much less obvious than a separation at the equator, and I wondered if it could be a coincidence.鈥�

However, Hodnebrog says he now agrees it is likely a 鈥渞obust feature, and potentially another fascinating property of the Earth鈥�.

The connection to ENSO may also be significant, says Hodnebrog. Unlike the north-south symmetry, which appears to be weakening due to the effects of climate change on sea ice and clouds, the east-west symmetry is currently stable, though models suggest it could weaken in future. 鈥淎 potential future asymmetry could be an indication of changes in the atmospheric circulation,鈥� he says.

at the University of New South Wales, Sydney, says there is a high potential that the east-west symmetry is a coincidence.

鈥淓arth鈥檚 weather and climate communicate easily across longitudes,鈥� says Jucker. 鈥淭his is due to Earth鈥檚 rotation, which creates bands of circum-global easterly and westerly winds, and atmospheric perturbations preferentially propagating in the east-west direction as well.鈥�

If there are mechanisms that maintain the east-west symmetry, it could have implications for geoengineering schemes, Zhang says. For example, attempts to increase the albedo of one hemisphere might be negated by a global-scale feedback loop.

鈥淏efore making confident claims about the effects of geoengineering, we need a stronger understanding of how clouds, circulation, precipitation and planetary reflectivity respond across the coupled Earth system,鈥� says Zhang.

Destruction of rainforest for cattle ranching is making the Amazon biome more vulnerable to irreversible collapse, which could occur within decades if deforestation continues.

A landmark 2022 on tipping points found the Amazon would likely suffer widespread dieback at global warming of 3.5掳C and potentially as low as 2掳C. That鈥檚 worrying, as estimates put Earth on track to warm by about 2.6掳C to 2.7掳C above pre-industrial temperatures by 2100. But the research didn鈥檛 include deforestation, which has already resulted in the loss of at least 15 per cent of the Amazon.

at the Potsdam Institute for Climate Impact Research in Germany and his colleagues have now modelled Amazon dieback with scenarios involving both rising global temperatures and severe deforestation until 2050. If total forest loss increases to 22 per cent, the Amazon could suffer widespread dieback with as little as 1.5掳C of global warming, they found. The world has already experienced 1.3掳C to 1.4掳C of warming and could hit 1.5掳C by the end of this decade.

Deforestation slowed last year, but if it resurges, the Amazon could cross a tipping point as soon as 2031. The timing and extent of dieback predicted by the model varied depending on how much carbon humanity emits, with deforestation rates of 22 to 28 per cent leading to 62 to 77 per cent of the Amazon biome becoming grassland, savanna or scrubby forest.

鈥淲e found that there鈥檚 this about-2-degree reduction of the critical global warming threshold when deforestation is considered,鈥� says Wunderling. 鈥淭he reason why deforestation is so crucial is that it undermines this atmospheric moisture recycling feedback.鈥�

Vast atmospheric rivers carry moisture from the Atlantic Ocean across the Amazon. After rain falls on one part of the forest, the trees transpire some of that moisture back into the air, which carries it to another part to repeat the process. Up to 50 per cent of the rainfall in the western Amazon is recycled from the forest itself.

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But cutting down areas of the forest reduces this moisture recycling and kills off other areas downwind, which kills off further areas in a domino effect. 鈥淚t only needs a little bit of a push from global warming to make these cascading transitions possible,鈥� says Wunderling.

While concerning, the findings are based on a high deforestation rate that would eat into areas that are currently protected, according to at the University of Sussex in the UK, who worked on the 2022 tipping point study.

Brazil more than 28,000 square kilometres of primary forest in 2024, equalling its previous record. But it nearly halved that rate in 2025, and President Luiz In谩cio Lula da Silva has promised to halt Amazon deforestation by 2030. Achieving that would probably avoid the tipping point even if the world keeps warming.

鈥淪topping all deforestation is probably optimistic,鈥� Armstrong McKay says. 鈥淏ut even if there is some deforestation continuing, it probably won鈥檛 meet this worst-case scenario modelled here.鈥�

All the same, Brazil still lost about 0.5 per cent of its primary forest in 2025. And for the past two years, two-thirds of forest destruction has been due to wildfires, which typically start when farmers burn vegetation in deforested areas but then escape into the neighbouring forest.

Once almost unheard of, wildfires can now spread because the rainforest is hotter and drier, conditions that will be worsened by the El Ni帽o climate phase later this year. As a result, the study may be underestimating the vulnerability of the Amazon, according to at the University of Leeds, UK.

鈥淲e鈥檙e getting these much bigger fires,鈥� he says. 鈥淭hat is worrying if we have moved into a new kind of regime where that can happen more and more.鈥�

Already, the Amazon has from a carbon sink to a carbon source, and widespread dieback could emit enough carbon to heat the globe by as much as 0.2掳C. It would also destroy the world鈥檚 biggest store of terrestrial biodiversity.

鈥淲e really want to be backing away from that threshold, rather than creeping towards it,鈥� says Spracklen.