Average global yields of six staple crops could fall by more than 11% under a moderate warming scenario by the end of the century – even when accounting for how farmers could adapt to climate change, new research finds.
The study, published in Nature, examines changes in yields for cassava, maize, rice, sorghum, soya bean and wheat under two different warming scenarios.
But, unlike previous studies, it also factors in adaptive measures that farmers may employ to adjust to the changing climate.
It finds that implementing adaptation could reduce total yield losses by around 12% by the end of the century – although the world would still face “substantial losses”, it says.
The study also finds that the world’s “breadbaskets” – such as the US and Europe – will have less adaptive capacity than poorer regions, as their farming industries have been optimised for high yields, rather than resilience.
One researcher, who was not involved in the new study, tells Carbon Brief that these types of studies “are essential steps” towards better understanding adaptation in agriculture.
‘Partially protective’ adaptation
Globally, agriculture is projected to be one of the industries that is hit hardest by the impacts of climate change.
Along with rising average temperatures and changing rainfall patterns, increasingly frequent and severe weather extremes threaten planted crops.
However, large uncertainties remain around how farmers will adapt to future climate change.
Most previous research on the yield impacts of climate change either assumes that farmers will not adapt to the changes at all or that they can adapt infinitely, explains Dr Andrew Hultgren, an environmental economist at the University of Illinois Urbana-Champaign.
Hultgren, who led the new study, tells Carbon Brief:
“The question is: ‘What do real world farmers actually do?’ So that’s what we really set out to tackle…And what we find is that, essentially, neither of these extreme stories is really accurate. Farmers do adapt, but that adaptation is partially protective – not fully protective.”
The researchers model the impacts on crop yields under two emissions scenarios – moderate (RCP4.5) and very high (RCP8.5) – for two time periods – 2050 and 2098. They select six staple crops for their study: cassava, maize, rice, sorghum, soya bean and wheat.
For both emissions scenarios, the researchers apply projected future incomes consistent with SSP3 socioeconomic pathway. This portrays a “rocky road” of global development in the future due to rising geopolitical tensions driven by “regional rivalry”.
Under the moderate-emissions scenario, they find an overall decrease in staple crop yield of 8.3% in 2050 and 12.7% in 2098.
However, they find that these losses can be reduced somewhat by the introduction of adaptive measures, such as switching to different varieties of a crop or adjusting irrigation levels.
In order to account for adaptation, the researchers use data on crop yields from 12,658 sub-national regions to create a model that links changes in yields to exposure to extremely hot days.
This allows the researchers to project the impacts of adaptive measures without having to prescribe what, exactly, those measures would be, Hultgren says. Relatively lower losses on extreme heat days are “reflective of adaptation”, he adds.
In other words, if two regions with similar baseline climates and yields both experience a season of extreme heat, the one that has lower yield losses has more adaptations to climate change.
Factoring in adaptation and income growth, they find that the yield losses fall to 7.8% in 2050 and 11.2% in 2098 under moderate emissions. While these changes are relatively small, they are not insignificant, Hultgren argues:
“Twelve percent mitigation of losses is still a globally important amount of gains from adaptation.”
Dr Jyoti Singh, a climate-crop modeller at Columbia University’s Center for Climate Systems Research, tells Carbon Brief that the dataset assembled for the new study is its “most noteworthy strength”. Singh, who was not involved in the new work, adds that it “significantly contributes to empirical agricultural impact modelling”.
However, she says, there is a “big limitation” of the study in that empirical models are based only on past data – they cannot account for the full range of potential futures. Therefore, the results from the new study cannot be compared directly to results from models that more explicitly represent the processes that influence crop growth, she says.
Regional loss patterns
The losses are not equal across all six staples. The end-of-century losses range from just over 1% loss for rice yields to 22.4% loss for soya bean yields. This is because each of the crops has a different response to changes in temperature and rainfall.
The change in rice yield is particularly low, Hultgren explains, because the losses associated with overall warming are somewhat counterbalanced by yield increases due to rising nighttime temperatures.
In addition to the differences between crops, the researchers identify strong regional differences in the amount of future losses – as well as the extent to which adaptation will offset these losses.
In Africa, for example, the researchers project an overall yield decrease of 16% by 2098 with no adaptive measures in place. Adding in these adaptations reduces that yield loss to 11.6%. By contrast, adding adaptation to projections of staple yields in North America makes almost no change – reducing the losses from 21.0% to 20.8%.
The maps below show the percentage of yield losses for (clockwise from top-left) maize, soya bean, wheat, sorghum, cassava and rice in 2098 under a moderate-warming scenario that factors in adaptation.
The maps show that many of the staple crops studied suffer the most significant losses in current “breadbasket” regions of the world that produce much of the world’s calories, such as the US and Europe. In contrast, many lower-income, tropical regions see more modest losses. The authors write:
“Because such a large fraction of agricultural production is concentrated in these wealthy-but-low-adaption regions, they dominate projections of global calorie production, generating much of the global food security risk we document.”
However, Hultgren points out, subsistence farmers – particularly those who rely on cassava – will also be significantly impacted by climate change. The researchers identify the highest losses among the top two deciles of the global income distribution and the bottom decile.
This result was “surprising”, Hultgren says. Typically, he explains, research has shown that poorer areas are the hardest-hit by climate change.
He adds that the finding is reflective of the trade-off between average yields and adaptive measures. In high-producing regions, farmers have generally relied on planting the highest-yielding varieties, instead of crop varieties that might have lower average yields, but are more resilient to changes in climate.
Hultgren tells Carbon Brief:
“Adaptation is costly…That’s why losses in the breadbasket portion of the world are so large, because farmers have to essentially pay a high price. Either in terms of actual financial inputs or in terms of just average yield losses, they have to pay a high price in order to get the adaptation they need.”
‘Giving up breakfast’
By combining the projected yields for all six crops, the researchers also estimate the total impact of warming on global calories.
They find a “nearly linear” decrease in global calorific output of 554tn kilocalories per 1C of warming – equivalent to about 120 kcal per person per day per 1C. (The recommended daily intake is typically around 2,000kcal for women and 2,500kcal for men.)
Hultgren tells Carbon Brief:
“If you think about a 3C warmer future, that’s like a population that is giving up breakfast every day – that would be the level of the caloric output loss.”
That result “should raise questions” about global food security and international political stability, Hultgren says.
The study’s method of linking global calories to changes in temperature is one of the “key innovations” of the new study, Singh says. She adds that it “improve[s the] policy relevance” of the work.
Singh tells Carbon Brief:
“Real-world adaptation decisions, from changing crop types to investing in irrigation or adopting resilient varieties, vary significantly depending on policies and farmers’ knowledge, resource access and financial capacity.
“Studies like this one, even if not fully comprehensive, are essential steps toward understanding and incorporating adaptive capacity into yield projections, moving us closer to more realistic agricultural impact assessment efforts.”
The post Staple crops yields face ‘substantial losses’ in warming world – even with adaptation appeared first on Carbon Brief.
Staple crops yields face ‘substantial losses’ in warming world – even with adaptation
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Congress, including its climate strategy out to 2030, according to the Hong Kong-based South China Morning Post. The plan called for China to cut its carbon emissions per unit of gross domestic product (GDP) by 17% from 2026 to 2030, which “may allow for continued increase in emissions given the rate of GDP growth”, reported Reuters. The newswire added that the plan also had targets to reach peak coal in the next five years and replace 30m tonnes per year of coal with renewables.
ACTIVE YET PRUDENT: Bloomberg described the new plan as “cautious”, stating that it “frustrat[es] hopes for tighter policy that would drive the nation to peak carbon emissions well before president Xi Jinping’s 2030 deadline”. Carbon Brief has just published an in-depth analysis of the plan. China Daily reported that the strategy “highlights measures to promote the climate targets of peaking carbon dioxide emissions before 2030”, which China said it would work towards “actively yet prudently”.
Around the world
- EU RULES: The European Commission has proposed new “made in Europe” rules to support domestic low-carbon industries, “against fierce competition from China”, reported Agence France-Presse. Carbon Brief examined what it means for climate efforts.
- RECORD HEAT: The US National Oceanic and Atmospheric Administration has said there is a 50-60% chance that the El Niño weather pattern could return this year, amplifying the effect of global warming and potentially driving temperatures to “record highs”, according to Euronews.
- FLAGSHIP FUND: The African Development Bank’s “flagship clean energy fund” plans to more than double its financing to $2.5bn for African renewables over the next two years, reported the Associated Press.
- NO WITHDRAWAL: Vanuatu has defied US efforts to force the Pacific-island nation to drop a UN draft resolution calling on the world to implement a landmark International Court of Justice (ICJ) ruling on climate, according to the Guardian.
98
The number of nations that submitted their national reports on tackling nature loss to the UN on time – just half of the 196 countries that are part of the UN biodiversity treaty – according to analysis by Carbon Brief.
Latest climate research
- Sea levels are already “much higher than assumed” in most assessments of the threat posed by sea-level rise, due to “inadequate” modelling assumptions | Nature
- Accelerating human-caused global warming could see the Paris Agreement’s 1.5C limit crossed before 2030 | Geophysical Research Letters covered by Carbon Brief
- Future “super El Niño events” could “significantly lower” solar power generation due to a reduction in solar irradiance in key regions, such as California and east China | Communications Earth & Environment
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
UK greenhouse gas emissions in 2025 fell to 54% below 1990 levels, the baseline year for its legally binding climate goals, according to new Carbon Brief analysis. Over the same period, data from the World Bank shows that the UK’s economy has expanded by 95%, meaning that emissions have been decoupling from growth.
Spotlight
Bristol’s ‘pioneering’ community wind turbine
Following the recent launch of the UK government’s local power plan, Carbon Brief visits one of the country’s community-energy success stories.
The Lawrence Weston housing estate is set apart from the main city of Bristol, wedged between the tree-lined grounds of a stately home and a sprawl of warehouses and waste incinerators. It is one of the most deprived areas in the city.
Yet, just across the M5 motorway stands a structure that has brought the spoils of the energy transition directly to this historically forgotten estate – a 4.2 megawatt (MW) wind turbine.
The turbine is owned by local charity Ambition Lawrence Weston and all the profits from its electricity sales – around £100,000 a year – go to the community. In the UK’s local power plan, it was singled out by energy secretary Ed Miliband as a “pioneering” project.
‘Sustainable income’
On a recent visit to the estate by Carbon Brief, Ambition Lawrence Weston’s development manager, Mark Pepper, rattled off the story behind the wind turbine.
In 2012, Pepper and his team were approache