Limiting warming to 2C above pre-industrial temperatures may not be enough to prevent “extreme global climate outcomes”, according to research published in Nature.

The authors simulate climate extremes – such as drought in breadbasket regions and flooding in populated areas – under a 2C warming scenario using a range of different global climate models.

They find that the “worst-case” model projections in a 2C warmer world are often more severe than the “average” scenarios in a 3C or 4C warmer world.

An author on the study tells Carbon Brief that, for policymakers planning around risk, it is “really important” to account for these potential extremes at 2C.

The findings are “sobering” and “demonstrate that the risks at 2C of global warming may be significantly higher than previously thought”, according to one scientist who was not involved in the study.

He adds that the methods used in the research would “offer a very useful contribution” to any future “global assessment of avoidable climate-change risks”.

High-risk scenarios

As the planet warms, climate extremes such as floods and droughts are becoming more intense and frequent. For policymakers to effectively plan and adapt to upcoming changes, they need to understand how severe these events could become.

Scientists routinely use global climate models to simulate how extremes may change over the coming decades. One well-established way to present these results is to run simulations using multiple models, then take the average of these results.

This average is known as the “multimodel mean”. Model results typically cluster around the mean, giving scientists more confidence in these results, but there are often also individual projections that sit notably higher or lower.

Prof Erich Fischer is a lecturer in environmental systems science at ETH Zurich and an author on the paper. He tells Carbon Brief that focusing on the multimodel mean is a “very valuable” communication tool for climate scientists, providing a “simpler” message than showing the full range of results.

For example, he tells Carbon Brief that the Intergovernmental Panel on Climate Change (IPCC) – the world’s most authoritative source on climate change – uses the multimodel mean to produce many of its maps.

However, Fischer warns that from a “risk perspective”, focusing solely on the multimodel mean could give a “misleading picture”. For example, he adds, the changes that specific regions may see could be “much, much higher” than the global average.

He tells Carbon Brief that for policymakers planning around risk, it is “really important” to account for more extreme cases too.

To demonstrate this, the study authors select 42 models from the Coupled Model Intercomparison Project 6 (CMIP6). These are the models that are used most widely in the latest set of IPCC reports.

Their approach is illustrated in the diagram below. Note that this illustration is not based on real model runs, but is intended to give an example of what a set of results could look like.

The beige strip on the right shows the spread of results, where each horizontal bar indicates a different model. The models simulating the “worst-case” outcomes (red lines) are at the top and those showing the “best-case” climate outcomes (blue lines) are at the bottom. The majority of models are clustered towards the centre of the bar, close to the multimodel mean (thick black line).

The authors selected three types of events to analyse:

• Rainfall extremes in highly populated areas, which may induce flooding
• Concurrent droughts in global breadbaskets, which threaten food security
• Fire weather extremes across the world’s forests

For each event type, the authors assess the spread of results. They rank the model outputs by the severity of each type of event and compare these to the multimodel mean at different levels of warming – including 2C, 3C and 4C above pre-industrial temperatures.

In many instances, the “worst-case climate outcomes” in a 2C world are more severe than the multimodel mean in a 3C or 4C world.

Prof Rowan Sutton, director of the Met Office Hadley Centre, who was not involved in the study, tells Carbon Brief that the study’s findings are “sobering”. He adds that the paper “demonstrates that the risks at 2C of global warming may be significantly higher than previously thought”.

In its latest assessment report, the IPCC projected that, under current policies, the world could reach 2C of warming between 2037 and 2084, with a central estimate of 2052. (For more on when the IPCC says warming thresholds will be passed, read Carbon Brief’s explainer.)

Breadbasket drought

The analysis of drought in key breadbasket regions provided the “most striking results”, Dr Emanuele Bevacqua, a researcher at the Helmholtz Centre for Environmental Research and lead author of the study, tells Carbon Brief.

To assess the worst-case scenario, the authors simulated drought frequency in “critical breadbasket areas across the world”, he explains.

These are the regions where most of the world’s maize, wheat, soybean and rice is grown, including regions of northern and southern America, Europe, south-eastern Asia and Australia.

The spread of model results is shown below.

The vertical bars indicate the percentage change in average drought frequency between a pre-industrial and 2C warmer world, where more-frequent drought is at the top of the bar and less-frequent drought is at the bottom.

On the left bar, each horizontal line indicates one model. The models showing the “worst-case climate outcomes” are highlighted at the top of the bar. On the right bar, the horizontal bars show the multimodel means for warming levels of 2C, 2.5C, 3C and 4C.

The percentage change in drought frequency in key breadbasket regions between a pre-industrial and 2C warmer world. On the beige bar (left), each horizontal line indicates a model. On the grey bar (right), the horizontal bars show the multimodel means for warming levels of 2C, 2.5C, 3C and 4C. Source: Bevacqua et al. (2026)

They find that 10 of the 42 models simulate a level of drought frequency at a 2C warming level that is higher than the multimodel mean at 4C warming.

(Some models also project a lower level of drought frequency at 2C warming than the multimodel mean. However, the focus of the study is to capture the most severe risks, which are particularly relevant for risk management.)

Bevacqua tells Carbon Brief that this result “makes it very clear that even if we stop [warming] at 2C, we cannot rule out the fact that we might end up in a worst-case outcome”.

The authors also conduct their analysis for extreme rainfall in populated regions. Although they find a wide range of model results, none of the simulations of extreme rainfall at 2C are higher than the multimodal mean at 4C.

Meanwhile, analysing the risk of wildfires to the world’s forests reveals that four of the models simulate more severe fire risk at 2C than the multimodel mean at 3C and none simulate more severe fire risk at 2C than at 4C.

The spread of model results for rainfall (left) and wildfire (right) are shown below.

Dr Karen McKinnon is an associate professor in statistics and the environment at the University of California, Los Angeles. McKinnon, who was not involved in the study, tells Carbon Brief that the study highlights that “risks are obscured when considering averages across multiple climate models”.

‘Worst-case scenarios’

The authors find that the ranking of models was different across the three case studies. In other words, the same models did not produce the “worst-case” climate outcomes in every type of event.

When assessing the impact of future extremes, the findings emphasise the need to select models that “sample the full range of possible climate outcomes”, the paper says. It adds:

“Currently, large-scale initiatives such as the latest protocol of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) rely on a limited subset of climate models that likely omits the best- and worst-case climate models.”

ISIMIP is a global modelling effort to project the impacts of climate change across different sectors. Bevacqua notes:

“[O]ur results suggest that ISIMIP-based simulations probably underestimate the range of possible global impacts at a fixed global warming level of +2C.”

He adds:

“This is worrying and calls for new approaches that can somehow lead to accounting for this.”

The study also shows that many “best-case” model outcomes for a 2C world project a lower level of risk than the multimodel mean. However, Fischer notes that “even the best-case scenario” shows that extremes will become more severe with warming.

Fischer says that the study authors are not “doomscrolling” and notes that “landing somewhere in the middle is still the more likely outcome”. However, he emphasises the importance of considering the high-impact model outcomes for planning around risk.

Communicating risk

Climate scientists and policymakers have been discussing how best to assess and communicate climate risk for decades.

Dr Robert Vautard – senior climate scientist at France’s National Centre for Scientific Research at Institut Pierre-Simon Laplac, who was not involved in the study – tells Carbon Brief that the study provides “very insightful examples of outcomes for communicating risks”.

However, he questions whether the “global indices” used in this study would be relevant for developing “regional” adaptation plans, noting that worst-case impacts in the model “may not be the most problematic locally”.

Last month, a group of leading climate scientists published a comment article – also in Nature – calling for a global climate risk assessment that identifies the “worst-case scenarios” and helps societies to prepare for them.

The article says:

“Global assessments made by IPCC have played, and continue to play, a crucial part in assessing the evidence about climate change. But the IPCC produces science assessments, rather than risk assessments. Its main focus has been to set out what is known with the greatest confidence.

“A climate risk assessment offers different information – it makes clear the scale and severity of risks, to inform judgments about the priority to be given to avoiding or mitigating them.”

Sutton, the Hadley Centre director, is an author on the article. He tells Carbon Brief that “from a policy and decision-making perspective, climate change is a problem of risk assessment and risk management”.

He says that the methods used in this study “offer a very useful contribution to a global assessment of avoidable climate-change risks”.

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The post Limiting global warming to 2C would not ‘rule out’ extreme impacts appeared first on Carbon Brief.

Limiting global warming to 2C would not ‘rule out’ extreme impacts

We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.

This is an online version of Carbon Brief’s fortnightly Cropped email newsletter.
Subscribe for free here.

Key developments

Seabed mining talks stall

UNFINISHED BUSINESS: The International Seabed Authority (ISA) ended a two-week meeting in Kingston, Jamaica, without agreement on the “long-delayed” code for deep-sea mining, which “remains both unfinished and deeply contested”, said Oceanographic. Several countries raised “fundamental scientific, environmental and governance gaps” in the draft regulations, it added. CBC News reported that although the ISA’s executive secretary, Leticia Carvalho, had previously said she “hoped a mining code could be finalised this year”, she “did not provide a new timeline” following the most recent talks.

DOUBLE TROUBLE: Meanwhile, federal regulators in the US have announced that they have identified nearly 70m acres (283,000 square kilometres) of seabed off the Northern Mariana Islands “that could be open to mineral leasing”, reported E&E News. The outlet noted that this recommendation was nearly double the government’s initial area under consideration, announced last autumn.

PROCESS PROBLEMS: The CBC News article noted that 40 member countries now support a moratorium on deep-sea mining, but the ISA has “faced mounting pressure in recent months after the US…moved to begin approving mining outside the ISA process”. In the Conversation, an international-law expert from Duke University wrote: “The Trump administration’s attempt to unilaterally exploit the seabed resources of the global commons will severely undermine part of the rules-based international order that the US built and of which it has been the main beneficiary.”

England’s new ‘blueprint’ for land use

‘BLUEPRINT’: The UK government released its “long-awaited and much-delayed” land-use framework, detailing how England can optimise its land for food, housing, climate and nature, reported Carbon Brief. The “blueprint” found that “England has enough land to meet all of its objectives, if land is used efficiently”, the outlet added. The Guardian said that “farmers and campaigners broadly welcomed the framework”, with the president of the National Farmers’ Union saying that implementation “will require clear guidance, the right policy framework and incentives to avoid unintended outcomes”.

PRACTICAL MATTERS: Alongside the framework, the Environment, food and rural affairs committee of the UK parliament “launched a major inquiry into how England’s land is used”, reported FarmingUK. The inquiry will focus on how the land-use framework “works in practice”, it added. The outlet said: “Looking ahead, the committee will scrutinise how government policy [on land use] is coordinated across departments.”

SLOW PROGRESS: Meanwhile, the National Audit Office found that nature-restoration progress across England has “slowed due to ‘recent funding uncertainty’”, reported Agriland. The office examined the Nature for Climate Fund, a programme under the Department for Environment, Food & Rural Affairs, which was established in 2020 and “led to a substantial increase in tree-planting and peatland restoration”, the outlet said. However, the report also found that “targets in England will continue to be missed” without substantial changes, said the Forestry Journal.

News and views

• PROTECTED WATERS: On 10 March, outgoing Chilean president Gabriel Boric signed a decree to expand and “fully protect” two marine protected areas that “harbour the highest concentration of marine species found nowhere else on Earth”, Island Conservation reported. The new administration told the Guardian that its “intention is not to eliminate protections” and, barring legal and technical issues, it will allow the areas “to go forward as planned”.
• BUSINESS CLASH: Following “clashes” with the agribusiness sector, Brazil launched its new climate plan, which calls for a 49-58% reduction in greenhouse gas emissions from 2022 levels by 2035, reported Folha de Sao Paolo. Meanwhile, Climate Home News wrote that the “Tropical Forest Forever Facility” – which Brazil championed – is “unlikely to make payments to rainforest countries until at least 2028”.
• SAVE THE FISHES: A new UN report identified 325 freshwater fish species “requiring coordinated international conservation action” to address declining populations due to overexploitation, habitat degradation and other compounding pressures, said Down to Earth. The report was launched at the 15th Conference of the Parties to the UN Convention on the Conservation of Migratory Species of Wild Animals, which began on Monday in Campo Grande, Brazil.
• FACE PALM: A Climate Home News and SVT investigation found that Neste – the world’s largest producer of sustainable aviation fuel (SAF) – was sourcing “key ingredients from an opaque supply chain” that allowed “fresh palm oil to be passed off as waste”. Neste said it would look into the outlets’ findings, adding that it was “currently not aware of any verified cases of fraud” in its raw-materials sourcing.
• CRITICAL HABITAT: The US government plans to approve the country’s first critical-minerals mine in Patagonia, Arizona, even as locals warn of potential water and biodiversity impacts, Inside Climate News reported. The project site – which holds “one of the largest undeveloped zinc resources in the world” – borders “one of the most important biodiversity hotspots in North America”, which is home to 12 endangered species, including jaguars and Mexican spotted owls, the outlet added.
• RE-PEAT OFFENDERS: More than 370,000 tonnes of peat were exported from Ireland in 2025, with revenues totalling around €40m – “despite there being no known legal commercial peat extraction operation in the country”, said the Irish Times. This represents a higher volume than was exported in 2023 or 2024, but a decrease from the nearly one million tonnes exported in 2020, it added.
• ‘FIELDS OF IRON’: Rural voters in Denmark have begun to “sour” on solar power, with one populist leader in 2024 saying “no to fields of iron!”, said the Guardian. Danish PM Mette Frederiksen “failed to secure a majority” in the country’s general election on Tuesday, where the climate footprint of agriculture has been a concern for voters, reported BBC News.

Spotlight

Plate half full

This week, Carbon Brief looks at the impact of the US-Israel-Iran war on India’s kitchens, restaurants, workers and farmers – and what it means for the climate.

On 23 March, two Indian-flagged tankers made their way through the mine-laden Strait of Hormuz, hugging Iran’s coastline.

The ships are carrying more than 90,000 tonnes of liquefied petroleum gas (LPG), equivalent to roughly one day of the country’s cooking gas consumption.

In India – the world’s second-largest LPG importer – gas is intrinsically tied to food security.

With 60% of these imports sourced from Gulf countries, the war’s immediate impacts have been acutely visible in India’s kitchens and restaurants.

Lunch on the move

Since 10 March, many Indian cities and towns have seen snaking queues and skirmishes breaking out as India’s poor rushed to refill gas cylinders in the heat of an early summer.

As the government prioritised the 340m households that use LPG over commercial establishments, restaurants have faced “catastrophic closures”.

Ashok Vada Pav – birthplace of Mumbai’s vada pav, or potato burger, which has been described as the “soul of the [city’s] working class” – has shut its doors. Ramashraya – serving south Indian breakfasts since 1939 – had to turn away customers who have been coming there for decades.

However, hot lunches – cooked at home or purchased from the city’s many canteens – continue to travel the length of Mumbai in tiered steel tiffins carried by the iconic dabbawallahs.

Ramdas Karwande, president of the Mumbai Tiffin Box Suppliers Association, told Carbon Brief that, of the 80,000 lunches that dabbawallahs carry across the city each day, 40% are typically from caterers. That number has halved in the past weeks, he said.

Karwande explained:

“People who come to this city from places far away have no choice but to eat canteen food. But home food is still on the move, because everyone needs to eat somehow.”

Fuel to firewood

In an address to parliament on Monday, India’s prime minister Narendra Modi likened the fallout of the war to that of the Covid-19 pandemic – a comparison that has drawn criticism.

The cooking gas shortages have prompted an exodus of migrant workers leaving cities for their home states, where biomass cooking remains accessible.

Cities, such as Delhi and Mumbai, have put a pause on emissions curbs for dirtier fuels since 14 March, as poorer families facing soaring black-market gas prices turn to wood, kerosene and coal.

While government gas and biogas schemes have led to a decrease in firewood usage in many states over many years, analysts have said the current crisis “offers a critical moment to rethink India’s cooking energy mix”.

In Mumbai’s wealthy suburb of Khar, induction stoves have been “flying off shelves”, Jaffair Sheikh, who sells appliances at an upmarket electronic retail store, told Carbon Brief. He added:

“We’re selling 20 units a day, when we used to sell almost zero before this war.”

However, only 5% of India’s households have access to electric cooking devices and the country’s grid is still largely powered by coal.

Away from the cities, there is a looming fear of the war’s impact on agriculture, given India’s dependence on the Gulf for fertiliser imports.

Siraj Hussain, India’s former agriculture secretary, told Carbon Brief:

“Gas is the main raw material for urea – and urea stocks are grossly insufficient to meet even kharif season (May to July) demand. But if the government can reduce supply to states where excessive fertiliser is used and increase supply to states where consumption is low, to some extent, this deficit will not be as harmful as it would be otherwise.”

Crop stock and biofuel fears

Punjab’s farmers, meanwhile, were already worried about the impact of an early summer on wheat production.

However, Hussain told Carbon Brief that India’s food security in terms of wheat and rice “will not be affected too much” because the country is “sitting on” excessive stocks. He added that he hopes the war will “persuade the government” to reduce its use of rice for ethanol production.

Still, food inflation is already being felt across the country. Karwande added:

“Everyone is tense. The monthly payments we get are going down and running a house is now difficult: the same problems we had during lockdown are back. Oil, sugar, everything has become expensive. This is not just our problem; this is everybody’s problem. The government has to do something.”

Watch, read, listen

FARMERS’ FUTURES: High Country News explored how farmers in the Colorado River basin are dealing with water shortages “amid deep political divisions about the river’s future”.

FOOD SHOCK: Experts on Al Jazeera’s Counting the Cost podcast looked at whether the US-Israel war on Iran could “​​trigger the next global food shock”.

LYNX IN BIO: BBC News featured the winning images from the Wildlife Photographer of the Year People’s Choice Award. The photos will be on display at London’s Natural History Museum until 12 July.

ECO BREAKDOWN: Mongabay detailed the causes of the “mental health crisis” impacting conservationists, including biodiversity decline, climate change, low wages and burnout.

New science

• Less than half of the Amazon rainforest that was affected by the 2023-24 drought is “expected to recover to pre-drought conditions” within seven years | Proceedings of the National Academy of Sciences
• Beavers can turn the ecosystems surrounding streams into “persistent” sinks of carbon that can sequester an order of magnitude more than non-beaver-modified ecosystems can store | Communications Earth & Environment
• Climate change-induced heat could result in half a trillion hours of lost productivity by 2055 in a low-emissions scenario, disproportionately impacting low-income countries and agricultural workers | GeoHealth

In the diary

• 23 March-2 April: Third meeting of the preparatory commission for the High Seas Treaty, New York
• 24-27 March: 64th session of the Intergovernmental Panel on Climate Change, Bangkok
• 26-29 March: 14th ministerial conference of the World Trade Organization, Yaoundé, Cameroon

Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to cropped@carbonbrief.org

Cropped 11 March 2026: Iran water worries | Seabed-mining treaty progress | Women farmers and climate change

Cropped

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11.03.26

Cropped 25 February 2026: Food inflation strikes | El Niño looms | Biodiversity talks stagnate

Cropped

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25.02.26

Cropped 11 February 2026: Aftershocks of US withdrawals | Biodiversity and business risks | Deep-sea mining tensions

Cropped

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11.02.26

Cropped 28 January 2026: Ocean biodiversity boost; Nature and national security; Mangrove defence

Cropped

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28.01.26

The post Cropped 25 March 2026: Seabed mining talks stall | ‘Blueprint’ for land use | India feels Iran war impacts appeared first on Carbon Brief.

Cropped 25 March 2026: Seabed mining talks stall | ‘Blueprint’ for land use | India feels Iran war impacts

The global energy shock triggered by the Iran war could give countries the chance to build a “new geopolitical balance” by forging a coalition committed to phasing out fossil fuels, Colombian Environment Minister Irene Vélez Torres said.

Delegates from about 45 nations are set to meet next month in Colombia’s Caribbean city of Santa Marta for the first conference on the transition away from fossil fuels, after a drive by 80 countries at COP30 failed to deliver a roadmap to phase out planet-heating coal, oil and gas.

Vélez Torres told an online press briefing her “maximum aspiration” for the summit was to “incline geopolitics towards a coalition of countries willing to eliminate fossil fuels” that can start taking action without having to negotiate agreements by consensus at UN talks.

“Ever since COP30 there has been growing momentum. The current crisis only gives us more relevance. We have a possibility to materialise a new geopolitical balance,” she said.

She added “it’s not the moment” to formalise this coalition or give it a name, but said that “as conversations move forward, and we can meet at a second conference to consolidate shared visions, something more formal can be created”.

The conflict in the Middle East has disrupted about a fifth of the world’s gas passing through the Strait of Hormuz, particularly heading towards Asia. This has led to growing calls for investment in renewables as a way to strengthen energy security and economic stability, as oil and gas prices skyrocket.

COP30 president André Corrêa do Lago, Brazil’s top climate diplomat, told the online briefing that building a parallel process on phasing out fossil fuels outside the UN climate regime – which requires slow negotiations with oil and gas producers to reach consensus – can be “extremely useful”.

COP30 new roadmap proposal

After governments failed to kickstart the creation of a roadmap away from fossil fuels at COP30, Corrêa do Lago proposed to draft a voluntary proposal instead, which he said would be launched towards the second half of the year.

He added that, because it is not a formal document under the UN process, the voluntary roadmap was not meant to be adopted by countries at COP31 later this year, but to contribute to continued debate.

“The more that we create a document that incorporates the positions, figures and concerns of various countries, the more influence it will have on debates at the UNFCCC and the Paris Agreement,” he said.

UN head calls for platform for “honest dialogue” on fossil fuel transition

Countries have been asked to submit inputs to the Brazil-led roadmap. Meanwhile, the Australian COP31 “president of negotiations” Chris Bowen has vowed to continue debates on the fossil fuel transition, while Turkish COP president Murat Kurum rejected it as a major focus and said he will “safeguard the development priorities of the countries”.

Vélez Torres added that both the Santa Marta conference and Brazil’s roadmap were “deeply complementary”, with the summit focusing more on channelling technical support, finance and “creating an honest space where we can put all the cards on the table”.

Carlos Nobre, a veteran Brazilian climate scientist, said the push for a transition away from fossil fuels was “essential”, and added that countries must focus on accelerating a “super-rapid” energy transition at COP31 to prevent global temperatures from crossing dangerous climate tipping points such as melting permafrost or the collapse of the Amazon rainforest.

Colombia and Brazil head to polls

While both Colombia and Brazil have led the push for a global phase-out of fossil fuels, the two South American countries are heading to the polls later this year. Both countries face anti-climate movements promising to change course if elected.

Vélez Torres warned of “great political risks of a relapse”, referring to a potential new government reversing the current government’s halt on all new coal, oil and gas exploration. Far-right candidate Abelardo de la Espriella has proposed to resume production, particularly venturing into shale gas fracking.

“However, we think we are building a bloc that is bigger than a country. The sense of continuity and sense of progress that we are giving to this discussion, I think are going to be difficult to relapse,” she said.

Corrêa do Lago said “this year we have to show the world what alternatives are viable”.

“We have to work together and not let that those who are betting on a general disaster divide those who are searching for solutions,” he added.

The post Iran war could boost fossil fuel phase-out push, says Colombian minister appeared first on Climate Home News.

Iran war could boost fossil fuel phase-out push, says Colombian minister