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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).

Study methodology, including running multiple global climate models and ranking the resulting models based on the severity of the climate impact. Source: Bevacqua et al. (2026)
Study methodology, including running multiple global climate models and ranking the resulting models based on the severity of the climate impact. Source: Bevacqua et al. (2026)

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)

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.

The percentage change in rainfall (left) and wildfires (right) 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)
The percentage change in rainfall (left) and wildfires (right) 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)

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”.

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

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New Zealand moves to protect business with law curtailing climate litigation

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New Zealand’s parliament has adopted a controversial new law blocking a whole avenue of climate litigation and shutting down its most advanced corporate lawsuit, which has been blamed by the government for shaking business confidence and investment.

The Climate Change Response (Tort Liability) Amendment Bill, expected to take effect in the coming days after it is formally signed by the Governor-General, prevents all current and future civil claims for climate loss or harm under tort law.

Justice minister Paul Goldsmith said last week that the aim was to give businesses “certainty around their climate change obligations”, noting it would not alter the government’s responsibilities under the Climate Change Response Act 2002 nor business obligations under the Emissions Trading Scheme.

“Our response to climate change is best managed by the Government at a national level and not through piece-meal litigation in the courts,” he added in a statement.

Such litigation, he said, “risks developing a new regime that contradicts the framework Parliament has already enacted” to tackle climate change.

    Goldsmith singled out a key domestic climate lawsuit brought by Northland iwi leader and activist Mike Smith against six big companies: dairy firms Fonterra and Dairy Holdings, energy firms Genesis Energy and Z Energy, New Zealand Steel and coal mining firm BT Mining. A seventh original defendant, Channel Infrastructure, was dropped after it permanently decommissioned its Marsden Point oil refinery.

    Smith argued that these companies had caused him harm under public nuisance and negligence law, as well as a third breach of a duty to cease contributing to climate change that has yet to be tested domestically. He did not seek financial compensation, instead asking for the companies to immediately stop emitting or contributing to net greenhouse gas emissions.

    In one of the most advanced corporate climate accountability lawsuits in the world, a trial had been scheduled for April 2027 after the Supreme Court unanimously allowed the case to continue.

    Corporate lobbying in the shadows

    Smith described the passing of the bill as “deeply concerning”, particularly as it coincided with the Supreme Court hearing another of his climate lawsuits. In that case, Smith v Attorney-General, he argues that the government’s response to climate change and its impacts on Māori communities in particular breaches rights to life and culture.

    “That timing raises profound questions about the separation of powers and the rule of law,” said Smith. “Whatever one’s view of the merits of these cases, it is deeply troubling when parliament intervenes to remove a legal pathway while the courts are actively considering fundamental questions about climate responsibility, rights and the crown’s obligations.”

    The bill – which says that no person (including the government) can be found liable in tort for emissions-related climate change effects – followed major lobbying efforts by the companies defending themselves in Smith’s lawsuit. They outlined a proposed legal amendment in a briefing note to the government in 2024.

    The centre-right government has been fiercely criticised over its lack of transparency in relation to this lobbying activity. The national ombudsman recently found that the Prime Minister’s Office effectively withheld information requested by the Environmental Law Initiative about meetings, discussions and conversations regarding Smith’s case.

    Green groups fail to stop bill

    The bill sparked huge concern among environmental campaigners in New Zealand and elsewhere. Greenpeace Aotearoa called it a “shocking abuse of executive power” and the vast majority of submissions to a parliamentary inquiry said it should be rejected.

    But in the end, it was adopted with little resistance, moving relatively smoothly through parliament, passing its third reading by 67 votes to 53. Sam Bookman, climate law lecturer at Melbourne Law School, told Climate Home News he was not surprised by this, given that the coalition government has a secure majority.

    A complaint has been made to the UN special rapporteur on climate change and human rights by Smith, the National Iwi Chairs Forum Pou Tikanga and youth coalition Climate Clinic Aotearoa over what they see as the government’s heavy-handed approach. Smith is also challenging the new law in yet another lawsuit.

    “Pathetic”: New Zealand plans to barely cut emissions between 2030 and 2035

    Bookman thinks it “very unlikely” that such a challenge will succeed, noting that New Zealand’s constitution is firmly anchored in parliamentary sovereignty.

    But the expert in climate law does not see the bill as the end of legal action in the country, noting that New Zealand has a “sophisticated climate litigation landscape with a growing number of specialist and experienced lawyers and NGOs”.

    The country is also approaching its next general election in November, and some opposition parties have pledged to restore access to the courts if elected.

    Amanda Larsson, global project lead on agriculture for Greenpeace International, said: “This law deserves to be tested, and I strongly encourage the international climate litigation community to unite and help defend New Zealanders’ fundamental right to hold polluters accountable before this becomes a global blueprint.”

    Copycat legislation on the rise

    New Zealand’s move is part of a small but growing legislative effort to shut down climate litigation around the world.

    In the US, Republican politicians introduced legislation in the House and Senate in April that would shield fossil fuel firms from climate liability lawsuits. Similar laws have already been passed at state level in Tennessee, Utah, Iowa and Louisiana.

    The German state of Bavaria has put forward a similar proposal to the Federal Council, aiming to block private climate claims as well as the recognition and enforcement of foreign judgments imposing such liability. There are also proposals to limit available remedies and actions in the Netherlands and Belgium.

    UN General Assembly backs “climate obligations” set by world’s top court

    Bookman said he expects more efforts to counter climate damages litigation and advised plaintiffs to think about how to respond, including drawing on broader support in opposing them.

    “Even though it’s very hard for plaintiffs to win these types of cases, companies are very eager to avoid the expense, embarrassment and political accountability that come even with unsuccessful lawsuits,” he said.

    The post New Zealand moves to protect business with law curtailing climate litigation appeared first on Climate Home News.

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    Indonesia’s nickel production cuts are not enough to create a sustainable industry 

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    Bhima Yudhistira Adhinegara is the Executive Director of the Center of Economic and Law Studies (CELIOS), an Indonesia-based economic think tank. Muhammad Zulfikar Rakhmat is the Director of the China-Indonesia desk at CELIOS. 

    Indonesia produces around 60% of the world’s nickel, a metal used to manufacture batteries for electric vehicles (EVs) – more than any other country in the world. But in 2026, the government sharply reduced how much of its nickel can be extracted from the ground.

    Production quotas were reduced by around 40% this year compared to 2025. Weda Bay, the largest nickel mine on Earth, had its allowance cut by more than 70% and exhausted its full-year quota by the end of May, halting mining entirely; it cannot resume large-scale extraction until next year unless regulators grant an extension.

    The policy has sparked a vivid debate in Indonesian policy circles: how can the country shift its strategy from a decade of mining vast quantities of cheap nickel to producing a high-value and low-carbon material that the rest of the world wants for EV batteries.

    The cuts aren’t a silver bullet to clean up Indonesia’s nickel industry, whose smelters are powered by coal – the most polluting fossil fuels. But alongside stricter enforcement of environmental rules, it is one side of efforts to produce more sustainable nickel for a premium.

    Restricting Indonesia’s nickel output

    Production quotas were introduced to stop the collapse of nickel prices because of oversupply in the market. Prices had fallen more than 40% in 2023 alone and kept sliding as Indonesian supply kept growing, hitting a four-year low of around $13,900 a ton in late 2025.

    Critics called the recent tightening of production quotas proof that Indonesia’s nickel strategy has failed, arguing that the industry shouldn’t need to throttle its own output to survive. But when assessed against what the policy was supposed to do – push up nickel prices – it has worked. Prices jumped to $20,000 a ton in May, the highest since 2024.

      Chinese industry groups representing companies that have invested billions to mine and refine the country’s nickel were furious, warning Indonesia’s president Prabowo Subianto that the cuts put $50 billion worth of investment at risk. But much of that Chinese capital is sunk into smelters and processing plants built specifically to run on Indonesian ore, and cannot simply be moved elsewhere. That gives Jakarta more room to hold its ground than the warning suggests.

      Stronger environmental enforcement

      Since the start of the year, Indonesia’s forestry task force has seized more than four million hectares of land from mines and plantations operating illegally in protected forests, collecting over two trillion rupiah ($113 million) in fines.

      This included 148 hectares seized from Weda Bay for lacking a forestry permit. The share of nickel produced from illegal small-scale mining also fell from about a quarter in 2022 to roughly 10% by 2024.

      The crackdown responds to serious environmental damages in the nickel industry. On Obi Island, a waste pond collapsed after heavy rain in June 2025, flooding three villages and killing a resident. Internal company tests found chromium-6 – a carcinogen – in the water, in quantities far above the legal limit. The footprint of another mine near Raja Ampat, which is home to some of the world’s richest coral reefs, grew 60-fold in just eight years.

      A coastal village is wedged between the sea and a large nickel mine in Indonesia
      The fishing villages of Tapunggaya in Sulawesi, Indonesia, are squeezed between the sea and an expanding nickel mine (Photo by Garry Lotulung/NurPhoto)

      The market is responding to early cleanup efforts. Low-carbon nickel now sells for a real premium, roughly $18,800 to $19,300 a ton compared with $17,900 to $18,300 otherwise, as carmakers seek to source cleaner materials to comply with the European Union’s new emissions rules for imports.

      In turn, this is incentivising the industry to do more to green its operations. Vale Indonesia’s smelter in South Sulawesi now runs almost entirely on hydropower, for example.

      None of this addresses coal use, however. Major Indonesian nickel producers still emitted an estimated 15 million metric tons of greenhouse gases in 2023. Indonesia may be cracking down on illegal mining and rewarding cleaner producers but it is still running its mines on the dirtiest fuel available.

      Unequal benefits

      For Indonesia to truly benefit from producing cleaner and high-value nickel, it needs to reap the economic benefits too. Although the industry has boosted the country’s economic growth, the reality on the ground tells a different story.

      Konawe in Southeast Sulawesi is home to a major smelting complex. Growth in the district jumped from 6% to 22% between 2015 and 2023, driven almost entirely by the nickel industry, according to a study by the Lowy Institute study. At the same time, poverty levels increased slightly and unemployment remained unchanged.

        In Halmahera, another epicentre of the nickel industry, spending by the poorest fifth grew just 5% between 2019 and 2022, compared with 28% for the wealthiest fifth, according to a separate study.

        Part of the reason for this inequality is the system for transferring mining royalties to district authorities where the mines are located. In theory, they are entitled to the largest share. But in practice, payments are delayed, companies routinely dispute what they owe and royalties are pooled and distributed across a larger area.

        The Natural Resource Governance Institute has found that decentralisation handed local governments power to approve new mines faster than they could build their capacity to manage them. Higher output raises national income on paper, but local governments remain constrained by fiscal rules and infrastructure costs that scale with mining.

        None of this makes the 2026 quota cuts a mistake. Indonesia has every right to defend its pricing power over a resource it controls. But limiting extraction isn’t going to fix underlying issues around environmental enforcement and revenue-sharing. That requires rules that are consistently enforced, royalties that reach communities living by the mines, and a plan to wean smelters off coal.

        The post Indonesia’s nickel production cuts are not enough to create a sustainable industry  appeared first on Climate Home News.

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        Risk of “catastrophic” oil spill reaching Kimberley coast found in Woodside’s Scott Reef gas drilling plans

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        SYDNEY, Monday 24 August 2026 – New analysis of Woodside modelling released by Greenpeace Australia Pacific and Environs Kimberley has revealed the oil and gas corporation’s plans to drill at Scott Reef could cause an oil spill up to 30 times bigger than the 2009 Montara disaster, impacting the Kimberley coastline and reaching as far as Indonesia.

        The new analysis details the “catastrophic” oil spill risk put to environmental regulators for approval by Woodside in its Browse to North West Shelf Project (Browse) plans, the worst-case scenario being a blowout directly below Scott Reef, polluting whale migratory pathways and covering isolated turtle nesting ground with oil condensate.

        An FOI application (F348) revealed the federal environment department (DCCEEW) asked offshore oil and gas regulator NOPSEMA to look into the oil spill risk in 2025. NOPSEMA’s response to the application refused access to its report, and one document shows DCCEEW sought further advice this year.

        Greenpeace and Environs Kimberley are calling on the Federal Government to publicly release the NOPSEMA report given the risk of an uncontrolled release of oil condensate from directly below Scott Reef.

        Hannah Schuch, Senior Campaigner at Greenpeace Australia Pacific, said: “Woodside is aware that drilling at Scott Reef risks a massive oil spill that would have severe, far-reaching consequences. It appears environmental regulators are aware too.

        “The state and federal governments need to take this risk from Woodside’s drilling plans seriously, as they could end up allowing the worst oil spill in Australian history.

        “The pygmy blue whales that migrate up and down the WA coast with their newborns each year could be swimming and feeding in toxic, oil-slicked water. Woodside’s proposal to drill at Scott Reef is an environmental disaster waiting to happen, and the WA and federal governments have one surefire way to prevent catastrophe — reject Browse.”

        Martin Prichard, Executive Director at Environs Kimberley, said: “A catastrophic oil spill by Woodside would be disastrous not just for marine life in the area but also for the Kimberley’s $500 million tourism industry.

        “The state and federal governments will see five marine parks on the Kimberley coast included in the risk area of a catastrophic Woodside oil spill.

        “The Montara oil spill was disastrous for West Timor with the toxic oil destroying seaweed farmers’ livelihoods. The Kimberley dodged a bullet with Montara, we were lucky the spill didn’t head our way. Myself and a crew flew over the Montara oil spill and followed it as far as we could. It was like a scene from a disaster movie.”

        After the WA Environmental Protection Authority deemed Browse “unacceptable” due, in part, to oil spill risk, Woodside submitted a mitigation plan based on technology that has never been used “in anger”, a weakness stated in an independent expert review of the plan.

        Professor Richard Steiner, independent oil spill expert, said: “A large offshore spill is impossible to effectively contain or recover. Historically, only 2-6% of total spill volume is recovered and the ecological injury from the release of toxic hydrocarbons in the sea can be severe, extensive, and long-term.

        “Here in Alaska, government research concludes that several marine populations injured by the 1989 Exxon Valdez oil spill, including whales, fish, and seabirds, are still not recovering today, 37 years later. We should expect similar long-term ecological impacts in Western Australia if there were to be a major oil spill. The only sure way to avoid the risk of a catastrophic marine oil spill is to not develop oil and gas projects in marine environments.”

        -ENDS-

        Media contact

        Emma Sangalli on emma.sangalli@greenpeace.org or 0431 513 465

        Risk of “catastrophic” oil spill reaching Kimberley coast found in Woodside’s Scott Reef gas drilling plans

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