Cutting emissions in line with the 1.5C warming limit, rather than following current climate policies, could curb long-term sea level rise by 64cm, a new study says.
The research, published in Nature Climate Change, projects how much sea level rise will be unavoidable – or “locked in” – by the year 2300, due to emissions over the coming decades.
According to the authors, 29cm of global average sea level rise is already in the pipeline due to the emissions that were released up to the year 2020.
Following current climate policies until the year 2090 will “lock in” an additional 79cm of sea level rise for the year 2300, the study finds.
However, reducing emissions in line with 1.5C would cut this additional sea level rise to 15cm.
The analysis shows that “if we reduce emissions rapidly in the coming decades, there is a clear path to limiting the legacy of sea level rise”, the lead author of the study tells Carbon Brief.
The study also explores regional sea level rise, showing that Pacific small-island nations will face some of the highest rates of sea level rise.
A scientist not involved in the research tells Carbon Brief that the paper “exposes a deep inequity” between nations, arguing that this makes “ambitious” action to cut greenhouse gas emissions “not just a climate necessity, but a climate-justice imperative”.
‘Locked in’
Average global sea level has risen by more than 20cm since 1900, driven mainly by human-caused climate change through thermal expansion of the ocean and the melting of glaciers and ice sheets.
Rising seas are already threatening to wipe out small-island nations, jeopardising the security, livelihoods and cultures of people who live in these areas. Meanwhile, coastal regions around the world are facing more frequent flooding, erosion and saltwater intrusion.
The authors of the new study explain that emissions released over the coming decades will affect global sea levels for hundreds of years. This is because the oceans and ice sheets respond slowly to past and present warming, they note.
The authors call this “locked in” or “committed” sea level rise.
The study explains that sea level projections are generally based on 21st century emissions pathways, but notes that “late-century emissions then dominate the longer-term sea-level response and mask the impact of near-term emissions”.
In contrast, this study assesses the impact of emissions both early and late in the 21st century – including past emissions and those projected to occur under different emissions pathways. The research investigates how much sea level rise will be locked in by the year 2300 through these emissions.
According to the authors, 29cm of global average sea level rise, compared to 1995-2014, is already locked in due to the emissions that were released up to the year 2020.
Rising seas
The study uses emulators – simple climate models with lower time and computational costs than full-scale Earth system models – to model how much sea level rise will be locked in by 2300 due to 21st century emissions.
The authors chose five emissions pathways and ran multiple model runs where they simulated sudden stops in emissions at the end of each decade for each pathway. This allowed them to isolate the emissions just until these dates.
For example, modelling a sudden drop in emissions in the year 2050 allows the authors to calculate how much sea level rise over the next two centuries is driven solely by human-caused emissions released over the next two decades.
The authors use five emissions pathways:
- SSP1-1.9: A very-low emissions reductions pathway “consistent with” the Paris Agreement’s 1.5C limit
- SSP1-2.6: A “low” emissions pathway consistent with 2C of warming
- SSP2-4.5: A “current climate policy-like trajectory”
- SSP3-7.0: A “high” emissions pathway
- SSP5-8.5: A “very-high emissions” pathway
The left-most panel shows how much additional sea level rise is locked in for the year 2300 due to emissions produced between 2020 and 2030. The next three panels show the results for emissions produced between 2020 and 2050, 2070 and 2090, respectively.
The plot shows that higher levels of greenhouse gas emissions lock in more sea level rise for the year 2300.
The authors find that, under the SSP2-4.5 “current climate policies” scenario, human-produced greenhouse gas emissions over 2020-50 will lock in an additional 29cm of sea level rise by the year 2300. This number grows to 79cm when including emissions out to 2090 under this scenario.
Meanwhile, under the scenario consistent with the 1.5C limit, only 15cm of additional sea level rise will be locked in by 2090.
This means that efforts to cut greenhouse gas emissions over the coming decades could curb long-term sea level rise by an extra 64cm.
The study authors say that their results “reinforce how every increment of additional peak warming from cumulative emissions irreversibly increases sea level rise”.
Dr Alexander Nauels is a science adviser at Climate Analytics and lead author on the study. He tells Carbon Brief that the world is “already committed to a really substantive amount of sea level rise” and stresses that this must be considered in terms of “adaptation, planning and risk management”.
However, he adds, “if we reduce emissions rapidly in the coming decades, there is a clear path to limiting the legacy of sea level rise that we would produce in the coming decades”.
Dr Catia Domingues, is a researcher at the UK’s National Oceanography Centre and was not involved in the study. She tells Carbon Brief that the study’s methodology is “clever and necessary”. She adds:
“[The study] clearly shows how the emissions from just the next 30 years, under current climate policies, will write an irreversible chapter for centuries to come, locking in significant sea level rise on their own.”
Warming levels
The authors also calculate the committed sea level rise at different warming levels.
The chart below plots sea level rise against warming level for every scenario and time period used in the study. It highlights how higher levels of warming commit the world to ever higher seas.
Committed sea level rise by 2300 at different warming levels, under SSP1-1.9 (light blue), SSP1-2.6 (dark blue), SSP2-4.5 (yellow), SSP3-7.0 (red) and SSP5-8.5 (dark red) pathways. Circles, X’s, squares and crosses indicate data points for 2030, 2050, 2070 and 2090 respectively. The green and blue lines show the 1.5C and 2C temperature thresholds. Source: Nauels et al (2025).
The authors note that the relationship between global temperature and committed sea level rise to 2300 is not “linear”, noting that the amount of sea level rise that is locked in by warming accelerates as global temperatures rise.
The authors explain that this is due to a “non-linear increase in ice mass loss in a warmer world” – in other words, physical feedbacks mean that higher levels of warming could see disproportionately large increases in ice losses.
Nauels tells Carbon Brief many sea level processes, such as ice-sheet responses, are still not “fully understood”. This means that when looking out to 2300, there can be “large uncertainties” in results, he adds.
Nevertheless, he argues that it is “still very important to explore the longer-term sea level response, because of the huge risk that is attached to it”.
Inequity
The main findings of the study focus on global average sea level rise. However, the authors note that sea level rise is not consistent across the world, with some regions facing faster rates of sea level rise than others.
This is largely due to ocean currents, driven by wind, warming, evaporation and rainfall, which push large masses of water around the planet. It is also caused by the bumpy, non-uniform surface of the earth.
To show these differences, the authors also selected a handful of coastal regions to study.
Nauels tells Carbon Brief that the study authors decided to focus on a handful of regions that “diverge” from the average global trend.
For example, they find that Pago Pago – the capital of American Samoa, which is made up of a string of coastal villages – will experience greater committed sea level rise than the global average.
On the other hand, Oslo is experiencing “land uplift” and actually shows a drop in sea level under the lowest warming scenario.
The NOC’s Domingues tells Carbon Brief that the study “exposes a deep inequity” between nations. She adds:
“This makes ambitious mitigation not just a climate necessity, but a climate-justice imperative.”
The post Rapid emissions cuts would avoid 64cm of ‘locked in’ sea level rise by 2300 appeared first on Carbon Brief.
Rapid emissions cuts would avoid 64cm of ‘locked in’ sea level rise by 2300
June Rubis is a steering group committee member for the Cali Fund, from Sarawak in Malaysian Borneo.
At COP16 in Cali, governments made a significant commitment: at least half of the funding from the new Cali Fund should support the self-identified needs of Indigenous Peoples and local communities, including women and youth. It was a watershed moment for multilateral benefit-sharing.
The challenge now is to translate that commitment into access arrangements that recognise the different institutions, priorities and decision-making processes of Indigenous Peoples and local communities.
For generations, biodiversity and traditional Indigenous knowledge have provided significant value to companies who depend on nature’s genetic diversity to discover new drugs that fight diseases, create products that improve health, and grow crops resilient to extreme heat and flooding events. While some compounds are sampled directly from the source country, increasingly the digital blueprints are held in online public databases which are freely accessible to use for innovation and research.
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The Cali Fund was established at COP16 to encourage commercial users of Digital Sequence Information, or DSI, to share benefits arising from its use. Estimates suggest it could generate over $3.5 billion a year – a stark contrast to the modest $10,656 currently committed to the fund from just five SMEs, underlining how much progress must be made at COP17 over the next two weeks.
The COP16 decision that set up the fund offers two routes for money to reach Indigenous Peoples and local communities: through government authorities, and through direct payments to institutions identified by Indigenous Peoples and local communities themselves.
Varied ways of organising
Indigenous Peoples and local communities organise through a wide range of institutions. Some have national or regional organisations experienced in managing international grants. Others work through territorial organisations, customary institutions, community associations, cooperatives or networks. Some have professional finance teams and audited accounts; others have extensive experience governing territories, collective resources or conservation work without having been organised around international funding requirements.
For direct access, some questions are already apparent. Which institutions should be able to receive funds? How should they be identified? What fiduciary standards should apply? How should safeguards and accountability work where institutional capacities differ? What support may be needed where institutions have strong community mandates but less experience with international finance?
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If access is designed mainly around institutions that already meet the expectations of large international finance mechanisms, early funding will tend to favour those already familiar to funders. They will gain further experience and become better positioned for future funding, while institutions with less administrative capacity may remain outside the system despite strong community mandates and long histories of stewardship.
These first decisions matter most, because they set the terms for everyone who follows.
The role of intermediaries requires care. Some Indigenous organisations may want a fiscal host to hold and manage funds on their behalf. Communities may choose to work through an NGO they trust. Government-facilitated arrangements may work well in particular national contexts.
What matters is the function an intermediary performs and the authority that comes with it. Providing administrative support is different from deciding which Indigenous organisations qualify, which priorities can receive support, or how success will be assessed. Direct access means communities keep that decision-making authority.
Decision-making power
The COP16 decision refers to institutions that Indigenous Peoples and local communities identify. But authority among Indigenous Peoples does not sit in one kind of body. It may sit with territorial organisations, customary institutions, community associations or combinations of these. Legal recognition and customary authority do not always align neatly.
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An important feature of the Cali Fund’s governance is that Indigenous Peoples and local communities participate as full members of the Steering Committee, rather than as observers. Seven Indigenous Peoples and local community representatives, one from each of the seven socio-cultural regions, participate in consensus-based decision-making alongside representatives of governments and UN entities. Six additional representatives from civil society, scientific institutions and the private sector participate as observers.
That representation carries responsibility. Institutional legitimacy, access and representation take different forms across the seven socio-cultural regions. Indigenous Peoples and local communities members therefore have an important role in bringing those differences into the Fund’s governance and in ensuring that arrangements developed for one context do not become the assumed model for everyone else.
Safeguards and clear responsibilities
COP17 can establish the core principles and direction, while allowing operational pathways to develop in ways that respond to different regional contexts. The decisions countries take in Yerevan will shape how that flexibility is realised in practice.
The choices made around access will influence which institutions are able to participate, which routes become established and which forms of authority are recognised within the funding architecture. The aim should be an architecture with enough structure to maintain confidence while allowing for different forms of Indigenous and community governance.
A credible direct-access pathway will need safeguards, financial oversight and clear responsibilities. This would give the 50% commitment a stronger institutional foundation.
The Cali Fund’s importance will ultimately depend not only on how much funding reaches Indigenous Peoples and local communities, but on whether they are able to determine how the money is accessed, governed and used. This requires access pathways that recognise their institutions, priorities and decision-making processes, rather than requiring them to conform to a single predetermined model.
The post COP17 must settle who decides how Cali Fund money is disbursed appeared first on Climate Home News.
COP17 must settle who decides how Cali Fund money is disbursed
The UK government has approved extraction at the Jackdaw gas field in the North Sea, despite acknowledging that this decision could make it harder for Britain to convince other countries to move away from fossil fuel production.
UK energy secretary Miatta Fahnbulleh approved the drilling on Wednesday after months of high-profile debate, fuelled in part by interventions from US President Donald Trump. She argued that the project would boost energy security in the wake of the Middle East fossil fuel crisis, protect hundreds of jobs and add £2.9 billion ($3.88bn) to the UK economy.
She said Jackdaw’s gas would be cleaner than imported gas and would not prevent the UK from meeting its legally-binding carbon targets and its goal of net zero by 2050. As the field is already licensed, she said extraction was consistent with the Labour Party’s 2024 manifesto promise not to issue any new oil and gas licenses.
The same morning, the government announced a new Energy Wealth Fund to reinvest oil and gas revenues in the climate transition. It will start with £2 billion ($2.67bn) from the government and be topped up over time with tax revenues from offshore oil and gas production.
Climate campaigners in the UK and abroad were quick to condemn the decision, while a leading legal expert told Climate Home News it goes against the advice of the International Court of Justice. Meanwhile, the government’s own documents reveal that it recognises the drilling could damage the UK’s reputation and its ability to push forward the global transition away from fossil fuels.
“Climate leadership” blow
The 92-page decision document says Fahnbulleh “acknowledges that international standing on climate is important and accepts that a decision to grant consent may not further the UK’s international climate leadership.”
It adds: “She acknowledges concerns about the potential implications for the UK’s credibility and influence – including the difficulty inherent in encouraging other states to move away from fossil fuel production while the UK continues, in a limited and transitional way, to draw on its own domestic resources.”
While noting that Jackdaw has not been issued with a new license – just permission to extract gas – the document says Fahnbulleh “accepts this does not fully resolve the underlying tension in the UK’s position” but “considers this alongside the substance of the UK’s wider record [on emissions reduction], which remains significant”.
It continues that she accepts these concerns are “legitimate” and weigh against approving gas extraction, but only gives this argument a “moderate negative weight” set against the benefits of gas production.
“Huge” wrong signal
In international climate talks, the UK has long supported the transition away from fossil fuels and is one of very few major oil and gas producers to ban new licenses. Across the North Sea, the Norwegian government continues to make offshore areas available for oil and gas exploration through annual licensing rounds.
Climate experts and campaigners shared the concern, acknowledged in the decision document, that approving Jackdaw could set a precedent for fossil fuel production elsewhere. Sam Fankhauser, professor of climate change economics at Oxford University, said the direct climate impact of Jackdaw is “much smaller than the debate around it would suggest” but the “wrong signal it sends, however, is huge”.
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Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change, said that while Jackdaw’s output will be very small, “it will signal to other fossil fuel producers that they too should carry on with business as usual, less than a month before the COP31”.
Kenyan campaigner Mohamed Adow, director of Power Shift Africa, called the decision “a serious blow to Britain’s international climate credibility” as “the UK cannot expect developing countries to move away from fossil fuels while giving the green light to new drilling in its own backyard”.
International Court of Justice
In July 2025, the International Court of Justice (ICJ) advised that government failure to take appropriate climate action “including through fossil fuel production” may amount to an internationally wrongful act.
The UK voted in favour of a United Nations resolution welcoming the advisory opinion. Yet, in its Jackdaw decision document, it notes that the ICJ opinion is not legally binding and says the UK does not accept the court’s opinion that the customary international law duty to prevent significant harm to the environment applies to climate change.
Fahnbulleh concludes that, although it will have “significant effect on the environment”, gas drilling in Jackdaw “would not lead to significant harm to the environment” – and so does not breach any duty to prevent such harm. Instead, the government document says the duty should be considered “as a matter of policy rather than legal obligation”.
Margaretha Wewerinke-Singh, who led Vanuatu’s legal team pushing for the ICJ’s advisory opinion, told Climate Home News that treating the duty as a matter of policy rather than legal obligation is “not how international law works”. “An advisory opinion is not a judgement,” she said, “but it states the law as it stands, and that law binds the UK whether or not it accepts it.”
“Even as a matter of policy,” she added, “the decision asks the wrong question: whether Jackdaw on its own would cause significant harm. The Court found that accumulated emissions are already causing significant harm. What matters is whether approving new production is consistent with the stringent due diligence the duty requires.”
Public support for decision
While the decision was criticised by climate campaigners and the opposition Green party, polling reported by Politico suggests that 55% of British adults support drilling at Jackdaw, with just 14% opposed. Even supporters of the UK’s net zero target back new drilling by more than two to one, the polling found.
Jackdaw is one of two North Sea oil and gas fields the government has been debating whether to extract more from for months. While Jackdaw is a small gas field, the other, Rosebank, is a much larger field that holds mostly oil.
Rosebank’s emissions are estimated to be around seven times higher than Jackdaw’s. Fahnbulleh told Sky News that Rosebank is “different” to Jackdaw because its oil would be exported, whereas Jackdaw’s gas will be used in the UK, adding that she will consider it “in its own right”.
The Guardian reported on Wednesday that UK officials say Fahnbulleh is minded to refuse approval for Rosebank. She has not yet taken a final decision on Rosebank, the newspaper said, but a ruling is expected later this year.
The post UK approves gas drilling despite admitting blow to “climate leadership” status appeared first on Climate Home News.
UK approves gas drilling despite admitting blow to “climate leadership” status