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
The head of the United Nations has called on all countries to deliver plans for phasing out their production and consumption of fossil fuels, as rising oil prices and climate shocks threaten energy and human security.
In his farewell speech to the UN General Assembly (UNGA) in New York on Tuesday, outgoing UN Secretary-General António Guterres for the first time urged “every government to adopt a national plan to transition away from fossil fuels” aligned with limiting warming to 1.5C. The plans, he said, should include “clear timelines and protection for affected workers and communities”.
“We know fossil fuel interests won’t step aside on their own. For decades, Big Oil has treated the atmosphere as an open sewer – and cashed in on the consequences,” Guterres told diplomats in his speech opening the leaders’ segment of the assembly, also calling out the industry’s windfall profits after Russia’s invasion of Ukraine.
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COP31 electrification pledge leaves out clean power commitment
Campaigners and experts say the goal’s effectiveness in reducing emissions may be limited unless countries agree to meet it using only clean energy -
Climate change and energy transition rise up national security agenda
Leaders highlighted the national security risks posed by global warming and fossil fuel dependency at New York Climate Week
At last year’s COP30 climate summit in Belém, a group of about 80 governments led a failed push to develop a global roadmap to transition away from fossil fuels. Brazil instead proposed to draft a voluntary report that will be presented this year ahead of COP31 after countries and organisations submitted their views to the process.
Governments first agreed to transition away from fossil fuels in energy systems at COP28 in Dubai in 2023, but have since failed to agree at UN climate talks on how to move forward with that commitment, as efforts to do so have been effectively blocked by large fossil fuel-producing countries.
France, Netherlands issue plans
A few countries have moved forward with their own transition plans. France launched the first one at an international conference on the issue in April and the Netherlands followed suit this month. Not being major fossil fuel producers, both European nations aim to end their coal, oil and gas consumption by 2050, although the Dutch plan was criticised for not setting specific phase-out dates for the dirty fuels.
Adão Soares Barbosa, climate ambassador from Timor-Leste and chair of the Least Developed Countries (LDC) group in the UN climate negotiations, told a press briefing on Tuesday that last year’s discussions on shifting away from fossil fuels need to continue at COP31, adding that developed countries should lead the way with transition plans and curb their use of fossil fuels.
“We are expecting that we can make a request to major-emitting countries to limit emissions from this sector,” he said. “For LDCs, we’ll also try to reduce fossil fuel use, but it will depend on national circumstances.”
Samoa’s lead negotiator Anna Rasmussen said small island states have outlined their energy transition plans in their nationally determined contributions (NDCs) – countries’ plans for meeting the Paris Agreement goals – but added “we’re still waiting” for climate finance to help implement those plans.
Despite the global push to clean up the energy mix, countries leading climate talks are themselves also expanding fossil fuel production. COP31 co-presidents Australia and Türkiye have both recently given the green light to mine and drill more coal, oil and gas, and still depend on fossil fuels for 60% and 56% of their electricity production respectively.
Fossil fuel expansion threatens COP31 hosts’ credibility, experts warn
COP30 host nation Brazil has also persisted with its plans to explore potential new oil reserves near the mouth of the Amazon River – a region known as the Equatorial Margin.
These are moving ahead despite President Luiz Inácio Lula da Silva announcing last year at the Belém climate summit that the country would develop its own fossil fuel phase-out plan. This is still under development with little information about its progress and may be hampered by elections next month.
“We have achieved our self sufficiency in oil and will continue to explore the potential of new reserves, such as those in the Equatorial Margin,” Lula said in his speech to the UNGA on Tuesday. “But we will not abandon the environmental agenda,” he insisted. “We will move forward with the roadmap for the decarbonisation of the Brazilian economy.”
Transition far cheaper than status quo
Speaking at the main Climate Week NYC venue, Mads Christensen, executive director of Greenpeace International, said given the fast-shifting cost dynamics for both fossil fuels and renewables, countries should revise their existing energy plans because they are now out of date.
Gas power generation now costs around 150 euros per megawatt compared with around 50 euros for solar with battery storage – making the latter two-thirds cheaper.
“If these plans were updated, I think we would have a much faster transition because it simply makes good financial sense,” he said.
Tzeporah Berman, founder and chair of the Fossil Fuel Treaty Initiative, told Climate Home News that the Santa Marta process for transitioning away from fossil fuels (TAFF), launched at April’s conference, could help countries discuss, design and develop their national roadmaps, as well as mobilise the international cooperation required to actually deliver them.
“Many countries want not only national roadmaps but a global roadmap off the highway to hell,” she added. “A global plan is necessary to ensure the rules aren’t rigged against those who want to do the right thing and so all countries can make credible commitments.”
The second TAFF conference will be held in the Pacific island nation of Tuvalu next spring, co-chaired by Ireland. In New York, Tuvalu’s climate minister Maina Vakafua Talia called for stepped-up efforts to tackle the fossil fuel use that is threatening his country’s “demise” by driving global warming.
“The world is running out of time, and so I ask every government to come to… Tuvalu with solutions – real solutions, not false solutions – for us to ensure that we have a pathway and a way forward,” he urged.
The post UN chief urges countries to adopt fossil fuel transition plans with timelines appeared first on Climate Home News.
UN chief urges countries to adopt fossil fuel transition plans with timelines
COP31’s flagship initiative to accelerate the electrification of the world’s economy has been criticised for failing to include a commitment to produce the power from clean energy.
Governments that sign the voluntary pledge at this year’s UN climate summit will commit to increasing electricity’s share of total energy consumption to 35% globally by 2035 in line “with pathways consistent with keeping 1.5C alive”, the text unveiled by the Turkish presidency on Tuesday says.
While the document says that the electrification goal is “complementary to efforts to expand renewable energy and improve energy efficiency”, governments are not explicitly asked to commit to producing the extra power with clean sources and driving down greenhouse gas emissions.
The text instead says the “use of clean electricity” will vary according to national circumstances. Fossil fuels are not mentioned by name, although the pledge cites the COP28 Global Stocktake decision, which called for “transitioning away from fossil fuels” in energy systems.
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Climate change and energy transition rise up national security agenda
Leaders highlighted the national security risks posed by global warming and fossil fuel dependency at New York Climate Week -
Fossil fuel expansion threatens COP31 hosts’ credibility, experts warn
Türkiye and Australia are pushing coal, oil and gas at home with no national timeline for their own fossil fuel phase-out
COP31 president Murat Kurum said earlier this month that the push to make electrification more “widespread” – through measures like the rollout of electric vehicles and heat pumps – will “automatically” lead to a reduction in the use of fossil fuels.
But many campaigners disagree, criticising the proposed pledge for failing to give an explicit signal on the fossil fuel transition.
Lack of clarity on energy sources
“Let’s not let electrification become the Trojan horse of our times, used to hide new fossil fuel consumption rather than promote renewable energy,” Claire Smith from civil society umbrella group Beyond Fossil Fuels said in reaction to the pledge’s publication.
She added that the commitment will only help address the climate crisis if electrification is powered by a flexible energy system where solar and wind are complemented by enhanced grids and storage.
The pledge’s text says that the electricity goal should be supported by “diverse and sustainable energy sources”, but it stops short of explaining what these sources are.
Alden Meyer, an international climate policy expert and senior associate at think-tank E3G, said the details of the pledge matter to how effective it will be in helping bring planet-heating emissions down.
“It has to be clean, and we haven’t got enough clarity on a guarantee that it will be a decarbonisation move,” he told Climate Home News.
China’s industrial engine starts to break its fossil fuel habit
According to an annual electricity review from energy think-tank Ember, in 2025 renewables edged ahead of coal power for the first time in 100 years. Continued growth in solar and wind pushed the share of renewables above a third of global electricity generation to just under 34%, compared with coal at 33%, it said.
Janet Milongo, energy Transition lead at CAN International, said success cannot be measured simply by how much of the world’s final energy consumption becomes electric.
“We must ask what generates that electricity, who has access to it, who owns the infrastructure, and whether it is helping communities transition away from fossil fuels,” she added.
Electrification alone can’t meet climate goals
Analysis published by the IEA on Tuesday, alongside the pledge, found that it would already be cost-effective to raise electricity’s share of global energy use from 23% today to around 33% with existing technologies, putting the COP31 goal “within striking distance”. Based on current policies, however, the share reaches only about 30% by 2035.
Hitting the 35% target would cut fossil fuel importers’ import bills by around $400 billion a year by 2035, the IEA said. At the higher prices caused by the conflict in the Middle East, that saving rises to more than $500 billion.
Speaking at New York Climate Week on Tuesday, IEA executive director Fatih Birol said the agency’s figures show that in 2026, about 80% of all new power plants built will run on renewables, with a few percentage points coming from nuclear power and the rest from fossils fuels. “So therefore, electrification itself will lead reduction of the [greenhouse gas] emissions,” he added.
However, the IEA warned in its new report that electrification “by itself is not enough” to meet the world’s climate targets. It noted that, if “low-emission” sources of power continue to simply grow in line with current policy scenarios, that would be only just enough to cover the extra demand from electrification, driving a modest decline in emissions.
Matt Webb, associate director of global clean power diplomacy at E3G, said the pledge is a “welcome signal of leadership” and can help COP31 be a “critical moment” for countries to double down on the energy commitments made at COP28.
But to secure the full benefits of electrification, he added, it is essential that we “urgently clean up” by speeding up the rollout of renewables and developing credible national plans to transition away from fossil fuels.
The post COP31 electrification pledge leaves out clean power commitment appeared first on Climate Home News.
COP31 electrification pledge leaves out clean power commitment
People around the world have donated almost $90 million to a government-led campaign to help Nepal recover from its recent devastating Himalayan flood, according to a Nepali climate negotiator, even as the UN chief slammed the tiny amount of money in a new fund to deal with such disasters.
Individuals and companies from Nepal and abroad have chipped in from $5 to “many millions” of dollars to the Prime Minister’s Disaster Relief Fund, Manjeet Dhakal, an advisor to the poorest countries at UN climate talks, told an event on Monday focused on early warning systems.
The prompt and substantial response from the public contrasts with the slower, more limited support that is potentially on offer from the UN’s new Fund for Responding to Loss and Damage (FRLD), set up by governments to compensate developing countries for climate disasters.
Comment: Human security relies on adapting to the world’s new climate reality
Over three weeks have passed since Nepal’s finance and environment ministers asked the FRLD board to take an urgent decision to allocate funding to help Nepal protect people and restore essential services in the wake of the disaster, which caused around 1,450 deaths and left more than 5,000 people missing.
“Time is of the essence,” the ministers wrote in an appeal to the FRLD on August 31, which was swiftly followed by a letter from a group of developing-country board members urging the FRLD board’s co-chairs to organise an extraordinary meeting to come up with a response.
Loss and damage fund hesitates
Yet, despite informal online meetings, the co-chairs have yet to convene a meeting with the power to allocate funds. The board’s next scheduled meeting begins on December 15.
Dhakal said on Monday that the request has “received some positive response, but still there is some discussion ongoing about how to respond to that”.
“If they can’t respond in a timely manner, then is [the fund] fit for purpose in terms of disasters that the world would be facing in the coming years? The scale and intensity of these disasters is increasing,” he said.
With just $820 million pledged to it by rich countries and not all of that yet delivered, the FRLD has earmarked just $350 million to spend in its initial phase and without further contributions could run out of money next year.
Because of these limited funds, and a huge number of requests for funding totalling nearly $3 billion, the FRLD has said it will only give out a maximum of $20 million to each project for now. It has yet to approve funding for any projects.
Dhakal recently told The Nation magazine that this amount was just a “symbolic gesture”. Nepal’s government has estimated the costs of recovery and reconstruction at $4.8 billion, with homes, roads, bridges, hospitals and hydropower stations in the affected area needing to be repaired and rebuilt.
“Ridiculously small” funding
In a speech to the UN General Assembly on Tuesday, the body’s outgoing Secretary-General António Guterres criticised the “ridiculously small” level of funds made available by wealthy governments to the FRLD. Developed countries should “make the loss and damage fund work at scale”, he said.
The Portuguese diplomat told world leaders that when he travelled to Nepal three years ago, he had “sounded the alarm on accelerating glacier melt, warning that the rooftops of the world are caving in”.
“Some dismissed it all as overstating dangers, but as tragic events have shown, impacts are arriving sooner, hitting harder, and spreading further than many anticipated,” he said.
A recent study by scientists with the World Weather Attribution group found that climate change contributed to the rock-ice avalanche which sparked a huge flash flood along a river valley on the Nepal-Tibet border.
Speaking at a separate event in New York on Monday, leading climate scientist Johan Rockström highlighted those findings on the role of global warming in the Himalayan disaster.
“This will be potentially the first poster-child case of a loss and damage invoice, because here we have a proven case of a catastrophe which would not have occurred if it hadn’t been for human-caused climate change,” he said.
The post As loss and damage fund stalls, Nepal crowdfunds flood relief appeared first on Climate Home News.
As loss and damage fund stalls, Nepal crowdfunds flood relief
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