The UK government’s official climate advisers are now “more optimistic” that the country can hit its emissions targets than they were before the Labour government was elected in July 2024.
Speaking ahead of the launch of the Climate Change Committee’s 2025 progress report, Prof Piers Forster, the CCC’s interim chair, told journalists it would be “possible” to meet the UK’s 2030 international climate goal, as well as its 2050 target to cut emissions to net-zero.
Moreover, Forster responded to attacks on climate policy from opposition parties, the Conservatives and Reform UK, by saying that reaching net-zero would, “ultimately, be good for the UK economy”.
The CCC’s report points to progress in areas such as windfarm planning rules, plans for clean power by 2030 and the accelerating adoption of clean-energy technologies for heat and transport.
It says that 38% of the emissions cuts needed to hit the UK’s 2030 target are now backed by “credible” policies, up from 25% two years earlier.
However, it says “significant risks” remain – and its top recommendation is for government action to reduce electricity prices, which would support the electrification of heat, transport and industry.
Carbon Brief has covered the CCC’s annual progress reports in 2024, 2023, 2022, 2021 and 2020.
- Change of tone
- Overall progress
- Policy gaps
- Road transport
- Buildings
- Industry
- Fossil fuels and hydrogen
- Electricity
- Agriculture and land
- Aviation and shipping
- Other sectors
Change of tone
This is the first progress report from the CCC to assess climate policy and action under the new Labour government, which took office in July 2024.
Last year’s edition had said that “urgent action is needed” and that the UK was “not on track” for its 2030 international climate goal, namely, a 68% reduction in emissions relative to 1990 levels.
In contrast, the 2025 report says: “This target is within reach, provided the government stays the course.”
Speaking at a pre-launch press briefing, CCC interim chair Prof Piers Forster said: “[This is] an optimistic report, [showing] that it is possible for the country to meet its climate commitments.”
Moreover, in comments aligned with the shift in language since last year, he said that the report was “more optimistic” than the 2024 edition. Forster explained:
“We are not a political organisation and our job as a committee is just to look at the evidence, but, in terms of looking at the evidence, we are more optimistic than we were this time last year.”
The reasons for this were a mixture of policies from the previous government starting to deliver and the impact of decisions taken by the new administration, he said.
While the tone is relatively optimistic, the latest progress report uses less prescriptive language than previous editions, according to Carbon Brief analysis shown in the figure below.
For example, the word “must” occurs once every 10 pages in this year’s report, down from seven times in 2021. Similarly, the word “should” only occurs four times per 10 pages, down from 13.
This shift in language appears to be a continuation of the approach taken by the committee in its advice on the UK’s seventh “carbon budget”, published in February.
(Under the Climate Change Act 2008, the government has until June 2026 to legislate for this budget, which is a legally binding emissions limit for the five-year period from 2038 to 2042.)
The committee has faced inaccurate criticism from some opponents of climate action, who have argued that it was, in effect, setting government policy.
Pushing back on this, Forster had reiterated in February: “[O]ur core responsibility…is to give…the very best non-partisan advice possible…It’s not up to us to make the policy, it’s up to government.”
Beyond the overall tone of the latest progress report, it also puts a stronger emphasis than last year’s on the need for action to reduce emissions.
It sets out the rationale for the world reaching net-zero carbon dioxide (CO2) emissions to stop global warming, but also asserts the benefits this would bring to the UK in terms of energy security, a more efficient economy and lower bills:
“[C]ontinued reliance on fossil fuels undermines UK energy security…[A] fossil-fuelled future would leave the UK increasingly dependent on imports, and energy bills would remain subject to volatile fossil fuel prices.”
In language that could be interpreted as pushback against the leader of the opposition, the Conservative’s Kemi Badenoch, who recently falsely claimed that reaching net-zero emissions by 2050 was both “impossible” and only possible “by bankrupting us”, the CCC report states:
“The science is unambiguous. Only by achieving net-zero CO2 emissions, with deep reductions in other greenhouse gases, can the UK stop contributing to an ever-warmer climate…The 2050 net-zero target for the UK remains deliverable and affordable, with whole-economy costs estimated at an annual average of 0.2% of GDP.”
Asked directly if he agreed that the net-zero by 2050 target was “impossible” and would come with “catastrophic” costs – as Badenoch has asserted – Forster said that on the contrary, it was “possible” and would, “ultimately, be good for the UK economy”. He told journalists:
“We think that, provided there is further government policy, it is possible both to reach our [2030 target], our carbon budgets and then, ultimately, get to net-zero…[and that] while the benefit doesn’t come instantly…it will, ultimately, be good for the UK economy.”
The report also makes the point that the UK is far from alone in its efforts, with global investments in clean-energy technologies reaching $2tn last year, double the sum going to fossil fuels. It adds:
“Most of the world is investing heavily in low-carbon technologies, driven by falling costs, energy security concerns and a realisation of the need to respond to rising climate impacts.”
(This is despite the Trump administration’s withdrawal from the Paris Agreement and a “period of uncertainty” in international relations since the US election, the report notes.)
Overall progress
Last year’s report, published just days after Labour’s “landslide” election victory, had set the scene for the new administration, saying that it needed to “make up lost ground” to get back on track.
That report had called on the new government to “limit the damage” from Conservative climate policy rollbacks, which had been implemented ahead of the election.
This year’s report looks at how things have progressed since then, based on three sets of metrics:
- First, it looks at changes to the UK’s greenhouse gas emissions over the past year.
- Second, it looks at indicators of progress on the ground, such as the uptake of electric vehicles (EVs), the rollout of electric heat pumps and the rate of tree-planting.
- Third, it looks at policy changes introduced over the past year by the new government.
The assessment includes policy changes introduced up until 23 May 2025, meaning that it does not consider the June spending review or the industrial strategy published earlier this week.
Greenhouse gas emissions have more than halved since 1990, with a 50.4% reduction, making the UK “one of the leading economies in the world”, Forster said. The report adds:
“The UK should…be proud of its place among a leading group of economies demonstrating consistent and sustained decarbonisation.”
It says that UK emissions fell again during 2024, with a 2.5% reduction marking the tenth year of steady decline, excluding the Covid-19 pandemic and subsequent rebound.
Echoing Carbon Brief analysis published in March, the CCC says that the latest drop in emissions was due to the power sector, industry and transport, where EVs are starting to have an impact.
However, the report emphasises once again that progress to date has largely come in the electricity sector, where the UK became the first country in the G7 to phase out coal power in 2024.
Indeed, the CCC says that electricity supply is now only the UK’s sixth-largest source of emissions, after surface transport, buildings, industry, agriculture and aviation, as shown in the figure below.
In order to continue cutting emissions to meet UK climate goals, the CCC says that reductions will be needed across a broader range of sectors, including transport, buildings, industry and land-use.
The pace of emissions cuts outside the power sector – an average of 8m tonnes of CO2 equivalent (MtCO2e) per year since 2008 – is roughly on track for the fourth carbon budget covering 2023-27.
However, the report says this pace will need to “more than double” toward the end of the decade, hitting 19MtCO2e per year, in order to hit the UK’s NDC and sixth carbon budget.
Turning to the indicators of progress on the ground, the CCC says that there are some “clear signs” of such shifts starting to take place, in areas such as transport, buildings and land-use.
For example, the report points to “significant increases” in the rates of heat-pump rollout (up 56% year-on-year in 2024), tree-planting (+59%) and peatland restoration (+47%).
(See the sections below for further detail on policies and progress in each sector.)
Policy gaps
Turning to its assessment of government climate policy, the CCC report says there has also been some “positive progress” since Labour came to office last year.
Specifically, it points to the removal of planning barriers for onshore wind and heat pumps, as well as implementation of the “clean heat market mechanism” to drive heat-pump sales, reinstatement of the 2030 combustion car ban and publication of the 2030 clean-power action plan.
As a result, the CCC says that there are now “credible policies” in place to make 38% of the emissions cuts needed to hit the UK’s 2030 target, up from 25% in 2023 and 32% last year.
At the same time, the share of emissions savings subject to policies facing “some” or “significant risks” has fallen from 53% in 2023 and 50% in 2024, down to 43% in the latest report.
These improvements are illustrated in the figure below, which shows that the credibility of UK climate policies towards the 2030 target has been steadily increasing.
Nevertheless, there are still “insufficient plans” to make 14% of the cuts needed by 2030, the same share as last year. The biggest policy gaps are around heat-pump rollout, the report says.
The CCC says: “With 39% of policies and plans needed to hit the 2030 NDC rated as having significant risks, or insufficient or unquantified plans, the government must act swiftly.”
The figure below illustrates the implications of falling to “act swiftly” more clearly.
If only the most “credible” policies actually deliver emissions savings (solid dark blue line) then the UK would miss its international targets for 2030 and 2035 (black circles) by significant margins.
The UK would get somewhat closer to its goals, if emissions cuts are successfully achieved as a result of policies subject to “some” (light blue) or “significant” delivery risks (grey line).
At the pre-launch briefing, Dr Emily Nurse, head of net-zero at the CCC, told journalists that further action was needed to get on track for the 2030 target. She said:
“Around three-fifths of what’s needed is covered by either credible plans or [those] having some risks…The UK can hit its upcoming emissions reduction targets and remain on track for net-zero, but only with further policy action.”
The government has the chance to fill these policy gaps when it publishes its updated “carbon budget delivery plan”, which has a deadline of 29 October this year.
This plan must set out how the government intends to meet the UK’s legally binding climate goals, after the previous administration’s plan was ruled unlawful by the High Court.
While there has been “good or moderate progress” on 20 of the 35 policy recommendations made last year, the CCC says there has been “no progress” on its top recommendation to make electricity cheaper.
The report says this remains its top recommendation for the second year in a row.
The reason for emphasising this, it says, is that electrification of transport, heat and industry will be the key to making required emissions cuts over the next decade, according to the CCC, with these shifts being facilitated by the expansion and continued decarbonisation of the power sector.
CCC chief executive Emma Pinchbeck told journalists that making progress in lowering electricity prices was “absolutely critical”, particularly relative to the price of gas. She said:
“The reason we keep banging on about [this], very simply, [is] that the evidence from every other country that’s had a successful rollout of electric technologies – particularly for heat – is that you need a three-to-one electricity-to-gas price ratio.”
(At present, domestic electricity prices are roughly four times higher than gas prices.)
Pinchbeck reiterated the committee’s call for the government to remove policy “levies” from electricity bills, adding that failing to do so would mean “slowing down” the transition. She said:
“If you’re effectively taxing your future fuel, you’re slowing down your energy transition, when the economy is going to become more and more dependent on electricity…It is just sensible economic policy to have cheap fuel going into your economy.”
While Pinchbeck welcomed plans in the government’s just-published industrial strategy to cut levies on industrial electricity bills, she said that it should do the same for households.
Road transport
Road-transport emissions fell for a second consecutive year in 2024, says the report.
The number of electric vehicles (EVs) on UK roads is roughly doubling every two years.
If this trend continues, the road-transport sector will produce the emissions savings required for its contribution to the UK’s 2030 climate target, the CCC says (see below).
EVs made up 19.6% of new car sales in 2024, compared to 16.1% the previous year, according to the report. In the first quarter of 2025, this figure rose to 20.7%.
This represents “strong growth”, but is below the headline targets of the zero-emission vehicle (ZEV) mandate, a government regulation that requires car manufacturers to sell an increasing percentage of zero-emission vehicles each year, the CCC says.
The mandate targets a 22% market share for 2024 and a 28% share for 2025, according to the CCC.
The CCC notes that lower-cost EVs are becoming increasingly available. It adds that “price parity with petrol cars has already been reached in parts of the second-hand market”, with this milestone set to arrive for new cars by between 2026 and 2028.
Overall, there has been a “small improvement” in the UK’s policy efforts to decarbonise road transport since last year’s report, it says.
This is largely down to Labour’s decision to reinstate a 2030 ban on the sale of new petrol and diesel vehicles, which was weakened to 2035 under Conservative prime minister Rishi Sunak, explains the report.
The CCC describes the move as a “welcome market signal to accelerate the transition to EVs”.
As well as reinstating the 2030 ban, the government announced changes to the ZEV mandate.
The government essentially weakened the mandate by extending flexibilities and allowing the sale of hybrid vehicles between 2030 and 2035.
Ministers said this move was in response to import tariffs announced by Donald Trump.
The CCC says the changes “risk allowing existing planned plugin hybrid vehicle sales to slightly reduce the emissions savings from EVs”, adding:
“It is also possible that manufacturers could divert investment towards [hybrids], diluting the consumer offer for EVs – we currently think that this risk is minimal due to progress in scaling up the EV market to date, but it is something that we will monitor closely.”
It adds that “for the transition to accelerate, further reductions in the cost of purchasing EVs, as well as improved access to, and reduced costs of, local public charging, are needed”.
Buildings
Heat pump installations increased by 56% in 2024 compared to the year before, the report says. Some 98,000 heat pumps were installed.
A total of 23,000 heat pumps were installed under the Boiler Upgrade Scheme, which allows homeowners to claim grants for replacing fossil-fuel boilers. This is an increase of 83% on 2023 levels, says the CCC.
However, the speed at which heat pumps are rolled out remains one of the “biggest risks” to the UK meeting its 2030 climate target, it adds.
The UK’s heat pump market share is around 4%, much lower than comparable countries, such as Ireland (30%) and the Netherlands (31%), the CCC says.
The government has taken steps to “remove planning barriers” for heat pumps. This includes amending the planning policy in England to remove the requirement for planning permission for heat pumps located less than 1m from a property boundary.
However, the government has “not yet provided clarity on whether [it] will continue with the proposed phase-out of new fossil fuel boiler installations from 2035”, or “make alternative plans to ensure that low-carbon heating reaches the installation rates required”, the CCC says.
The report adds that the ratio of residential electricity to gas prices is “significantly off track”.
The ratio is important because it underpins the “underlying cost savings of switching to electric technologies are reflected in the bills paid by households and businesses”, the CCC says, continuing:
“Action has not been taken to remove policy costs from electricity prices which would address this, despite it being our first recommendation last year…Currently, a typical household with a heat pump is paying around £490 per year in policy costs, which inflate their bills above the underlying cost of the additional electricity used.”
Data from other nations suggests that the “market share of heat pump installations are correlated with more favourable electricity-to-gas price ratios”, says the CCC (see chart below).
Forster told the press briefing that the CCC’s “biggest recommendation” to government remains reducing the price of electricity in relation to gas:
“By far the most important recommendation we have for the government is to reduce the cost of electricity, both for households and for businesses and industry as well…If we want the country to benefit from the transition to electrification, we have to see it reflected in utility bills.”
The report adds that, on efforts to increase the energy efficiency of residential buildings, the “proportion of homes with insulated cavity walls has steadily increased over recent years, but this will need to accelerate later in the decade” to be in line with net-zero.
Industry
Industry emissions decreased by 4.7MtCO2e in 2024, compared to the year before, the CCC says. Emissions are now 48% lower than 2008 levels.
From 2023-24, annual emissions dropped quickly due to the removal of blast furnaces at Port Talbot steelworks in 2024. They are due to be replaced by electric arc furnaces by 2027, with the move leading to 2,500 job losses.
The government should have developed a “more proactive and decisive transition plan” for Port Talbot and the report describes the UK’s upcoming steel strategy as “an opportunity to set out plans for the low-carbon transition at Scunthorpe steelworks and other UK steel production”.
To deliver the emissions savings needed to meet the UK’s 2030 climate goal, companies will “increasingly need to switch to electric alternatives to fossil-fuelled technology”, the report says, adding:
“A high ratio of [industrial] electricity-to-gas prices currently presents a barrier to this.”
It adds that, currently, “there is now no major source of government support for manufacturers to invest in electrification”.
The CCC notes that the government did not launch the latest round of the Industrial Energy Transformation Fund, which was due in December 2024. It has “not clarified whether this or similar funding will continue”.
On 23 June, the UK government announced a 10-year industrial strategy, including measures to slash the price of electricity for energy-intensive businesses from 2027 by exempting them from green levies.
In the press briefing, Pinchbeck described the move as “good”, but urged the government to introduce similar measures for household electricity bills, too. (See: Buildings.)
On efforts to introduce carbon capture and storage (CCS) technologies to UK industries, the report says progress “is not on track to be deployed at the pace required” by government plans to reach net-zero.
Fossil fuels and hydrogen
The report says that the UK’s “continued reliance on fossil fuels undermines energy security”, continuing:
“Household energy bills rose sharply following Russia’s invasion of Ukraine and have remained high since. It is the price of gas that has driven up both gas and electricity bills.”
(See Carbon Brief’s factcheck on what is causing high electricity bills in the UK.)
The report does not directly address the Labour government’s policies on oil and gas production in the North Sea.
Labour has ruled out new oil and gas licences. However, the government has indicated it might approve new projects that already have a licence, if they can pass a new environmental impact assessment that will consider the emissions from burning the oil and gas produced.
In regards to the North Sea, the report says:
“With North Sea resources largely used up, a fossil-fuelled future would leave the UK increasingly dependent on imports and energy bills would remain subject to volatile fossil fuel prices.”
The CCC adds that the “main progress in the fuel-supply sector in the past year has been around low-carbon hydrogen production”.
In the 2024 autumn budget, the government confirmed support for 11 “electrolytic”
hydrogen production projects, which are expected to start operating by the end of 2026. (These projects use electricity to split water into hydrogen and oxygen.)
Electricity
The UK’s transition away from fossil fuels to renewable energy in its electricity supply continued to drive the bulk of emissions reductions in 2024, the CCC says. It accounted for 41% of the total in-year reduction in emissions.
From the 1990s until 2024, the power sector has transformed from the largest source of emissions to only the sixth largest, behind aviation. (See: Overall progress.)
The UK’s last coal-fired power plant, Ratcliffe-on-Soar, closed in October 2024. (See Carbon Brief’s detailed explainer on how the UK became the first G7 nation to phase out coal.)
Coal emissions from electricity generation were 99% lower in 2024 than in 2008 and will reach zero in 2025, the CCC says. It describes this as a “major milestone on the UK’s path to a decarbonised power system”.
Falling gas generation accounted for 72% of emissions reductions in the power sector in 2024, the CCC says.
The electricity supplied by gas fell by 15% in 2024, compared to the previous year. This was “made up with roughly equal proportions of imports and low-carbon generation”.
The rollout of wind and solar capacity in 2024 was larger than in any of the previous six years, the report says.
But to achieve the government’s goal of “clean power” by 2030, total renewable capacity will need to more than double.
Based on projects in the pipeline, both offshore and onshore wind “appear on track” for the government’s goal, according to the CCC.
However, “roll-out of solar is significantly off track and will need to improve to deliver its contribution to a decarbonised electricity system”.
The report says that, overall, “positive policy progress has been made in decarbonising electricity supply over the past year”.
It continues that “concrete steps have been made to remove barriers and support the deployment of low-carbon technology”.
These steps include removing barriers facing onshore wind developments, “streamlin[ing]” the approval of nationally significant infrastructure, including renewable projects and introducing reforms to speed up connecting projects to the grid.
However, the CCC adds that there are “remaining uncertainties on the future electricity market arrangements and further challenges to deploying infrastructure to overcome”.
Agriculture and land
There was a “significant increase” in both tree-planting and peatland restoration in 2024, the report says.
Some 20,700 hectares of new trees were planted, an increase of 59% on the year before and the highest rate in 20 years, it adds, as shown in the chart below.
Over the same period, the restoration of peatlands increased by 47%.
This “demonstrates that a rapid increase in rates is feasible” for the land-use sector, the CCC says.
However, woodland creation remains “slightly off track”. (Carbon Brief reported last year that successive UK governments have fallen so far short of their tree-planting targets since 2020 that they have failed to plant an area of forest nearly equivalent to the size of Birmingham.)
In addition, Scotland accounted for 73% of the total trees planted from 2023-24 and the CCC has “concerns that recent reductions in funding for woodland creation in Scotland could reverse this trend”.
A target to have 35,000 hectares of peat under restoration in England by 2025 is also “expected to be missed”.
Livestock numbers continued to fall in 2024, the report says.
Meat eating has declined steeply over the past couple of years. The average amount of meat eaten per person each week dropped by around 100g from 2020-22, according to CCC data.
Pinchbeck told the press briefing that meat-eating in the UK is now lower than what the CCC had anticipated in its central pathway for meeting net-zero:
“There’s lots of factors behind that, including the cost of living crisis. So we are not necessarily saying that trend will increase. Farming is facing a number of pressures, outside having to deal with a changing climate, reduced crop yields [and] difficulty making farms sustainable.”
Both the reduction in livestock and meat eating are “key to freeing up land required to increase tree-planting and peatland restoration”, the report says.
The government’s progress on addressing land-use sector emissions with policies has been “mixed” over the past year, according to the CCC.
The government is expected to produce a long-awaited land-use framework by the end of this year, but it “remains unclear how this framework will drive change on the ground”, the advisers say.
The government paused the sustainable farming incentive, part of the environmental land management (ELM) schemes, in March 2025.
This was due to all of the funding being allocated, which is “positive”, says the CCC. However, the decision has left a “gap in delivery grants for on-farm actions”.
The Nature for Climate Fund has been extended by one year, but is “unclear” what will happen to this scheme in the long term, it adds.
Aviation and shipping
Emissions in the aviation sector increased by 9% year-on-year in 2024, “marking a return to pre-pandemic levels”, the report says.
In government and CCC scenarios for net-zero, emissions stay flat and start slowly decreasing over the rest of the decade, the report says, adding:
“Aviation emissions will likely exceed the trajectories assumed in all [these] pathways if they continue to increase, posing a risk to the UK’s emissions targets.”
The biggest driver of aviation emissions since 1990 has been “rising demand for international flights, particularly leisure”, it continues.
Aviation now causes more emissions than the UK’s entire power grid. In 1990, aviation emissions were 10 times lower than those from electricity, according to the report.
The CCC “recommends that the government should develop and implement policy that ensures the aviation sector takes responsibility for mitigating its emissions and, ultimately, achieving net-zero”, adding:
“This includes paying for permanent engineered removals to balance out all remaining emissions. Robust contingencies should also be in place to address any delays in decarbonisation, including through managing the forecasted increase in aviation demand.”
The share of sustainable aviation fuel (SAF) as a proportion of all jet fuel rose from 0.7% to 2.1% from 2023-24, the CCC says.
It notes that the SAF mandate came into force in January 2025 and the sustainable aviation fuel bill was introduced to parliament in May.
Achieving the government’s target of 10% of jet fuel from SAF by 2030 “remains uncertain as different types of SAF will need to scale up”, it adds.
There are currently no operational UK SAF plants, but some are under construction.
On shipping, the report notes that the UK has set out a maritime decarbonisation strategy, with an aim to reduce the domestic maritime sector’s fuel lifecycle emissions to zero by 2050 and interim goals of cutting pollution by 30% by 2030 and 80% by 2040, compared to 2008.
The targets are “broadly aligned” with government plans for net-zero, the CCC says.
Other sectors
Another sector tracked by the CCC is “engineered removals”, technologies that suck CO2 out of the atmosphere.
Aside from small experiments, there is no deployment of such technologies in the UK. However, the government’s pathway for net-zero expects such methods to remove 6MtCO2e from the atmosphere by 2030, the report says, adding:
“This sector will need to develop and scale up notably over the coming five years.”
One of the CCC’s “top 10” priority actions is for the government to “finalise business models for large-scale deployment of engineered removals”.
On this, the advisers say:
“There has been little progress…This puts the contribution of engineered removals to the UK’s 2030 NDC at increasing risk.”
Another issue assessed by the CCC is waste, which produced 26.7MtCO2e in 2024, making it the eighth most polluting sector.
The report says there has been “some progress” on waste policy, but notes the government is “yet to confirm its intention to prevent biodegradable waste from going to landfill, a key measure to reduce emissions from waste”.
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CCC: UK climate advisers now ‘more optimistic’ net-zero goals can be met
Climate Change
Explainer: How sea level rise poses an ‘existential threat’ to humans, heritage and nature
For millions of people around the world, rising sea levels are already reshaping economies, livelihoods and cultures.
The world’s oceans are currently rising at a faster rate than at any time in at least the past three millennia, with human influence the “dominant cause” of sea level rise since at least 1970.
At the UN general assembly in New York this week, world leaders are set to adopt a high-level declaration on the “existential threats” posed by sea level rise.
The declaration notes: “Sea level rise is not a distant scenario, but a real and lived experience for many.”
On average, global sea levels rose by 20 centimetres (cm) between 1901 and 2018.
This is due to both the melting of glaciers and ice sheets and the expansion of seawater as it warms, as well as changes in land-water storage.
The rate of the rise has accelerated in recent years, with ocean levels rising 10.6cm since 1993.
Sea level rise can vary locally due to seismic and volcanic activity, groundwater extraction and changes to the Earth’s surface resulting from ice melt.
Under a moderate-emissions scenario, scientists predict that global average sea level will rise an additional 56cm by 2100, relative to a 1995-2014 baseline.
Here, Carbon Brief unpacks some of the key ways that sea level rise threatens both societies and ecosystems.
Cities and coastal communities
Around 770 million people – 10% of the world’s population – are at “acute risk” of negative impacts from sea level rise, according to a report from the UN secretary general released last month.
(The report defines locations at acute risk as those that are less than five metres above the high-tide line.)
The people at risk include the residents of several of the world’s largest cities, including Mumbai and Kolkata in India and Shenzhen and Guangzhou in China. It also encompasses the entire populations of many island nations. (See: Small island developing states.)
There are two ways to consider sea level rise.
Global-average sea level rise is the amount the ocean surface has moved upwards, on average, relative to a baseline.
Relative, or local, sea level rise, is how much the ocean has risen in a given place. This can vary from the global average due to a number of factors, including land motion and ocean circulation, as well as changes to the Earth’s surface, rotation and gravitational pull due to the melting of the ice sheets.
Higher sea levels bring with them myriad dangers for coastal communities: they can increase persistent flooding and inundation, strengthen dangerous storm surges and erode beaches and cliffs. Sea level rise also causes the water table of coastal land to rise, which exacerbates flood risk.
The frequency of 100-year “extreme sea level events” has already increased 12-fold since 1900. These are events where high tides, storm surges and relative sea level rise combine to produce exceptionally high sea levels. Under a moderate-emissions scenario, these events are likely to occur at least annually – and, potentially, even more frequently – in many places by the end of the century.
In addition to damage to homes and other buildings, critical infrastructure – such as water systems and wastewater management projects – is increasingly vulnerable to flooding as a result of sea level rise. Flooding can cut communities off from essential services, such as hospitals and markets, with low-income and other marginalised groups disproportionately affected.
Inland encroachment of seawater leads to the saltwater intrusion and threatens agriculture in low-lying coastal areas.
Vertical land motion can also amplify the risk of rising seas. This includes a shifting of the land in response to seismic or volcanic activity or to land sinking, known as subsidence. The changes in local sea level due to these types of vertical motion can equal or surpass the contributions of climate-driven sea level rise.
Many of the coastal cities experiencing the largest changes in their relative sea level are located in east and south-east Asia. One notable example is Jakarta, Indonesia, which has been sinking by up to 15cm per year over the past decade, due largely to the overextraction of groundwater, which leads to the collapse of underground aquifers.
But even as the risks from sea level rise increase, population growth in coastal areas continues to outstrip that of inland areas. Between 2000 and 2018, the global population grew by slightly more than 23%. The population living within 5km of a coast increased by 28% over that same time.
The associated development of coastal areas means that, even without future sea level rise, global losses from flooding in the world’s largest 136 coastal cities could reach up to $52bn per year by 2050 – up from $6bn in 2005.
In response to the growing threats posed by sea level rise, communities around the world have implemented a number of adaptive actions.
In 2003, the Italian city of Venice began a years-long project to construct three floodgates that could be raised during high tide events to protect the city’s lagoon from the encroachment of the Adriatic Sea. The system was engaged for the first time in October 2020 and then another 48 times in the following two years.
Other communities have opted for less technologically intensive adaptations, including constructing seawalls, restoring mangrove forests and marshes, disincentivising development in high-risk areas and relocating residents, buildings and infrastructure to higher ground or inland areas.
However, existing adaptations may not be sufficient to protect communities. Under a low-emissions scenario, these protections may be breached 10 times as frequently over the next 30 years as they currently are.
Biodiversity and coastal ecosystems
The world’s coastal ecosystems are rapidly being destroyed due to both development and sea level rise.
This combination of pressures is called “coastal squeeze”, where ecosystems that may have otherwise shifted inland in response to sea level rise find their paths blocked by human-made structures.
Coastal squeeze has contributed to the widespread loss of the world’s wetlands.
Globally, nearly 28m hectares of coastal wetlands – including estuaries, tidal flats, mangroves and seagrass – have disappeared since 1970, according to the 2025 “global wetland outlook” report. This is an area equivalent to roughly the size of Ecuador.
Although the report names conversion to agriculture as the largest driver of wetland loss, it notes:
“Climate change is increasingly exacerbating the impact of other drivers on wetlands and human wellbeing through changes in the frequency and intensity of extreme weather events, associated fires, floods and droughts and through sea level rise.”
In the continental US, just 16% of coastal wetlands are migrating inland at rates that exceed local sea level rise. Nearly three-quarters of sites are moving at rates that do not outpace sea level rise, while 11% are submerging.
Low-lying islands are particularly threatened by sea level rise, due to their large amounts of coastline relative to their land areas. At the same time, islands are often “hotspots” of biodiversity, with many home to species found nowhere else in the world. More than 20% of the Earth’s known plant species are found only on islands.
A 2013 study modelled the impact of different amounts of sea level rise on 10 island biodiversity hotspots, comprising nearly 4,450 individual islands. It found that in a future with one metre of sea level rise, around 6% of the island habitat area would be completely submerged, while more than 11% of the hotspot islands would see their land area reduced by at least half. This could put dozens of species at risk of extinction, the study said.
In 2024, researchers documented the first known extirpation, or local extinction, of a plant species in the US due to sea level rise. Hurricanes and storm surges – amplified by sea level rise – began to kill off the only US population of the Key Largo cactus in the 2010s.
The remaining cacti suffered from soil erosion and saltwater intrusion and the final remaining specimens were removed in 2021 in an effort to cultivate them in greenhouses. (Other Caribbean islands, including Cuba, do still have surviving populations of the cactus.)
As native flora and fauna are diminished or even eliminated by rising sea levels, coastal ecosystems may become vulnerable to colonisation by invasive alien species, further harming biodiversity.
And as coastal communities are forced to relocate due to sea level rise, there are knock-on effects for biodiversity as they develop on new lands. These secondary biodiversity impacts are likely to be particularly prevalent in south-east Asia, due to the large number of people living in low-lying areas who may be forced to migrate due to sea level rise.
Small island developing states
Sea level rise poses an “acute and disproportionate” threat to small island developing states, says the recent UN report. It adds:
“Even under moderate scenarios, rising seas will render many low-lying coastal zones and small island developing states increasingly uninhabitable without extraordinary adaptation.”
Climate change is already resulting in loss and damage to small island nations, which are particularly vulnerable to both climate change in general and sea level rise specifically.
This vulnerability is in large part due to the geography of these countries. Several small island Pacific states are made up of atolls – ring-shaped coral or sandy islands that encircle lagoons. These often have average elevations of 1-2 metres above sea level and maximum elevations of 3-5 metres above sea level.
Some modelling evidence has shown that reef islands can grow vertically in response to sea level rise, as waves washing over the islands transport sediment from the ocean onto the surface. However, the strength of such waves would likely make these islands unsuitable for building on.
Other research has shown that Pacific islands respond in many different ways to rising sea levels, with “complex” outcomes, both positive and negative.
In addition, most of the small-island nations in the Pacific Ocean are located in a region where relative sea level rise from the melting of the Antarctic ice sheet is projected to be 11-33% higher than the global average rise in 2100 – regardless of emissions scenario.
The effects of this higher-than-average sea level rise is already evident.
In 1999, Kiribati lost two small, uninhabited islands to the rising seas. Several uninhabited islands in the Solomon Islands had vanished by 2014, while a further six islands had been severely eroded by the ocean, necessitating the relocation of some communities.
In addition, most small island developing states are located in parts of the ocean that are often hit by tropical cyclones. Sea level rise can enhance storm surge, leading to greater destruction during such storms.
However, small island developing states are also vulnerable “because they lack the means to address the impacts on their own”, reads the UN report.
According to the UN, these countries will require up to $6bn annually by 2035 in order to adapt to climate change. However, they received just $1.2bn in public adaptation finance in 2022-23.
Currently, small island developing states experience “expected” annual climate damages of $1.64bn due to coastal flooding, equivalent to 0.13% of their cumulative GDP. But, even if warming were limited to 1.5C above pre-industrial temperatures, these annual damages are projected to grow to $24bn.
In the international policy arena, questions have arisen over what should happen to island nations’ maritime boundaries as their land is enveloped by the sea. This is because maritime holdings, such as exclusive economic zones, are determined based on a country’s land borders.
However, a 2025 report by the UN International Law Commission considered the legal implications of sea level rise. It concluded that international law allows for countries’ borders to stay the same, “notwithstanding changes to the coastline as a result of climate change-related sea level rise”. It also noted:
“There is a need to develop legal and practical solutions to better protect persons affected by sea level rise, including those who remain in situ and those who are internally or externally displaced by it.”
Other small islands also face similar issues in their exposure to threats posed by sea level rise.
Coral reefs
Coral reefs are among the ecosystems that are most vulnerable to climate change.
They are also being visibly affected already – almost entirely due to ocean warming. Even though these ecosystems are completely submerged to begin with, they are also impacted by sea level rise.
As the ocean rises, the water over shallow ecosystems deepens.
The effects of this are twofold. Deeper water reduces the temperatures experienced by reefs. This can act as a buffer against marine heatwaves and global ocean warming.
At the same time, the increased depth reduces the amount of light that can reach the coral communities, which can impact their survival.
In addition, sea level rise-assisted erosion will add more sediment to the near-shore waters. These particles can settle on corals, impeding their ability to feed and reproduce, as well as interfering with photosynthesis by the zooxanthellae algae that live symbiotically with corals. Together, this leads to slower coral growth and increased stress on reefs.
So far, reefs in some parts of the world have been able to “keep pace” with sea level rise, growing vertically at accelerated rates and therefore maintaining suitable levels of light availability.
However, modelling has shown that few reefs have the capacity to continue to maintain their distance from the surface under a moderate-emissions scenario.
As coral reefs degrade, the seafloor below them can wear away. This erosion is contributing to greater apparent levels of sea level rise on coral reefs in the Caribbean, as well as the US states of Florida and Hawaii.
Sea level rise may also have the ability to spur reef growth in shallow environments previously thought to be uninhabitable for corals. In Sanya Bay in the northern South China Sea, sea level rise since the mid-1980s has allowed for the recolonisation of a reef that had been dormant for more than five millennia.
But the opportunities for such recolonisation are far outstripped by the loss of coral elsewhere. Since 1980, the world has lost nearly 10% of its coral cover due to climate change-induced ocean warming. The UN declaration reads:
“Every fraction of a degree of global warming increases the risks to coral reefs.”
Heritage sites
Throughout human history, many societies developed along rivers and coastlines, due to the abundance of food and ease of transportation. However, their proximity to the sea means that many of these sites are now at risk of being damaged or destroyed by sea level rise.
Cultural heritage includes “physical sites, living heritage, traditional lands, burial grounds, underwater cultural heritage, archaeological and sacred sites and culturally significant coastal landscapes”, according to the UN sea level rise report.
Several studies have mapped the cultural and natural heritage sites that are most at risk from flooding and erosion due to sea level rise.
There are 49 Unesco world heritage sites located at low elevations along the coast of the Mediterranean Sea. Nearly every one of these is already at risk from erosion or severe flooding events – 42 face issues with erosion, while 37 are at risk from a 100-year flood event. Both of these risks will increase over the remainder of the century as sea levels continue to rise.
The locations at risk include the archaeological sites of the ancient cities of Carthage in present-day Tunisia and Ephesus in Turkey, the ruins of Pompeii and Herculaneum in Italy and the medieval Cathedral of St James in Šibenik, Croatia.
The sea level rise associated with warming of 3C above pre-industrial temperatures would impact nearly one-fifth of all Unesco cultural world heritage sites. The sites at risk include Japan’s Hiroshima Peace Memorial, South Africa’s Robben Island, Chile’s Rapa Nui and the Sydney Opera House. Many of these become vulnerable at lower levels of global warming.
In Africa, 56 out of 284 cultural and natural heritage sites already face threats from flooding or erosion due to sea level rise. This number is expected to nearly triple – to 191 threatened sites – by 2050 under a moderate-emissions scenario. However, mitigating emissions could reduce the number of very-highly exposed sites – those with at least 75% of their area vulnerable – by one-quarter.
Globally, there are 386 Unesco heritage sites along the coast that are, at most, 20 metres above sea level and are therefore potentially affected by coastal erosion and flood hazards.
These threatened sites include 289 cultural heritage sites and 91 natural heritage sites, as well as six “mixed” sites that are recognised for both their cultural and natural significance.
The UN declaration calls for action to mitigate damage to significant sites, saying:
“Protection, preservation and documentation of cultural heritage is a priority.”
The post Explainer: How sea level rise poses an ‘existential threat’ to humans, heritage and nature appeared first on Carbon Brief.
Explainer: How sea level rise poses an ‘existential threat’ to humans, heritage and nature
The Nepali government has requested $20m from the UN fund for “loss and damage”, following the devastating floods that hit the country in late August.
This amounts to just 0.7% of the $2.7bn it has estimated in “physical damage” to infrastructure and “economic losses” from the flooding, according to Carbon Brief analysis.
The $20m request would, nevertheless, make Nepal the fourth-largest claimant to the UN loss-and-damage fund, which is intended to help deal with climate-related disasters.
Developing countries have already made 176 applications to the UN fund for responding to loss and damage, requesting, in total, $2.8bn to help recover from a variety of damaging events, such as drought, floods and storms.
Yet, to date, predominantly developed nations have only pledged $0.8bn to support the fund.
This means requests to the fund are already three times larger than the total amount pledged, raising questions about its potential to respond to emergencies.
As yet, no funding has been paid out of the fund to developing countries grappling with intensifying and more frequent climate change-induced disasters since it was established in 2023.
Nepal’s needs
On 26 August, Nepal was hit by flash floods following a catastrophic rock-ice avalanche in the Himalayan border region. The flooding has killed more than 1,400 people, with thousands still missing.
Days later, the Nepali government sought an “urgent response” from the board of the UN fund for climate-driven loss and damage.
It subsequently requested $20m in “financial compensation” from the fund. This is the maximum amount that can currently be requested for a single project.
“Loss and damage” is a term used to describe how climate change is causing serious and, in many cases, irreversible impacts around the world. Nations established the UN fund in 2023, after decades of effort by climate-vulnerable nations.
Nepal’s national disaster management authority has now released an extensive rapid preliminary assessment of “damage and needs” from the floods.
As the chart below shows, Nepal’s $20m loss-and-damage claim would only cover 0.7% of what authorities describe as $2.7bn in “total damage and loss” from the floods.
When accounting for another $4.8bn in “recovery and reconstruction” costs – part of how loss and damage is internationally defined – then Nepal’s $20m claim would be just 0.3% of the needs it estimates.
Reacting to the analysis, Nepal’s climate negotiator Raju Pandit Chhetri tells Carbon Brief that the country’s $20m request was for “rapid response”, adding:
“That money is going to be a peanut if it was to be invested into reconstruction.”
Requests vs pledges
Vulnerable, developing countries have long argued that developed nations should be held responsible for loss and damage, while countries such as the US have blocked moves that could have led to them being liable for climate-related damages
From December 2025 until July 2026, developing countries made 176 applications to the loss-and-damage fund, requesting over $2.8bn in assistance.
So far, predominantly developed countries have pledged only $822m to the fund. (Some nations that are not categorised as “developed” under the UN, such as the UAE and South Korea, have also committed funds.)
Funding requests from developing countries to date are, therefore, more than triple what has been pledged.
Moreover, only around half of the money pledged so far has been paid into the fund by donor nations, with large sums from France, Italy and the UAE still outstanding.
The fund has made $342m available in its initial funding round in July 2026. However, as of September, no money from the fund has been distributed to any countries facing climate-related disasters.
According to Carbon Brief analysis, off the 176 loss-and-damage fund requests received from 118 countries, more than 60% are from least developed countries – such as Nepal – and small-island nations. So far, each individual funding request is capped at $20m.
The flood-related request is Nepal’s fourth appeal to the fund and, as the chart below shows, this makes it the fourth-largest claimant overall.
Nine other countries have made multiple requests to the fund. Madagascar – hit by back-to-back cyclones after a prolonged drought – has made six requests in total.
Drought-ravaged Suriname, Ecuador, Brazil and Barbados have specified that their funding requests are part of an “emergency response”.
‘Rapid response’
Nepal’s $20m claim has sparked a conversation on climate justice and the ability of the loss-and-damage fund to deliver, in the face of increasingly frequent extreme-weather events.
In a letter sent five days after the disaster, Nepal’s finance minister Dr Swarnim Wagle appealed to the fund’s board to mobilise an “urgent response” that would “signal” that the fund:
“[I]s capable of responding with humanity, speed, flexibility and solidarity when climate-vulnerable countries face losses and damages beyond their capacity to address alone.”
Board members from Asia-Pacific and African countries wrote a letter in support of the Himalayan country in crisis, urging the board to convene and “potentially agree to a provisional set-aside allocation of resources to support rapid response funding for Nepal”.
They pointed out that the board’s response to Nepal could offer “procedural lessons” in how to strengthen its “rapid-response” to sudden-onset extreme-weather events. Such support is explicitly part of the fund’s mandate.
On 14 September, developed-country members of the fund’s board wrote that they supported a “consultation” on Nepal, but made no commitments in terms of actual funding.
Harjeet Singh, loss-and-damage expert and global convenor of the Fill the Fund campaign, tells Carbon Brief that the fund’s board deals with most funding requests as regular projects, rather than emergencies. Singh continues:
“Developed countries gave a really cold response to Nepal’s request. They have not addressed it because they know that if this happens once, they are going to be under pressure all the time. This is unacceptable.”
Meanwhile, BBC News reported that Nepal plans to use climate attribution studies to strengthen its claim.
According to a rapid attribution study by World Weather Attribution and climate experts who spoke to Carbon Brief, factors such as glacial retreat and permafrost thaw that played a key role in the disaster have been linked to climate change. A full attribution study is pending.
Nepal’s prime minister Balendra Shah will address the UN general assembly on 24 September and is expected to raise issues around climate justice, loss and damage and the vulnerability of mountain countries.
The next board meeting of the loss and damage fund is on 15 December, two months from now, and a fortnight after the conclusion of COP31 in Turkey.
Pandit Chhetri tells Carbon Brief:
“It’s a shame that, until now, the fund has not been able to even give a penny to developing countries. And, starkly, the event in Nepal only demonstrates why this kind of fund is so important for highly vulnerable, poor, developing countries.”
Pandit Chhetri adds that, after nearly three weeks since the disaster, there is yet to be a decision on the request and that the country has “only received messages of solidarity”, with no assurance of rapid response funds. He says that it is “quite an interesting scene for [us] to observe”, adding:
“If the fund cannot respond in a crisis like this for a country like Nepal – when you have this massive destruction and devastation – then what is the use of the fund itself? That’s why it is a test for the fund, though the resources are limited.”
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The post Analysis: Nepal’s $20m ‘loss-and-damage’ claim only covers 0.7% of flood costs appeared first on Carbon Brief.
Analysis: Nepal’s $20m ‘loss-and-damage’ claim only covers 0.7% of flood costs
Hi, I’m Daniel and I am the Chief Mate. Having worked at Greenpeace for over 31 years I often work as the Captain on all Greenpeace ships.
The oceans connect everyone. Our goal this trip is to turn visibility into accountability by documenting impacts, informing the public, and strengthening protections for Australia’s Commonwealth Marine Parks.
https://www.greenpeace.org.au/team/daniel/
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