Lake Titicaca in South America. Its water levels are receding, partly due to shifts in rainfall caused by Amazon deforestation. Photograph: Benjamin Swift/The Guardian
It took an FOI request to bring this national security assessment to light. For ‘doomsayers’ like us, it is the ultimate vindication
…
When the report at last appeared, thanks to an FoI request lodged by the Green Alliance, The Times reported that it had been significantly “abridged”, I expect by the same goons. Some of its starkest conclusions had been omitted. Even so, the assessment – believed to have been compiled by the joint intelligence committee (on which the heads of MI5, MI6 and GCHQ sit) – is not exactly reassuring.
It echoes warnings some of us have made for years, only to be dismissed as nutters, doomsayers and extremists. It tells us that “ecosystem degradation is occurring across all regions. Every critical ecosystem is on a pathway to collapse (irreversible loss of function beyond repair).” This presents a threat to “UK national security and prosperity”. It says “the world is already experiencing impacts including crop failures, intensified natural disasters and infectious disease outbreaks. Threats will increase with degradation and intensify with collapse.” The results will include geopolitical and economic instability, increased conflict and competition for resources. “It is unlikely the UK would be able to maintain food security if ecosystem collapse drives geopolitical competition for food.” It also warns that “conflict and military escalation will become more likely, both within and between states, as groups compete for arable land and food and water resources”.
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But what was cut from the report is, according to The Times, even graver, including a warning that the shrinkage of glaciers in the Himalayas, causing declining river flow, would “almost certainly escalate tensions” between China, India and Pakistan, leading to the possibility of nuclear war. Again, some of us have been trying to persuade governments to focus on this threat with little success.
…
The report, notably shorter than most of its kind, gives every appearance of having been hastily and crudely truncated.
…
I know this government exists only to disappoint us. But its environmental failures are even more striking than its failures on other issues. When the ruling party compares unfavourably with the one that brought us Boris Johnson and Liz Truss, it’s worse than a betrayal. It’s a threat to our survival.
dizzy: It was difficult to select extracts from this article, suggest that you read the original.
Nigel Farage urges you to ignore facts and reality and be a climate science denier like him and his Deputy Richard Tice. He says that Reform UK has received £Millions and £Millions from the fossil fuel industry to promote climate denial and destroy the planet.Donald Trump urges you to be a Climate Science denier like him. He says that he makes millions and millions for destroying the planet, Burn, Baby, Burn and Flood, Baby, Flood.Elon Musk urges you to be a Fascist like him, says that you can ignore facts and reality then.
A crowd of people watching the setting sun from a hill in Ealing, west London
MINISTERS blocked the publication of an intelligence report warning that climate change could cause “global competition for food” by the 2030s and trigger nuclear war in Asia.
The study, reportedly held back by Number 10 last autumn for being too negative, also highlights the potential for a massive increase in climate refugees.
A freedom of information request forced the release of the report put together in part by the joint intelligence committee, the body overseeing MI5 and MI6.
But the government only published an abridged version of the study, describing a “realistic possibility” that the decline of forests and glacier-fed rivers would lead to “global competition for food” beginning in the 2030s.
The unabridged version of the study goes further, according to The Times.
It describes a “reasonable worst-case scenario” in which several ecosystems could pass a tipping point as soon as 2030 after which it would be impossible to stop environmental degradation. This includes forests in Canada and Russia, as well as glaciers in the Himalayas that feed rivers on which two billion people depend.
Melting glaciers in the Asian mountain range would “almost certainly escalate tensions” between China, India and Pakistan, intelligence chiefs warned, which could potentially lead to nuclear conflict.
Britain would struggle to feed itself unless it made big investments into supply chains, the report said.
Donald Trump urges you to be a Climate Science denier like him. He says that he makes millions and millions for destroying the planet, Burn, Baby, Burn and Flood, Baby, Flood.Nigel Farage urges you to ignore facts and reality and be a climate science denier like him and his Deputy Richard Tice. He says that Reform UK has received £Millions and £Millions from the fossil fuel industry to promote climate denial and destroy the planet.Elon Musk urges you to be a Fascist like him, says that you can ignore facts and reality then.
This photo shows the site of a forest fire in Penco, Biobío region, Chile on January 18, 2026. (Photo by Xinhua via Getty Images)
“The first priority, as you know, in these emergencies is always to fight and extinguish the fire. But we cannot forget, at any time, that there are human tragedies here,” said the country’s president.
On the heels of another historically hot year for Earth, disasters tied to the fossil fuel-driven climate emergency have yet again turned deadly, with wildfires in Chile’s Ñuble and Biobío regions killing at least 18 people—a figure that Chilean President Gabriel Boric said he expects to rise.
The South American leader on Sunday declared a “state of catastrophe” in the two regions, where ongoing wildfires have also forced more than 50,000 people to evacuate. The Associated Pressreported that during a Sunday press conference in Concepción, Boric estimated that “certainly more than a thousand” homes had already been impacted in just Biobío.
“The first priority, as you know, in these emergencies is always to fight and extinguish the fire. But we cannot forget, at any time, that there are human tragedies here, families who are suffering,” the president said. “These are difficult times.”
According to the BBC, “The bulk of the evacuations were carried out in the cities of Penco and Lirquen, just north of Concepción, which have a combined population of 60,000.”
🚨 #Urgente | Región del Biobío: Continuamos desplegados en distintos puntos de la región, facilitando y agilizando el tránsito vehicular de los equipos de emergencia en las zonas más afectadas por los incendios forestales. Asimismo, estamos apoyando a las familias que… pic.twitter.com/ECCV7x3RAA
Some Penco residents told the AP that they were surprised by the fire overnight.
“Many people didn’t evacuate. They stayed in their houses because they thought the fire would stop at the edge of the forest,” 55-year-old John Guzmán told the outlet. “It was completely out of control. No one expected it.”
Chile’s National Forest Corporation (CONAF) said that as of late Monday morning, crews were fighting 26 fires across the regions.
Authorities say adverse conditions like strong winds and high temperatures helped wildfires spread and complicated firefighters’ abilities to control the fires. Much of Chile was under extreme heat alerts, with temperatures expected to reach up to 38ºC (100ºF) from Santiago to Biobío on Sunday and Monday.
Both Chile and Argentina have experienced extreme temperatures and heatwaves since the beginning of the year, with devastating wildfires breaking out in Argentina’s Patagonia earlier this month.
Scientists have warned and research continues to show that, as one Australian expert who led a relevant 2024 study put it to the Guardian, “the fingerprints of climate change are all over” the world’s rise in extreme wildfires.
“We’ve long seen model projections of how fire weather is increasing with climate change,” Calum Cunningham of Australia’s University of Tasmania said when that study was released. “But now we’re at the point where the wildfires themselves, the manifestation of climate change, are occurring in front of our eyes. This is the effect of what we’re doing to the atmosphere, so action is urgent.”
Sharing the Guardian‘s report on the current fires in Chile, British climate scientist Bill McGuire declared: “This is what climate breakdown looks like. But this is just the beginning…”
Chilean President Gabriel Boric declared a state of catastrophe in two regions in the south of the country as raging wildfires forced at least 20,000 people to evacuate and left at least 18 people dead https://t.co/1TJt5oHSZqpic.twitter.com/FReiQo1lha
The most recent United Nations Climate Change Conference, where world leaders aim to coordinate a global response to the planetary crisis, was held in another South American nation that has faced devastating wildfires—and those intentionally set by various industries—in recent years: Brazil. COP30 concluded in November with a deal that doesn’t even include the words “fossil fuels.”
“This is an empty deal,” Nikki Reisch of the Center for International Environmental Law said at the time. “COP30 provides a stark reminder that the answers to the climate crisis do not lie inside the climate talks—they lie with the people and movements leading the way toward a just, equitable, fossil-free future. The science is settled and the law is clear: We must keep fossil fuels in the ground and make polluters pay.”
Elon Musk urges you to be a Fascist like him, says that you can ignore facts and reality then.Donald Trump urges you to be a Climate Science denier like him. He says that he makes millions and millions for destroying the planet, Burn, Baby, Burn and Flood, Baby, Flood.Orcas discuss Donald Trump and the killer apes’ concept of democracy. Front Orca warns that Trump is crashing his country’s economy and that everything he does he does for the fantastically wealthy.
Original article by republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).
Environmental Protection Agency Administrator Lee Zeldin listens as President Donald Trump holds a Cabinet meeting in the Cabinet Room of the White House in Washington, DC on August 26, 2025. (Photo by Mandel Ngan/AFP via Getty Images)
“Administrator Zeldin is removing all incentives for big polluters to follow the law and turning a blind eye to those who suffer from the impacts of pollution.”
The Trump administration settled just 15 of the illegal pollution cases referred by the US Environmental Protection Agency in the first year of President Donald Trump’s second term in the White House, according to data compiled by a government watchdog—the latest evidence that Trump officials are placing corporate profits above the EPA’s mission to “protect human health and the environment.”
“Under [EPA Administrator] Lee Zeldin, anti-pollution enforcement is dying a quick death,” said Tim Whitehouse, executive director of PEER and a former enforcement attorney at EPA.
The DOJ lodged just one environmental consent decree in a case regarding a statutory violation of the Clean Air Act from the day Trump was inaugurated just over a year ago until now—signaling that the agency “virtually stopped enforcing” the landmark law that regulates air pollution.
“Enforcing the Clean Air Act means going after violators within the oil, gas, petrochemical, coal, and motor vehicle industries that account for most air pollution,” reads the report. “But these White House favorites will be shielded from any serious enforcement, at least, while Lee Zeldin remains EPA’s administrator.”
“For the sake of our health and the environment, Congress and the American people need to push back against Lee Zeldin’s dismantling of EPA’s environmental enforcement program.”
In the first year of his first term, Trump’s DOJ settled 26 Clean Air Act cases, even more than the 22 the department prosecuted in Biden’s first year.
The report warns that plummeting enforcement actions are likely to contribute to health harms in vulnerable communities located near waterways that are filled with “algae blooms, bacteria, or toxic chemicals” and near energy and chemical industry infrastructure, where people are more likely to suffer asthma attacks and heart disease caused by smog and soot.
“Enforcing environmental laws ensures that polluters are held accountable and prevented from dumping their pollution on others for profit,” said Joanna Citron Day, general counsel for PEER and a former senior counsel at DOJ’s Environmental Enforcement Section. “For the sake of our health and the environment, Congress and the American people need to push back against Lee Zeldin’s dismantling of EPA’s environmental enforcement program.”
EPA’s own enforcement and compliance database identifies 2,374 major air pollution sources that have not had a full compliance evaluation in at least five years, and shows that no enforcement action has been taken at more than 400 sources that are marked as a “high priority.”
Nearly 900 pollution sources reported to the EPA that they exceeded their wastewater discharge limits at least 50 times in the past two years.
The agency has also repealed its rules limiting carbon pollution from gas-powered cars, arguing that the EPA lacks the authority to regulate carbon.
As public health risks mount, PEER noted, Zeldin is moving forward with plans to stop calculating the health benefits of rules aimed at reducing air pollution, and issued a memo last month detailing a “compliance first” policy emphasizing a “cooperative, industry-friendly approach” to environmental regulation.
“Administrator Zeldin is removing all incentives for big polluters to follow the law,” said Whitehouse, “and turning a blind eye to those who suffer from the impacts of pollution.”
Donald Trump urges you to be a Climate Science denier like him. He says that he makes millions and millions for destroying the planet, Burn, Baby, Burn and Flood, Baby, Flood.Elon Musk urges you to be a Fascist like him, says that you can ignore facts and reality then.Orcas discuss Donald Trump and the killer apes’ concept of democracy. Front Orca warns that Trump is crashing his country’s economy and that everything he does he does for the fantastically wealthy.
The year 2025 was in the top-three warmest years on record, with average surface temperatures reaching around 1.44C above pre-industrial levels across eight independent datasets.
The different temperature records confirm that last year was either the second or third warmest since observations began in the mid-1800s, with razor-thin margins between 2025 and 2023.
Last year also set a new record for ocean heat content, with the oceans absorbing more than 90% of the heat trapped by increasing greenhouse gas concentrations in the atmosphere.
Here, Carbon Brief examines the latest data across the Earth’s oceans, atmosphere, cryosphere and surface temperature. (Use the links below to navigate between sections.)
Noteworthy findings from this 2025 review include…
Ocean heat content: It was the warmest year on record for ocean heat content and one of the largest year-over-year increases in ocean heat content. In 2025, the oceans added 39 times more heat than all annual human energy use.
Global surface temperatures:The year 2025 is effectively tied with 2023 as the second-warmest year on record – coming in at between 1.33C and 1.53C above pre-industrial levels across different temperature datasets and 1.44C in the synthesis of all groups.
Second warmest over land: Global temperatures over the world’s land regions – where humans live and primarily experience climate impacts – were 2C above pre-industrial levels, just below the record set in 2024.
Third warmest over oceans: Global sea surface temperatures were 1C above pre-industrial levels, dropping from 2024 record levels due to fading El Niño conditions.
Regional warming: It was the warmest year on record in areas where, collectively, more than 9% of the global population lives.
Unusual warmth: The exceptionally warm, record-setting temperatures over the past three years (2023-25) were driven by continued increases in human emissions of greenhouse gases, reductions in planet-cooling sulphur dioxide aerosols, variability related to a strong El Niño event and a strong peak in the 11-year solar cycle.
Greenhouse gases: Concentrations reached record levels for carbon dioxide (CO2), methane and nitrous oxide.
Sea ice extent: Arctic sea ice saw its lowest winter peak on record as well as its 10th-lowest summer minimum extent, while Antarctic sea ice saw its third-lowest minimum extent.
Looking ahead to 2026: Carbon Brief predicts that global average surface temperatures in 2026 are likely to be between the second and fourth warmest on record, similar to 2023 and 2025, at around 1.4C above pre-industrial levels.
Ocean heat content sets a new record
The year 2025 was the warmest on record for the heat content of the world’s oceans.
Ocean heat content (OHC) increased by around 500 zettajoules – billion trillion joules – since the 1940s.
The heat increase in 2025 alone compared to 2024 – about 23 zettajoules – is around 39 times as much as the total energy produced by all human activities on Earth in 2023 (the latest year in which global primary energy statistics are available). It was also the largest increase in ocean heat content since 2017 (following the strong El Niño event of 2016).
Human-emitted greenhouse gases trap extra heat in the atmosphere. While some of this warms the Earth’s surface, the vast majority – around of 93% – goes into the oceans. About two-thirds of this accumulates in the top 700 metres, but some also ends up in the deep oceans.
The figure below shows annual OHC estimates from the Chinese Institute for Atmospheric Physics (IAP) between 1950 and present for the upper 700 metres (light blue shading) and 700-2,000 metres (dark blue) of the ocean.
Annual global ocean heat content (in zettajoules – billion trillion joules, or 10^21 joules) for the 0-700 metre and 700-2,000 metre layers. Data updated from Cheng et al. (2024). Chart by Carbon Brief.
In a new paper published last week, researchers found that the rate of OHC increase over the past 15 years is unprecedented over the observational record in the IAP dataset. More broadly, there has been a distinct acceleration in OHC after 1991 – and recent OHC growth rates are generally consistent with satellite measurements of Earth energy imbalance (EEI).
(Energy imbalance is a measure of how much surplus heat there is in the Earth’s climate system. It is the difference between how much energy enters Earth’s atmosphere from the sun and how excess heat is radiated back into space as the world warms.)
In many ways, OHC represents a much better measure of climate change than global average surface temperatures, because it is where most of the extra heat ends up and is much less variable on a year-to-year basis than surface temperatures.
The analysis reveals that global surface temperatures were between the second and third warmest since records began in the mid-1800s. Temperatures effectively tied with 2023 within the margin of uncertainty, below the record set last year in 2024.
The figure below shows global surface temperature records from the eight datasets.
Global surface temperature records can be calculated back to 1850, though some groups such as NASA GISTEMP choose to start their records in 1880 when more data was available.
Prior to 1850, records exist for some specific regions, but are not sufficiently widespread to calculate global temperatures with high accuracy (though newly published research has attempted to extend this back to 1781).
These longer surface temperature records are created by combining ship- and buoy-based measurements of ocean sea surface temperatures with temperature readings of the surface air temperature from weather stations on land. (Copernicus ERA5 and JRA-3Q are an exception, as they use weather model-based reanalysis to combine lots of different data sources over time.)
Some differences between temperature records are apparent early in the record, particularly prior to 1900 when observations are more sparse and results are more sensitive to how different groups fill in the gaps between observations. However, there is strong agreement between the different temperature records for the period since 1970, as shown in the figure below.
Annual global average surface temperatures as in the prior chart, but showing the period from 1970-2025. Chart by Carbon Brief.
Global temperatures over the past three years clearly stand out as much warmer than anything that has come before, well above the prior record set in 2016. More broadly, the 11 warmest years on record all happened in the past 11 years.
Two of the eight datasets analysed by Carbon Brief – NASA and DCENT – had 2025 as the second-warmest year behind 2024, while six of the datasets had 2025 as the third-warmest year behind both 2023 and 2024.
However, in nearly all cases the difference between 2023 and 2025 falls within each dataset’s published uncertainty range, making it effectively a tie between the two years.
The table below shows the reported 2025 global temperature anomalies (relative to each group’s 1850-1900 pre-industrial baseline), as well as a 2025 value using a common pre-industrial baseline between the 1850-1900 and 1981-2010 periods across the five groups with data back to 1850 (NOAA, Hadley/UEA, Berkeley Earth, DCENT and China-MST).
Dataset
2025 Reported
2025 With common baseline
Ranking
NASA GISTEMP
1.39
1.45
Second
Hadley/UEA HadCRUT5
1.41
1.39
Third
NOAA GlobalTemp
1.33
1.41
Third
Berkeley Earth
1.44
1.44
Third
Copernicus ERA5
1.47
1.47
Third
JRA-3Q
1.46
1.46
Third
DCENT
1.53
1.44
Second
China-MST
1.39
1.42
Third
Reported temperature anomalies range from as low as 1.33C (NOAA) to as high as 1.53C (DCENT), primarily reflecting differences in the early part of the record. The 2025 values with a common baseline have a much smaller range, from 1.41C (NOAA) to 1.47C (Copernicus).
Separate land and ocean temperatures are not available yet from all of these groups. However, Berkeley Earth reports that global land temperatures in 2025 were the second warmest on record, at 2.03C above pre-industrial levels, while ocean temperatures were the third warmest at 1.03C.
Land and ocean temperature rise since the pre-industrial 1850-1900 period. Figure from Berkeley Earth.
Global land regions – where the global human population lives – has generally been warming around 70% faster than the oceans and 40% faster than the global average since 1970.
The year started off quite hot, with January 2025 setting a new record as the warmest January. All other months of the year ended up being either the second or third warmest on record after 2024 and 2023.
The figure below shows each month of 2025 in dark red, compared to all prior years since 1850. Each year is coloured based on the decade in which it occurred, with the clear warming over time visible, as well as the margin by which both 2023, 2024 and 2025 exceeded past years.
Monthly global surface temperatures for each year since 1850, using the average of the eight different temperature datasets assessed by Carbon Brief. Anomalies are shown relative to the pre-industrial 1850-1900 period.
Extreme regional temperatures
While the globe as a whole was tied as the second warmest on record, many different regions of the planet set new records in 2025.
The figure below shows how global temperature deviated from the average in 2025 across the world. Areas shaded in red were warmer than the baseline period (1951-80) used by Berkeley Earth, whereas the few blue areas experienced cooler temperatures.
Collectively, approximately 770 million people – 9.3% of Earth’s population – live in places that experienced their warmest year on record in 2025. This was mostly concentrated in Asia, including around 450 million people in China.
The figure below highlights regions of the planet that experienced their top-five warmest (red shading) or coldest (blue) temperatures on record in 2025. Overall, around 9% of the planet set a new record, including 11% of the land and 8% of the ocean. No location on the planet experienced record cold temperatures – or even top-five record cold temperatures – for the year as a whole.
Regions of the world among the five warmest (reds) of five coolest (blues) on record for average annual temperatures in 2025. Figure from Berkeley Earth.
Drivers of recent record warmth
Global temperatures over the past three years have been unusually warm, well above what would be expected given the long-term warming trend of around 0.2C per decade since the 1970s.
Recent research has found that global warming has accelerated in recent years to around 0.27C per decade, though this acceleration is largely in-line with climate model projections under scenarios where greenhouse gas emissions continue to rise while emissions of planet cooling aerosols are reduced.
According to analysis from Berkeley Earth, the odds of global temperatures over 2023-25 occurring as a result of greenhouse gas emissions and natural variations in the Earth’s climate alone “is less than one-in-100” and “likely indicates that recent years have been impacted by additional warming factor(s)”.
The figure below shows how the exceptional warming spike of 2023-25 compares to the longer-term warming trend and historical climate variability.
Global surface temperatures between 1965 and 2025 (blue) along with the linear trend (black) and range (grey) from 1970-2019. The red line shows a locally linear regression that captures recent acceleration. Figure from Berkeley Earth.
Carbon Brief recently explored the drivers of recent warmth in more detail, finding that it is likely to have been driven by a combination of:
A strong El Niño event that developed in the latter part of 2023.
An unusual volcanic eruption in Tonga in 2022 that put a large amount of aerosols and water vapor into the upper atmosphere.
A stronger-than-expected solar cycle.
This is illustrated in the figure below, which provides an estimate of the impact of each of these different factors on 2023 and 2024 temperatures, along with their respective uncertainties.
The sum of all the factors is shown in the “combined” bar, while the actual warming compared to expectations is shown in red. The upper chart shows 2023, while the lower one shows 2024.
Attribution of 2023 and 2024 unusual warmth. Light blue bars show individual factors and their uncertainties, the dark blue bar shows the combined effects and combination of uncertainties and the red bar shows the actual warming compared with expectations. HTHH refers to the Hunga Tonga-Hunga Ha’apai volcano. Adapted from Figure 12 in WMO’s state of the global climate 2024 report.
The first bar includes both El Niño and natural year-to-year climate variability; the height of the bar reflects the best estimate of El Niño’s effects, while the uncertainty range encompasses year-to-year variability in global temperatures that may be – at least in part – unrelated to El Niño.
While a similar analysis has yet to be undertaken for 2025, the end of El Nino conditions and the development of a modest La Nina would have driven temperatures down, while the warming impact of shipping, Chinese aerosol declines would have slightly increased. The warming effect of the solar cycle would likely have remained flat or slightly declined as solar cycle 25 passed its peak.
Finally, a World Meteorological Organization (WMO) assessment of the Hunga Tonga-Hunga Ha’apai volcano found that “the record-high global surface temperatures in 2023-24 were not due to the Hunga eruption”.
The report suggested that the volcano had a small cooling effect (-0.03C) globally in 2023 and 2024. This might switch to a small warming effect (+0.03C) in 2025 and 2026 as the planet-cooling aerosols from the volcano fall back down to the surface but some of the stratospheric water vapour remains, it noted.
However, it added, these effects are “indistinguishable from background variability in the current climate”.
El Niño and La Niña are generally the largest drivers of year-to-year variability in global temperatures. The figure below shows the El Niño (red shading) and La Niña (blue) conditions over the past 40 years (collectively referred to as the El Niño-Southern Oscillation, or “ENSO”).
Carbon Brief has used the historical relationship between ENSO conditions and temperature to effectively remove the effects of El Niño and La Niña events from global temperatures, as shown in the figure below.
This analysis indicates that El Niño cooled global temperatures in 2025 around -0.05C, following a boost to global temperatures of around 0.12C in 2024, compared to the estimate of global temperatures with both El Niño and La Niña events removed.
Annual global average surface temperatures from the average of the eight datasets, as well as Carbon Brief’s estimate of global temperatures with the effect of El Niño and La Niña (ENSO) events removed using the Foster and Rahmstorf (2011) approach. Chart by Carbon Brief.
This suggests that the shift from El Nino to La Nina conditions can fully explain the decline in global temperatures between 2024 and 2025 and that 2025 would have likely been the warmest year in the observational record if it had not been for the effects of ENSO.
Scientists provided estimates of where they expected 2025 temperatures to end up at the start of the year.
The figure below shows estimates by four different groups that provided temperature predictions for the year prior to any data being collected – the Met Office, NASA’s Dr Gavin Schmidt, Berkeley Earth and Carbon Brief’s own estimate — compared to what actually transpired.
Temperature predictions for 2025 from UK Met Office, NASA’s Dr Gavin Schmidt, Berkeley Earth and Carbon Brief’s estimate relative to pre-industrial (1850-1900) temperatures and compared to the historical average of the eight observational datasets. Chart by Carbon Brief.
Unlike in 2023 –and, to a lesser extent, 2024 –when start-of-year predictions were notably low, 2025 fell reasonably in-line with what was expected. The Met Office estimate was nearly exactly on target, with Berkeley Earth’s being close as well. Carbon Brief and Schmidt’s estimates were a little on the low side, but actual temperatures were well within the estimated error bars.
Observations in-line with climate model projections
Climate models provide physics-based estimates of future warming given different assumptions about future emissions, greenhouse gas concentrations and other climate-influencing factors.
Here, Carbon Brief examines a collection of climate models – known as CMIP6 – used in the 2021 science report of the IPCC’s sixth assessment.
In CMIP6, model estimates of temperatures prior to 2015 are a “hindcast” using known past climate influences, while temperatures projected from 2015 onward are a “forecast” based on an estimate of how things might change.
The figure below shows how observations compare to the full ensemble of 37 CMIP6 models under the middle-of-the-road SSP2-4.5 emissions scenario for future projections. The red line represents the average of all the models and the red areas showing the 5th to 95th percentile range. The average of the eight observational temperature datasets are plotted as dots on top of the climate model data.
The chart illustrates how observations have generally been a bit below the model average over the past two decades, were slightly above model average in 2024 and are more or less dead on in 2025.
Annual global average surface temperatures from CMIP6 models and observations between 1950 and 2030 (through 2025 for observations). Models use the SSP2-4.5 scenario after 2015. Anomalies plotted with respect to a 1850-1900 baseline. Chart by Carbon Brief.
However, the ensemble of CMIP6 models differs from the main projection of future warming in the recent IPCC AR6 report. A subset of CMIP6 models have unrealistically high climate sensitivity and they reproduce historical observations poorly.
To account for this, rather than simply averaging all the models – as had been done in prior assessments – the IPCC employed an approach that effectively weights models by their performance. As a result, the models align better with the range of climate sensitivity derived from multiple different lines of evidence.
The chart below shows the assessed warming projections from the IPCC AR6 report in red, with historical observations since 1850 as black dots.
Annual global average surface temperatures from the average of eight datasets (black dots) along the 30-year LOWESS fit (red line), combined the AR6 assessed warming projection for SSP2-4.5 as published and without any baseline alignment. Chart by Carbon Brief.
The chart reveals that observed global surface temperatures (black dots) are further above the modeled central estimate 2023-25, but generally remain within the IPCC assessed range.
Climate models broadly expect an acceleration of warming in the current period in a scenario like SSP2-4.5 where emissions of CO2 and other greenhouse gases continue to modestly increase, but emissions of planet-cooling aerosols like sulphur dioxide are rapidly reduced.
Second-warmest atmospheric temperatures
In addition to surface measurements over the world’s land and oceans, satellite microwave sounding units have been providing estimates of temperatures at various layers of the atmosphere since 1979.
The lowest layer of the atmosphere that satellite microwave units provide temperature estimates for is the lower troposphere. This data reflects temperatures a few kilometres above the Earth’s surface. It reveals a pattern of warming in the lowest troposphere that is similar – though not identical – to surface temperature changes.
The records produced by Remote Sensing Systems (RSS), the University of Alabama, Huntsville (UAH) and NOAA show 2025 as the second warmest year on record in the lower troposphere, after 2024. The chart below shows the three records for the lower troposphere, using a more recent baseline period (1981-2010) given the absence of satellite data before 1979.
Global average lower-troposphere temperatures from RSS version 4 (dark blue), UAH version 6 (mid-blue) and NOAA STAR version 5 (light blue) for the period from 1979-2025, relative to a 1981-2010 baseline. Chart by Carbon Brief.
The lower troposphere tends to be influenced more strongly by El Niño and La Niña events than the surface. Therefore, satellite records show correspondingly larger warming or cooling spikes during these events. This explains why there was both a bigger increase between 2023 and 2024 and a bigger decline between 2024 and 2025 in the satellite record than in surface records.
The lower-tropospheric temperature records show large differences after the early 2000s. RSS shows an overall rate of warming quite similar to surface temperature records, while UAH and NOAA show considerably slower warming in recent years than has been observed on the surface.
Greenhouse gas concentrations reach new highs
Greenhouse gas concentrations reached a new high in 2025, driven by human-caused emissions from fossil fuels, land use and agriculture.
Three greenhouse gases – CO2, methane (CH4) and nitrous oxide (N2O) – are responsible for the bulk of additional heat trapped by human activities. CO2 is by far the largest factor, accounting for roughly 42% of the increase in global surface temperatures since the pre-industrial era (1850-1900).
Methane accounts for 28%, while nitrous oxide accounts for around 5%. The remaining 25% comes from other factors including carbon monoxide, black carbon and halocarbons, such as chlorofluorocarbons (CFCs).
Human emissions of greenhouse gases have increased atmospheric concentrations of CO2, methane and nitrous oxide to their highest levels in at least a few million years – if not longer.
The figure below shows concentrations of these greenhouse gases – in parts per million (ppm) for CO2 and parts per billion (ppb) for methane and nitrous oxide – from the early 1980s through to October 2025 for CO2 and September 2025 for CH4 and N2O (the most recent data currently available).
Global concentrations of CO2, methane (CH4) and nitrous oxide (N2O). Based on data from NOAA’s Earth Systems Research Laboratory. Note that the y-axes do not start at zero. Chart by Carbon Brief.
Sea level is rising rapidly
Modern-day sea levels have risen to a new high, due to a combination of melting land ice (such as glaciers and ice sheets), the thermal expansion of water as it warms and changes in land water storage.
In recent years, there have been larger contributions to sea level rise from melting ice sheets and glaciers, as warmer temperatures accelerate ice sheet losses in Greenland and Antarctica.
Since the early 1990s, the increase in global sea level has been estimated using altimeter data from satellites. Earlier global sea levels have been reconstructed from a network of global tide gauge measurements. This allows researchers to estimate how sea level has changed since the late 1800s.
The chart below shows five different modern sea level rise datasets (blue lines), along with satellite altimeter measurements as assessed by AVISO (in black) after 1993. (As sea level rise data has not yet been released for the whole year, the 2025 value is estimated based on data through to November.)
Global average sea level rise reconstructed from tide gauge data between 1880 and 2025 from Frederikse et al. (2020), Dangendorf et al. (2019), Hay et al. (2015), Church and White (2011), and Palmer et al. (2021). Satellite altimeter data from 1993 (black) to present is taken from AVISO. Chart by Carbon Brief.
Sea levels have risen by over 0.2 metres (200mm) since 1900. While sea level rise estimates mostly agree in recent decades, larger divergences are evident before 1980. There is also evidence of accelerating sea level rise over the post-1993 period when high-quality satellite altimetry data is available.
(To understand more on how climate change is accelerating sea level rise, read Carbon Brief’s explainer.)
Shrinking glaciers and ice sheets
A significant portion of global sea level rise is being driven by melting glaciers on land.
Scientists measure the mass of glaciers around the world using a variety of remote-sensing techniques, as well as through GRACE measurements of the Earth’s gravitational field. The balance between snow falling on a glacier and ice loss through melting and the breaking off – or “calving” – of icebergs determines if glaciers grow or shrink over time.
The World Glacier Monitoring Service is an international consortium that tracks more than 130 different glaciers in 19 different regions around the world. The figure below shows the change in global average glacier mass from 1950 through to the end of 2024. (2025 values are not yet available.) Note that glacier melt is reported in metres of water equivalent, which is a measure of how much mass has been lost on average.
Global average glacier melt over the 1950-2024 period from the World Glacier Monitoring Service, in metres of water equivalent. Carbon Brief.
Greenland ice sheets have become a larger contributor to sea level rise in recent years due to accelerating loss of mass. The year 2025 was the 29th in a row where Greenland lost ice overall, with 105bn tonnes of ice lost over the 12 months from September 2024 to August 2025. Greenland last saw an annual net gain of ice in 1996.
The figure below shows the cumulative mass balance change – that is, the net ice loss – from Greenland between 1970 and 2025. The authors find that Greenland has lost around 6tn tonnes of ice over the past 50 years – more than 700 tonnes lost per person for every person on the planet.
Cumulative ice loss from Greenland in billion metric tonnes (gigatonnes) between 1970 and 2025 from Mankoff et al 2021. Chart by Carbon Brief.
Lowest winter Arctic sea ice extent
Arctic sea ice saw its lowest winter peak on record as well as its 10th-lowest summer minimum extent, while Antarctic sea ice saw its third-lowest minimum extent.
Both the Arctic and Antarctic were at the low end of the historical (1979-2010) range for most of 2025, with new daily lows recorded for Arctic sea ice extent in January, February, March, June and December.
The figure below shows both Arctic (red line) and Antarctic (blue line) sea ice extent for each day of the year, along with how it compares to the historical range (corresponding shading).
Arctic and Antarctic daily sea ice extent from the US National Snow and Ice Data Center. The bold lines show daily 2025 values, the shaded area indicates the two standard deviation range in historical values between 1979 and 2010. The dotted black lines show the record lows for each pole. Chart by Carbon Brief.
Looking ahead to 2026
There is reason for caution when estimating likely temperatures for 2026.
In 2023, temperatures were significantly higher than predictions made at the start of the year, while 2024 temperatures were towards the high end of annual predictions. Temperatures in 2025 were more in-line with predictions, albeit still on the higher side for three out of the four predictions included above.
There are currently weak La Niña conditions currently present in the tropical Pacific, which are expected to extend through February. This would somewhat suppress temperatures in the first half of the year. However, the latest forecasts suggest a growing likelihood of El Niño conditions developing by June, which may lead to warmer temperatures in late 2026 – and potentially much warmer temperatures in 2027.
Carbon Brief predicts that global average surface temperatures in 2026 are likely to be between the second and fourth warmest on record, similar to 2023 and 2025, at around 1.4C above pre-industrial levels.
The figure below shows the four different 2026 predictions compared to the average of eight different temperature records explored in this article. (These have been “normalised” to show 2026 warming relative to the 2023-25 average to allow a clear comparison, given that each of the predictions was originally presented for a different temperature record.)
Carbon Brief’s prediction of likely 2026 temperatures is based on a statistical model using the average temperature of the past year, the latest monthly temperature and projections of ENSO conditions over the first three months of 2026.
Temperature projections for 2026 from the Met Office, NASA’s Dr Gavin Schmidt, Berkeley Earth and Carbon Brief, relative to pre-industrial (1850-1900) temperatures and compared to the historical average of eight different surface temperature datasets. Chart by Carbon Brief.
The Met Office, Dr Schmidt, Berkeley Earth and Carbon Brief estimates all have 2026 ending up as somewhere between the second- and fourth-warmest year on record, with the best estimate as being more or less tied with 2023 and 2025.
There is a very small chance that 2026 could end up beating 2024 as the warmest year on record, or end up below 2016 as the fifth or sixth warmest year.
However, with the growing likelihood of El Niño conditions developing in the second half of 2026, it is increasingly likely that 2027 will challenge 2024 for the title of the warmest year on record. The rate of warming has notably accelerated over the past 15 years and the period of exceptionally warm years that started in 2023 shows no signs of abating.
Experienced climbers scale a rock face near the historic Dumbarton castle in Glasgow, releasing a banner that reads “Climate on a Cliff Edge.” One activist, dressed as a globe, symbolically looms near the edge, while another plays the bagpipes on the shores below. | Photo courtesy of Extinction Rebellion and Mark Richards
Donald Trump urges you to be a Climate Science denier like him. He says that he makes millions and millions for destroying the planet, Burn, Baby, Burn and Flood, Baby, Flood.Nigel Farage urges you to ignore facts and reality and be a climate science denier like him and his Deputy Richard Tice. He says that Reform UK has received £Millions and £Millions from the fossil fuel industry to promote climate denial and destroy the planet.
A crowd of people watching the setting sun from a hill in Ealing, west London
