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Scientists comment on Copernicus data that shows 2025 was the third hottest year on record.
Prof Richard Allan, climate scientist at the University of Reading, said:
“The record global warmth of 2023 to 2025 is not a surprise given the growing heating from rising greenhouse gas concentrations combined with a reduced cooling effect from declining particle aerosol pollution as countries strive to clean the air we breathe. It is also expected that polar regions will warm up faster than the rest of the globe as observed, though the record warmth in Antarctica and depleted global sea ice coverage are notable.
“The jump in global surface temperatures in 2023 are understood in the context of the continued human-caused heating of our planet combined with natural fluctuations that included an unusually lengthy La Niña cool phase flipping into a warm El Niño that peaked in 2024. Yet the sustained warmth into 2025, without the natural warming influence of El Niño, underscores the urgency of halting the heating of planet Earth and growing climate impacts by rapidly cutting greenhouse gases across all sectors of society.”
Prof John Marsham, Professor of Atmospheric Science, University of Leeds, said:
“This is, sadly, expected. With each new record, and each new devastating extreme, the media understandably ask climate scientists for comment. But in a brief quote it is hard to describe just how serious the risks to humanity are, as we rapidly take ourselves out of the climate our entire agriculturally-based civilisation is based on.
“Impacts on ecosystems, and human food and water systems are rapidly escalating and we are risking a climate that, in my kids’ lifetimes, is almost as different from our natural climate as the last ice-age was, only hotter instead of colder.
“This will be catastrophic for ecosystems, human health, and our food and water systems. At the recent National Emergency Briefing on Climate and Nature, MPs heard that the UK taking action can be profit making, even if other countries don’t act – with renewables lowering costs, creating jobs and providing energy security.
“We need people to call for urgent action, and hold both politicians and the media to account.”
Dr Karsten Haustein, Climate Scientist, Leipzig University, said:
“2025 is like a broken record. While no new all-time record has been broken, the latest three-year period has broken the 1.5°C limit for the first time. Also like a broken record, we keep saying that our carbon emissions need to come down quickly, yet progress is excruciatingly slow.
“While the 1.5°C limit is technically still not exceeded, it is only a matter of one to five years from now. 2025 reinforces the notion that the man-made warming trend has slightly increased over the last few years. Notably, Antarctica saw its warmest year, after a decade with cooler than average conditions likely due to natural variability. The fact that the 1.5°C limit has been exceeded for an average three-year period means that everyone should be prepared for more adverse weather, especially heat-related extremes. Their number will continue to increase every year until we end our toxic relationship with fossil fuels.”
Dr Chloe Brimicombe, Climate Scientist, University of Oxford, said:
“This new report highlights the importance of climate change, with evidence that the last 3 years are above the 1.5C target and that we could reach the targets in the Paris agreement (the most important international policy) almost a decade earlier than previous evidence showed.
“This report shows the rising number of extreme weather impacts that exceeding 1.5C over this average causes and how that impacts us all day to day, with some regions and individuals more vulnerable than others.
“Since it was found that the world was warming, progress has been made to limit this. But, thinking forward in 2026, we have a number of key UK Government climate policy documents being published and other international events such as meetings that take place as part of UN processes. These provide excellent platforms for climate action.
“This report also brings into focus topics like AI and Geoengineering. To resolve climate change technology is only one part of the solution; it would need to be used both ethically and morally and the guidelines and agreements do not exist at the moment to facilitate this.”
Prof Bill McGuire, Professor Emeritus of Geophysical & Climate Hazards at UCL, said:
“These are grim but far from unexpected tidings. To all intents and purposes, the 1.5C limit is now dead in the water. Whichever way you look at it, dangerous climate breakdown has arrived, but with little sign that the world is prepared, or even paying serious attention.
“If we are to stop dangerous becoming catastrophic, then we need to fight even more to stop every tonne of carbon being emitted, and prevent every fraction of a degree rise in the global temperature. Failure to do this will inevitably consign our children and their children – and countless generations down the line – to a hothouse hell”.
Declared interests
Richard Allan: “no conflicting interests”
Chloe Brimicombe: “No competing interests to disclose”
John Marsham: “No conflicts of interest”
Karsten Haustein: “No conflict of interests”
For all other experts, no reply to our request for DOIs was received.