The planet experienced its third-warmest year on record in 2025, and average temperatures have exceeded 1.5 degrees Celsius of global warming over three years, the longest period since records began, EU scientists said on Wednesday.
The data from the European Union's European Centre for Medium-Range Weather Forecasts (ECMWF) found that the last three years were the planet's three hottest since records began - with 2025 marginally cooler than 2023, by just 0.01 C.
Britain's national weather service, the UK Met Office, confirmed its own data ranked 2025 as the third-warmest in records going back to 1850. The World Meteorological Organization will publish its temperature figures later on Wednesday.
The hottest year on record was 2024.
Extreme weather conditions
ECMWF said the planet also just had its first three-year period in which the average global temperature was 1.5 C above the pre-industrial era - the limit beyond which scientists expect global warming will unleash severe impacts, some of them irreversible.
"1.5 C is not a cliff edge. However, we know that every fraction of a degree matters, particularly for worsening extreme weather events," said Samantha Burgess, strategic lead for climate at ECMWF.
Governments pledged under the 2015 Paris Agreement to try to avoid exceeding 1.5 C of global warming, measured as a decades-long average temperature compared with the pre-industrial era.
But their failure to reduce greenhouse gas emissions means that level could now be breached before 2030 - a decade earlier than had been predicted when the Paris accord was signed in 2015, ECMWF said.
"We are bound to pass it," said Carlo Buontempo, director of the EU's Copernicus Climate Change Service. "The choice we now have is how to best manage the inevitable overshoot and its consequences on societies and natural systems."
Political pushback
Currently, the world's long-term warming level is about 1.4 C above the pre-industrial era, ECMWF said. Measured on a short-term basis, the world already breached 1.5 C in 2024.
Exceeding the long-term 1.5 C limit - even if only temporarily - would lead to more extreme and widespread impacts, including hotter and longer heatwaves, and more powerful storms and floods.
In 2025, wildfires in Europe produced the highest total emissions on record, while scientific studies confirmed specific weather events were made worse by climate change - including Hurricane Melissa in the Caribbean and monsoon rains in Pakistan which killed more than 1,000 people in floods.
Despite these worsening impacts, climate science is facing increased political pushback. U.S. President Donald Trump, who has called climate change "the greatest con job", last week withdrew from dozens of U.N. entities including the scientific Intergovernmental Panel on Climate Change.
The long-established consensus among the world's scientists is that climate change is real, mostly caused by humans, and getting worse. Its main cause is greenhouse gas emissions from burning fossil fuels such as coal, oil and gas, which trap heat in the atmosphere.