BRUSSELS: The planet recorded its third warmest year on record in 2025, extending a spell of unprecedented heat, with no relief expected in 2026, US researchers and EU climate observers said on Wednesday.
The past 11 years have been the warmest on record, with 2024 topping the podium and 2023 coming in second, according to the EU's Copernicus Climate Change Service and Berkeley Earth, a nonprofit research organization based in California.
For the first time, global temperatures exceeded 1.5°C above pre-industrial times on average over the past three years, Copernicus said in its annual report.
“The warming peak observed between 2023 and 2025 has been extreme and suggests an acceleration in the rate of Earth's warming,” Berkeley Earth said in a separate report.
The landmark 2015 Paris Agreement commits the world to limiting warming to well below 2°C and continuing efforts to keep it at 1.5°C, a long-term goal that scientists say would help avoid the worst consequences of climate change.
UN chief Antonio Guterres warned in October that exceeding 1.5°C was “inevitable” but that the world could limit this exceedance period by cutting greenhouse gas emissions as quickly as possible.
Copernicus said the 1.5°C limit “could be reached by the end of this decade, more than a decade earlier than expected.”
But efforts to contain global warming suffered another setback last week when President Donald Trump said he would pull the United States, the world's second-largest polluter after China, from the key U.N. climate treaty.
Temperatures were 1.47°C above pre-industrial times in 2025 (just a fraction colder than in 2023), after 1.6°C in 2024, according to the EU climate monitor.
According to Berkeley Earth, about 770 million people experienced record-warm annual conditions where they live, while record-breaking annual average cold was not recorded anywhere.
Antarctica experienced its warmest year on record, while it was the second warmest in the Arctic, Copernicus said.
A AFP Analysis of Copernicus data from last month found that Central Asia, the Sahel region and northern Europe experienced their hottest year on record in 2025.
2026: the warmest room?
Both Berkeley and Copernicus warned that 2026 would not break the trend.
If the El Niño weather phenomenon warms up this year, “this could turn 2026 into another record year,” said Carlo Buontempo, director of the Copernicus Climate Change Service. AFP.
“Temperatures are rising. Therefore, we are likely to see new records. It doesn't matter too much whether it will be 2026, 2027 or 2028. The direction of travel is very, very clear,” Buontempo said.
Berkeley Earth said it expected this year to be similar to 2025, “with the most likely outcome being about the fourth warmest year since 1850.”
Fight against emissions
The reports come at a time when efforts to reduce greenhouse gas emissions, the main driver of climate change, are stalling in developed countries.
Emissions rose in the United States last year, breaking a two-year streak of declines, as harsh winters and the rise of AI fueled energy demand, think tank Rhodium Group said on Tuesday.
The pace of greenhouse gas emission reductions slowed in Germany and France.
“While greenhouse gas emissions remain the dominant driver of global warming, the magnitude of this recent increase suggests that additional factors have amplified recent warming beyond what we would expect from greenhouse gases and natural variability alone,” said Berkeley Earth Chief Scientist Robert Rohde.
The organization said international rules reducing sulfur in ship fuel since 2020 may have contributed to warming by reducing emissions of sulfur dioxide, which form aerosols that reflect sunlight away from Earth.
