Scientists: 2025 third-hottest year on record

Last year, 2025, was the third-hottest year ever recorded, according to scientists, as continued fossil fuel pollution drove what experts described as “exceptional” global temperatures.

New data from the EU’s Copernicus Climate Change Service shows that 2025 capped a scorching three-year period in which average global surface air temperatures reached 1.52C above pre-industrial levels, Caliber.Az reports. 

Copernicus said 2025 was marginally cooler than 2023 but still far hotter than any year prior to 2023. Scientists now warn that current warming rates could push the world beyond the Paris agreement’s 1.5C limit before the end of the decade—more than 10 years earlier than anticipated when the accord was signed in 2015. The Paris threshold is measured as a 30-year average to smooth out natural climate variability.

“We are bound to pass it,” Carlo Buontempo, director of the Copernicus climate change service, told The Guardian. “The choice we now have is how to best manage the inevitable overshoot and its consequences.”

The findings, published on January 14, are based on the reanalysis of billions of weather observations from satellites, aircraft, ships and ground stations. Several climate-monitoring organisations in Europe and the United States independently compiled the data, producing closely aligned results.

Copernicus’s ERA5 dataset calculated that 2025 was 1.47C warmer than the pre-industrial period, while the UK Met Office’s HadCRUT5 dataset estimated slightly lower warming of 1.41C. Berkeley Earth, a US-based non-profit, placed warming at 1.44C.

The hottest year on record remains 2024, which was marked by widespread heatwaves and wildfires. The Met Office said the last three years were made especially hot by natural climate variability and reductions in aerosol pollution that previously masked some warming.

Tim Osborn, director of the University of East Anglia’s climate research unit, said the El Niño weather pattern added around 0.1C to global temperatures in 2023 and 2024, contributing to the sharp rise in heat.

“This natural influence weakened by 2025,” he said. “And therefore the global temperature we observed in 2025 provides a clearer picture of the underlying warming.”

Copernicus reported that January 2025 was the hottest January ever recorded, while March, April and May were each the second-warmest for their respective months. All months except February and December were warmer than the same months in any year before 2023.

Polar regions experienced particularly severe warming. Antarctica recorded its hottest year on record, while the Arctic saw its second-hottest. Global sea ice fell to its lowest February level since satellite monitoring began in the 1970s. Over the course of the year, half of the world’s land area experienced more days than average of “strong” heat stress, when temperatures feel above 32C.

Berkeley Earth estimated that 8.5% of the global population lived in regions experiencing record-high annual temperatures in 2025 and warned that similar heat is likely in 2026.

Bill McGuire, emeritus professor of climate hazards at University College London, said the results were “grim but far from unexpected tidings”.

“To all intents and purposes, the 1.5C limit is now dead in the water,” he said. “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.”

Despite rapid growth in renewable energy, global emissions have continued to rise since the Paris agreement was signed. Laurence Rouil, director of the Copernicus atmosphere monitoring service, said the 2025 data made clear that human activity remains the dominant cause of rising temperatures.

“The atmosphere is sending us a message,” she said. “And we must listen.”

By Sabina Mammadli