Global forecast for 2025 sees temperatures falling back below 1.5°C

The average global surface temperature during 2025 will be between 1.29°C and 1.53°C – and most likely 1.41°C – above the pre-industrial average, according to a forecast by the Met Office, the UK’s national weather and climate service. That is slightly cooler than 2024, which is set to be the first calendar year to exceed 1.5°C.

“2024 will end up being near the top of our forecast confidence interval,” says Nick Dunstone of the Met Office. “This can happen by chance, but taken together with 2023 the observed global temperatures have been somewhat warmer than forecast.”

The forecasted fall in surface temperature in 2025 will be a result of heat being transferred from the atmosphere to the oceans due to the La Niña phenomenon, and does not mean the planet as a whole has stopped warming. The overall heat content of the oceans and atmosphere continues to rise because of increasing carbon dioxide emissions from human activities leading to higher atmospheric levels of CO2.

“Like most other climate prediction systems, the Met Office systems are going for a weak La Niña event in the coming months,” says Dunstone.

During La Niñas, cooler waters rise up in the Pacific and spread across the surface, resulting in a net transfer of heat from the atmosphere to the oceans. During El Niños, the opposite happens. An El Niño in 2023 contributed to that year’s record-smashing surface temperatures, which were then exceeded in 2024. However, the El Niño alone does not fully explain the record temperatures.

Other possible factors include the Tonga volcanic eruption in 2022 that injected large quantities of water vapour into the stratosphere, faster than anticipated reductions in aerosol emissions from industry and shipping, and changes in low clouds, says Dunstone.

“It is clearly important for climate scientists to establish the cause of the recent surge in global warming, so we can make more confident predictions about the coming years and decades,” he says.