Next year is set to be among the world’s hottest years, after 2024 breaks the 1.5C warming threshold for the first time, the Met Office said.
The Met Office outlook for 2025 suggests it is likely to be one of the three warmest years on record, with global average temperatures around 1.4C above pre-industrial levels, just behind 2024 and 2023.
This year is expected to be the warmest year on record and is now almost certain to exceed 1.5C above the pre-industrial period for the first time in a “sobering milestone in climate history” as the world exceeds, temporarily, a threshold beyond which the worst impacts of climate change are expected.
It means 2024 will beat the previous record of 1.45C set the year before in 2023.
Climate change is the main driver for the record heat, although global temperatures in 2023 and 2024 were also slightly pushed up by the El Nino process of natural climate variation, in which warmth from the tropical Pacific warms the Earth’s atmosphere, the experts said.
But although the Pacific is shifting to a cooler La Nina phase, 2025 is still expected to see average global temperatures well above anything seen before 2023.
Next year is forecast to be between 1.29C and 1.53C above pre-industrial averages, with a central estimate of 1.41C, the Met Office said.
Professor Adam Scaife, who leads the team that produced the Met Office’s global forecast for 2025, said: “Interestingly, the warm 2025 predicted global temperatures occur despite the tropical Pacific moving towards a La Nina phase which is driving slightly cooler conditions.
“Years, such as 2025, which aren’t dominated by the warming influence of El Nino, should be cooler.
“2016 was an El Nino year and at the time it was the warmest year on record for global temperature.
“In comparison to our forecast for 2025 though, 2016 is now looking decidedly cool.”
The Met Office flagged the chance that 2024 would see average global temperatures exceeding 1.5C above pre-industrial levels in its annual forecast late last year.
Global warming of 1.5C is seen as threshold beyond which increasingly dangerous heatwaves, storms, rising seas, melting ice and environmental collapse will be felt, and countries have pledged to “pursue efforts” to curb temperature rises to that level under the global Paris climate treaty.
The Met Office’s Dr Nick Dunstone, who led production of the forecast, said: “A year ago our forecast for 2024 highlighted the first chance of exceeding 1.5C.
“Although this appears to have happened, it’s important to recognise that a temporary exceedance of 1.5C doesn’t mean a breach of the Paris Agreement.”
“But the first year above 1.5C is certainly a sobering milestone in climate history,” he said.
The Met Office said it used a 20-year average to assess current global warming levels, including future climate projections and recent observations, which currently gave a long-term average of 1.3C above the pre-industrial period of 1850-1900.