The internationally agreed goal to keep the world’s temperature rise below 1.5C is now “deader than a doornail”, with 2024 almost certain to be the first individual year above this threshold, climate scientists have gloomily concluded – even as world leaders gather for climate talks on how to remain within this boundary.

Three of the five leading research groups monitoring global temperatures consider 2024 on track to be at least 1.5C (2.7F) hotter than pre-industrial times, underlining it as the warmest year on record, beating a mark set just last year. The past 10 consecutive years have already been the hottest 10 years ever recorded.

“The goal to avoid exceeding 1.5C is deader than a doornail. It’s almost impossible to avoid at this point because we’ve just waited too long to act,” said Zeke Hausfather, climate research lead at Stripe and a research scientist at Berkeley Earth. “We are speeding past the 1.5C line an accelerating way and that will continue until global emissions stop climbing.”