For the first time, global warming has exceeded 1.5°C across an entire year, according to the EU’s climate service.

World leaders promised in 2015 to try to limit the long-term temperature rise to 1.5°C, which is seen as crucial to help avoid the most damaging impacts. This first year-long breach doesn’t break that landmark “Paris agreement”, but it does bring the world closer to doing so in the long-term. Urgent action to cut carbon emissions can still slow warming, scientists say.

“This far exceeds anything that is acceptable,” Prof Sir Bob Watson, a former chair of the UN’s climate body, told the BBC Radio 4’s Today Programme. “Look what’s happened this year with only 1.5°C – we’ve seen floods, we’ve seen droughts, we’ve seen heatwaves and wildfires all over the world, and we’re starting to see less agricultural productivity and some problems with water quality and quantity.”

Limiting long-term warming to 1.5°C above “pre-industrial” levels – before humans started burning large amounts of fossil fuels – has become a key symbol of international efforts to tackle climate change. A landmark UN report in 2018 said that the risks from climate change – such as intense heatwaves, rising sea-levels and loss of wildlife – were much higher at 2°C of warming than at 1.5°C. But temperatures have kept rising at a concerning pace, data from the EU’s Copernicus Climate Change Service from the past year shows, illustrated in the graph below. The period from February 2023 to January 2024 reached 1.52°C of warming.