For the first time, global warming has exceeded 1.5C across an entire year, according to the EU's climate service, Ednews reports citing the BBC.
World leaders promised in 2015 to try to limit the long-term temperature rise to 1.5C, 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 1.5C - we've seen floods, we've seen droughts, we've seen heatwaves and wildfires all over the world."
The period from February 2023 to January 2024 reached 1.52C of warming, according to the EU's Copernicus Climate Change Service. The following graph shows how that compares with previous years.
