2024 was the hottest year on record, and the 1st to breach the 1.5 C global warming limit, data reveals (2025)

For the first time, global warming exceeded 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels in 2024, new data has shown. That makes 2024 the hottest year on record.

Earth's average temperature in 2024 was around 2.9 F (1.6 C) above pre-industrial levels as greenhouse gas emissions hit an all-time high, according to the European Commission's Copernicus Climate Service.

And the effects of climate breakdown, and the human suffering it causes, are already evident — in unprecedented heatwaves, storms, droughts, floods and wildfires witnessed around the world.

"We are now teetering on the edge of passing the 1.5ºC level defined in the Paris Agreement and the average of the last two years is already above this level," Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF), said in a statement. "These high global temperatures, coupled with record global atmospheric water vapour levels in 2024, meant unprecedented heatwaves and heavy rainfall events, causing misery for millions of people."

Global warming of 2 C (3.6 F) is considered an important threshold, as warming beyond this greatly increases the likelihood of devastating and irreversible climate breakdown. This includes the collapse of most of the Greenland and West Antarctic ice sheets, extreme heat waves, severe droughts, water stress, and extreme weather across large parts of the globe.

Related: The most important and shocking climate stories of 2024

Around 200 countries pledged to limit global temperature rises to 1.5 C or under in the 2015 Paris Agreement. As this target refers to an average taken over more than two decades, today's news doesn't mean the agreement is defunct, but it does make meeting the target perilously uncertain.

"There's an extremely high likelihood that we will overshoot the long-term average of 1.5 C and the Paris Agreement limit," Burgess said at a news conference on Thursday (Jan 9.).

Last year's record temperatures can be partly explained by El Niño, a climate cycle lasting between 9-12 months that causes waters in the eastern tropical Pacific to grow warmer than usual, affecting global weather patterns.

However, following El Niño's end in April 2024, temperatures did not return to their previous averages — sparking debate among scientists about whether other weather patterns, cuts to shipping pollution, or reductions in cloud cover could be driving the apparent acceleration in global warming.

"Not every year is going to break records, but the long-term trend is clear," Gavin Schmidt, director of NASA's Goddard Institute for Space Studies (GISS) in New York, said in a statement. "We're already seeing the impact in extreme rainfall, heat waves, and increased flood risk, which are going to keep getting worse as long as emissions continue."

It's too early to say what this means for 2025. Global sea surface temperatures, which hit a record high in 2024, appear to now be cooling to more typical levels. And La Niña, El Niño's cooler counterpart, has developed in the equatorial Pacific Ocean, which should reduce temperatures further.

"All of the internationally produced global temperature datasets show that 2024 was the hottest year since records began in 1850," Carlo Buontempo, Director of the Copernicus Climate Change Service, said in the statement. "Humanity is in charge of its own destiny but how we respond to the climate challenge should be based on evidence. The future is in our hands — swift and decisive action can still alter the trajectory of our future climate."