2024 exceeded the 1.5 C warming limit for the first time

New data shows the planet has taken a big step towards warming by more than 1.5°C, despite world leaders vowing to try to avoid this a decade ago.

Europe’s Copernicus climate service, one of the world’s leading data providers, said on Friday that 2024 was the first calendar year to exceed the symbolic threshold, as well as the world’s hottest.

This does not mean that the international target of 1.5C, which is considered a long-term average over decades, has been breached, but it does bring us closer to it as fossil fuel emissions continue to warm the atmosphere.

Last week UN chief António Guterres described the recent record-breaking heat wave as a “climate breakdown”.

“We must get off this path to ruin, and we have no time to lose,” he said in his New Year’s message, calling on countries to cut greenhouse gas emissions by 2025.

The average global temperature by 2024 was about 1.6C above pre-industrial times – the time before humans started burning large amounts of fossil fuels – according to Copernicus data.

This It broke the record set in 2023 Just over 0.1C, meaning the last 10 years are now the warmest 10 years on record.

The Met Office, Nasa and other climate groups will release their data later on Friday. Everyone is expected to agree that 2024 was the hottest on record, even if the exact figures vary slightly.

Last year’s heat is mainly due to human emissions of planet-warming gases, such as carbon dioxide, which are still at record levels.

Natural weather patterns such as El Niño – where surface waters in the eastern tropical Pacific become unusually warm – played a smaller role.

“The biggest contributor to our climate is the concentration of greenhouse gases in the atmosphere,” Copernicus deputy director Samantha Burgess told the BBC.

The 1.5C figure has become a powerful symbol in international climate negotiations since it was agreed in Paris in 2015, with many of the most vulnerable countries considering it a matter of survival.

The risks of climate change, such as extreme heat waves, rising sea levels and loss of wildlife, would be much greater at 2C warming than at 1.5C. 2018 UN landmark report.

However, the world is getting closer to crossing the 1.5 C barrier.

“It is difficult to predict exactly when we will cross the 1.5 C threshold in the long term, but we are obviously very close now,” says Myles Allen of Oxford University’s Department of Physics and co-author of the UN report.

The current trajectory would likely see the world exceed 1.5 C of long-term warming by the early 2030s. This would be politically significant, but it would not be a game over for climate action.

“It’s not like 1.49C is OK, and 1.51C is the apocalypse – every tenth of a degree matters and climate impacts get worse with more warming,” explained Zeke Hausfather, of Berkeley Earth. a group of researchers. USA

Even fractions of a degree of global warming could lead to more frequent and intense extreme weather, such as heat waves and heavy rainfall.

In 2024, the world saw it Blistering temperatures in West Africastretch out drought in some parts of South Americalife Precipitation in central Europe and some in particular strong tropical storms Hitting North America and South Asia.

These events were some of them more intense due to climate change last year, according to the World Weather Attribution group.

Also this week, as new figures come in, Los Angeles has been plagued by devastating fires fueled by high winds and a lack of rain.

Although there are many actors involved in this week’s events, Experts say the conditions for California wildfires are becoming more likely in a warming world.

It wasn’t just air temperatures that set new records in 2024 The world’s sea level also reached a new daily levelwhile the total amount of moisture in the atmosphere reached record levels.

It’s no wonder the world is breaking new records: 2024 was expected to be the hottest ever, thanks to the El Niño weather pattern. it ended around April last year – on human-caused warming.

But it is expected to be less than the margin of several records in recent years, and some scientists fear it could mean an acceleration of warming.

“I think it’s safe to say that the temperatures in 2023 and 2024 surprised most climate scientists – we didn’t think we’d see a year above 1.5C so early,” says Dr Hausfather.

“We have had an additional warming of about 0.2 C since 2023, which we cannot fully explain, apart from climate change and what we expected from El Niño,” agreed climate physicist Helge Gößling of the Alfred Wegener Institute in Germany. .

Several theories have been proposed to explain this “extra” warmth, such as a reduction in low-level cloud cover that tends to cool the planet, and prolonged ocean warming at the end of El Niño.

“The question is whether this acceleration is something permanent related to human activities, which means we will have more warming in the future, or whether it is part of natural variability,” added Dr. Gößling.

“At the moment it is very difficult to say.”

Despite this uncertainty, scientists emphasize that humans still have control over the future climate, and that drastic reductions in emissions can mitigate the effects of warming.

“Even if it’s 1.5 degrees out of the window, we can probably limit warming to 1.6, 1.7 or 1.8 degrees this century,” says Dr Hausfather.

“That will be much better than if we burn coal, oil and gas non-stop and end up at 3C or 4C – it’s still important.”