BBCThe planet has taken a major step towards warming by more than 1.5 degrees Celsius, despite world leaders vowing a decade ago to try to avoid it, new data shows.
The European Copernicus Climate Service, one of the world's leading providers of data, said on Friday that 2024 is the first calendar year to exceed the symbolic threshold, as well as the world's hottest year on record.
This does not mean that the international target of 1.5°C temperature reduction has been broken, as this indicates a long-term average over decades, but it does bring us closer to achieving this as fossil fuel emissions continue to heat the atmosphere.
Last week, UN Secretary-General António Guterres described the recent rise in temperatures as a “climate collapse.”
“We must get off this road to ruin – and we have no time to waste,” he said in his New Year message, calling on countries to reduce greenhouse gas emissions in 2025.
Average global temperatures for 2024 were about 1.6 degrees Celsius higher than in the pre-industrial period – the time before humans began burning large amounts of fossil fuels – according to the Copernicus data.
this Breaks the record set in 2023 By just over 0.1°C, this means the past 10 years are now the 10 warmest years on record.
The Met Office, NASA and other climate groups are due to release their own data later on Friday. Everyone is expected to agree that 2024 was the hottest year on record, although exact numbers vary slightly.
Last year's heat was mostly due to human emissions of greenhouse gases, such as carbon dioxide, which remain at record levels.
Natural weather patterns such as El Niño – where surface waters in the eastern tropical Pacific Ocean become unusually warm – played a smaller role.
Samantha Burgess, deputy director of Copernicus, told the BBC: “The biggest contribution ever to affecting our climate is the concentrations of greenhouse gases in the atmosphere.”
The 1.5°C 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 viewing it as a matter of survival.
Risks from climate change, such as extreme heatwaves, rising sea levels and loss of wildlife, will be much higher at 2°C of temperature rise than at 1.5°C, according to a new report. Landmark UN report from 2018.
However, the world was getting closer and closer to breaching the 1.5°C barrier.
“It is difficult to predict exactly when we will exceed the 1.5°C threshold in the long term, but it is clear that we are very close now,” says Miles Allen of the Department of Physics at the University of Oxford, and author of the UN report.
The current trajectory will likely see the world surpass 1.5°C of long-term temperature rise by the early 2030s. This will be politically important, but it does not mean game over for climate action.
“It's not as if 1.49°C is good and 1.51°C is the end of the world — every tenth of a degree matters and climate impacts get progressively worse the higher we get,” says Zeke Hausfather, a climate scientist at Berkeley Earth, a research group at the University of California. Our temperatures. US.
Even fractions of a degree of global temperature can lead to more frequent and intense extreme weather, such as heatwaves and torrential rains.
In the year 2024, the world witnessed High temperatures in West Africalengthy Drought in parts of South Americasevere Rainfall in Central Europe Some in particular Strong tropical storms Hit North America and South Asia.
These events were just some of those It is becoming more severe due to climate change Over the past year, according to the World Weather Attribution Group.
Even this week, as the new numbers were released, Los Angeles had suffered devastating wildfires fueled by high winds and lack of rain.
While there are many contributing factors to this week's events, Experts say conditions conducive to wildfires in California are becoming more likely In a warm world.
It's not just air temperatures that set new records in 2024 The world's sea level also reached a new daily highWhile the total amount of moisture in the atmosphere has reached record levels.
That the world is breaking new records is no surprise: 2024 was always expected to be a hot year, due to the influence of the El Niño weather pattern – which… It ended around April of last year – In addition to human-caused warming.
But the margin of many records in recent years has been less than expected, as some scientists fear that this represents an acceleration in global 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 1.5°C this early,” says Dr Hausfather.
“Since 2023, we have seen about 0.2°C of additional warming that we cannot fully explain, on top of what we expected from climate change and El Niño,” agrees Helge Gosling, a climate physicist at the Alfred Wegener Institute in Germany.
Various theories have been proposed to explain this “extra” warming, such as an apparent reduction in low-level cloud cover that tends to cool the planet, and a prolonged warming of the ocean after the end of El Niño.
Dr Gosling adds: “The question is whether this acceleration is an ongoing thing linked to human activities, meaning we will see a sharp rise in temperatures in the future, or whether it is part of natural fluctuations.”
“Right now it's very difficult to say.”
Despite this uncertainty, scientists stress that humans can still control the climate of the future, and that sharp reductions in emissions could reduce the consequences of global warming.
“Even if 1.5 degrees Celsius is outside the window, we can still probably limit temperature rise to 1.6 degrees Celsius, 1.7 degrees Celsius, or 1.8 degrees Celsius in this century,” says Dr. Hausfather.
“That would be a lot better than if we continued burning coal, oil and gas unabated and ended up at 3 or 4 degrees Celsius – it still really matters.”
