The world has never been closer to surpassing the global heating limit of 1.5 degrees Celsius (2.7 Fahrenheit), even if only temporarily, the United Nations meteorological agency warned.
The World Meteorological Organization confirmed on Tuesday that 2023 was the hottest year on record by a clear margin. In a climate report, it found that records had been “broken again, in some cases” for key indicators such as greenhouse gas pollution, surface temperatures, ocean warming and acidification, sea level rise, Antarctic sea ice cover, and glaciers. to retreat.
Andrea Celeste Saulo, Secretary-General of the World Meteorological Organization, said the organization “is now issuing a red alert to the world.”
The report found that temperatures near Earth's surface were 1.45 degrees Celsius higher last year than in the late 19th century, when people began destroying nature on an industrial scale and burning large amounts of coal, oil and gas.
The 0.12°C margin of error in the temperature estimate is large enough for the possibility that the Earth has already warmed 1.5°C. But that doesn't mean world leaders have reneged on the promise they made in Paris in 2015 to stop global warming to that level by the end of the century, scientists warn, because they measure global warming using a 30-year average rather than calculating the rise. In one year.
The report documented violent extreme weather events – especially heat – on every inhabited continent. Rapid attribution studies have shown that some weather events have become stronger or more likely due to climate change.
“If we don’t stop burning fossil fuels, the climate will continue to warm, making life more dangerous, unpredictable and more expensive for billions,” said Frederik Otto, a climate scientist at Imperial College London who was not involved in the report. of people on earth.”
Climate scientists are divided over whether extreme temperatures seen at the start of 2024 represent an unexpected acceleration of the climate crisis. Some indicators, such as sea surface temperatures, were unexpectedly high – even taking into account the return of the ocean-warming weather pattern, El Niño – while other weather events reached rare extreme levels sooner than thought.
“In terms of temperatures, it can be said that a year like 2023, although extreme, is already possible in current climate simulations of humanity,” said Andreas Fink, a meteorologist at the Karlsruhe Institute of Technology who was not involved in the report. Hot climate. But not all extreme weather events can be simulated using current climate models.
The World Meteorological Organization has found a “ray of hope” in the growth of renewable energy. The report found that the amount of renewable energy added in 2023 was nearly 50% greater than the previous year, bringing it to the highest rate observed in the past two decades.
Simon Lewis, professor of global change science at University College London, said the climate situation represents an “accelerating crisis” for humanity. “This is, unfortunately, just the beginning of much worse impacts to come, given that carbon emissions are still rising and there is huge new investment continuing in fossil fuel extraction.”
The report concluded that marine heatwaves would burn a third of the world's oceans on average per day in 2023, damaging vital ecosystems and food systems. By the end of the year, only 10% of the oceans had escaped heatwave conditions.
Climate change has also exacerbated extreme weather events that have left people hungry and forced them from their homes, even if they are not the main factor in their suffering. The report found that the number of people suffering from “severe” food insecurity has more than doubled since 2019 to reach 333 million people in 2023, concentrated in Africa and South Asia.
The unequal impact of climate change is already being felt, said Carsten Hosten, a climate scientist at the University of Leipzig who was not involved in the report. On the other hand, public debate continues to pretend that the problems of the Global South do not matter [the global north] – And that the consequences of climate change can be overcome one way or another through technology.