2024 Temperatures Are on Track for a Record High, Researchers Find

The new report also says that global warming has hit a threshold, at least temporarily, that countries had pledged to avoid.

This year will almost certainly be the hottest year on record, beating the high set in 2023, researchers announced on Wednesday.

The assessment, by the Copernicus Climate Change Service, the European Union agency that monitors global warming, also forecast that 2024 would be the first calendar year in which global temperatures consistently rose 1.5 degrees Celsius above preindustrial levels. That’s the temperature threshold that countries agreed, in the Paris Agreement, that the planet should avoid crossing. Beyond that amount of warming, scientists say, the Earth will face irreversible damage.

Greenhouse gas emissions from the burning of fossil fuels are dangerously heating up the planet, imperiling biodiversity, increasing sea level rise and making extreme weather events more common and more destructive.

“These type of events will get worse and they will get more frequent,” said Samantha Burgess, deputy director of Copernicus. Recent storms like Hurricanes Helene and Milton and the flooding in Spain demonstrate just how devastating weather intensified by warming can be.

Still, it’s important to note that a single year above 1.5 degrees Celsius does not mean the Paris Agreement target has been missed.

Under the terms of the pact, for that to happen, temperatures would have to stay at or above 1.5 degrees over a 20-year period. Each year has natural variability, so one year that’s warmer or cooler is not as important as the general trend of warming. It’s that signal, the steady crawl of record hot year after record hot year, that has alarmed experts.

“It’s not good news, but it doesn’t mean we’ve broken the agreement,” Dr. Burgess said. If the trend continues for the next decade and greenhouses gas concentrations in the atmosphere remain at similar levels, that trajectory is more likely to be irreversible, she said.

The Copernicus report comes a week ahead of COP29, the annual United Nations climate talks at which countries come together to try to update national plans to address climate change. This year, the meeting will be held in Baku, Azerbaijan.

A climate report issued by the United Nations last month found that the world’s current climate plans are inadequate, only providing a 2.6 percent reduction in greenhouse gas emissions by 2030 compared to 2019 levels. The Intergovernmental Panel on Climate Change has said that reduction needs to be an order of magnitude larger: at least a 43 percent reduction by 2030 and 60 percent by 2035.

Even if the world stopped burning fossil fuels tomorrow, there would still be a lag in the reduction of global temperatures. That’s because it would take a while for the oceans and the land to absorb the carbon dioxide that’s already in the atmosphere. The Mediterranean would continue to warm. Droughts would drag on for many seasons.

“The reality is, every fraction of a degree matters,” Dr. Burgess said. “The sooner globally we cut emissions, the sooner our climate will stabilize.”

If President-elect Donald J. Trump withdraws the United States from the Paris accord, as he has promised, and as he did during his first administration, it would be “very bad news,” according to Diana Urge-Vorsatz, a professor at Central European University and vice chairwoman of the Intergovernmental Panel on Climate Change, the U.N. body that provides governments with scientific information to develop climate policies.

But she noted that during Mr. Trump’s last administration, cities, states and companies worked to overcome shortfalls by taking over climate leadership. “Let’s hope again,” Dr. Urge-Vorsatz said, “that other actors will step up and perhaps even take stronger action.”

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