Second-warmest November on record means that 2024 is likely to be Earth's hottest year, report says

Earth just experienced its second-warmest November on record — second only to 2023 — making it all but certain that 2024 will end as the hottest year ever measured, according to a report Monday by European climate service Copernicus.

Last year was the hottest on record due to human-caused climate change coupled with the effects of an El Nino. But after this summer registered as the hottest on record — Phoenix sweltered through 113 consecutive days with a high temperature of at least 100 degrees Fahrenheit (37.7 Celsius) — scientists were anticipating that 2024 would set a new annual record as well.

In November, global temperatures averaged 14.10C (57.38F). Last year's global average temperature was 14.98C (59F). Through November, this year's average global temperature is 0.14C (32F) above the same period last year.

Jennifer Francis, a climate scientist at the Woodwell Climate Research Center in Cape Cod, who wasn't involved in the report, said the big story about November is that “like 2023, it beat out previous Novembers by a large margin.”

This also likely will be the first calendar year in which the average temperature was more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial times, the report said. The 2015 Paris Agreement said human-caused warming should be limited to 2 degrees Celsius (3.6 degrees Fahrenheit), and ideally below 1.5. In the following years, the world's top scientist said limiting to 1.5 was crucial to stave off the worst impacts of climate change, such as increasing destructive and frequent extreme weather events. Scientists say the main cause of climate change is the burning of fossil fuels like coal, oil and natural gas.

That “does not mean that the Paris Agreement has been breached, but it does mean ambitious climate action is more urgent than ever,” Copernicus Deputy Director Samantha Burgess said in a news release.

Francis said the new records are “terrible news for people and ecosystems.”

“The pace of warming is so fast that plants and animals cannot adapt as they always have during previous changes in the Earth’s climate. More species will go extinct, which disrupts natural food webs they’re a part of. Agriculture will suffer as pollinators decline and pests flourish,” she said, also warning that coastal communities will be vulnerable to sea-level rise.

Heat waves over the oceans and a loss of reflective sea ice and snow cover probably contributed to the temperature increase this year, experts said. Copernicus said the extent of Antarctic sea ice in November was 10% below average, a record.

Oceans absorb about 90% of the heat trapped by greenhouse gases, later releasing heat and water vapor back into the atmosphere.

Last year's record heat was caused partly by an El Nino — a temporary natural warming of parts of the central Pacific that alters weather worldwide.

But that ended earlier this year and a cooling effect that often follows, called La Nina, failed to materialize, leaving the scientific community “a little perplexed by what’s going on here ... why temperatures are staying high,” said Jonathan Overpeck, a climate scientist at the University of Michigan.

One explanation is that an El Nino releases more heat to the atmosphere because of warmer ocean waters, then "we’re not getting the cooling effect that often in decades gone by helps bring the temperature back down,” Overpeck said. "So it does look like this could be contributing to the acceleration of global warming.

But this year, he said, “is such a big jump following yet another jump, and that’s a scary thing.”

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