The exceptional heat that first enveloped the planet last summer will continue strongly until 2024: last month recorded the hottest January ever measured, the European Union’s climate monitor announced on Thursday.
It was also the warmest January on record in the oceans, according to the European Union’s Copernicus Climate Change Service. Sea surface temperatures were slightly lower than in August 2023, the warmest ocean month on record. And the sea temperature continued to rise in the first days of February, surpassing the daily records recorded last August.
Oceans absorb the vast majority of the extra heat that greenhouse gases in the atmosphere trap near the Earth’s surface, making them a reliable indicator of how much and how quickly we are warming the planet. Warmer oceans provide more fuel for hurricanes and atmospheric river storms and can disrupt marine life.
January is the eighth consecutive month in which average air temperatures, both on the continents and in the seas, have surpassed all previous records for that time of year. Ultimately, 2023 was the hottest year on Earth in more than a century and a half.
The main driver of all this heat is no mystery to scientists: the burning of fossil fuels, deforestation and other human activities have steadily raised the mercury for more than a century. The current El Niño climate cycle is also allowing more heat to be released from the ocean into the atmosphere.
However, precisely why the Earth has been so hot for so long in recent months remains a topic of debate among researchers, who are waiting for more data to come in to see if other factors, less predictable and perhaps less understood, they could also be at play. work around the margins.
“Rapidly reducing greenhouse gas emissions is the only way to stop the rise in global temperatures,” Samantha Burgess, deputy director of Copernicus, said in a statement.
According to Copernicus data, temperatures in January were well above average in eastern Canada, northwest Africa, the Middle East and Central Asia, although much of the interior United States was colder than usual. Parts of South America were warmer than normal and drier, contributing to the recent wildfires that devastated central Chile.
The intensity of recent underwater heat waves led the National Oceanic and Atmospheric Administration in December to add three new levels to its ocean heat alert system to indicate where corals might be bleaching or dying.
An El Niño pattern like the one currently seen in the Pacific is associated with warmer years for the planet, as well as a number of effects on precipitation and temperatures in specific regions.
But as humans warm the planet, the effects that meteorologists once could safely expect El Niño to have on local temperatures are no longer as predictable, said Michelle L’Heureux, a NOAA scientist who studies El Niño and its opposite phase, La Niña.
“In regions that previously tended to have below-average temperatures during El Niño, you almost never see that anymore,” Ms. L’Heureux said. “You see something that’s closer to average, or even still leaning above average.”