Earth Clocks Hottest January on Record, Marking 12 Months Above 1.5 Degree Celsius Warming Threshold

Though the world has not officially breached the Paris Agreement, the historic heat on land and at sea is a “significant milestone”

dry, cracked ground on the shores of a heavily receded reservoir in eastern Spain.
Dry and cracked ground at the La Vinuela reservoir near Málaga, Spain, last year. Reservoirs in the country's Catalonia region have fallen to 16 percent capacity amid years of drought and extreme heat. Jesus Merida / SOPA Images / LightRocket via Getty Images

The new year has picked up right where 2023, the hottest year ever measured, left off.

Last month was the hottest January ever recorded worldwide, both on land and at sea, scientists from the European Union’s Copernicus Climate Change Service shared in a statement this week. Globally, air temperatures averaged 13.14 degrees Celsius, breaking the previous record, set in 2020, by 0.12 degrees.

In context, the world has now experienced eight consecutive months, dating back to June 2023, of the highest recorded temperatures for each respective month. And, boosted by January’s heat, Earth’s global temperature has averaged 1.52 degrees Celsius above pre-industrial norms since last February.

This means the planet has, on average, eclipsed the 1.5 degree Celsius warming threshold set in the 2015 Paris Agreement for a full 12 months—though experts say it would take several years above the threshold for countries to have officially breached the deal. Regardless, passing the one-year mark for the first time is a “significant milestone,” Matt Patterson, an atmospheric physicist at the University of Oxford, tells Reuters’ Kate Abnett and Gloria Dickie.

“2024 starts with another record-breaking month,” Samantha Burgess, the deputy director of the Copernicus Climate Change Service, says in the statement. “Rapid reductions in greenhouse gas emissions are the only way to stop global temperatures increasing.”

Surface air temperature anomaly for January 2024 relative to the January average for the period 1991-2020
Surface air temperature anomaly for January 2024, relative to the January average for the period 1991-2020 Copernicus Climate Change Service / ECMWF

The world’s oceans also felt the heat. With sea surface temperatures for the month averaging 20.97 degrees Celsius, oceans surpassed the previous January record, set in 2016, by 0.26 degrees. The extent of sea ice in the Arctic was close to normal, while Antarctic sea ice clocked its sixth lowest coverage ever recorded for January, at 18 percent below the average. And in early February, temperatures at sea remained above any other time in the record, which dates to 1979.

Last month’s heat has been felt acutely across the world, especially as the El Niño weather phenomenon—which exacerbates hotter conditions—continues.

In Chile, wildfires powered by drought and heat have ravaged the country’s Pacific coast, killing more than 100 people. With hundreds more missing, and the death toll expected to climb, officials say these fires could be the country’s deadliest on record.

In eastern Spain, where a three-year drought has continued into 2024, the lack of water has reached dire levels. Reservoirs in the region of Catalonia have fallen to 16 percent of capacity, and the Iberian peninsula is at its driest point in 1,200 years. Strict water limits—including bans on car washes and filling swimming pools—have been enacted in more than 200 towns and cities, including Barcelona, as the country moves to build desalination plants and considers importing water via ships.

And in southern California, a powerful atmospheric river dropped about 75 percent of an entire year’s worth of rain on the Los Angeles area, weather that scientists have again attributed to El Niño’s heat and climate change.

“These synchronized fires and floods in Chile and California are certainly a reminder of the weather extremes and their impacts in otherwise benign Mediterranean climates,” John Abatzoglou, a climate scientist at the University of California, Merced, tells the New York Times’ Somini Sengupta. Climate change and El Niño “are the main instruments in the orchestra for individual extreme events… with the drum of climate change beating louder and louder as the years go by.”

Daily sea surface temperature (°C) averaged over the extra-polar global ocean (60°S–60°N) for 2015 (blue), 2016 (yellow), 2023 (red), and 2024 (black line). All other years between 1979 and 2022 are shown with grey lines.
Daily sea surface temperature averages for 2015 (blue), 2016 (yellow), 2023 (red) and 2024 (black). All other years between 1979 and 2022 are shown with gray lines. Copernicus Climate Change Service / ECMWF

Earlier this month, some scientists proposed the creation of a sixth category for hurricanes, which are growing more powerful in a warming world.

Scientists from the National Oceanic and Atmospheric Administration (NOAA) said in January that 2024 has a “one in three chance” of being hotter than last year, with a 99 percent chance it would rank in the top-five warmest years since modern records began, Reuters’ Gloria Dickie reports.

“Look what’s happened this year with only 1.5 degrees Celsius” of warming, Bob Watson, a former chair of the United Nations Intergovernmental Panel on Climate Change, tells CBS News’ Li Cohen and Haley Ott. “We’ve seen floods, we’ve seen droughts, we’ve seen heatwaves and wildfires all over the world, and we’re starting to see less agricultural productivity and some problems with water quality and quantity.”

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