January 2025 was the hottest January in recorded history

January 2025 was the hottest January in recorded human history, with global temperatures entering record territory according to the Copernicus/ECMWF ERA5 dataset. According to climate scientist Zeke Hausfather’s newsletter The Climate Brink, January 2025 was warmer than every preceding January chronicled by scientists, surpassing the prior record set in January 2024 “by a sizable margin.”

“This means that January 2025 stands out as anomalous even by the standards of the last two years,” Hausfather explains. Writing for Discover Magazine, Tom Yulsman points out that scientists expected this January to be cooler than preceding Januaries because of the ocean current cycles like El Niño and La Niña. Yet those predictions did not come to pass.

“We don’t have El Niño to kick around anymore,” Yulsman said. “It actually dissipated months ago. Adding to the puzzle is the fact that we’re in the midst of a La Niña, which typically cools things down.”

The year 2024 was the warmest year in modern history, with average global temperatures exceeding 1.5º C above pre-industrial levels for the first time ever. The Atlantic hurricane season was unusually extreme, droughts and wildfires imposed widespread suffering and — despite all of this — humans still dumped a record-breaking 37.4 billion tons of carbon dioxide into the atmosphere through fossil fuel use. The total carbon dioxide concentration in the atmosphere has increased from 280 ppm before the Industrial Revolution to 420 ppm as of 2023, according to the National Oceanic and Atmospheric Administration (NOAA).

“This human release of heat-trapping gasses is the primary cause of the increases in extreme weather, flood, drought, heatwaves and generally ‘weird weather’ that we are all experiencing,” Dr. Twila Moon, the deputy lead scientist and science communication liaison at the NSIDC (National Snow and Ice Data Center), told Salon in December. “It is well known that reducing these emissions is key to minimizing risk and damage into the future. And how to achieve these reductions is well mapped out, with the technology to do it. The pressure is now focused on social, cultural, business and political will.”