(NEW YORK) — It may have been a frigid January for much of the U.S., but that didn’t stop the planet from breaking another temperature record.
Earth just experienced its warmest January on record, according to data analyzed by the Copernicus Climate Change Service.
Despite a record-breaking snowfall in the south, persistent cold temperatures across the northeast and an emerging La Niña event in the Pacific Ocean, which is supposed to cool things down, January 2025 was still warmer than any previous start to the year in the organization’s dataset going back to 1940.
The average surface air temperature was 55.81 degrees Fahrenheit. That’s 1.42 degrees Fahrenheit above the 1991-2020 average for the month of January. It also makes the global average temperature over the past 12 months 2.9 degrees Fahrenheit above the 1850-1900 pre-industrial average.
For context, the Paris Agreement — which President Donald Trump withdrew the U.S. from last month — set 2.7 degrees Fahrenheit as a ceiling to avoid the worst impacts of climate change.
Similarly, global daily sea surface temperatures across most of the world’s oceans remain well above average and registered as the second-highest January value on record, just behind 2024.
Last month’s temperature was unprecedented compared to similar global climate cycles in the past, where temperatures dropped with El Niño long gone and La Niña conditions in place.
The increase’s magnitude and persistence have shocked many climate experts, leaving them somewhat puzzled about what else could be behind the remarkable rise.
In addition to human-amplified climate change and natural global climate cycles, a growing amount of research suggests that a decrease in atmospheric aerosols could be a significant contributor to the rapid warming.
Atmospheric aerosols are tiny particles that reflect sunlight into space and reduce global temperatures. However, their concentrations have greatly diminished due to international efforts to reduce air pollution in recent decades. Now, more sunlight reaches the Earth’s surface, creating a heating effect.
For decades, we’ve been removing aerosols from our air without fully realizing the potential cascading effects of these actions.
To help solve this puzzle, climate scientists are eagerly awaiting the first batch of operational data from NASA’s newest Earth-observing satellite, PACE (Plankton, Aerosol, Cloud, ocean Ecosystem), launched nearly a year ago. This data will provide more insight into how various atmospheric aerosols behave and interact with each other.
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