Climate scientists are left puzzled after last month’s record-breaking warm January, which broke the previous year’s record by nearly 0.1C. Despite expecting slightly cooler temperatures due to a shift away from El Niño, the opposite occurred, with January 2025 ending up 1.75C warmer than average temperatures in the late 19th Century.
The world’s warming trend is attributed to human activities releasing greenhouse gases, mainly from burning fossil fuels. However, scientists are struggling to explain why last month was particularly hot. Decades-long warming trends and surprisingly large temperature records since mid-2023 suggest that something more complex is at play.
Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, attributes the trend to increasing greenhouse gases in the atmosphere. However, the specifics of exactly why 2023, 2024, and 2025 were so warm are unclear.
La Niña conditions are currently developing, which should have led to cooler temperatures. Instead, the natural El Niño weather pattern boosted global temperatures earlier last year, releasing extra heat into the atmosphere. Theories suggest a prolonged response of oceans to the 2023-24 El Niño event or a reduction in atmospheric aerosols could be contributing factors.
Aerosol numbers have been falling due to air pollution reductions, which may not be masking as much long-term warming from greenhouse gases. This lack of cooling effect has led some scientists to suggest an “extra cloud feedback,” where a warming ocean causes low-level reflective clouds to dissipate, further warming the planet.
Researchers are uncertain about the reasons behind the recent warmth, but they agree that global temperatures will continue to rise unless emissions are reduced. Dr. Samantha Burgess notes that further records will follow as humanity continues to heat up the planet, and 2025 is likely to be one of the cooler years in the future.
Source: https://www.bbc.com/news/articles/cwyjk92w9k1o