January 2025 was the hottest month on record, surprising scientists despite an abnormally chilly United States and a cooling La Nina, the European climate service Copernicus has said.
The revelation coincides with a new study by a former top NASA scientist, James Hansen, and others which argues that global warming is accelerating, The Associated Press reported. Scientists, though, remain divided on if global warming is accelerating.
January 2025 globally was 0.09 degrees Celsius warmer than it in was in 2024, the previous hottest January. It was the 18th month of the last 19 that the world hit or passed the internationally agreed upon warming limit of 1.5 degrees Celsius above pre-industrial times.
Scientists won't regard the limit as breached unless and until global temperatures stay above it for 20 years.
What's fuelling the heat?
The biggest driver of record heat is greenhouse gas build-up from the burning of coal, oil and natural gas but the natural contributions to temperature change have not been acting quite as expected, said Samantha Burgess, strategic lead for climate for the European weather agency.
Several scientists also said burning of fossil fuels is one of the contributors to record warm weather, AP reported.
El Nino and La Nina
When the central Pacific is especially warm, it's an El Nino.
El Nino's cooler flip side, a La Nina, tends to dampen the effects of global warming a bit, making record temperatures far less likely.
A La Nina started in January after brewing for months. Just last month, climate scientists were predicting that 2025 wouldn't be as hot as 2024 or 2023, with the La Nina a major reason.
The last 10 years are the 10 hottest on record and are likely the hottest in 125,000 years, Burgess said.
“Even though the equatorial Pacific isn't creating conditions that are warming for our global climate, we're still seeing record temperatures,” Burgess said, adding much of that is because of record warm water temperatures in the rest of the world's oceans.
January was unseasonably mild in the Arctic. Parts of the Canadian Arctic had temperatures 30 degrees Celsius (54 degrees Fahrenheit) warmer than average and temperatures got so warm sea ice started melting in places, Burgess said.
World breaches major threshold
This is the first time any year passed the 1.5-degree threshold except for a 2023 measurement by Berkeley Earth, which was originally funded by philanthropists who were skeptical of global warming.
Scientists were quick to point out that the 1.5 goal is for long-term warming, now defined as a 20-year average. Warming since pre-industrial times over the long term is now at 1.3 degrees Celsius (2.3 degrees Celsius).
With inputs from agencies
Discover the latest Business News, Sensex, and Nifty updates. Obtain Personal Finance insights, tax queries, and expert opinions on Moneycontrol or download the Moneycontrol App to stay updated!
