The surprising January heat record coincides with a new study by a climate science heavyweight, former top NASA scientist James Hansen, and others arguing that global warming is accelerating. January globally was 0. It was the 18th month of the last 19 that the world hit or passed the internationally agreed upon warming limit of 1.
Copernicus records date to , but other U. By far the biggest driver of record heat is greenhouse gas buildup 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. The big natural factor in global temperatures is usually the natural cycle of changes in the equatorial Pacific Ocean waters.
Last year was a substantial El Nino, though it ended last June and the year was even warmer than initially expected, the hottest on record. A La Nina started in January after brewing for months. For Americans, news of a record warm January might seem odd given how cold it was.
But the U. January was unseasonably mild in the Arctic. Parts of the Canadian Arctic had temperatures 30 C 54 F warmer than average and temperatures got so warm sea ice started melting in places, Burgess said.
Copernicus said the Arctic this month tied the January record for lowest sea ice. The U. In a study in the journal Environment: Science and Policy for Sustainable Development , Hansen and colleagues said the last 15 years have warmed at about twice the rate of the previous 40 years.
