With 2014 in the books, it's officially taken the title of hottest year on record. That ranking comes courtesy of data released by the Japan Meteorological Agency, the first of four major global temperature record keepers to release their data for last year.
The upward march of the world’s average temperature since 1891 is a trademark of human-influenced global warming with 2014 being the latest stop on the climb. All 10 of the hottest years have come since 1998.
One big difference between 2014 and 1998 is that the latter was on the tail end of a super El Niño, which has the tendency to spike temperatures.
Joe Romm of Climate Progress also notes that heat in Australia early in the year and California’s hottest year further contributed to the heat. Seasonal temperatures also paint a picture of a planet that didn’t get a break. Spring, summer and fall were all record-setting hot. Last winter was the only season not to set a record, and even that was still the sixth-warmest winter
JMA is one of the four major groups that use both ground measurements and satellites to compute the planet’s average temperature. The other three include NASA and the National Oceanic and Atmospheric Administration in the United States and the Hadley Centre in the U.K. There are subtle differences in how they analyse temperature data, but there’s generally broad agreement, particularly the upward trend in temperatures over the past century.
The other groups are expected to release their data in the coming weeks and confirm that 2014 was indeed the hottest year on record. And some scientists think it could get even hotter sooner. Strong trade winds in the Pacific have likely had a dampening effect on the global average temperature by essentially allowing the ocean to store more heat, but those winds are expected to weaken in the near future as part of a natural fluctuation.