Now that we’re past all the 2013 retrospectives and jokes about 2014 New Year’s resolutions, we’ve hit the time of year to check in on the final tally for last year’s global average surface temperatures. Up to bat Tuesday were the datasets managed by NASA and the US National Oceanic and Atmospheric Administration, which were updated with a joint press conference.
NASA put 2013 at 0.6 degrees Celsius (1.1 degree Fahrenheit) warmer than the 1951-1980 baseline, tying it with 2009 and 2006 for the seventh warmest year in the record, which goes back to 1880. NOAA calculated a global average of 0.58 degrees Celsius—tied for fourth warmest in that dataset. The two datasets handle the paucity of temperature stations in the polar regions differently, which leads to slight differences in the calculated averages.
The El Niño-Southern Oscillation, which is a major source of year-to-year variability in global average surface temperatures, was effectively neutral last year. The last decade has been dominated by La Niña conditions, in which a large area of cooler surface water in the Pacific Ocean brings down the global average.
via Ars Technica http://ift.tt/LPL0lU