19 December 2017: The World Meteorological Organization (WMO) announced that 2017 is set to be among the three warmest years on record with respect to global land and ocean temperatures, and the warmest year without an El Niño. The first 11 months of 2017 were the third warmest on record, behind 2016 and 2015, and Arctic and Antarctic sea ice cover remain at near record lows.

During November 2017, warmer-than-average temperatures dominated much of globe, with the most notable temperature departures from average across the Northern Hemisphere. WMO scientist Omar Baddour stressed the importance of the overall, long-term warming trend since the late 1970s, and especially this century, noting that along with rising temperatures, more extreme weather with massive socioeconomic impacts is being observed.

In the Arctic, the average temperature observed at the weather station at Utqiaġvik, Alaska changed so rapidly that it triggered an algorithm for detecting artificial changes and disqualified itself from the temperature analysis. Arctic temperatures are increasing at double the rate of the global temperature increase. According to the Arctic Report Card, a peer-reviewed annual update on the region, the Arctic shows no sign of returning to the reliably frozen region it was decades ago, although 2017 did break fewer records than in 2016. In addition, the current observed rate of sea ice decline and warming temperatures are higher than at any time over the last 1,500 years. The 2017 report card also includes a special report on how the warming trend is: affecting fisheries in the eastern Bering Sea; compromising roads, homes and infrastructure due to permafrost thaw; and threatening high latitudes with more frequent wildfires.

For the first time, the yearly report determined that extreme weather events could not have happened without human-caused climate change.

Another report titled, ‘Explaining Extreme Events in 2016 from a Climate Perspective,’ published in the Bulletin of the American Meteorological Society (BAMS), presents peer-reviewed analyses of extreme weather across five continents and two oceans during 2016. It examines both historical observations and model simulations to determine whether and by how much climate change may have influenced particular extreme events. This is the first year the report has determined that extreme events could not have happened without human-caused climate change. [WMO Press Release] [WMO Provisional Statement on State of Climate in 2017] [WMO Press Release on the Arctic] [Arctic Report Card] [WMO Press Release on BAMS Report] [Publication: Explaining Extreme Events from a Climate Perspective]