Dec 21, 2016

North Pole, Nov – Dec, 2016

World Weather Attribution
  • States that in 2016, the North Pole and the surrounding Arctic region saw record-high temperatures in November and December and record-low ice extent
    • Mid-November saw an early winter “heat wave” with the temperature on November 11 reaching -7 ºC (19 ºF) – that is 15 ºC (27 ºF) above normal for the time of year
    • The monthly mean November temperature was 13 ºC (23 ºF) above normal on the pole
  • Quantifies how rare the event was by computing the November-December averaged temperature around the North Pole (80–90 ºN) in the ERA-interim reanalysis augmented with the ECMWF analysis and forecast up to December 25 and persistence up to December 31
  • Reconstructs Arctic temperatures back to about 1900, which clearly shows how the warmth in Nov-Dec 2016 is unprecedented over that period
  • Finds that a warm event like the one in Nov-Dec 2016 would have been extremely unlikely in the climate of a century ago
    • The probability was so small it is hard to estimate, but less than 0.1 percent per year
  • The model analyses show that the event would also have been extremely unlikely in a world without anthropogenic emissions of greenhouse gases and aerosols, attributing the cause of the change to human influences
  • Concludes that if nothing is done to slow climate change, by the time global warming reaches 2 ºC (3.6 ºF) events like this winter would become common at the North Pole, happening every few years