Thursday, December 22, 2016

Unprecedented Arctic warming may become the new normal

As we come to the end of a year that will break all records as the warmest year worldwide since records began (replacing the previous record set in 2015, which in turn replaced 2014, etc), scientists from the Arctic Research Program of the National Oceanic and Atmospheric Administration (NOAA) have just published a new report that should have us even more worried.
While climate change scientists are warning us about the perils of a 1.5°C - 2°C increase in temperatures, parts of the Arctic have recorded temperatures of up to 19°C above observed averages over the last couple of months. At the North Pole itself, mean temperatures in November were almost 13°C above normal, and the forecast for the next few days is expected to see even higher warmer-than-average discrepancies. In general terms, the Arctic overall has been warming at least twice as fast as the global average.
As a result of all this, the freeze-up of ice in the Arctic Ocean is much later than usual, and it is expected that Arctic ice coverage this spring and summer may be at a record low (Arctic sea ice during the summer of 2016 was at the second lowest levels ever recorded). This in turn will lead to even more warming as there will be less ice to reflect the sun's rays in a classic positive feedback loop (ice typically reflects 50-70% of the solar energy that hits it, while water reflects only about 6%).
According to the NOAA, warm episodes like this one are not unheard of in the Arctic, and typically occur about every 1,000 years. Recently, however, as a result of anthropological global warming, the likelihood of such spells has increased to about once every 50 years, and, if climate change continues at its current pace, it could become a very common phenomenon, of the order of once every 2 years.
And then Donald Trump was elected, an event that threatens to throw all meteorological predictions to the proverbial wind...

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