Apr 19, 2017

How a Melting Arctic Changes Everything

by
Eric Roston and Blacki Migliozzi
,
Bloomberg
Image: NASA NSIDC, Sea Ice Age V3
Image: NASA NSIDC, Sea Ice Age V3

The world as a whole has warmed about 0.9 degrees Celsius (1.7 degrees Fahrenheit) since 1880. Arctic temperatures have risen twice that amount during the same time period. The most recent year analyzed, October 2015 to September 2016, was 3.5C warmer than the early 1900s, according to the 2016 Arctic Report Card. Northern Canada, Svalbard, Norway and Russia’s Kara Sea reached an astounding 14C (25F) higher than normal last fall.

Scientists refer to these dramatic physical changes as “Arctic amplification,” or positive feedback loops. It’s a little bit like compound interest. A small change snowballs, and Arctic conditions become much less Arctic, much more quickly.

...

Scientists track the number of “freezing-degree days,” a running seasonal tally of the amount of time it’s been cold enough for water to freeze. The 2016-2017 winter season has seen a dramatic shortfall in coldness—more than 20 percent below the average, a record.

The heat is making quick work of its natural prey: ice.

Scientists track the number of “freezing-degree days,” a running seasonal tally of the amount of time it’s been cold enough for water to freeze. The 2016-2017 winter season has seen a dramatic shortfall in coldness—more than 20 percent below the average, a record.