In 1984, there was 1.8 million sq km of “old ice” in the Arctic region.
NASA has made a time lapse video that shows Arctic Sea’s loss of ice due to warming summers over last three decades, highlighting the catastrophic changes global warming is having on our environment.
“What we’ve seen over the years is that the older is disappearing.” Said Walt Meier, a sea ice researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This older thicker ice is like the bulwark of sea ice: a warm summer will melt all the young, thin ice away but it can’t completely get rid of the older ice. But this older ice is becoming weaker because there’s less of it and the remaining old ice is more broken up and thinner, so that bulwark is not as good as it used to be.
This ice is somewhat cyclical, with ice forming during the winter and melting during the summer, but NASA explained that this balance of power is tipping.
In 1984, there was 1.8 million sq km of “old ice” in the Arctic region, however by September 2016 there was only 110,000 sq km left.
“We’ve lost most of the older ice: In the 1980s, multiyear ice made up 20 percent of the sea ice cover. Now it’s only about 3 percent, the older ice was like the insurance policy of the Arctic Sea ice pack as we lose it, the likelihood for a largely ice-free summer in the Arctic increases” said Meier, who is a collaborator of the group at the University of Colorado and National Snow and Ice Data Center in Boulder, Colarado, the center that currently maintains the Arctic sea ice age data.
https://www.youtube.com/watch?v=6ZAuRpK4tkc