Wednesday, September 27, 2017

More Bad News on the Antarctic Glaciers

Yesterday I shared a story about a large iceberg breaking off from Antarctica as the Pine Island Glacier there continues to calve at an alarming rate. That story comes on the heels of the news this past summer that a chunk of ice the size of Delaware collapsed off the Larsen C Ice Shelf. Now, we get word that things in the Antarctic may be worse than we thought, as climate change begins to truly take hold on the frozen continent.

According to a new report published in the Earth and Planetary Science Letters journal, the glaciers found on Western Antarctica are now melting at three times the rate that is typical for the region. A recent study discovered that the ocean waters in Marguerite Bay were 1 to 2 degrees warmer than usual, which was enough to cause four major glaciers found there to double the rate at which they marched toward the sea and triple the amount of ice that they lost. Those glaciers went from losing 7-10 feet (2-3 meters) of ice each year, to as much as 33 feet (10 meters) per year.

That news alone is bad enough, but it turns out that the data collected on the movement of these glaciers was taken from 2008 to 2012, which means that the rate of advancement and ice loss may be even more now. When the study was originally being conducted, the rate of acceleration was alarming and it is not likely that it has slowed any since then.

The glaciers in Marguerite Bay were once somewhat protected by an ice shelf that extended out into the sea. That shelf is now gone and the warmer ocean waters are working directly on the glacier instead. This is the same process that has just started on the Larsen C as well, where the ice shel broke off earlier this summer, removing the buffer zone between the glacier and the ocean. That means we should see accelerated movement and melting there soon too.

What does this all mean for the rest of the planet? With about 90% of the world's fresh water supply held in the ice on Antarctica, the melt off is likely to cause ocean levels around the world to rise. That process has probably already started, and it will eventually alter the way of life for millions of people around the globe.

 In my opinion, how we deal with this, and other climate issues moving forward, is the great challenge of our times.

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