Runaway Glaciers in West Antarctica

14 05 2014

Mark Cochrane

Mark Cochrane

Another guest post from our resident Climate Scientist, Mark Cochrane…….  Mark had expressed some concern about the West Antarctic Ice Sheet in an earlier post way back in 2012….  This is his latest offering on the matter which has gone somewhat viral on the internet.  Some experts say it would take 200 to 900 years to melt it all, but ho knows how fast everything can change these days?

 

 

 

Whether you realize it or not, another milestone has been passed on the road to planetary change.

In the western Antarctic we have now apparently passed the point of no return for one quarter of the ice sheet to melt (link). What this means is roughly 4 ft (>1m) of sea level rise. At the most conservative this will take more than a century but if you have noticed anything climate related over the last several years it is that things are happening much faster than believed possible.

The way this has been put in motion is as follows. The western Antarctic ice sheet, like the rest of the ice sheets, is a relic of the ice ages. What is different about it, however, is that much of it is grounded below the sea level. In basic terms, this means that it is frozen to the land surface even though the sea level has risen to the point that it would float if it weren’t welded to the land. With the warming of the planet though, sea water temperatures have risen to the point that  they are melting the ice below the surface. As they melt, the ice at the interface between the ice sheet and the submerged ground surface the ice lifts. This is happening in all of the submerged valley basins in the western Antarctic.

Globally, sea level is rising at 3mm/yr (1/8 in/yr) at present. This may seem a sedate pace but it is a gallop by any measure since the last ice age.

Note, this doesn’t account for sea level change from melting ice in Greenland, Eastern Antarctica or the rest of the world. What this research shows is that there is nothing humanity can do to stop the decay of 1/4 of the western Antarctic ice sheet. This region does not melt in isolation though so we will have >1m of sea level rise even if we get our collective act together. Don’t worry though, this is not unprecedented, it may have happened as recently at 500,000 years ago…

And for your information……..:

and finally for some hilarity…  (LANGUAGE WARNING)

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