West Antarctic Ice Sheet and Ocean Upwelling

Science writer Marc Airhart writes in Geology: “The new IPCC reports on climate change had essentially sidestepped the issue of Antarctica’s potential contribution to sea level rise. The authors pointed out, rightly, that there was just too much uncertainty to make predictions.”

So what’s going on with study of the West Antarctic Ice Sheet? The new theory has to do with ocean upwelling.

“Antarctica is encircled by atmospheric currents that largely insulate it from the rest of Earth’s climate and keep it colder than it otherwise would be,” Airhart writes. These air currents push water away from the continent. “As surface water is pushed away, warm deep water rises to replace it.” The stronger the air currents, the more the upwelling. It looks like what is happening is that as the world climate warms, these air currents become stronger and there is more upwelling.

This is the hypothesis. There isn’t enough observational data to validate this hypothesis yet.

However, it has been observed that the antarctic glaciers aren’t melting from the top, they’re melting from underneath.  If the West Antarctic Ice Sheet lost it’s “plug”, the Thwaits Glacier, the rest of the WAIS might follow.

 NASA’s Dr. Jim Hansen predicts a 5 meter (16 1/2 feet) rise in sea level by the end of this century.  Back in 1991, the EPA estimated the cost of a one meter rise in sea level would be around $250-$500 billion dollars.  But the fact that this rise will  be happening everywhere all at once, in the midst of an economic recession … really, I have no idea of what the fallout of something like that would be.  It will be a disaster, but a disaster in slow-motion. 


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