Tuesday, May 13, 2014

Update: Collapse Of Parts of West Antarctica Ice Sheet Has Begun

UPDATE:5-20-14: Doubling of Antarctic ice loss revealed by European satellite

It was also the European model that predicted Hurricane Sandy exactly.

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How does it feel to be the generation watching the beginning of the extinction of the human species? Even though these glaciers may not totally melt for a couple more centuries the rise in sea level brought by them now is already affecting coastlines and that means affecting us. So the next time you hear anyone say humans aren't pushing this or that "Antarctic ice is increasing" you will know they are lying to you by omission by design. There is a difference in land ice and sea ice in Antarctica and the dynamics of that is not known nor cared about by the Rush Limbaughs of the world.

This isn't about your politics or your portfolios. This is about survival. As we all know when faced with imminent harm to ourselves/danger to our lives and especially our children (ever see a mother defend her child?) and those we love we humans go into preservation mode in an attempt to save our lives and especially the lives of those we love. That mechanism is part of our DNA. This is one hell of a time to forget that.

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Scientists Warn of Rising Oceans From Polar Melt

A large section of the mighty West Antarctica ice sheet has begun falling apart and its continued melting now appears to be unstoppable, two groups of scientists reported on Monday. If the findings hold up, they suggest that the melting could destabilize neighboring parts of the ice sheet and a rise in sea level of 10 feet or more may be unavoidable in coming centuries.

Global warming caused by the human-driven release of greenhouse gases has helped to destabilize the ice sheet, though other factors may also be involved, the scientists said.

The rise of the sea is likely to continue to be relatively slow for the rest of the 21st century, the scientists added, but in the more distant future it may accelerate markedly, potentially throwing society into crisis.

“This is really happening,” Thomas P. Wagner, who runs NASA’s programs on polar ice and helped oversee some of the research, said in an interview. “There’s nothing to stop it now. But you are still limited by the physics of how fast the ice can flow.”

Two scientific papers released on Monday by the journals Science and Geophysical Research Letters came to similar conclusions by different means. Both groups of scientists found that West Antarctic glaciers had retreated far enough to set off an inherent instability in the ice sheet, one that experts have feared for decades. NASA called a telephone news conference Monday to highlight the urgency of the findings.

The West Antarctic ice sheet sits in a bowl-shaped depression in the earth, with the base of the ice below sea level. Warm ocean water is causing the ice sitting along the rim of the bowl to thin and retreat. As the front edge of the ice pulls away from the rim and enters deeper water, it can retreat much faster than before.

In one of the new papers, a team led by Eric Rignot, a glaciologist at the University of California, Irvine, used satellite and air measurements to document an accelerating retreat over the past several decades of six glaciers draining into the Amundsen Sea region. And with updated mapping of the terrain beneath the ice sheet, the team was able to rule out the presence of any mountains or hills significant enough to slow the retreat.

“Today we present observational evidence that a large sector of the West Antarctic ice sheet has gone into irreversible retreat,” Dr. Rignot said in the NASA news conference. “It has passed the point of no return.”

snip

Scientists said the ice sheet was not melting because of warmer air temperatures, but rather because relatively warm water that occurs naturally in the depths of the ocean was being pulled to the surface by an intensification, over the past several decades, of the powerful winds that encircle Antarctica.

And while the cause of the stronger winds is somewhat unclear, many researchers consider human-induced global warming to be a significant factor. The winds help to isolate Antarctica and keep it cold at the surface, but as global warming proceeds, that means a sharper temperature difference between the Antarctic and the rest of the globe. That temperature difference provides further energy for the winds, which in turn stir up the ocean waters.

snip

Richard B. Alley, a climate scientist at Pennsylvania State University who was not involved in the new research but has studied the polar ice sheets for decades, said he found the new papers compelling. Though he had long feared the possibility of ice-sheet collapse, when he learned of the new findings, “it shook me a little bit,” Dr. Alley said.

He added that while a large rise of the sea may now be inevitable from West Antarctica, continued release of greenhouse gases will almost certainly make the situation worse. The heat-trapping gases could destabilize other parts of Antarctica as well as the Greenland ice sheet, potentially causing enough sea-level rise that many of the world’s coastal cities would eventually have to be abandoned.

“If we have indeed lit the fuse on West Antarctica, it’s very hard to imagine putting the fuse out,” Dr. Alley said. “But there’s a bunch more fuses, and there’s a bunch more matches, and we have a decision now: Do we light those?”

End of excerpt

(Bolding my emphasis)


A NASA animation shows glacier changes detected in the highly dynamic Amundsen Embayment of West Antarctica.
Publish Date May 12, 2014

Also see:



West Antarctic Ice Sheet Stability

Water In The Anthropocene

Satellite Data Shows Sea Level Rise

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