Climatic changes appear to be destabilizing vast ice sheets of western Antarctica that had previously seemed relatively protected from global warming, researchers reported Sunday, raising the prospect of faster sea-level rise than current estimates.
While the overall loss is a tiny fraction of the miles-deep ice that covers much of Antarctica, scientists said the new finding is important because the continent holds about 90 percent of Earth's ice, and until now, large-scale ice loss there had been limited to the peninsula that juts out toward the tip of South America. In addition, researchers found that the rate of ice loss in the affected areas has accelerated over the past 10 years -- as it has on most glaciers and ice sheets around the world.
"Without doubt, Antarctica as a whole is now losing ice yearly, and each year it's losing more," said Eric Rignot, lead author of a paper published online in the journal Nature Geoscience.
The Antarctic ice sheet is shrinking despite land temperatures for the continent remaining essentially unchanged, except for the fast-warming peninsula. The cause, Rignot said, may be changes in the flow of the warmer water of the Antarctic Circumpolar Current that circles much of the continent. "Something must be changing the ocean to trigger such changes," said Rignot, a senior scientist with NASA's Jet Propulsion Laboratory. "We believe it is related to global climate forcing."
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Posted by John Ray
How much do you want to bet that all of the sea level rise estimates don't take into accoutn the increase in surface area as the levels rise, requiring a larger amount of melting for the next incrimental rise. Instead, they probably just do what you did, the rise was x last year and straightline it out over time. That is highly flawed. What happens when sea levels rise to where they then flow into areas currently under sea level. That will require lots of melting just to fill these 'empty bowls' up. Then there is the fact of melting ice reducing the salinity of water, thus reducing it's freezing point. I would love to see a paper that addresses these issues!
ReplyDeleteP.S - Maybe that .5 mm rise in the seas is due to all the new ships launched that year. Add a ship and it will displace it's weight in water. Add an ice cube into a glass and the level in the glass goes up!