More than 2 trillion tons of land ice in Greenland, Alaska and Antarctica have been lost since 2003 due to melting, according to new NASA satellite data. It’s the latest round of evidence of the toll global warming is taking around the world, and scientists say this is just the beginning.
More than half of the loss of landlocked ice in the past five years occurred in Greenland, and the rate of ice melt seems to be accelerating. NASA geophysicist Scott Luthcke says the water melting from Greenland between 2003 and 2008 would fill up about 11 Chesapeake Bays.
From MSNBC:
The news was better for Alaska. After a precipitous drop in 2005, land ice increased slightly in 2008 because of large winter snowfalls, Luthcke said. Since 2003, when the NASA satellite started taking measurements, Alaska has lost 400 billion tons of land ice.
In assessing climate change, scientists generally look at several years to determine the overall trend.
Melting of land ice, unlike sea ice, increases sea levels very slightly. In the 1990s, Greenland didn’t add to world sea level rise; now that island is adding about half a millimeter of sea level rise a year, NASA ice scientist Jay Zwally said in a telephone interview from the conference.
Between Greenland, Antarctica and Alaska, melting land ice has raised global sea levels about one-fifth of an inch in the past five years, Luthcke said. Sea levels also rise from water expanding as it warms.
That’s not the only bad news that will be presented today at the American Geophysical Union conference in San Francisco. Other research points to more melting concerns from global warming, especially with sea ice. Scientists are expected to announce that parts of the Arctic north of Alaska were 9 to 10 degrees warmer this past fall, which is a strong early indication of what researchers call the Arctic amplification effect. That’s when the Arctic warms faster than predicted and warming there is accelerating faster than elsewhere around the world.
Two other studies being presented at the conference assess how Arctic thawing is releasing methane, a potent greenhouse gas. The methane production is caused by a loss of sea ice warming the water, which then melts the permafrost in Alaska. The second study shows that large amounts of frozen methane trapped in lakebeds and sea bottoms in Siberia are starting to bubble to the surface in alarming amounts. The amounts of methane in the region could dramatically increase global warming if they get released.
Link [MSNBC]
