Greenland Thaw, Biggest in 50 Years
Greenland Thaw, Biggest in 50 Years
By Viola Woolcott
On Tuesday Scientists said that climate change is responsible for the causes of the greatest thaw of Greenland’s ice in half a century, perhaps heralding a wider meltdown that would quicken a rise in world sea levels.
Adding to recent evidence of faster Antarctic and Arctic thaws a group of researchers wrote in the Journal of Climate:
“We attribute significantly increased Greenland summer warmth and ice melt since 1990 to global warming.“
“The Greenland ice sheet is likely to be highly susceptible to ongoing global warming.”
If it were to start, and even though if the process would take centuries, Greenland contains enough ice to raise world sea levels by 7 meters, which are 23 ft.
Excluding ice losses from glaciers slipping into the sea, melt water from Greenland totalled 453 cubic km, which are 110 cubic miles in 1998, which is the most ahead of 2003, 2006, 1995 and 2002 in detailed records stretching back to the 1950s.
Edward Hanna of England’s University of Sheffield who led the study with colleagues in Belgium, the United States and Denmark. Said that preliminary data showed that 2007 would rank second or third highest and confirm the last decade as the biggest melt.
It may also be a side-effect of climate change that the water runoff has been largely offset by rising snowfalls in Greenland and that even freezing air can contain more moisture, and therefore if it gets slightly less chilly deliver more snow.
Continued warming could threaten with an irreversible meltdown. By 2010 the typical climate models point to a warming for Greenland of 4-5 degrees Celsius which equals 7.2 - 9 Fahrenheit.
Hanna said:
“The ice probably wouldn’t grow back under current conditions.”
“If you have an extra 3-5 degrees Celsius warming … then you can reach a point of no return … bringing the eventual demise of the ice sheet. That could take probably 1,000 or 2,000 years.”
Antarctica lost billions of tonnes of ice over the last decade, contributing more to rising sea levels around the world, a climate researcher said on Monday.
The U.N. Climate Panel, projects a rise in sea levels of between 18 - 59 cms, which are 7-23 inches by 2100. The Panel blames global warming mainly on human emissions of greenhouse gases from burning fossil fuels and they assume that the little-understood rate of ice flow from Greenland and Antarctica will not change from 1993-2003, when their mass losses accounted for less than half of annual sea level gains of 3.1 mm, which are 0.12 inch.
Greenland also had a warm period around 1940 Hanna said. He also says that the warming was triggered by natural variations in the Arctic climate, maybe shifts in ocean currents. Today the Greenland warming fits a far broader trend across the planet.
Filed under: Environment | Green Issues on January 16th, 2008
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