Greenland’s ice sheets melting at a frightening rate

A huge mass of ice that covers most of Greenland is melting at a frightening rate, almost three times faster than it did five years ago, and the pace is speeding year by year, the scientists say.

According to a new study, conducted by a US-based research team led by Chinese scientist Chen Jianli, Greenland is currently losing 240 cubic kilometres of ice each year since 2004, and accelerating. The researchers’ team estimated the loss after assessing ice mass changes over Greenland between 2002 and 2005.

Earlier study showed that the annual loss of the Greenland ice sheet was nearly 90 cubic kilometres between 1997 and 2003.

"Our result confirms that the island's ice is melting at an accelerated pace," Chen, now a geophysicist at the Centre for Space Research at the University of Texas, said.

Ice sheet is approximately five kilometres thick in some parts of the Greenland.

The researchers in their study, published online by the journal Science, stated that the consequences are already evident in a small but threatening rise in sea levels around the world, a pace that is also speeding. This could have a severe repercussion as global sea levels will soar by 6.5 metres if all the ice on Greenland were to melt, which could come out with many islands being engulfed and even the countries situated on the sea-level such as the Netherlands.

Chen and his fellow researchers extract their ice-loss results from a more accurate method, gravity field variation data gathered through the Gravity Recovery and Climate Experiment (GRACE) satellite mission.

About a decade's satellite observations from a team of the University of Texas, Jianli Chen said, "We have only been watching the ice cap melt during a relatively short period."

"But we are seeing the strongest evidence of it yet, and in the near future the pace of melting will accelerate even more," Chan added.

The GRACE satellite mission was collectively rolled-out by the National Aeronautics and Space Administration (NASA) in the United States and Germany's Aerospace Research Centre and Space Agency (DLR) in 2002. The GRACE satellite explores the Earth's gravity fields by measuring the distance between two identical satellites.

"We also invented a novel technique to recover and filter important signals from space background noise," Chen said. Chen and his research team also discovered that a glacier in southeast Greenland has had its highest melting rate since 2004, with annual ice loss of 90 cubic kilometres.

"With GRACE, we can define each glacier's individual ice change, which was not possible using previous techniques," he noted. "It is a real technological advance, which provides the best ever method to study long-term climate change."

Now, the challenge remains to scientists is to examine whether the island is losing more ice mass through melting than it gains from new snow.