UN Secretary-General Ban Ki-moon and Intergovernmental Panel on Climate Change Chairman R.K. Pachauri are expecting a stronger leadership role from the next United States President in fighting global climate change.  These expectations are based upon results of a study that show the Greenland icesheets may be melting 3-4 times faster than expected, the two declared at a ceremony marking the 20th anniversary of the IPCC in Geneva on Sunday.

If the results hold true, it would mean a far more limited amount of time left to reverse global warming process. “I would say about six or seven years.  We need to think about change rather quickly because unless we do that, then the impacts of climate change are going to get more and more serious,” Pachauri said.

The timing of this call for American action couldn’t be better as the United States Presidential Election approaches.

“Now with the expected change of the administration of the United States, of course I would expect that the future president, whoever may be, will have to exercise greater leadership,” Ban told journalists at the ceremony.

Scientists at the University of Wisconsin and Columbia University’s Center for Climate Systems Research analyzed the disappearance of the Laurentide Ice Sheet, the last ice sheet to melt completely in the Northern Hemisphere and the closest example of what can be expected to happen to the Greenland Ice Sheet in the next century. Their findings show that sea level rise as a result of ice sheet melt can happen very rapidly. The study will be published online this week in Nature Geoscience.

“We have never seen an ice sheet retreat significantly or even disappear before, yet this may happen for the Greenland Ice Sheet in the coming centuries to millennia,” said Anders Carlson, the study’s lead author and assistant professor of geology and geophysics at the University of Wisconsin-Madison. “What we don’t know is the rate of melting of the Greenland Ice Sheet. The geologic data we compiled on the retreat history of the Laurentide Ice Sheet, however, gives us a window into how fast these large blocks of ice can melt and raise sea level.”

The simulations of the Laurentide rapid melting episode show that the driving factors for the thinning of the ice sheet were increased solar radiation caused by a change in the earth’s orbit which increased summer temperatures. Similar temperature increases may occur over Greenland by the end of this century.

IPCC predictions for changes in sea level for the next century are mainly based on the expansion of the oceans through warming, accounting less for contributions from ice sheet melt. This analysis of the Laurentide Ice sheet finds that the ice sheet 9,000 years ago was under similar pressure to melt as the Greenland Ice Sheet will be by the year 2100, implying a greater potential for mass loss on Greenland and resulting sea level rise. (Although this finding should not be extrapolated for an absolute prediction in sea level rise over the next ten years.)

Souces: 1, 2, 3, 4, 5, 6

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