Hesselbjerg Christensen: Danish researchers' model suggest that Greenland has passed its tipping point, past the point of no return, will completely melt

Greenland close to unavoidable meltdown

FOTO: JOHN MCCONNICO (arkivfoto)/AP

Fears that a Greenland meltdown is unavoidable.

by Julian Isherwood, politiken.dk, January 7, 2011

The result of an international scientific paper, based on data and models from the Danish Meteorological Institute, is suggesting that an eventual meltdown of Greenland’s ice-cap is almost unavoidable.

According to the model used in a paper published in the Journal of Hydrometeorology, irrespective of how much CO2 emissions are limited, Greenland will reach a point of no return in 2040 at the latest.

“This is a very worrying result as it shows that melting can go a lot quicker than we normally think,” says one of the report’s co-authors, Jens Hesselbjerg Christensen.

The report, entitled “Greenland Ice Sheet Surface Mass-Balance Modeling in a 131-Yr Perspective, 1950–2080” and prepared by research centres at the University of Alaska Fairbanks, the University of Colorado and the Danish Meteorological Institute says that the ice-cap mass balance: “was close to equilibrium during the relatively cold 1970s and 1980s and lost mass rapidly as the climate warmed in the 1990s and 2000s with no indication of deceleration”.

“It is essential to predict and assess the impact of future climate on the Greenland Ice Sheet (GRIS), which is believed to be influenced by human activities. We must establish the present and future state of the GrIS surface melt extent and surface mass balance, including freshwater flux,to detect warning signs indicative of its future response,” the report says.

After 2040, on a time scale of 1,000 years ahead, it will not be possible for the giant Greenland ice-cap to be re-created and return to current levels.

“Over the next 30 years the amount of snowfall will not compensate for melting,” Hesselbjerg Christensen tells pol.dk adding: “Based on our model, I would almost say that the point of no return has already been passed. Our result shows in principle that permanent meltdown is unavoidable.”

Hesselbjerg Christensen is head of Denmark’s Climate Centre and is a co-author of the latest UN Intergovernmental Panel on Climate Change (IPCC) report on regional climate change.

He says, however, that according to the model it will take more than 1,000 years before the Greenland ice-cap has more or less disappeared.

“If Greenland’s ice-cap melted completely, it would result in a 6-7 metre increase in world sea levels,” Hesselbjerg Christensen says.

Link:  http://politiken.dk/newsinenglish/ECE1161570/greenland-close-to-unavoidable-meltdown/