Washington, Dec 17 (Inditop.com) Polar ice sheets are vulnerable to large-scale melting even under moderate warming conditions, according to a report by Princeton and Harvard scientists.
Such melting, triggered by two more degrees of warming, would raise global sea levels by as many as six to nine metres, said the report.
This rise would inundate low-lying coastal areas like New Orleans and other parts of southern Louisiana in the US, including much of Bangladesh and the Netherlands, displacing millions of people, unless unprecedented and expensive coastal protection are undertaken.
If greenhouse emissions are not abated, the findings indicate the planet could lock itself into a level of warming sufficient to trigger the outcome during this century itself.
Robert Kopp, associate professor, led the study along with his Princeton geoscience counterparts Adam Maloof, Michael Oppenheimer and Jerry Mitrovica of Harvard.
They compiled an extensive database of geological sea level indicators for a period known as the last interglacial stage about 125,000 years ago.
Polar temperatures during this stage were likely to be three to five degrees Celsius warmer than today, as is expected to occur in the future if temperatures reach about two to three degrees Celsius above pre-industrial levels.
“The last interglacial stage provides a historical analog for futures with a fairly moderate amount of warming; the high sea levels during the stage suggest that significant chunks of major ice sheets could disappear over a period of centuries in such futures,” Kopp said.
“Yet if the global economy continues to depend heavily on fossil fuels, we’re on track to have significantly more warming by the end of the century than occurred during the last interglacial. I find this somewhat worrisome,” Kopp added.
Oppenheimer added: “Despite the uncertainties inherent in such a study, these findings should send a strong message to the governments negotiating in Copenhagen that the time to avoid disastrous outcomes may run out sooner than expected.”
These findings were published in the Wednesday issue of Nature.
