Earth melts as sea levels rise

As the rate of global warming continues, sea levels are expected to rise leading to disastrous consequences.

3 April 2006
MUMBAI, INDIA

According to two studies published in Science by Dr Jonathan Overpeck, of the University of Arizona in Tucson, and colleagues, the threshold that would trigger a rise in sea levels by several meters may be reached, as early as the end of this century. When this happens, the study suggests, the temperature in Greenland in the year 2100 would be what it was 130,00 years ago when melting ice had raised sea levels by 3-4 meters.

Apart from the possible melting of Greenland, the study also suggests that almost half of the West Antarctic ice sheet could have melted within 500 years.

The reason? The rate of warming is directly related to rising greenhouse gases. Meanwhile, Greenland remains a particularly vulnerable region. In a BBC report, co-author Meredith Nettles at the Lamont-Doherty Earth Observatory in New York, US, says "Greenland's glaciers deliver large quantities of fresh water to the oceans, so the implications for climate change are serious. We believe further warming of the climate is likely to accelerate the behaviour we've documented."

Greenland has glaciers as large as Manhattan and as tall as the Empire State Building, and which can move 10m in less than a minute, according to Harvard University scientists. Such movement would be sufficient to generate seismic waves. These "earthquakes" being caused by the glacier movement are also increasing in frequency, according to the journal.

Pointing to the 'danger zone' that Earth could be entering, Dr.Overpeck said, "These processes of rapid ice sheet retreat are already happening. It just takes a while to get metres of sea level rise. But our study says that if we warm the Earth by more than two times the equivalent of pre-industrial carbon dioxide levels, we could be entering the danger zone."

This process is not reversible, he added, saying, "The ice sheet retreat and sea level rise on the order of what happened 130,000 years ago is inevitable and irreversible."

Geoscientist Michael Oppenheimer of Princeton University agreed that these findings should be taken as a "serious warning sign."

The researchers used simulated climate warming using computer models configured at simulating Earth's climate 130,000 years ago. From comparisons with simulations of future warming, they were able to make an estimation of a rise in sea levels of over 1 meter per century.