Doomsday Scenarios about Antarctic Ice Melt May be Exaggerated

A group of French and British scientists who study how a rise in greenhouse gas levels may affect ice sheets in the polar south found that the doomsday scenarios about Antarctic ice melt may be exaggerated.

Researchers said the ice melt from the Antarctic would significantly raise global sea levels but not as much as previous studies had suggested. The team used computer models to simulate how the Antarctic ice sheet would cope with rising temperatures, if emissions rose at a medium to high rate.

According to the new findings, sea levels may not rise more than 4 inches or 10 cm by the end of the century, so other scenarios that claim an 11 inch or 30 cm sea-level rise or more have just 20 percent chance to happen.

The study, which was published in the journal Nature, was based on measurements of the bedrock and ice sheet dynamics and up-to-date satellite data on the continent. That data revealed that, indeed, the region has been thinning in its western parts especially in the Amundsen Sea, where glaciers’ decline was deemed ‘irreversible’ by a cohort of studies.

Tamsin Edwards, co-author of the study and researcher with the Open University, in the UK, explained that other scientists performed various simulations but they failed to compare their predictions with today’s reality and re-weigh those predictions based on new data.

“With our model we have done some 3,000 simulations,”

Edwards added.

After the simulations researchers compared their predictions with what is happening in the Amundsen Sea. They were especially interested in the pace of melting. If the melting rate was slower predictions were given a ‘lower weight’ in the coming years.

The team argued that no other research team adjusted their models through real physics observations. Their worst-case scenario, after adjustments were done, is a 4 inch global sea level rise by 2010.

This result is consistent with a 2013 study carried out by the Intergovernmental Panel on Climate Change. Scientists said that the scenarios who claim that we are heading toward a 20-inch or even 40 inch sea-level rise by 2100 “aren’t plausible.”

The group argued that bedrock under the Antarctic ice sheet plays a huge role in the sheet’s dynamics. Edwards explained that the bed has some parts that are so rough and bumpy that they do not allow ice to melt as fast as previous models suggested.

Still, the ‘doomsday scenarios’ are plausible for a wider timeframe such as several hundred or a thousand years.
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