A recent study shows that warm water is attacking the Antarctic ice sheet from below and accelerating melting.
The study, which was published last week in the journal Science, shows that the warming of waters for thousands of miles around the Antarctic ice sheet is not local and will significantly raise sea levels in the next couple of centuries. The ice shelf in question accounts for nearly 70% percent of fresh water globally. A study in May stated that the melting of the west Antarctic was inevitable and a question of when not if. The same study estimated that if it melted entirely the global sea level would rise about 16 feet.
That’s bad news for people all over the world as coastal regions are highly populated areas often with dense populations.
Antarctic ice: The balance has been turned on its head
“In Antarctica overall, there’s an increased amount of melting,” said Karen Heywood of the University of East Anglia, U.K., a co-author of the Science report. “It means the balance is out of kilter.”
That balance is a combination of winds, ocean currents, and snowfall that affect the mile thick ice layer on a continent twice the size of Australia. While the west ice sheet melting has been accelerated tremendously, parts of the east sheet are actually gaining ice, something that climate change deniers will presumably focus on if they take the time to read the study.
The gains in the east are not outweighing the losses in the west though, with the European satellite Cryosat’s data suggesting that Antarctica lost roughly 160 billion metric tons of ice over the last four years with a rise of sea levels around half a millimeter each year.
Accelerated melting a result of rising water temperatures
The Science study focused on the warming of the underside of the ice shelves and tried to determine whether this was occurring based on a change in ocean currents or overall warmer waters. The study determined that it was the latter citing rising temperatures in both the Amundsen Sea and the Bellingshausen Sea over the last 40 years.
“The warming of the water column that hugs the shelf extends for several thousands of miles,” said Sunke Schmidtko, an oceanographer at the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany and a co-author of the study
“Although we’re very worried about west Antarctica at the moment, if the warm water gets closer to east Antarctica that might melt next,” said Dr. Heywood. “It won’t happen tomorrow but it could happen in a few decades or hundreds of years.”