Ice shelves are extensions of glaciers that float on an ocean’s surface. These permanent floating platforms are extremely important in protecting the ice sheets of the glaciers from flowing into the oceans, which increases their levels.
The Petermann Ice Shelf is the second-largest ice shelf in Greenland. If this huge ice shelf breaks down, it may not recover till the Earth’s climate cools down considerably in the future, according to a recent study published in Nature Communication.
A team of scientists from Stockholm University and the University of California, Irvine, conducted the study to explore whether Petermann could recover from a possible break-up due to climate change. The researchers resorted to a computer model to predict the recovery of the ice shelf.
Henning Akesson, of Stockholm University and the lead author of the study, said, “Even if Earth’s climate stopped warming, it would be difficult to rebuild this ice shelf once it has fallen apart. If Petermann is lost, we would have to go ‘back in time’ towards a cooler climate reminiscent of the period before the industrial revolution to regrow Petermann. Ice shelves reduce mass loss from our polar ice sheets. These gatekeepers thereby limit sea-level rise, caused by climate warming. The rationale to avoid break-up of ice shelves in the first place should be clearer than ever.”
Greenland’s glaciers are melting at a fast pace and Petermann is one of the remaining ice shelves. Scientists are continuously watching the glaciers of Greenland. Back in 2010 and 2012, a huge iceberg whose size was estimated to be equal to less than half of Delhi’s area broke off from the ice shelf. This led to a 40% loss of the floating ice shelf. Again in 2018, a crack was discovered in the middle of the ice shelf. Scientists believe that further break-up or collapse of the ice shelf would result in speeding up of ice flow into the ocean. Petermann’s health is thus an important cause of concern for glaciologists and climate scientists.
Scientists are also gravely concerned about the possible break-up of larger ice shelves in Antarctica that might not also recover. “This is just the first step. But chances are that our findings are not unique to the Petermann Glacier and Greenland. If they are not, near-future warming of polar oceans may push the ice shelves protecting the Earth’s ice sheets into a new retreated high-discharge state which may be exceedingly difficult to recover from,” Akesson added.