One-third of Antarctica’s ice shelf is at risk of collapse with global warming

In a prediction study, scientists found that 34% of the area of ​​all Antarctic ice shelves, measuring about half a million square kilometers, could be destabilized if world temperatures increased by 4 degrees. About 67% of the ice shelf area on the Antarctic Peninsula would be at risk of destabilization under this scenario, the researchers said.

Ice platforms are permanent floating ice platforms attached to areas of the coast, formed where glaciers that flow from the land meet the sea. They can help limit the rise in global sea level by acting as a dam, slowing the flow of melting ice and water in the oceans.

Each summer, the ice on the surface of the ice shelves melts and hits smaller cracks in the snow below, where it usually freezes again. But when there is a lot of melting and little snow, that water accumulates on the surface of the ice or flows into cracks. This deepens and widens the cracks, causing the platform to fracture and collapse in the sea.

“Ice shelves are important buffers that prevent land-based glaciers from flowing freely into the ocean and contribute to rising sea levels. When they collapse, it’s like a giant cork being removed from a bottle, allowing quantities unimaginable water from the glaciers to fall into the sea, “said the study’s lead author, Ella Gilbert, a climate scientist at the University of Reading’s Department of Meteorology, in a statement.

Gilbert told CNN that low-lying coastal areas, particularly small island states like Vanuatu and Tuvalu, in the South Pacific Ocean, are at greatest risk with rising global sea levels.

“However, coastal areas around the world would be vulnerable and countries with less resources available to mitigate and adapt to rising sea levels will see worse consequences,” she said.

In the new study, which used high-resolution regional climate modeling to predict the impact of increased melting and water runoff on the stability of the ice shelf, the researchers say that limiting the temperature rise to 2 degrees Celsius instead of 4 degrees Celsius would halve the area at risk and potentially prevent a significant rise in sea level.

The Intergovernmental Panel on Climate Change concluded in a historic report that we only have until 2030 to drastically reduce our dependence on fossil fuels and prevent the planet from reaching the crucial limit of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-levels -industrial.

Net global carbon dioxide emissions would need to drop 45% from 2010 levels by 2030 and reach “net zero” by 2050 to keep warming around 1.5 degrees Celsius.

“The findings highlight the importance of limiting increases in global temperature, as set out in the Paris Agreement, if we are to avoid the worst consequences of climate change, including rising sea levels,” added Gilbert.

In the Paris agreement, 197 countries agreed to the goal of keeping global temperatures “well below” 2 degrees Celsius above pre-industrial levels and to seek efforts to limit them to 1.5 degrees Celsius.

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But we are on the way to a world that will be 3.2 degrees Celsius warmer by the end of the century.

Gilbert told CNN that rising temperatures mean that the melt occurs more often and more intensely.

The researchers identified four ice shelves that would be threatened by a warmer climate: the Larsen C, Shackleton, Pine Island and Wilkins ice shelves, which are vulnerable due to their geography and the expected runoff in those areas.

Larsen C is the largest remaining ice shelf on the Antarctic Peninsula, and the Pine Island glacier has received a lot of attention in recent years because it is melting rapidly in response to climate change, said Gilbert.

If these ice shelves collapse, which is not guaranteed, the glaciers they currently restrict would go into the ocean, contributing to sea level rise – potentially by tens of centimeters, she explained.

The study was published Thursday in the journal Geophysical Research Letters.