Uncertain W. Antarctic ice sheet collapse ‘inevitable’: study

Uncertain W. Antarctic ice sheet collapse ‘inevitable’: study

The Isle of Pines and Thwaites glaciers in West Antarctica contain enough ice to raise sea levels by three metres.

The Isle of Pines and Thwaites glaciers in West Antarctica contain enough ice to raise sea levels by three metres.

The dramatic collapse of the West Antarctic Ice Sheet – which would trigger catastrophic sea level rise – is not “inevitable”, scientists said on Monday after research tracking the region’s recent response to climate change.

As global temperatures rise, there is growing concern that warming could trigger so-called tipping points that trigger the irreversible melting of the world’s vast ice sheets and eventually take enough oceans to map significantly withdraw the world.

New research published on Monday suggests a complex interplay of factors influencing the melting of the West Antarctic Ice Sheet, which includes the huge and unstable Pine and Thwaites Island glaciers – known as the “Doomsday Glacier” – which global sea levels could rise more together. than three meters (10 feet).

Using satellite imagery as well as ocean and climate records between 2003 and 2015, an international team of researchers found that while the West Antarctic Ice Sheet continued to retreat, the pace of ice loss slowed across a vulnerable coastal region.

Their study, published in the journal Nature Communicationconcluded that this slowdown was caused by changes in sea temperature caused by offshore winds, with significant differences in impact depending on the region.

Researchers said this raises questions about how rising temperatures will affect the Antarctic, and that oceanic and atmospheric conditions will play a key role.

“That means ice sheet collapse is not inevitable,” said co-author Professor Eric Steig of the University of Washington in Seattle.

“It depends on how the climate changes in the next few years, which we can influence in a positive way by reducing greenhouse gas emissions.”

The researchers noted that while the speed of ice retreat increased in one region, the Bellingshausen Sea, after 2003, it slowed in the Amundsen Sea.

‘blink of an eye’

They concluded that this was a result of changes in the strength and direction of offshore surface winds, which can alter ocean currents and disrupt the layer of cold water around Antarctica and relatively warmer water to flush towards the ice.

Both the North and South pole regions have warmed by around three degrees Celsius compared to late 19th century levels, almost three times the global average.

Scientists are increasingly concerned that the Pine Island and Thwaites glaciers have reached a “tipping point” that could see irreversible melting regardless of cuts in greenhouse gas emissions.

Anders Levermann, a climate scientist at the Potsdam Institute for Climate Impact Research who was not involved in the latest study, welcomed the approach of bringing together multiple observations and records, although the study period was “blink of an eye in terms of ice”.

“I think we have to live and plan and do our sea level projections and our coastal planning with a hypothesis that the West Antarctic Ice Sheet is destabilized and we get three and a half meters of sea level rise just from this part of the planet. individually,” he said, adding however that this would happen “over hundreds to thousands of years”.

The United Nations’ scientific advisory panel on climate change, the IPCC, has predicted that the oceans will rise by up to a meter by the end of the century, and even more after that.

Hundreds of millions of people live within a few meters of sea level.

While cutting planet-warming emissions is seen as the first and most important way to stop the melting of the West Antarctic ice sheet, scientists have also come up with a range of high-tech proposals to save and stop the gargantuan ice shelf.

Levermann has researched ideas including using snow cannons to pump trillions of tons of ice back on top of the frozen region.

Other proposals include building columns the size of the Eiffel Tower on the seabed to support it from below, and a 100m high, 100 kilometer long berm to prevent hot water from flowing underneath.

More information:
Interdecadal climate variability drives differential ice response along the West Antarctic Pacific, Nature Communication (2023). DOI: 10.1038/s41467-022-35471-3

© 2023 AFP

Quote: Runaway W. Antarctic ice sheet collapse not ‘inevitable’: study (2023, 22 January) retrieved on 22 January 2023 from https://phys.org/news/2023-01-runaway-antarctic-ice-sheet-collapse. html

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