Antarctic ice sheet collapse not ‘inevitable’: study

Antarctic ice sheet collapse not ‘inevitable’: study

The Pine Island and Thwaites Glaciers in West Antarctica contain enough ice to raise sea level by three meters

The Pine Island and Thwaites Glaciers in West Antarctica contain enough ice to raise sea level by three metres.

The runaway collapse of the West Antarctic ice sheet, which would cause a catastrophic rise in sea levels, is not “inevitable,” scientists said Monday following 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 irreversible melting of the world’s massive ice sheets and ultimately raise the oceans enough to return. to drastically draw the world map.

New research published Monday suggests a complex interplay of factors affecting the melting of the West Antarctic Ice Sheet, which is home to the massive and unstable Pine Island and Thwaites Glaciers, dubbed the “Doomsday Glacier,” which together could raise global sea levels by more than three meters (10 feet).

Using satellite images, as well as ocean and climate records between 2003 and 2015, an international team of researchers found that as the West Antarctic ice sheet continued to recede, the rate of ice loss was slowing in a vulnerable region of the coast.

Their study, published in the journal nature communicationsconcluded that this slowdown was due to changes in ocean temperatures that were caused by offshore winds, with pronounced differences in impact by region.

The researchers said this raises questions about how rising temperatures will affect Antarctica, with ocean and atmospheric conditions playing 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 coming decades, what we could positively influence by reducing greenhouse gas emissions.”

The researchers found that while in one region, in the Bellingshausen Sea, the rate of ice retreat accelerated after 2003, it slowed in the Amundsen Sea.

‘In a blink of an eye’

They concluded that this was due to changes in the strength and direction of offshore surface winds, which can change ocean currents and disturb the cold-water layer around Antarctica and push the water relatively warmer towards ice.

Both the north and south polar regions have warmed by about three degrees Celsius compared to late 19th century levels, nearly 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 related to the latest study, welcomed the approach of gathering multiple observations and records, even though the study period was “a blink of an eye.” in terms of ice”.

“I think we still have to live and plan and do our sea level projections and coastal planning with the assumption that the West Antarctic ice sheet is destabilized and we’ll get twelve feet of sea level rise just in this area of ​​the planet.” alone,” she said, adding however that this would happen “over centuries or millennia.”

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

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

While reducing planet-warming emissions is considered the first and most important way to stop the melting of the West Antarctic Ice Sheet, scientists have also come up with a number of high-tech suggestions to save the gigantic ice shelf. and avoid it.

Levermann has investigated ideas that include using snow cannons to pump trillions of tons of ice over the frozen region.

Other suggestions have included building Eiffel Tower-sized columns into the seabed to support it from below, and a 100-meter-high, 100-kilometre-long berm to block the hot water flowing below.

More information:
Interdecadal climate variability induces a differential ice response along the Pacific-facing West Antarctic, nature communications (2023). DOI: 10.1038/s41467-022-35471-3

© 2023 AFP

Citation: Runaway W. Antarctic Ice Sheet Collapse Not ‘Inevitable’: Study (January 22, 2023) Accessed January 22, 2023 at https://phys.org/news/2023-01-runaway- antarctic-ice-sheet-collapse.html

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