The uncontrolled collapse of the West Antarctic ice sheet — which would lead to catastrophic sea level rise — is not “inevitable,” scientists said Monday after research tracked the region’s recent response to climate change.
As global temperatures rise, there is growing concern that warming could trigger so-called tipping points leading to the irreversible melting of the world’s vast ice sheets, and eventually raising the oceans enough to radically redraw the world map.
New research published Monday demonstrates the complex interplay of factors influencing the melting of the West Antarctic ice sheet, which is home to the massive and unstable Pine Island and Thwaites glaciers – dubbed the “doomsday glaciers” – which together could raise surface levels. global ocean by more 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 as the West Antarctic ice sheet continued to shrink, the rate of ice loss in vulnerable coastal regions slowed.
Their study, published in the journal Nature Communications, concluded that the slowdown was due to changes in ocean temperatures caused by offshore winds, with different effects depending on the region.
Researchers say this raises questions about how warming will affect Antarctica, where ocean and atmospheric conditions play a major role.
“This means that ice sheet collapse is inevitable,” said co-author Professor Eric Steig of the University of Washington in Seattle.
“It depends on how the climate will change over the coming decades, which we can influence positively by reducing greenhouse gas emissions.”
The researchers noted that while in one area, in the Bellingshausen Sea, the rate of ice loss accelerated after 2003, it slowed down in the Amundsen Sea.
– ‘in the blink of an eye’ –
They concluded that this was caused by changes in the strength and direction of offshore surface winds, which could change ocean currents and disrupt the cold water layer around Antarctica and the flow of relatively warmer water towards the ice.
The Arctic and Antarctic 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 glaciers on Pine Island and Thwaites have reached a “tipping point” that could cause irreversible melting regardless of reductions in greenhouse gas emissions.
Anders Levermann, a climatologist at the Potsdam Institute for Climate Impact Research who was not associated with the new study, welcomes the approach of combining multiple observations and notes, even though the study period is “the blink of an eye on ice”.
“I think we still have to live, plan and do sea level projections and coastal planning assuming the West Antarctic ice sheet has been disrupted and we will rise to three and a half meters of sea level over this area of the planet. alone,” he said, adding that this would happen “over a period of time.” Centuries and millennia.”
The United Nations Scientific Advisory Panel on Climate Change, the intergovernmental agency on climate change, has predicted a sea level rise of up to 1 meter by the end of this century, and even more after that.
Hundreds of millions of people live within a few meters of sea level.
While reducing greenhouse emissions is seen as the first and most important way to stop the melting of the West Antarctic ice sheet, scientists are also advancing a series of high-tech proposals to save and prevent the massive ice sheet.
Leverman explored ideas including using snow cannons to pump trillions of tons of ice into frozen areas.
Other suggestions include building columns the size of the Eiffel Tower on the seafloor to support it from below, and a 100-metre-long, 100-kilometer-long sandbank to prevent warm water from flowing beneath.
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