‘Unprecedented’ artificial snow plan could stop Antarctic ice retreat
The retreat of the Antarctic ice shelf due to global warming could be stopped with an ambitious plan from scientists to generate trillions of tons of snow from ocean water.
Scientists believe that global warming has already caused so much melting at the south pole that the giant ice sheet is now on course to disintegrate, which would trigger an eventual global sea level rise of at least three metres over centuries.
Anders Levermann, a professor at Germany’s Potsdam Institute for Climate Impact Research, has suggested that water could be pumped out of the ocean and snowed onto the ice sheet at a rate of several hundred billion tons per year over a few decades.
He said that data suggests this would effectively prevent the loss of ice in Antarctica but it would not be without its drawbacks.
“We are fully aware of the disruptive character such an intervention would have,” admitted Johannes Feldmann, a co-author on the study.
They calculated that uplifting, desalinating and heating the ocean water as well as powering the snow cannons would require an amount of electric power in the order of several tens of thousands high-end wind turbines.
“Putting up such a wind farm and the further infrastructure in the Amundsen Sea and the massive extraction of ocean water itself would essentially mean losing a unique natural reserve. Further, the harsh Antarctic climate makes the technical challenges difficult to anticipate and hard to handle while the potential hazardous impacts to the region are likely to be devastating,” Feldmann added.
With the droughts, floods, storms and wildfires associated with climate change intensifying globally, some scientists have begun to seriously contemplate interventions that would have been dismissed as wildly impractical even a few years ago.
Echoing many other climate scientists, Levermann said the most urgent priority was to deliver the rapid cuts in carbon emissions needed to meet the temperature goals of the 2015 Paris Agreement, which is aimed at averting runaway climate impacts.
The full sea-level rise projected to follow the collapse of the West Antarctic Ice Sheet might not unfold for hundreds of years, he added, but low-lying populations will be vulnerable sooner than that.
“The sea level rise from Western Antarctica will eventually submerge Hamburg, Shanghai, New York and Hong Kong,” he said. “You can’t negotiate with physics: that’s the dilemma here.”
Melting ice sheets in Greenland, the Arctic and shrinking glaciers around the world would worsen the problem, and sea levels could ultimately rise at least five metres even if countries manage to implement the Paris pact.
Levermann and his co-authors used computer models to calculate that the West Antarctic Ice Sheet could be stabilised by depositing a minimum of 7,400 gigatonnes of artificial snow over 10 years around the Pine Island and Thwaites glaciers.
The paper did not give a cost for such an intervention, which Levermann suggested could be borne by governments.
“The apparent absurdity of the endeavour to let it snow in Antarctica to stop an ice instability reflects the breathtaking dimension of the sea-level problem,” he concluded. “Yet as scientists we feel it is our duty to inform society about each and every potential option to counter the problems ahead. As unbelievable as it might seem: In order to prevent an unprecedented risk, humankind might have to make an unprecedented effort, too.”
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