By Adam Vaughan
Pumping colossal amounts of ocean water onto the West Antarctic ice sheet could stop it collapsing and causing drastic sea level rise that would threaten cities including Tokyo and New York.
But the German and US researchers who have explored the idea admit the drastic intervention would require an “unprecedented effort for humankind in one of the harshest environments of the planet”. The fix would also be extremely expensive, incredibly hard to do and risk potentially devastating impacts for the region’s unique ecosystem.
Five years ago, studies suggested the West Antarctic ice sheet had already started an unstoppable collapse. While the process will take centuries, it would raise sea levels to a height that would have dire consequences for major coastal cities.
The threat is so grave, it requires an exploration and discussion of bold ideas to stop the ice sheet’s collapse, says Anders Levermann of the Potsdam Institute in Germany. “I’m certain the impact is so big it justifies this sort of thinking. It doesn’t mean it justifies the measure,” he says.
Previous far-out ideas to stop the loss of the ice sheet have included building an island to stop the flow off the ice shelf. Levermann and colleagues instead modelled a more direct approach that would involve pumping ocean water onto the sheet, adding it either in liquid form or as snow. They found stabilising the collapse would require at least 7400 gigatonnes of the stuff over 10 years. “It’s a lot of ice. It’s huge,” says Levermann. He says while he is against global scale geoengineering proposals such as giant sunshades, the water pumping idea is different and more surgical.
Even if society agreed on such a scheme, it faces mind-boggling obstacles. Around 145GW of wind farm capacity would be needed for the pumping, 12 times that installed in Europe last year. Temperatures would be too low for existing turbines, so new materials would be needed. The infrastructure would also turn the region into an “industrial compound”, says Levermann. Costs would likely be hundreds of billions of dollars, he adds.
Not going to happen
“This publication gives an indication of quite how challenging it would be to attempt to halt ice sheet collapse through direct human intervention,” says Emily Shuckburgh at the University of Cambridge.
Clive Hamilton at Charles Sturt University in Australia says: “The conditions under which such a scheme could be implemented are beyond anything feasible. It’s not going to happen.”
The priority for limiting sea level rises remains cutting greenhouse gas emissions, Levermann emphasises. Shuckburgh says the paper underlines the best option of managing the risk from Antarctica is to rapidly reduce emissions.
Journal reference: Science Advances, DOI: 10.1126/sciadv.aaw4132