Paris (AFP)
How to counter the thaw of West Antarctica and rising sea levels? Pumping the water from melting ice to reject it on the ice cap with snow cannons, suggests a study published Wednesday.
This area of Antarctica contains enough frozen water to raise the new oceans of the planet by about six meters. A mere one meter rise would force 190 million people from their homes and a three-meter increase would put megacities like New York, Shanghai and Tokyo at risk.
Scientists are particularly concerned that the Pine Island and Thwaites glaciers - which contain enough ice to raise sea levels by three meters - have reached a point of no return where they would continue to melt, no matter how hard they go. against greenhouse gas emissions.
While limiting global warming may not be enough to avoid disasters, various technological paths, often combined under the term of geo-engineering, are envisaged. But few of them concern the problem of rising sea levels.
Researchers at the Potsdam Institute for Climate Impact Research (PIK) have therefore devised this pumping solution for melted ice to project it onto the ice cap.
"It's a terrible thing to do, there is no doubt about it, and we do not suggest doing it at all costs," says Anders Levermann, physicist at PIK and lead author of the study in Science Advances.
"But all the models show that if we stick to the 2 ° C warming of the Paris Agreement, we will finally have a five-meter rise in sea level, if not more," he said. AFP.
- "Lunar Station" -
To stabilize glaciers, it would take at least 7.400 billion tons of snow.
Anders Levermann insists that this is only a hypothesis and that any such measure should be accompanied by a drastic reduction in greenhouse gas emissions for a chance to succeed.
The system could be powered by 12,000 wind turbines and include hundreds of snow cannons to spray powder on an area the size of Costa Rica.
Such an infrastructure, whose cost is not costed, would require "something resembling a lunar station in Antarctica," said Anders Levermann.
Solutions devised in the past to counteract the melting of West Antarctica included the construction of four 300-meter submarine columns to hold the glacier or a 50-100-meter-high wall 80-120 km long.
Anders Levermann admitted that the KPI project, if feasible, could have "terrible" effects in Antarctica, but that this would be worthwhile if it limits the rise in sea levels.
"It's as big as North America, from Mexico to Canada, there's no place on earth that's protected on such a scale," he says.
"We would make West Antarctic an industrialized zone," he admits. "But if we destabilize (the icecap), everything will change dramatically anyway."
© 2019 AFP