It sounds like something out of a science fiction novel but the problem it aims to address - the potential melting of the Thwaites and Pine Island glaciers in Antarctica which according to a recent article in The Guardian “act as plugs that prevent the giant ice sheets behind them from sliding into the ocean” - is far from a one in a million, way-in-the-distance hazard. It is estimated “that the loss of the Thwaites and Pine Island glaciers could be enough to raise sea levels around the world by three metres if they melted, a prospect now considered to be a real threat as global warming takes a grip of the region and causes sea temperatures to rise.”
Scientists and engineers around the world are proposing a massive (100 km long, 200 m high) curtain that would shield the glaciers from the warmer sea water that is increasingly buffeting them as the world warms.
Various techniques are proposed ranging from “[A] pipe – with holes drilled along it – would be laid down along the seabed and air pumped through it. The curtain of air bubbles that would rise from it might then be able to hold back the ingress of warm seawater” to an actual physical curtain of some kind. All this is not going to happen quickly and researchers will conduct tests in other locations over the next few years.