Let’s look before we leap into zany projects to save the world

Ideas like a sea curtain must be put to a clear cost-benefit analysis

- LARA WILLIAMS

The worse things get for the planet, the more unworkable the suggestions to save it become. Exhibit A: Proposals for climate cooling interventions focused on the polar regions, which are particularly vulnerable to climate change.

The Arctic, for instance, warmed nearly four times faster than the rest of the globe between 1979 and 2021. Since the poles help moderate the Earth's temperature by reflecting large amounts of solar radiation back into space and store an awful lot of freshwater in their enormous ice sheets, climate consequences there will be felt around the world.

We know what we need to do to protect these regions: Reduce our dependence on fossil fuels. Yet, some of the proposed methods, which would instead seek to treat the symptoms rather than the cause, may actually put the cold ends of the planet at greater risk, and would require unprecedented levels of global cooperation and pioneering feats of engineering.

Take, for instance, sea curtains. The idea is to install artificial structures to keep warm water from reaching the Antarctic and Greenland ice sheets, thus preventing glacier melt and sea-level rise. The Seabed Curtain project, a research programme led by University of the Arctic, envisions an 80km-long structure anchored to the seabed, 650m deep, with 150m tall curtains.

Sounds pretty ambitious, but you don’t know the half of it. A