The moon behind terrestrial clouds – could one similarly shade the sun to save the climate?
Image: AP
Astrophysicists suggest using large amounts of lunar dust to temporarily shade the sun. This could then cool the Earth’s climate. But the details of the strategy are complicated.
Ttheoretically it sounds like an elegant solution to the earth’s climate problem – even more so when you consider how difficult it is for the nations of the world to reduce their CO2-Reduce emissions: Couldn’t we simply reduce solar radiation and thus stop the further warming of the earth’s climate? The astrophysicists Benjamin Bromley, Sameer Khan and Scott Kenyon from the University of Utah and the Smithsonian Astrophysical Observatory in Cambridge have now pursued this idea in the journal “PLOS Climate”. Specifically, they have calculated various scenarios in which large amounts of dust are brought into the line of sight between the sun and the earth, in order to shade the solar radiation that reaches the earth.
The idea for such geoengineering is not new. There are model calculations according to which blocking one to two percent of the incoming sunlight would be enough to save the climate. It has already been discussed to distribute aerosols in the earth’s atmosphere for this purpose. However, there are many uncertainties, because it is difficult to predict how the aerosols will behave in the atmosphere over the long term. Solutions in space seem easier to control, such as huge parasols, a swarm of small satellites or tiny rock particles.