Russell Bewick, a space scientist at the University of Strathclyde, has suggested a scheme to combat climate change using asteroid dust to screen solar radiation. A near-Earth asteroid would be placed at the Earth-Sun Lagrange-1 (ESL-1) point and fitted with a mass-driver to spew asteroidal dust into space. The dust would settle in the weak gravitational well created by the asteroid as a cloud around 2600km across. Pulverising 5 per cent of the asteroid 1036 Ganymed would generate around 5 trillion tonnes of dust, and block 6.58 per cent of incident solar radiation at the Earth.
Asteroid Dust Could Fight Climate Change on Earth -- LiveScience
Rocketeer comments: Have to say that I regard geoengineering "solutions" as a monstrous waste of money at best, and actively bloody dangerous at worst.
Manipulation of a highly complex and poorly understood system is a classic opportunity for the Law of Unintended Consequences. What happens if the asteroidal dust is deployed, and the Sun then goes into a prolonged minimum of activity, causing an unanticipated extra drop in temperature? It's not as if you can turn the dust off again with any speed. Where you can turn a geoengineering system off again, you ...