Tackling Climate Change
An alternative to a carbon tax:
One idea put forth by a physicist involved in climate-control discussions would involve bombarding the Arctic stratosphere with specially engineered particles to deflect the sun’s rays, thereby lowering temperatures. Alternatively, a fleet of crop-dusting airplanes could deliver the particles by flying continuously around the Arctic Circle. An astronomer suggested placing a huge fleet of mirrors in orbit to divert solar radiation.
Here's the Wilson Quarterly essay that gives you the full monty - and the risks and drawbacks as well.