OT: I know how to solve global warming

[Hunpecked]

As ToddT has hinted, if you want to decrease solar radiation reaching the earth, increased emission of aerosols is a lot easier and cheaper than building orbital sunscreens. Recall that the explosion of Krakatoa in 1883 lowered global temperatures for years. The "year without a summer" in 1816 was caused by a series of volcanic eruptions.

http://en.wikipedia.org/wiki/Krakatoa
http://en.wikipedia.org/wiki/Year_Without_a_Summer

However, I wouldn't recommend such drastic action (or any action) to counter hypothetical catastrophes predicted by a field as immature and uncertain as climate science--especially when the earth is known to have been warmer than today with no ill effects (quite the opposite, in fact) on human civilization.