The Next Zeppelin?

The Guardian reports that the United States desires a leading role in the fight against climate change. In an article titled "US answer to global warming: smoke and giant space mirrors" (pun assuredly intended), the Guardian reports that Washington wants to develop technologies to block sunlight from entering earth's atmosphere. The technologies include giant mirrors in space and reflective dust pumped into the atmosphere.

Perhaps openmindedness is in order; that said, would any of this ever, um, fly? Giant mirrors and "magic" dust?

The US government document can be found here.

Questions: 1) which nation would be developing these technologies or would it be a mutual effort? 2) can we afford not to achieve consensus for years to come: the EU and Japan etc. trying to go the Kyoto way, while Americans would go it alone and continue emitting CO2, business as usual? 3) would Washington want this to be an internationally funded project on the basis that it would benefit everyone, a project whose costs would thereby need to be covered by all? 4) would something like this actually be feasible i.e. does it make sense? 5) how much would it cost? 6) who would produce these technologies: would the proceeds go to an American corporation X or some other interest group?