An interesting take on Stern report

This short article from TCS daily argues that cost of fighting global warming, as suggested in the recent Stern report, is much higher than it first appears. (Roughly $400 billion annually.) The writer suggests that if this is the sort of money involved, then maybe some global engineering solution (of the mirrors in space variety, for example) is not so out of the question after all.

Speaking of which, here's another suggestion for such a solution:

Angel and colleagues propose launching a constellation of trillions of small free-flying spacecraft a million miles above Earth into an orbit aligned with the Sun, called the L-1 orbit. The spacecraft would form a long, cylindrical cloud with a diameter about half that of Earth, and about 10 times longer.

Some 10 per cent of the sunlight passing through the 97,000 kilometre length of the cloud - pointing lengthwise between the Earth and the Sun - would be diverted away from our planet. The effect would be to uniformly reduce sunlight by about 2 per cent over the entire planet, enough to balance the heating caused by a doubling of atmospheric carbon dioxide.

But the trick is how to get them there:

According to Angel and colleagues, the sunshade could be deployed by a total 20 electromagnetic launchers launching a stack of 1 million flyers every 5 minutes for 10 years.

Oh. Suddenly sounds less than plausible. Do it from the moon instead would seem a much better bet!

This idea also made me wonder whether anyone has suggested nanotechnology as a possible shielding solution. I quite liked Michael Crichton's novel "Prey", about swarms of nano gnats that start eating people. Of course, that such devices will ever exist seems farfetched, but if something like them could be made on an industrial scale, and launched to live high in the atmosphere, could the swarm form a controllable high altitude dusty sunshade? Just thinking outside of the circle, folks...