With Richard Branson offering US$25 million to someone who can come up with a system to remove greenhouse gases (most importantly, CO2) from the atmosphere, a lot of people are probably wondering whether it is a pipe dream. Aside from the obvious option of growing more plants, I would be inclined to think so. In order to separate CO2 from air, then sequester it somewhere, it seems likely that you would need a lot more capital and energy than would be required to simply switch away from fossil fuels. It’s like turning on your air conditioning because your oven is making the house too hot. I don’t doubt that it is possible, but I doubt that it is a sensible solution.
That said, finding a technical solution to the greenhouse gas problem would please a very great many people. Though less likely to actually mitigate climate change, the ‘separate and sequester’ plan seems a lot more sensible than the sulfate injection plan, discussed previously. While it may be unlikely that someone will actually claim his prize (and it might distract research attention from more promising options like making more efficient solar panels), that is not to say it would be a bad thing if someone did.