This has reminded me that I have a blog, and it needs posting.
The basics- we are all cooked. Too much CO2 in the atmo, and it's unbelievably unrealistic to think we can mediate it by running our cars on corn.
So what do we do? Lovelock says we need to alter our agricultural practices- WORLDWIDE. So not likely either, but wait for it--- if all farmers were to pyrolyze (cook in a low O2 environment) their agricultural wastes (stalks, hulls, husks, cobs, corms, culms, leaves, etc) and make charcoal, and then BURY THE CHARCOAL IN THEIR FIELDS (which is a _totally_ obvious step to take, right?), global CO2 emissions would immediately fall to pre-industrial levels.
Something that nobody's covered (AFAICT), though, (at least in this recent burst of stories sparked by the New Scientist's interview) is that charcoal burial is totally helpful in the agricultural environment. You see: Charcoal, being the nearly pure carbon remains of plant matter, has a very high surface area. (all the squishy bits leave little channels and trails when they burn away). When charcoal is buried, this surface area becomes proper habitat for "critters"- bacteria, tardigrades (WATER BEARS) actinomycetes, mycorrhizia. Just like sinking a mothballed destroyer to start coral reefs.
THUSLY, we have Terra Preta. Miracle soil of the Aztecs. Rediscovered for the 21st century. Get onboard, bury some charcoal, make it happen.
PS, it just so happens that a byproduct of pyrolysis is long-chain hydrocarbons.