It’s easy to like the illus that goes with a takeout in today’s San Diego Union-Tribune‘s science section by Scott LaFee. His subject is the ambitious range of ideas for removing CO2 from the air. The fanciful art is quite elegant. A blocky cyber-tree reaches to the sky. Underground are what look like disconnected roots.
The merit of the story is to catch those of us who follow such things up on the man who wanted to scrub CO2 from the air with what look like monster flapjack flippers erected across hundreds of square miles of land (see illus in earlier post, April 19,’07). Lately, LaFee reports, the Columbia U. geophysicist behind the notion is thinking of a more organic variant. Rather than the big radiator-like air scrubbers held aloft, it makes better sense to put the CO2-grabbing membranes in the equivalent of tree branches. More space efficient. But it says here no foliage would be included – artistic rendering of rhombus-shaped leaves to the contrary.
The story leaves a ton of questions unanswered. One is about the idea of, rather than just burying the captured CO2, reducing it to a flammable form and using it as liquid fuel. That conversion has to, in itself, consume a lot of energy – where does that come from? Presumably, the author of the scheme has answers (nuclear ones, one guesses). As for the underground portion of the graphic, it represents not roots but real trees. They go with another big strategy a few climate-fixers are considering and whom LaFee interviewed. Forests absorb a lot of CO2 as they grow. Once mature the old trees die and rot, releasing CO2 about as fast as the forest’s saplings absorb it. The way out of that is to cut the trees and bury them deep, siphoning off biomass as fast as the forest piles it up. It’s been done. The timbers of medieval buildings around the world – and of houses built today too – are sequestered forest carbon, right?
-CP
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