Despite Kyoto, carbon dioxide emissions are up 30 percent globally since 1990. The oceans are acidifying as they absorb CO2 from the atmosphere. And new research suggests that even if we could turn off carbon dioxide emissions completely, climate changes may be irreversible.
So with all that bad news, attention is turning to fake plastic trees as a possible solution.
Yes alternative music aficianadoes, that is in fact the title of a terrific Radiohead song. But it is also the term adopted by fans of carbon dioxide “air capture” to describe a technology for curing global warming. The technology would do artificially what real wooden trees do naturally: suck CO2 out of the atmosphere. Once removed, the greenhouse gas could then be stuffed away some place where it couldn’t cause global warming.
Several air capture approaches are being developed, including “synthetic trees” that Columbia University geophysicist Klaus Lackner is trying to develop. But is it just crazy to think that we could actually afford to suck enough CO2 out of the atmosphere to make a difference? A study by the University of Colorado’s Roger Pielke, Jr., soon to be published in Environmental Science & Policy says no.
To summarize, the idealized exercise conducted here finds that air capture using 2008 technology is of about the same costs as the costs estimates for stabilization at 450 ppm or 550 ppm carbon dioxide presented by IPCC (2007a) and Stern (2007). If the costs of air capture decrease to $100 per ton of carbon, then over the 21st century air capture would in fact cost much less than the costs estimates for stabilization presented by IPCC (2007d) and Stern (2007). This surprising result suggests, at a minimum, that air capture should receive the same detailed analysis as other approaches to mitigation.
Pielke says air capture could complement efforts to reduce CO2 emissions, because such mitigation almost certainly will not be 100 percent effective. “Air capture . . . could be a form of ‘mopping up’ whatever is left of the task of mitigation,” he writes. And air capture on a very large scale could turn out to be essential if mitigation efforts fail abysmally.
Either way, Pielke is urging that more attention be paid to this option:
Would it be easier to transform the global energy system and change the energy consuming habits of 6.5 (going to 10) billion people around the world in a period of a few decades, or to engineer a solution to removing carbon dioxide directly from the ambient air? I don’t know what the answer is, but I lean pretty strongly toward the latter.