Air capture is an industrial process that captures CO2 from ambient air producing a pure CO2 stream for use or disposal. There is no doubt that air capture technologies could be developed . . .The Committee expresses considerable ignorance about the costs of air capture, simply calling them "high." Somehow the Committee was either unaware of or chose to ignore (I'm not sure which option is worse) the only peer-reviewed paper that compares to costs of air capture to other approaches to mitigation (i.e., as expressed by IPCC and Stern):
Pielke, Jr., R. A., 2009. An Idealized Assessment of the Economics of Air Capture of Carbon Dioxide in Mitigation Policy, Environmental Science & Policy, Vol. 12, Issue 3, pp. 216-225.
Funny how that sort of thing seems to happen a lot in climate science., but I digress. The report then has this very interesting nugget:
Proposals for new methods [of air capture] are still appearing (confidential submissions received) and it is very likely that substantial cost reductions are possible in future.So let's summarize what the Royal Society report says: Air capture is undoubtedly technologically feasible, it is "very likely" that "substantial cost reductions are possible," and "with relatively low environmental impacts and low risk of unanticipated consequences."
So then why hasn't air capture occupied a more central role in climate policy discussions? The Royal Society report suggests an answer to this as well:
Already, the politics of geoengineering are complex and contested, and the positions taken by scientists and other analysts may interweave policy preferences with technical judgements. . . Differences in professional and personal values may therefore play a significant role in the evaluation of geoengineering options relative to conventional mitigation and adaptation. The very discussion of geoengineering is controversial in some quarters because of a concern that it may weaken conventional mitigation efforts, or be seen as a ‘get out of jail free’ card by policy makers . . .