An excellent piece supporting a research program on solar radiation management geoengineering was published this week by the journal Nature, David W. Keith, Edward Parson & M. Granger Morgan, Research on Global Sun Block Needed Now, 463 Nature 426-27 (2010) (accessible without subscription).

Among the takeaways from the article:

1. Solar radiation management (SRM) geoengineering (defined as adding light-scattering aerosols to the upper atmosphere or increasing the lifetime and reflectivity of low-altitude clouds to exert a cooling effect) could offset projected temperature increases this century at a cost 100x less than through emissions cuts, or merely a few billions annually;
2. Research on SRM has been extremely limited to date, largely restricted to a handful of climate-model studies using very simple parameterizations of aerosol microphysics; the potential hazards of SRM (which the article indicates includes potentially less precipitation and less evaporation, potentially creating regional “winners” and “losers” can only be assessed through in-situ testing, which will cost millions of dollars;
3. It would be “reckless” to conduct the first large-scale SRM tests under an emergency scenario; we shoudl expand experiments gradually to scales big enough to produce barely detectable climate effects, and to reveal unexpected problems, but small enough to limit risks;
4. Research should be conducted using a “blue team/red team” approach, in which one team proposes an approach and the other works to identify risks and why proposals might not prove effective;
5. A better alternative to hasty pursuit of international regulation would be seeking to engender international cooperation and norms from the bottom up, as occurred with the landmine convention; this should include an international program of research and risk assessment by multiple independent teams;
6. While some fear that geoengineering research and potential deployment could lead to a “moral hazard,” i.e. weaken a commitment to mitigation, there’s a great threat to mitigation effort by allowing for the possibility of SRM without scrutiny of actual requirements, limitations and risks; moreover, if SRM proves unworkable or poses unacceptable risks, the sooner we discover this, the less of a moral hazard geoengineering will pose.

This piece would provide an excellent foundation for discussing geoengineering options. Among the potential questions for students that could flow from it include the following:

• Is it realistic to believe that an SRM program could be shut down once substantial research programs ensued, i.e. isn’t their a danger of a “political lock in” that would make deployment inevitable at some point, exacerbating the potential threat of moral hazard?;
• What is the potential moral hazard threat the geoengineering might pose for adaptation efforts?;
• Even if a bottom-up research approach is optimal, would we ultimately need international governance should we proceed with full-scale deployment, and if yes, what would be the appropriate regime(s) to do so?;
• Should any proposals for full-scale deployment of geoengineering include a liability mechanism for potential damages to the interests of some States?