The RAND Corporation has released a new study titled Governing Geoengineering Research, in which the authors combine a "vulnerability-and-response-option analysis framework" with a robust decisionmaking (RDM) model to explore possible consequences of different US policies on geoengineering research. While this quantitative, decision-analytic methodology is a welcome addition to the literature on geoengineering policy, employing this approach leads to fairly mundane results:
"This analysis offers the following preliminary results for policymakers. If U.S. policymakers believe that some type of SRM technology is possible, they ought to prefer the Strong Norms policy [i.e., promote research]. ... If they believe that successful SRM technology is unlikely, U.S. policymakers might prefer the Ban [i.e., oppose research] or No Norms [i.e., laissez faire] option to Strong Norms" (pp. 39-40).
In other words, if geoengineering works, support geoengineering research, and if geoengineering fails, forget about it. These conclusions are unremarkable, but the study is significant in signalling continuing interest in geoengineering on the part of the US defense establishment. The effects of this interest are, of course, open to debate.