The Problem Structure of Solar Radiation Management

Technologies for Solar Radiation Management (SRM) have been proposed as a measure for halting or slowing down global warming through the deliberate manipulation of planetary albedo. Due to their alleged cost-effectiveness and low technological requirements, as well as their potential unintended side effects, they raise a wide range of governance challenges. Today, a lively scholarly debate exists on potential ways for governing SRM. The starting point of this paper is that the diversity of views on governance options for SRM at least partially results from different (and often implicit) assumptions regarding the governance object itself. This paper starts from the notion that the effectiveness of any governance mechanism for SRM is not only a matter of institutional design but also depends on its particular problem structure. As SRM technologies are presently speculative and subject to a broad range of uncertainties, their problem-structural characteristics are equally speculative and uncertain. However, this paper attempts to develop a systematic account of different possible problem-structural configurations of SRM in order to assess the relative effectiveness of different types of institutional design. I develop a two-dimensional typological theory that is based on different assumptions regarding SRM deployment and termination. On one hand, SRM could potentially be deployed unilaterally (or by a small group of actors); or it might require a broader multilateral effort. On the other hand, a single actor (or a small group) might be capable of maintaining SRM deployment in the face of external shocks, including other actors' attempts to enforce its termination; or maintenance would require a multilateral coalition. The four resulting problem-structural configurations each render different types of collective action problems and pose different demands for institutional design. The possibility of multilateral deployment and maintenance is a classic freerider problem that requires mechanisms to disincentivize and deter defection. Unilateral deployment and maintenance, sometimes referred to as a "freedriver" problem, requires a preventive governance approach that changes the cost-benefit calculus of potential rogue actors, including through institutional linkages to the climate regime. The possibility of unilateral SRM deployment combined with the necessity of having a broader maintaining coalition in place to safeguard the system against external shocks makes the existence of any prior governance arrangement subject to moral hazard. Finally, a multilateral deployment threshold combined with the ability of single actors within the deploying coalition to protect the system against shocks creates a status quo bias that complicates the programme's eventual phase-out. While no precise probabilities can presently be attached to each of these possible problem-structural configurations, they highlight how discussions on SRM governance need to better take into account the relevance of non-institutional factors for institutional design.