Solar Radiation Management (SRM) is a potential technology to offset global climate change. While probably cheap, impact heterogeneities at a regional scale are expected to imply different optimum amounts of SRM for different countries. To avoid global externalities caused by excessive SRM, discussions have brought up liability regimes as a form of governance institution. I build a theoretical model of SRM liability that takes into account two specific challenges such regimes face when moving from traditional liability settings to SRM: The definition of 'harm' and the interpretation of the negligence rule in a setting with multiple victims and third-party beneficiaries. Considering two definitions of harm, an interpretation of strict liability and three interpretations of the negligence rule, I examine the performance of different liability regimes compared to the social optimum. I find that only one of the liability regimes leads to the first-best outcome. A numerical implementation into the Regional Climate Response model (Moreno-Cruz et al. 2012) of the liability model using climate model data from the Geoengineering Intercomparison Project illustrates the findings.
Tobias Pfrommer is a PhD student in economics at the University of Heidelberg. His research focuses on the incentive effects liability law provides for the use of novel technologies. In the specific context of solar geoengineering, he is particularly interested in the issue of attribution of harm and the interaction of liability regimes with the strategic setting solar geoengineering provides.