Risk Trade-offs Between Climate Change, Mitigation, and Solar Radiation Management

Climate change is fundamentally a problem of risk management, in which a portfolio of different response strategies can be employed to lower the probability (mitigation) or consequences (adaptation) of these risks. Solar radiation management (SRM), as one of two broad families of geoengineering approaches (the other being carbon dioxide reduction (CDR)), could also act to lower climate change risks through a relatively rapid lowering of global temperatures. However, SRM also incurs its own countervailing climate- and non-climate change-related risks. Two challenges present themselves to conducting any risk tradeoff analysis between SRM, mitigation, and climate change. First, the tradeoffs may in many cases be challenging to compare. Unlike mitigation or CDR on a massive scale, SRM is not climate change in reverse but instead an additional type of climate change meant to ameliorate the original version caused by rising greenhouse gas concentrations. While mitigation acts to reverse the temperature outcomes of climate change, SRM does this but may create changes to precipitation and other climatological conditions as well. Second, the uncertainties surrounding SRM approaches are large, which complicate any risk tradeoff analysis.

This paper has two objectives. First, we seek to lay the groundwork for an applied risk tradeoff analysis among these climate change risk reduction strategies by addressing some of the issues noted above. Second, we plan to apply these insights to further understanding the "risk compensation" question, i.e., whether or not the existence of a possibly more effective, cheaper, and overall "easier" SRM approach to lowering climate change risks would diminish the motivation to lower those same risks through mitigation.