Climate-economy Modeling Considering Solar Radiation Management and its Termination Risk

The combination of carbon dioxide (CO2) emissions mitigation and geoengineering options of solar radiation management (SRM) such as placing sunshades in space and stratospheric aerosol injection is discussed quantitatively using an extended version of the DICE-2007, an integrated assessment model for climate policy analysis. Though SRM measures can contribute considerably to the cost-effectiveness of climate change mitigation, they might cause harmful side effects, such as rapid air temperature increases, if the SRM implementation were to be discontinued for any reason. The author suggests a guideline for the use of SRM: namely, that unexpected SRM termination at any time would not exceed the constraints on the rate of global warming recommended by the German Advisory Council on Global Change. The paper describes a method to incorporate this guideline in the DICE-2007 model, and shows the result of the extended model, which recommends an 80% reduction of global industrial CO2 emissions below the 2005 level by the end of the 21st century while implementing a complementary SRM option to mitigate climate change.