Developing an integrated assessment model to explore optimal cost-benefit paths for Shared Socioeconomic Pathways scenarios

Most recent cost-benefit Integrated Assessment Models have used only one reference scenario and focused on reducing mainly CO2 emissions. This goal may not adequately account for the uncertainties arising from diverse socioeconomic developments and the potential for mitigating the effects of emissions of individual greenhouse gases, aerosols, and pollutants. We developed an Integrated Assessment Model framework by combining a socioeconomic module with a reduced-complexity climate module. We represented the Shared Socioeconomic Pathways (SSP) scenarios by 1) calculating a new set of marginal abatement cost curves based on the most recent integrated assessment model, 2) creating a new SSP-dependent damage function based on process-based impact simulation results, and 3) extending the evaluation time to the year 2450. The cost-benefit analysis revealed that the SSP scenarios achieved various rates of control for emissions of individual greenhouse gases, aerosols, and pollutants. The result was diverse patterns of optimal temperatures, including maximum temperature achieved and stabilized temperature by the end of the evaluation period. The model simulations showed the importance of distinguishing options for reducing emissions of greenhouse gases based on distinct socioeconomic growth scenarios. We also show an example of a long-term socioeconomic projection spanning several centuries as well as a variety of socioeconomic assumptions for assessing climate change policies with long-term consequences.