Managing Climate Risks With Solar Geoengineering: Tailoring Radiative Forcing, Reducing Ozone Loss, and Understanding Expert Perspectives

Abstract

Among the portfolio of options to reduce climate damage, solar geoengineering (SG) is a high-risk and highly uncertain method that is also the most economical in reducing global mean temperature. With the goal of eventually making decisions on deployment (or no deployment), research in the field covers a range of topics including the bounds of efficacy, potential impacts, and stakeholder perspectives. In addition, the risks and efficacies of SG must be positioned in the context of mitigation and adaption methods. This thesis addresses specific issues on each of these topics and evaluates one mitigation policy. The first part of the thesis discusses limitations on the spatial and temporal patterns that can be achieved using stratospheric sulfate injection. We find that globally uniform radiative forcing (RF) can be achieved and that there is a trade-off between the degree of spatial control and RF efficacy. The second part of the thesis studies the ozone impact of stratospheric injection of CaCO3 particles by experimentally determining the uptake coefficients of important gaseous ozone depleting species on CaCO3. It shows that previous assumptions of these reaction rates were too high and that the net impact of CaCO3 was over-estimated. The third part of the thesis shows results from detailed semi-structured interviews with US and Chinese experts on their views towards SG. We found that US and Chinese experts agree on a wide range of issues covering research and deployment of SG. The fourth part of the thesis investigates the effectiveness of Leadership of Energy and Environmental Design standards in improving building energy efficiencies using building energy benchmarking data from 1565 buildings in 10 US cities. Finally, the last part of the thesis discusses issues that might be important to SG research under a stochastic dynamic decision-making framework.