SGRP Seminar: Stratospheric Aerosol Injection: Informing Decisions

Stratospheric aerosol injection (SAI) could be used to cool the planet and reduce some of the impacts of climate change. The goal of SAI research is to help support informed decisions, not just about whether to deploy at all, but if so, how. This requires thinking carefully about deployment scenarios. In this talk, Prof. Douglas MacMartin will explore several different aspects of these scenarios. First, he will discuss the need to better understand the effects of the different choices that could be made about how to deploy, and the role of injection latitude in particular. This mostly boils down to whether deployment starts with modified existing aircraft at higher latitudes where the tropopause is lower, or with novel aircraft at lower latitudes; the latter has been assumed for most research but the former may be more likely. Next, he will explain which uncertainties “matter” and how to reduce these before and during deployment. Finally, he will discuss using emulators to explore a broader range of scenarios in order to develop a better understanding of at least the physical effects of poorly-done deployment.

Douglas MacMartin is an Associate Professor in the Sibley School of Mechanical and Aerospace Engineering at Cornell University. His research focuses on Sunlight Reflection Methods (SRM, also known as climate engineering, solar geoengineering, or climate intervention), with the aim of helping to develop the knowledge base necessary to support informed future societal decisions in this challenging and controversial field. He has published extensively on the subject, and in addition to public and academic presentations has provided briefings to the UN Environment Program and testimony to the US Congress, and was a member of the US National Academies panel that made recommendations on both research and governance in March 2021. He received his Ph.D. in Aeronautics and Astronautics from MIT in 1992; previous positions include United Technologies Research Center (1994-2000) and the California Institute of Technology (2000-2015). His research is funded by NSF and by the Cornell Atkinson Center for a Sustainable Future.