Should Geoengineering Be Part of an Overall Climate Strategy?

Guest Speaker: Douglas MacMartin

Senior Research Associate, Sibley School of Mechanical & Aerospace Engineering, Cornell University

Aggressively reducing our greenhouse gas emissions (mitigation) is essential, but will not be sufficient to avoid significant climate change. Carbon dioxide removal (CDR), if implemented at sufficient scale, could eventually reduce temperatures, but these ideas remain untested, and there will likely be a significant overshoot of the Paris-Agreement temperature targets, with associated climate impacts. This is the context for discussing solar geoengineering approaches to reflect sunlight and cool the climate, such as adding aerosols to the stratosphere. Climate model simulations suggest that a limited deployment, in addition to mitigation and CDR rather than instead of it, might reduce many climate impacts. However, there are substantial uncertainties in the climate system, as well as substantial challenges for governance.