6 April — Solar geoengineering versus carbon removal
Date: 6 April 2022
Time: 12:00pm ET
Location: Wean Hall 3701 & via Zoom
Speaker: David Keith
Topic: Solar geoengineering versus carbon removal
Abstract: Reducing temperatures in the next few centuries requires use of carbon removal (CDR) or solar geoengineering (SRM) or both. Emissions cuts should be the overwhelming focus of current effort but cutting emissions to zero can only stop adding to carbon burden increased temperature rise—they cannot reduce temperatures on policy-relevant timescales. CDR and SRM differ in many dimensions, yet it can be helpful to consider them as alternative methods of achieving the same fixed amount of additional cooling at some future time. We can then ask how the risks of CDR and SRM compare. A CDR facility—industrial or biological—achieves nothing the day it starts, but only cumulatively, year upon year. So, the earlier one demands the cooling, the faster one must build the removal industry, and the higher the social costs and environmental impacts per degree of cooling. I present preliminary results comparing air pollution mortality and land use disturbance from SRM and CDR. These quantitative comparisons suggest that—contrary to widespread assumptions—SRM may be a substantially less risky way to achieve a given amount of additional cooling than is CDR.
