Keith has worked on solar geoengineering since 1992, when he wrote one of the first assessments of the technology and its policy implications. Since Keith’s 1992 paper, which introduced a structured comparison of cost and risk, and a later review paper that first described the moral hazard and set geoengineering in the post-war history of weather control, Keith has sought answers to the questions:
How unequal? – First quantitative analysis of regional inequality of solar geoengineering.
How to reduce risks? – New method to reduce the amount of sulfur needed for a given radiative forcing; and, a novel class of self-levitated particles that might limit ozone loss.
What does the public think? – First large-scale survey of public perception.
How to regulate? – Proposed two-threshold system that combines deployment moratoria with a pathway for regulating small-scale research.
How to evaluate trade-offs? – Early economic analysis of optimal decisions under uncertainty and a value-of-information analysis while supervising the first economics Ph.D. to focus on geoengineering.
In 2013, Keith released a book, A Case for Climate Engineering, detailing a controversial strategy for slowing climate change. The book’s publisher’s blurb states: "A leading scientist long concerned about climate change, David Keith offers no naïve proposal for an easy fix to what is perhaps the most challenging question of our time. But he argues that after decades during which very little progress has been made in reducing carbon emissions, we must put climate engineering on the table and consider it responsibly... This book provides a clear and accessible overview of the costs and risks, and how climate engineering might fit into a larger program for managing climate change." He has also contributed to assessments focused on geoengineering. Keith was a member of the working group for UK Royal Society's 2009 report as well as the Bipartisan Policy Center Report. Keith is the co-director, with Gernot Wagner, of Harvard's Solar Geoengineering Research Program founded in 2017.
Public comments
In 2010, Keith testified before committees of the U.S. Congress and the UK Parliament. He presented to U.S. National Academy meetings in 2000, 2009 and 2013 and was coauthor of the geoengineering sub-chapter of the Third IPCC Report and served AR5. Keith has been featured on the Discovery Channel, did an interview on BBC News HARDTalk in November 2011, has participated in TED talks in September 2007, participated in a debate at the Royal Geographical Society in 2009, and appeared in a documentary on geoengineering currently under production. He also discussed his geoengineering idea to slow climate change by spraying reflective particles into the upper atmosphere on The Colbert Report.
