Kousky, CarolynRostapshova, OlgaToman, MichaelZeckhauser, Richard2010-09-292010Kousky, Carolyn, Olga Rostapshova, Michael Toman, and Richard Zeckhauser. 2010. Responding to Threats of Climate Change Mega-Catastrophes. HKS Faculty Research Working Paper Series, RWP10-008, John F. Kennedy School of Government, Harvard University.http://nrs.harvard.edu/urn-3:HUL.InstRepos:4454155There is a low but uncertain probability that climate change could trigger “mega-catastrophes,” severe and at least partly irreversible adverse effects across broad regions. This paper first discusses the state of current knowledge and the defining characteristics of potential climate change mega-catastrophes. While some of these characteristics present difficulties for using standard rational choice methods to evaluate response options, there is still a need to balance the benefits and costs of different possible responses with appropriate attention to the uncertainties. To that end, we present a qualitative analysis of three options for mitigating the risk of climate mega-catastrophes—drastic abatement of greenhouse gas emissions, development and implementation of geoengineering, and large-scale ex ante adaptation— against the criteria of efficacy, cost, robustness, and flexibility. We discuss the composition of a sound portfolio of initial investments in reducing the risk of climate change mega-catastrophes.en-USMBG - Markets, Business, and GovernmentEnvironment and Natural ResourcesClimate ChangeRegulatory PolicyEnergyResearch Paper or Report2010-09-29