Comprehensive evidence implies a higher social cost of CO2

Kevin Rennert and Brian C. Prest @ Resources for the Future

Video Recording

Slides

Abstract:
The social cost of carbon dioxide (SC-CO2) measures the monetized value of the damages to society caused by an incremental metric tonne of CO2 emissions and is a key metric informing climate policy. Used by governments and other decision-makers in benefit–cost analysis for over a decade, SC-CO2 estimates draw on climate science, economics, demography and other disciplines. However, a 2017 report by the US National Academies of Sciences, Engineering, and Medicine1 (NASEM) highlighted that current SC-CO2 estimates no longer reflect the latest research. The report provided a series of recommendations for improving the scientific basis, transparency and uncertainty characterization of SC-CO2 estimates. Here we show that improved probabilistic socioeconomic projections, climate models, damage functions, and discounting methods that collectively reflect theoretically consistent valuation of risk, substantially increase estimates of the SC-CO2. Our preferred mean SC-CO2 estimate is $185 per tonne of CO2 ($44–$413 per tCO2: 5%–95% range, 2020 US dollars) at a near-term risk-free discount rate of 2%, a value 3.6 times higher than the US government’s current value of $51 per tCO2. Our estimates incorporate updated scientific understanding throughout all components of SC-CO2 estimation in the new open-source Greenhouse Gas Impact Value Estimator (GIVE) model, in a manner fully responsive to the near-term NASEM recommendations. Our higher SC-CO2 values, compared with estimates currently used in policy evaluation, substantially increase the estimated benefits of greenhouse gas mitigation and thereby increase the expected net benefits of more stringent climate policies.

Bios:

Kevin Rennert joined RFF as a visiting fellow in 2017. Prior to his arrival at RFF, Rennert served as deputy associate administrator for the Office of Policy at the US Environmental Protection Agency. Leading up to his appointment in the Office of Policy, he worked as senior advisor on Energy for the Senate Finance Committee. In that role, Rennert advised the committee’s Chairman, Senator Ron Wyden (D-OR), on a wide range of topics related to clean energy, efficiency, and policies to reduce greenhouse gas emissions. From 2008 to 2014, he worked on energy and climate legislation as senior professional staff for the Senate Energy Committee. In that capacity, Rennert led the development of the Clean Energy Standard Act of 2012 (S. 2146), a presidential priority that would use market mechanisms to double the amount of electricity generated in the US from low or zero carbon sources by 2035. In 2010 and 2011, Rennert also taught graduate courses in energy policy as adjunct faculty in the Department of Strategic Management and Public Policy at George Washington University.

Brian Prest is an economist and fellow at RFF specializing in the economics of climate change, energy economics, and oil and gas supply. Prest uses economic theory and econometrics to improve energy and environmental policies by assessing their impacts on society. His recent work includes improving the scientific basis of the social cost of carbon and economic modeling of various policies around oil and gas supply. His research has been published in peer-reviewed journals such as Nature, the Brookings Papers on Economic Activity, the Journal of the Association of Environmental and Resource Economists, and the Journal of Environmental Economics and Management. His work has also been featured in popular press outlets including the Washington Post, the Wall Street Journal, the New York Times, Reuters, the Associated Press, and Barron’s.

Prest holds a PhD from Duke University and previously worked in both the public and private sectors. At the Congressional Budget Office, he developed economic models of various energy sectors to analyze the effects of proposed legislation, including the 2009 Waxman-Markey cap-and-trade bill and related Clean Electricity Standards. At NERA Economic Consulting, he conducted electricity market modeling, project valuation, and discounted cash flow analysis of various infrastructure investments in the United States, Latin America, Europe, Africa, and Southeast Asia, with a focus on the power sector.