As governments, firms, and universities advance ambitious greenhouse gas emission goals, the demand for emission offsets — projects that reduce or remove emissions relative to a counterfactual scenario — will increase. Reservations about an offset’s additionality, permanence, double-counting, and leakage pose environmental, economic, and political challenges. The authors review the role of offsets in regulatory compliance, as an incentive for early action, and in implementing voluntary emission goals

The United States and United Kingdom have longstanding traditions in use of environmental benefit-cost analysis (E-BCA). While there are similarities between how E-BCA is utilized, there are significant differences too, many of which mirror ongoing debates and recent developments in the literature on environmental and natural resource economics. We review the use of E-BCA in both countries across three themes: (a) the role of long-term discounting; (b) the estimation and use of carbon valuation; and, (c) the estimation and use of the value of a statistical life. 

This paper considers the treatment of co-benefits in benefit-cost analysis of federal air quality regulations. Using a comprehensive data set on all major Clean Air Act rules issued by the Environmental Protection Agency over the period 1997–2019, the authors show that (1) co-benefits make up a significant share of the monetized benefits; (2) among the categories of co-benefits, those associated with reductions in fine particulate matter are the most significant; and (3) co-benefits have been pivotal to the quantified net benefit calculation in nearly half of cases.

The seminal contributions of William Nordhaus to scholarship on the long-run macroeconomics of global climate change are clear. Much more challenging to identify are the impacts of Nordhaus and his research on public policy in this domain. The authors examine three conceptually distinct pathways for that influence: his personal participation in the policy world; his research’s direct contribution to the formulation and evaluation of public policy; and his research’s indirect role informing public policy

After reviewing emission mitigation’s poor performance and low-probability of delivering on long-term climate goals, the authors evaluate a three-pronged strategy for mitigating climate change risks: adding adaptation and amelioration — through solar radiation management (SRM) — to the emission mitigation approach.  They conclude by assessing the value of an iterative act-learn-act policy framework that engages all three prongs for limiting climate-change damages.

The Harvard Project has released a paper on China-U.S. cooperation on climate-change policy—jointly authored with researchers at China's National Center for Climate Change Strategy and International Cooperation.