Publications

Federal agencies will need to offer considered and detailed responses to objections raised in the notice-and-comment processes for individual regulations or administrative actions that apply the Working Group’s social cost valuations. Given its expertise, the Working Group should consider providing such responses now, so that agencies can then incorporate them into future actions. This report offers a blueprint for those responses.

The Interagency Working Group on the Social Cost of Greenhouse Gases can use the findings from expert elicitations to improve the U.S. federal government’s social cost of greenhouse gas estimates, which are used in regulatory cost-benefit analysis and other policy contexts. Our report highlights several component updates, incorporating data from expert elicitations, that the Working Group should consider during its current update of the social cost of greenhouse gas estimates.

In light of recent evidence, a new range of discount rates appropriate for calculating the social cost of greenhouse gases could be conservatively estimated as between 0.5%-2.5%, with a central estimate of 1.5%. Agencies should follow the Interagency Working Group’s guidance on applying new social cost of greenhouse gas estimates based on updated discount rates—and will need to justify their choices, including any departures from prior practices.

Debate has reemerged about whether federal agencies’ policy analyses should focus on those climate pollution costs that will occur only within U.S. borders, rather than on the full global valuation of climate damages. The Interagency Working Group on the Social Cost of Greenhouse Gases provides compelling justifications to focus on global estimates. Based on a wide range available evidence, the Working Group should consider recommending a domestic valuation of at least 75% or more of the global values for optional use as 5 a lower-bound estimate in sensitivity analysis.

Our report highlights numerous areas in which the federal government should apply the social cost of greenhouse gases beyond regulatory cost-benefit analysis. It is organized under the framework of “decision-making, budgeting, and procurement” laid out in the President’s executive order, identifying a number of relevant actions—like environmental reviews conducted under NEPA and the assessment of royalty rates for federal land-management. In short, application of the social cost of greenhouse gases would be extremely beneficial for any executive branch decision with significant greenhouse gas implications.