In April, the Environmental Protection Agency released a proposal to reduce greenhouse gas emissions from heavy-duty vehicles beginning in model year 2027. Jointly with six other organizations, we submitted comments on EPA’s application of the social cost of greenhouse gases in that rule. Our comments applaud the agency for appropriately applying the social cost of greenhouse gases to estimate the climate benefits of the proposed standards. We also suggest that EPA apply additional analysis to the rule and all alternatives using draft updated climate-damage valuations that EPA released in November 2022.