S. 1584 — Transparency and Honesty in Energy Regulations Act of 2025

This section establishes definitions for purposes of the Act, including (1) "Federal agency," which has the meaning given "agency" in 5 U.S.C. §551 (i.e., each authority of the U.S. government, excluding Congress, courts, territorial governments, D.C. government, and specified other entities); and (2)-(5) "social cost of carbon," "social cost of greenhouse gases," "social cost of methane," and "social cost of nitrous oxide," respectively, as monetized damage estimates associated with incremental emissions of carbon dioxide, greenhouse gases, methane, or nitrous oxide from specified Interagency Working Group and EPA documents (dated 2010 through April 2024) or any successors or substantially related documents. (As background, the social cost of carbon and analogous metrics quantify the long-term economic damages from additional emissions of the specified gases and are used in federal regulatory impact analyses under Executive Order 12866.)

This section prohibits the head of a federal agency from considering the social cost of carbon, the social cost of methane, the social cost of nitrous oxide, or the social cost of greenhouse gases—(1) as part of any cost-benefit or cost-effectiveness analysis required under any law, Executive Order 12866 (relating to regulatory planning and review), or Executive Order 13563 (relating to improving regulation and regulatory review); (2) in any rulemaking; (3) in the issuance of any guidance; (4) in taking any other agency action; or (5) as a justification for any rulemaking, guidance document, or agency action.

This section requires the head of each federal agency to submit to the Senate Committees on Environment and Public Works and Energy and Natural Resources and the House Committees on Energy and Commerce and Natural Resources, not later than 120 days after enactment, a report identifying the number of proposed and final rulemakings, guidance documents, and agency actions since January 2009 that used the social cost of carbon, social cost of greenhouse gases, social cost of methane, or social cost of nitrous oxide—including in any cost-benefit analysis under E.O. 12866 or other relevant authority.

This section limits environmental considerations in federal agency permitting adjudications and regulatory processes to those explicitly required by an Act of Congress—prohibiting all others—and requires use of the most robust available methodologies, excluding any that are arbitrary or ideologically motivated. Separately, the section requires agencies to base estimates of greenhouse gas emission changes, including domestic versus international effects and discount rates, on Office of Management and Budget (OMB) Circular A-4 (Sept. 17, 2003), and to update rules, regulations, policies, or actions for consistency with that guidance as appropriate and permitted by law.