The United States has no comprehensive federal climate change act, and as of 15 September 2026 it is, for the first time since the Paris Agreement's creation, not a Party to it: Executive Order 14162, signed on 20 January 2025, set its withdrawal in motion, and that withdrawal became effective on 27 January 2026, per the Harvard Environmental & Energy Law Program's own tracker, leaving the United States alongside only Libya, Yemen and Iran as non-Parties. Separately, a 7 January 2026 presidential memorandum directed withdrawal from 66 international bodies including the UNFCCC itself and the IPCC, a step the World Resources Institute's US director called "a strategic blunder"; the US Treasury separately withdrew from the Green Climate Fund and its Board seat, effective immediately. Among named states, Washington's Climate Commitment Act (2021, RCW 70A.65) runs a cap-and-invest programme operating since January 2023, requiring the state's largest polluters to hold allowances under a declining emissions cap. Mississippi's Geologic Sequestration of Carbon Dioxide Act (Title 53, Chapter 11 of the Mississippi Code) frames carbon dioxide as "a valuable commodity" and directs the state to seek primacy from the US Environmental Protection Agency for Class VI underground injection control wells, an industrial CO2 storage and enhanced-oil-recovery statute rather than a nature-based-market rule.
Projects
Chestnut Carbon
Turning marginal Southern farmland back into native forest, removing carbon and backing it with quality removal credits.
Living Carbon
Reforesting abandoned mine land and degraded farmland with native trees and faster-growing, photosynthesis-enhanced poplars.
Mast Reforestation
Replanting forests lost to wildfire, financed by carbon removal credits across the American West.
Regulation
Held out for Forest / REDD+: Candidate identified; not shown until its primary source is confirmed
NDC
the order directed the U.S. Ambassador to the UN to "immediately notify" the UN Secretary-General of withdrawal, "with the withdrawal designated to take effect upon notification" under the Agreement's own one-year clause; the Harvard Environmental & Energy Law Program tracker states "The United States' withdrawal from the Paris Agreement became effective on Jan. 27, 2026, following a year-long process"EO 14162 (2025-01-20); EELP tracker "Current Status" entry
The US filed its prior NDC (61-66% below 2005 by 2035) in December 2024, but as of 2026-01-27 it is no longer a Paris Agreement Party — joining only Libya, Yemen and Iran as non-signatories per the EELP tracker — so it currently carries no operative NDC.
Issuing body: Executive Office of the President · Corroborated
David Widawsky (WRI US Director): "Pulling out of the U.N. Framework Convention on Climate Change is a strategic blunder that gives away American advantage for nothing in return." … "Walking away doesn't just put America on the sidelines — it takes the U.S. out of the arena entirely."WRI statement, 2026-01-07
A presidential memorandum directed withdrawal from 66 international organizations/treaties including the UNFCCC and the IPCC — described by WRI and other observers as unprecedented (every UN member state had previously been an UNFCCC Party); the U.S. Treasury separately withdrew from the Green Climate Fund and its Board seat, effective immediately.
Issuing body: Executive Office of the President · Corroborated
Carbon market
"The Climate Commitment Act (CCA) caps and reduces greenhouse gas emissions from Washington's largest emitting sources and industries, allowing businesses to find the most efficient path to lower carbon emissions."RCW Chapter 70A.65
Washington's cap-and-invest programme requiring the state's largest polluters to hold allowances under a declining emissions cap, sub-national to and modeled distinctly from California's programme; Ecology is the implementing agency.
Issuing body: Washington State Department of Ecology · Corroborated
"in the public interest for a public purpose" that geologic sequestration will "benefit the citizens of the state and the state's environment"; "Carbon dioxide is a valuable commodity"; directs the state to "seek primacy from the U.S. Environmental Protection Agency for Class VI underground injection control wells"Miss. Code § 53-11-3 (legislative findings)
Industrial CO2-EOR/storage statute (not nature-based); frames sequestration as both an environmental-benefit and economic-development/oil-recovery measure — a dual framing distinct from California/Washington's emissions-cap model.
Issuing body: Mississippi State Oil and Gas Board · Single source
Forest / REDD+
See "Held out" note above.