EPA finalises repeal of most 2024 carbon limits on power plants

The Environmental Protection Agency has finalised a rule repealing most of the 2024 Carbon Pollution Standards, the Biden-era greenhouse-gas limits for fossil-fuel-fired power plants [s1]. The final rule was published in the Federal Register on 17 September 2026 and takes effect on 16 November 2026 [s1].

The 2024 standards had set the first federal carbon-emission limits built around carbon capture and storage for the power sector. The repeal removes the emission guidelines for existing coal- and oil- or gas-fired steam generating units, the carbon-capture-based standards for coal-fired steam units undertaking a large modification, and the carbon-capture-based standards for new base-load stationary combustion turbines — the so-called Phase 2 standards [s1]. In a proposal published the same day, the EPA went further, soliciting comment on rescinding the underlying finding that greenhouse-gas emissions from power plants "contribute significantly" to dangerous air pollution, and on repealing all greenhouse-gas requirements for those plants [s2].

What the agency says it is worth

The EPA frames the repeal chiefly as an exercise in avoided cost. Over the 2026 to 2047 period, the agency estimates the present value of compliance-cost savings for the power sector, in 2024 dollars discounted to 2025, at $160 billion using a 3 percent discount rate and $95 billion using a 7 percent discount rate [s1]. It puts the present value of the "real resource cost savings" — the capital, labour, fuel and material inputs the sector would otherwise have spent on compliance — at $280 billion at a 3 percent discount rate and $180 billion at 7 percent [s1].

Against those savings sit the emission reductions that will not now occur. In the rule, the EPA records a commenter's estimate that the standards it is repealing would have cut carbon-dioxide emissions by 1.38 billion metric tons over roughly two decades [s1]. The same commenter noted that the standards would also have secured reductions of tens of thousands of tons of particulate matter, sulfur dioxide and nitrogen oxides — the co-pollutants most closely tied to respiratory and cardiovascular harm [s1].

The agency does not dispute that the repealed standards would have reduced those co-pollutants. It argues instead that co-pollutant reductions "did not factor into the Agency's BSER determinations for the regulated pollutant — CO2," the pollutant the standards were written to control [s1]. BSER, the "best system of emission reduction," is the statutory test the EPA must apply under Clean Air Act section 111; the agency's case is that carbon capture and the other controls in the 2024 rule do not meet that test for these plants.

The grid the agency is pointing to

Much of the EPA's reasoning turns on how much the electricity system has already changed. Coal-fired generation's share of total US net generation fell from 52 percent in 2000 to 19 percent in 2022, a 58 percent decline in relative and absolute terms, while natural-gas-fired generation rose 181 percent over the same period to deliver 39 percent of net generation [s1]. The agency uses that shift to argue that the marginal carbon reductions available from the repealed standards were smaller than the 2024 rule assumed.

That framing is contested. The public-health case for the 2024 standards rested less on carbon alone than on the co-pollutants that fall alongside it: fine particulate matter, or PM2.5, is linked in a large body of epidemiology to premature cardiovascular and respiratory death, and to asthma exacerbations. Reductions in those pollutants are what turn a climate rule into a near-term health rule. By treating the co-pollutant benefits as legally irrelevant to the BSER determination, the repeal sets aside the mechanism through which the standards would have delivered health gains in the years before their climate effect was fully felt.

What is settled and what is not

Two things are clear from the documents. The repeal is final and dated, and it rests on a reweighting of known costs and known benefits rather than on new evidence that carbon capture is unsafe or that power-plant emissions are harmless [s1]. The companion action that would rescind the "significant contribution" finding itself is only a proposal, open for comment, and is not law [s2].

Several questions remain open. Legal challenges to major Clean Air Act rules are routine, and a rule of this size will almost certainly be litigated; the effective date of 16 November 2026 does not foreclose that [s1]. States retain their own authority to regulate power-plant emissions, so the practical effect will vary by jurisdiction. And the separate proposal to rescind the endangerment finding for power plants, if finalised, would remove the legal predicate for federal greenhouse-gas regulation of the sector altogether — a far larger step than the rate standards this rule repeals [s2].

For now, the measurable figures are the agency's own: tens of billions in projected compliance savings set against more than a billion metric tons of carbon dioxide, and the co-pollutant cuts, that the repealed standards were projected to prevent [s1].

Sources

• [s1] Partial Repeal of the Carbon Pollution Standards for Fossil Fuel-Fired Electric Generating Units — U.S. Environmental Protection Agency / Federal Register, 17 September 2026.
• [s2] Rescission of the Greenhouse Gas Findings for Fossil Fuel-Fired Power Plants and Repeal of Regulations for Power Plant Greenhouse Gas Emissions Under Clean Air Act Section 111 — U.S. Environmental Protection Agency / Federal Register, 17 September 2026.