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The year 2025 ranked among the warmest on record for surface temperatures—NASA reported it tied for second-warmest with 2023, while NOAA and most other monitoring teams placed it third-warmest, with 2023 and 2025 separated by only 0.02°C—recorded the hottest ocean heat content ever measured, and experienced the second-warmest in the lowest layer of the atmosphere where weather happens since satellite monitoring began.
The Environmental Protection Agency, meanwhile, spent the same period proposing to rescind the 2009 Endangerment Finding that greenhouse gases threaten public health. Without that finding, the EPA has no legal authority under the Clean Air Act to regulate pollution at all.
This is the collision at the heart of American governance: warming accelerates, happening in months and years, while the regulatory machinery designed to address it operates on timescales measured in multi-year rulemaking processes, mandatory comment periods, and litigation that stretches across presidential terms.
What the 2025 Records Show
Robert Rohde, chief scientist at Berkeley Earth, stated: “The last three years are indicative of an acceleration in the warming. They’re not consistent with the linear trend that we’ve been observing for the 50 years before that.”
Ocean heat content reached unprecedented levels. Arctic sea ice experienced near-record winter lows. These reflect fundamental changes in the planetary energy balance, with more energy entering the system through greenhouse gas forcing than escaping back into space.
A study by the Institute and Faculty of Actuaries found that pollution controls—particularly shipping regulations reducing sulfur dioxide emissions—have eliminated pollution particles that blocked some heat, revealing about 0.5 degrees Celsius of hidden warming. Industrial pollution had been acting as an inadvertent sunshade. As that pollution decreased through legitimate improvements, it revealed the true magnitude of greenhouse gas forcing beneath it.
How the EPA’s Authority Works
The EPA’s power to regulate greenhouse gases rests on a legal foundation built in stages. The Clean Air Act, enacted in 1970 and amended in 1990, grants the agency authority to establish pollution standards based on scientific findings about threats to public health and welfare. The statute requires standards “requisite to protect the public health” with an “adequate margin of safety.”
For greenhouse gases specifically, everything depends on the Endangerment Finding. This 2009 determination concluded that carbon dioxide and other greenhouse gases threaten the health and welfare of current and future generations. Without it, the EPA has no legal power to regulate climate pollution under the Clean Air Act.
The Trump administration’s proposal to rescind it represents a fundamental challenge to regulation—an attempt to eliminate the legal structure itself.
When the EPA wants to establish or update emissions standards, it must follow federal rules: propose a rule in the Federal Register, establish a public comment period (typically 60 to 90 days), analyze comments, and publish a final rule explaining how it responded to significant concerns. The agency must document everything that went into the decision—scientific studies, economic analyses, and legal memos—that supports the factual and legal basis for the decision. Courts reviewing the rule will examine whether the agency’s decision was unreasonable or not based on evidence.
This process typically requires several years from initial proposal to final rule. The EPA’s most recent major emissions standards took between three and five years, even with the agency prioritizing them. That timeline encompasses scientific review, economic modeling, working with other government agencies, and administrative procedures that federal law requires.
Major EPA rules now routinely face litigation from both environmental groups and industry groups. These cases often take years to resolve. A regulation issued in 2025 might not be fully litigated and certain to survive legal challenge until 2028 or 2029.
The Clean Air Act contains no provisions for faster ways to make rules when conditions get worse quickly. The statute assumes change proceeds at a pace that allows for deliberate, multi-year regulatory responses.
What the EPA Is Doing
Rather than accelerating emissions standards in response to 2025’s records, the EPA has undertaken a systematic dismantling of existing greenhouse gas regulations. In July 2025, the agency formally proposed rescinding the 2009 Endangerment Finding. The proposal relied heavily on a controversial Department of Energy report that characterized warming from carbon dioxide as “appear[ing] to be less damaging economically than commonly believed.” The EPA’s proposal cited this report’s economic framing as part of its rationale for reconsidering the endangerment determination, though the original 2009 finding was based primarily on physical and health impacts rather than economic damage assessments.
In November 2025, it announced delays to methane emissions reduction requirements, pushing compliance deadlines from 2025 to January 2027 and potentially beyond.
For decades, the EPA quantified health benefits—lives saved, heart attacks prevented, asthma attacks avoided—in dollar terms and used those calculations in cost-benefit analyses to justify pollution controls. Recent rule changes eliminate this practice, making it easier to justify weaker standards by obscuring their public health value.
An engineer at the University of Washington noted that “the obvious, most likely outcome of the rule change is an increase in emissions.” A geochemist at Columbia University’s Lamont-Doherty Earth Observatory stated that the EPA “clearly want[s] to remove this tool that has been useful for evaluating the impact of existing and new regulations.”
The Temporal Mismatch
Scientists have repeatedly emphasized that emissions reductions must accelerate dramatically to have any reasonable prospect of limiting temperature rise to even 2 degrees Celsius.
The United States is moving in the opposite direction. U.S. greenhouse gas emissions rose 2.4 percent in 2025 after two years of declines, according to analysis by the Rhodium Group.
If 2025’s temperature records demonstrate that warming is accelerating beyond previous models, and if closing the remaining carbon budget requires unprecedentedly rapid emissions reductions, then the EPA theoretically faces urgency that might match this accelerating timeline. But the administrative procedures governing EPA rulemaking contain no mechanisms for matching this urgency.
A proposed major emissions rule triggers a minimum 60-day comment period, often extending to 90 days or longer for rules affecting substantial industries. The EPA must then analyze comments—often tens of thousands for major rules—and produce a final rule with an administrative record that withstands legal scrutiny.
For power plant emissions standards, the agency must coordinate with the Electric Reliability Organization and state regulators to assess feasibility and grid reliability impacts. For vehicle emissions standards, the EPA must work with the National Highway Traffic Safety Administration and manufacturers to evaluate feasibility and costs, a process that can involve hundreds of technical meetings and millions of data points.
Even an expedited major rulemaking typically requires two to three years from proposal to final rule. An ordinarily paced rulemaking can require four to seven years or more.
The Supreme Court Problem
The Supreme Court’s 2022 decision in West Virginia v. Environmental Protection Agency imposed significant new legal constraints on the scope of regulations the EPA can establish. The Court held that the EPA lacked authority under the Clean Air Act’s ambiguous language to implement a broad regulatory scheme affecting major features of the electricity generation sector. The decision applied a court rule that says agencies need clear permission from Congress for big decisions.
The implications remain contested, but the core holding clearly constrains the EPA’s ability to issue aggressive regulations that would reshape major industries. Some legal analysts argue the decision permits modest emissions improvements but forecloses economy-wide regulatory schemes. Others interpret it more narrowly, suggesting it applies only to the specific type of rule at issue. The Trump administration’s Department of Justice has argued for the broadest interpretation, suggesting numerous EPA rules exceed the agency’s power given by Congress.
This legal uncertainty itself creates administrative paralysis. EPA officials evaluating whether to propose new emissions regulations must now conduct complex legal analysis about whether a proposed rule might exceed the agency’s authority as interpreted by the current Supreme Court. The Endangerment Finding rescission would eliminate the question by removing the EPA’s authority to regulate greenhouse gases at all, but until that rescission is finalized and survives legal challenge, the EPA operates in uncertainty about what it is allowed to do.
What Accelerated Response Would Require
Despite the current administration’s rollback trajectory, experts in law and policy have articulated what an EPA response to accelerating data might theoretically look like if political circumstances changed. First, it would likely require Congress to modify the Clean Air Act to clarify and expand the EPA’s authority over greenhouse gases, potentially creating explicit provisions for expedited rulemaking when science demonstrates accelerating warming. Current Clean Air Act language was written in 1970 and amended in 1990, before climate change was widely recognized as a major public health threat.
Second, responding adequately would likely require modifying the Administrative Procedure Act to create faster ways to make rules for urgent problems. The standard process where agencies announce rules and let people respond might be supplemented with emergency procedures available when scientific evidence demonstrates acute and deteriorating threats.
Third, the EPA would need to establish new internal processes for constantly checking data and deciding if rules need updating. This might include creating an office specifically tasked with evaluating whether existing standards require updating based on new data, with authority to rapidly convene scientific review panels.
Fourth, resolving the tension would require confronting the West Virginia v. EPA problem directly, either through Supreme Court reconsideration of the major questions doctrine or through congressional clarification of the EPA’s authority. If Congress explicitly gave power to establish broad greenhouse gas regulations designed to achieve specific temperature-limiting goals, courts would likely find such delegation satisfied even under the major questions doctrine.
The International Context
The United States, under the Biden administration, had committed to reducing greenhouse gas emissions by 50 to 52 percent below 2005 levels by 2030, a target intended to align with the Paris Agreement’s goals. Research by the Rhodium Group indicates that current policy trajectories will likely result in only a 35 percent reduction by 2030, leaving the United States substantially short of its Paris commitments.
Emissions continue rising despite international commitments to reduce them. Carbon emissions from fossil fuels were projected to reach an all-time high in 2025, according to research by the Carbon Budget initiative. The International Energy Agency reported that coal demand was on course to rise to a record 8.85 billion tons in 2025, with the largest increases expected in India and Southeast Asia.
The EPA’s institutional constraints reflect broader challenges in governance. Some countries have begun experimenting with potentially more rapid regulatory responses. The European Union has implemented systems that charge money for pollution and let companies buy and sell pollution rights that automatically change rules based on how much pollution is happening. But even European regulations have faced implementation challenges and legal disputes about whether they move sufficiently fast.
What Happens Next
The near-term future of EPA regulation will likely be determined by several competing factors. First, the Trump administration’s proposal to rescind the 2009 Endangerment Finding faces likely legal challenge from environmental groups. The Office of Management and Budget was expected to complete its review of the proposed rescission in late January or early February 2026, at which point the EPA would release its final decision. Legal experts anticipate groups will challenge the rescission on grounds that it contradicts established science, violates the Administrative Procedure Act by failing to respond adequately to public comments, and the president cannot ignore scientific findings made through rigorous agency procedures.
The litigation will be complex and will likely take years to resolve. Courts will examine whether the EPA’s rationale for rescission—that the 2009 findings relied on outdated science, focused excessively on worldwide rather than localized risks, and reflected overly pessimistic projections—stands up to scrutiny when compared against the body of science available in 2026. The National Academies of Sciences, Engineering, and Medicine previously reviewed the 2009 Endangerment Finding and concluded that it was “accurate” and its conclusions were “beyond scientific dispute.”
Second, depending on judicial outcomes, courts might impose constraints on the EPA’s ability to continue rolling back regulations. In December 2025, a federal judge ruled that the Trump administration’s cancellation of FEMA’s Building Resilient Infrastructure and Communities program was unlawful. This suggests courts may scrutinize the EPA’s rollbacks through rules about how government agencies should work, potentially finding some actions unreasonable or made without following the right steps.
Third, election cycles will likely influence the trajectory. If the 2026 or 2028 elections result in political shifts, a subsequent administration might move to restore the 2009 Endangerment Finding, re-establish emissions standards, or accelerate new regulations in response to accumulated data. Conversely, if the Trump administration consolidates control over EPA processes and successfully implements its regulatory rollback agenda, the system for making and enforcing rules could be fundamentally weakened for years or decades.
Fourth, emerging signs of El Niño development could interact with underlying trends to produce additional temperature records in 2026 and 2027. When weak La Niña conditions fade and El Niño develops, historical patterns suggest temperatures rise substantially, potentially making 2026 or 2027 the warmest years on record. This would provide fresh data and renewed arguments from environmental groups and scientists that the EPA must strengthen rather than weaken emissions standards.
The Fundamental Problem
The tension between accelerating change and the institutional processes designed to address it represents one of the central governance challenges confronting American law. The EPA’s regulatory authorities and procedures were designed for a different era when change proceeded at slower rates and scientific evidence accumulated more gradually.
Today’s science produces real-time datasets, satellite monitoring systems, and continuously updated models that show changes unfolding on monthly or seasonal timescales. The legal framework for responding to those changes operates on multi-year timescales.
This mismatch cannot be resolved through agency initiative alone. It requires congressional action, or at minimum, a Supreme Court willing to reconsider how traditional administrative law doctrines apply to crises exhibiting acceleration beyond what the law’s framers anticipated.
The 2025 data released in January 2026 constitutes the sort of evidence that, in a well-functioning governance system, would trigger regulatory acceleration and strengthened emissions standards. The year’s temperature records, the documented acceleration in rates, and the evidence of sensitivity being higher than previously modeled all point toward a need for more aggressive emissions reductions than current policies will produce.
Yet the EPA, under current political leadership, has moved decisively in the opposite direction, proposing to eliminate its foundational authority for regulation rather than expand it.
This reveals that the EPA’s regulatory constraints are not merely technical or administrative but fundamentally political. Whether the EPA will respond to acceleration is not ultimately a question about the Clean Air Act’s language or the Administrative Procedure Act’s procedures. It’s a question about political will and the relative power of constituencies favoring action versus those favoring regulatory restraint.
The regulatory processes exist to channel and constrain political decisions, not to eliminate them. When the political forces holding power within the executive branch move to constrain rather than accelerate regulation, the legal and administrative structures provide mechanisms for implementing that political choice, even if the choice contradicts what science and accelerating data appear to demand.
The years ahead will likely determine whether this political constraint proves durable or whether shifting coalitions, court decisions, election outcomes, or the mounting tangible costs of continuing acceleration will ultimately force the EPA and the federal government to confront the fundamental question of how to reconcile emergency conditions with legal and administrative processes designed for non-emergency policymaking.
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