On Thursday, 12 February 2026, President Donald Trump revoked the US Environmental Protection Agency’s 2009 “endangerment finding”, calling it the largest deregulation in US history. The move dismantles the legal basis the federal government has used for nearly 17 years to curb climate pollution from vehicles and other sources, igniting immediate backlash and legal threats from states and public‑interest groups. (apnews.com)

The 2009 finding concluded that six greenhouse gases, including carbon dioxide and methane, endanger public health and welfare-an action rooted in the US Supreme Court’s Massachusetts v. EPA ruling in 2007 that defined greenhouse gases as air pollutants under the Clean Air Act. In 2012, the DC Circuit upheld the finding and related vehicle rules, reinforcing EPA’s duty to act. Scrapping it attempts to reverse a decade and a half of settled science and law. (epa.gov)

EPA Administrator Lee Zeldin said the final rule eliminates federal greenhouse‑gas standards for light‑, medium‑ and heavy‑duty vehicles and wipes out “off‑cycle” credits-including those tied to automatic start‑stop systems. The agency framed the step as restoring “consumer choice” and cutting costs, but it also removes a key driver of cleaner engines and fuels. (epa.gov)

At the podium, the White House cast previous climate policy as an “EV mandate”. Fact‑checks tell a different story: there was no federal requirement forcing drivers to buy electric cars. Incentives and performance‑based standards shaped the market. Many of those incentives were later rolled back by Congress in 2025, which ended the main federal EV tax credits and approved resolutions voiding California’s ability to run tougher vehicle rules. (apnews.com)

Why it matters for emissions and health is straightforward. Transport is the largest slice of US greenhouse gases-around 28–29% in 2022-so weakening standards lifts pollution risks and slows progress. The American Lung Association reports 156 million people now live in counties with failing grades for ozone or fine particles, conditions worsened by heat and wildfire smoke. These are the co‑benefits climate policy usually improves. (epa.gov)

The scientific case for the endangerment finding has only strengthened. A National Academies review in September 2025 concluded evidence that climate pollution harms health and welfare is “beyond scientific dispute”, reaffirming that EPA’s 2009 judgment was accurate and is now underpinned by even stronger data. (nationalacademies.org)

Climate extremes are already costly. NOAA tallied a record 28 US billion‑dollar disasters in 2023 and 27 in 2024-events that killed hundreds and caused well over $270bn combined. Independent tallies indicate 2025 brought 23 more such disasters with about $115bn in damages. Weakening climate protections amid rising losses increases exposure for households, insurers and public budgets. (climate.gov)

Expect a fast‑moving legal fight. California’s attorney general vowed to sue, joined by national NGOs who argue the repeal defies Supreme Court precedent and the record the DC Circuit previously upheld. Multiple petitions are likely to land in the DC Circuit within days, with requests for a stay while judges weigh whether EPA can discard a finding courts have repeatedly endorsed. (oag.ca.gov)

The administration is also targeting power‑plant rules, proposing to repeal greenhouse‑gas standards under section 111 of the Clean Air Act. That strategy leans on the Supreme Court’s 2022 West Virginia v. EPA decision limiting generation‑shifting approaches, but it does not erase EPA’s responsibility to address dangerous pollutants when the evidence warrants it-a duty now in dispute because the endangerment finding has been pulled. (epa.gov)

States and markets will still shape momentum. Congress used the Congressional Review Act in June 2025 to void California’s vehicle waivers, but clean‑power policies remain widespread elsewhere: 100% clean‑electricity targets now cover dozens of states, the District of Columbia and Puerto Rico-together representing a substantial share of the US population and demand. Corporate clean‑energy procurement and utility resource plans are likely to continue, though with greater policy risk. (whitehouse.gov)

What could this mean for emissions trajectories? In earlier analysis of first‑term rollbacks-far narrower than today’s move-Rhodium Group estimated cumulative increases of about 1.8 gigatonnes of CO₂‑equivalent by 2035. Updated modelling will show the new baseline, but the direction of travel is clear: federal pull‑backs raise national totals unless states, firms and consumers do more. (rhg.com)

Public sentiment is shifting too. Gallup found a record‑high 48% of US adults in 2025 believed global warming will pose a serious threat in their lifetime, while Yale’s long‑running survey shows roughly two‑thirds of Americans are at least somewhat worried. Politicians may argue about mandates, but voters increasingly expect credible plans that cut pollution and keep energy bills predictable. (news.gallup.com)

What happens next is as much about solutions as courtroom briefs. States can tighten building codes, accelerate grid upgrades and keep zero‑emission transport on track through procurement and charging programmes. Cities can shield residents from heat and smoke with proven public‑health steps. Companies can hold to science‑based targets, sign longer‑term clean‑power deals and push suppliers to decarbonise. These actions won’t fully replace federal standards-but they can buy critical time while the courts decide whether this repeal stands. (lung.org)