By Forum Staff
The City on Monday announced that — as part of a coalition of dozens of cities, counties, and states from across the nation — it has filed three comment letters opposing the U.S. Environmental Protection Agency’s (EPA) proposed reversal of its 2009 “Endangerment Finding.” The landmark 2009 finding holds that greenhouse gas emissions — including those from motor vehicles — drive climate change and endanger public health and welfare. The new proposal — issued on August 1, 2025 — would deny the EPA’s authority to regulate harmful air pollution that contributes to climate change, harms public health, and would eliminate all existing EPA vehicle emission standards.
Additionally, earlier this month, the City of New York and a coalition of 19 attorneys general filed an amicus brief in the U.S. District Court for the District of Massachusetts in Environmental Defense Fund v. Wright, supporting the plaintiffs in a case challenging the authority of the Climate Working Group, convened by the U.S. Department of Energy in violation of Federal Advisory Committee Act requirements, to prepare a report that purports to undermine the scientific consensus on climate change.
The 2009 Endangerment Finding was the direct result of the landmark 2007 U.S. Supreme Court opinion in Massachusetts v. EPA, which confirmed the EPA’s authority under the Clean Air Act to regulate greenhouse gas emissions that threaten public health and welfare. In direct response to that opinion, and after more than two years of scientific review, the EPA determined, in 2009, that greenhouse gas emissions from motor vehicles contribute to air pollution that harm public health and welfare.
In their letter submitted to the EPA today, the coalition argues that rescinding the 2009 Endangerment Finding would violate settled law, Supreme Court precedent, and scientific consensus, endangering the lives of hundreds of millions of Americans, particularly those in communities disproportionately impacted by environmental harms.
Scientific research has proven that every region of the country is experiencing harms of climate change and motor vehicle pollution, including changes in temperature, precipitation, and sea level rise. Extreme summer heat — driven by climate change — is leading to increased rates of heat-related illnesses and deaths, particularly among vulnerable populations like children, the elderly, low-income individuals, and workers. Increasing rates of natural disasters — like wildfires, hurricanes, flooding, and droughts — not only have a devastating effect on public health and safety, but on state and local economies as well.
Climate change poses existential risks to New Yorkers’ health and safety. Sea level rise in New York City is putting communities and infrastructure at risk of regular flooding. Extreme weather events — such as Superstorm Sandy in 2012 and Hurricane Ida in 2021 — can result in injury and loss of life due to exposure, interrupted utility service, or lack of access to emergency services. Additionally, warming temperatures exacerbate or introduce health problems. On average, more than 500 New Yorkers die prematurely because of extreme heat in New York City each year.
Not only does the EPA’s proposed reversal ignore those facts, but it also violates the EPA’s legal obligations under the federal Clean Air Act to regulate greenhouse gas emissions to address climate change.
The coalition argues, in Monday’s letter, that the EPA’s new legal interpretations are inconsistent with the Clean Air Act and binding Supreme Court precedent, and that the proposal would mark a drastic reversal of its own longstanding findings without any explanation grounded in science. To make matters worse, the Climate Working Group report on which the EPA relies is substantively flawed, yet the EPA blindly accepts its findings and disregards the scientific consensus, which was just reaffirmed by the National Academies of Sciences, Engineering, and Medicine last week.
In filing this comment letter, the coalition urges the EPA to abandon its proposal to rescind the 2009 Endangerment Finding.
In withdrawing the 2009 Endangerment Finding, the EPA also proposes to repeal all existing federal greenhouse gas emissions standards for all motor vehicle classes and all years. In a second letter submitted to the EPA on Monday, the coalition explains that this unprecedented disruption to the regulatory norms of the last 15 years will harm states and local governments’ residents, industries, natural resources, and public investments.
Regulatory enforcement for greenhouse gas emissions is also crucial to vehicle affordability, consumer choice, and to the success of the American automotive industry. The greenhouse gas program for vehicles incentivizes automakers to innovate and create better cars, saving drivers hundreds of billions of dollars in fuel and maintenance costs, and helps support domestic manufacturing and jobs. Repealing that program, as the EPA now proposes, will shutter factories, kill jobs, and wipe out billions of dollars in investments by Congress, states, and local governments to keep the American auto industry thriving and globally competitive.
Earlier this month, the City joined another coalition of 27 localities from around the nation in filing a comment letter opposing the Climate Working Group report that EPA relied on in its proposed rescission of the 2009 Endangerment Finding.
In that comment letter, the coalition identified several legal flaws in the Climate Working Group report. In creating the Climate Working Group, the U.S. Department of Energy selected five widely known climate change skeptics, ignored well-established scientific integrity standards, and failed to comply with the Federal Advisory Committee Act’s procedures, which require the disclosure of all committee-related records and that committee meetings be open to the public.
The report — written in less than two months and filled with inaccuracies, factual omissions, and mischaracterizations of climate science research — attempts to critique decades of peer-reviewed scientific research establishing that the emission of greenhouse gases cause climate change and endanger public health and welfare.
In filing the comment letter, the coalition urged the Department of Energy to withdraw the unlawful and misguided Climate Working Group report.
“New York City is no stranger to the devastating effects of natural disasters. With more extreme weather events hitting the five boroughs more often, for our safety and to protect our economy, we must be prepared for the effects of climate change, including by putting in place stronger federal regulations of greenhouse gases,” said Mayor Eric Adams. “Attempts to undermine this scientific consensus should not be the basis for undoing important regulations that mitigate future environmental damage that threatens lives, brings harm to our communities, and hampers our economies. We are proud to stand with our partners from across the nation in taking multiple actions supporting long-held scientific findings that protect against environmental disasters in our communities.”
