WASHINGTON—U.S. Senator Chris Murphy (D-Conn.) joined U.S. Senator Sheldon Whitehouse (D-R.I.), Ranking Member of the Senate Environment and Public Works Committee, Senate Democratic Leader Chuck Schumer (D-N.Y.), and the entire Senate Democratic Caucus in demanding the Trump Administration withdraw its legally deficient and factually inaccurate proposed rollback of the endangerment finding that allows the Environmental Protection Agency (EPA) to control greenhouse gas emissions. The rollback, if finalized, would constitute a formal denial by the EPA that greenhouse gases pose a threat to public health and welfare—a position that defies decades of scientific evidence, agency precedent, and Supreme Court rulings. The 47 Senators called the repeal of the climate and public health protection a “dereliction of duty” and a “blatant failure to protect the American people.”

The endangerment finding is a 2009 scientific determination by EPA that greenhouse gases harm public health and welfare and is the legal basis for U.S. climate policy. It is grounded in extensive peer-reviewed science and confirmed by successive National Climate Assessments and reports from the Intergovernmental Panel on Climate Change. Twice, EPA’s scientific finding has withstood challenge at the D.C. Circuit, and both times, the Supreme Court declined to revisit the decision. Repealing the endangerment finding would ignore overwhelming scientific evidence and set the stage for rolling back air quality standards for power plants, airplanes, and more, making it easier to pollute.

“Scientists, financial experts, international governments, and the American public agree that climate change is a looming crisis. Greenhouse-gas driven climate change is driving extreme weather, flooding, erosion, sea-level rise, heat waves, drought, catastrophic wildfires, famine, smog pollution, and other disasters. These effects drive illness, hospital visits, and deaths, as well as displacement, asset loss, infrastructure damage, rising insurance premiums, declining home values, and long-term destabilization of the national economy …. And yet, in this proposal, EPA proposes to abdicate all responsibility to address this dangerous pollution,” wrote the Senators.

Not only do EPA’s actions fail to protect the American public from well-documented harms, but the agency’s justifications “are directly at odds with Supreme Court precedent, Congressional directive, and the facts.”

“The Court in [Massachusetts v. EPA] found that ‘[c]arbon dioxide, methane, nitrous oxide, and hydrofluorocarbons are without a doubt’ air pollutants under the Clean Air Act’s definition, and that ‘[t]he statute is unambiguous’ on this point,” wrote the Senators. And “[u]nder the clear terms of the Clean Air Act, EPA can avoid [making an endangerment finding] only if it determines that greenhouse gases do not contribute to climate change or if it provides some reasonable explanation as to why it cannot or will not exercise its discretion to determine whether they do.”

To justify the repeal, EPA Administrator Lee Zeldin has relied on a Department of Energy pseudoscientific report written by known climate deniers with close ties to fossil fuel and polluting industry actors. Rife with clear errors, cherry-picked data, and misrepresented facts, the report peddles the lie that human-caused climate change is not a threat.

But scientists have known for over a century that greenhouse gases drive climate change. “In 1896, Swedish scientist Svante Arrhenius concluded that greenhouse gas emissions from human activities contribute to a global “greenhouse effect”, driving global warming. One hundred and twenty-nine years later, the reality of human-caused climate change is not up for debate,” wrote the Senators.

“Congress established the Clean Air Act to protect the public health and welfare, and the Supreme Court confirmed that this includes EPA’s obligation to regulate greenhouse gases to the extent they endanger the same. The science is clear that they do so. We ask that you withdraw this proposal and reverse your decision to rescind the 2009 endangerment finding,” concluded the Senators.

In addition to Murphy, Whitehouse and Schumer, the letter was signed by the entire Senate Democratic Caucus, including U.S. Senators Angela Alsobrooks (D-Md.), Tammy Baldwin (D-Wis.), Michael Bennet (D-Colo.), Richard Blumenthal (D-Conn.), Lisa Blunt Rochester (D-Del.), Cory Booker (D-N.J.), Maria Cantwell (D-Wash.), Chris Coons (D-Del.), Catherine Cortez Masto (D-Nev.), Tammy Duckworth (D-Ill.), Dick Durbin (D-Ill.), John Fetterman (D-Pa.), Ruben Gallego (D-Ariz.), Kirsten Gillibrand (D-N.Y.), Maggie Hassan (D-N.H.), Martin Heinrich (D-N.M.), John Hickenlooper (D-Colo.), Mazie Hirono (D-Hawaii), Tim Kaine (D-Va.), Mark Kelly (D-Ariz.), Andy Kim (D-N.J.), Angus King (I-Maine), Amy Klobuchar (D-Minn.), Ben Ray Luján (D-N.M.), Ed Markey (D-Mass.), Jeff Merkley (D-Ore.), Patty Murray (D-Wash.), Jon Ossoff (D-Ga.), Alex Padilla (D-Calif.), Gary Peters (D-Mich.), Jack Reed (D-R.I.), Jacky Rosen (D-Nev.), Bernie Sanders (I-Vt.), Brian Schatz (D-Hawaii), Adam Schiff (D-Calif.), Jeanne Shaheen (D-N.H.), Elissa Slotkin (D-Mich.), Tina Smith (D-Minn.), Chris Van Hollen (D-Md.), Mark Warner (D-Va.), Raphael Warnock (D-Ga.), Elizabeth Warren (D-Mass.), Peter Welch (D-Vt.) and Ron Wyden (D-Ore.).

Full text of the Democratic caucus comment is available here.

The deadline to submit comments to EPA on the proposed rollback is September 22, 2025.