Trump Erases Climate Science Foundation in Historic Regulatory Rollback

In the Oval Office on Thursday, President Donald Trump signed what his administration calls "the largest deregulation in American history" — a sweeping reversal that erases the scientific foundation underlying 15 years of federal climate action. With the stroke of a pen, he overturned the 2009 endangerment finding, a landmark ruling that established greenhouse gases as a threat to public health and became the legal bedrock for virtually every federal effort to curb emissions.

The move doesn't just roll back regulations — it attempts to rewrite the scientific consensus that has guided climate policy across three presidential administrations.

The Science Under Siege

The 2009 endangerment finding wasn't a political statement but a scientific conclusion. The Environmental Protection Agency determined that six greenhouse gases, including carbon dioxide and methane, pose a danger to human health and welfare. This finding became the legal foundation for regulating emissions from vehicles, power plants, oil and gas operations, and even aircraft.

"The endangerment finding has really served as the lynchpin of US regulation of greenhouse gases," explains Meghan Greenfield, a former EPA and Department of Justice attorney. Without it, federal agencies lose their authority to limit planet-warming emissions across virtually every sector of the economy.

Trump dismissed the scientific basis as "a disastrous Obama era policy" and called climate action "the Green New Scam, one of the greatest scams in history." His administration promises the reversal will save more than $1 trillion and reduce automobile manufacturing costs by $2,400 per vehicle.

But the administration's own Department of Energy had to assemble a hand-picked panel of climate skeptics to challenge the scientific consensus — a panel that a federal judge recently ruled was formed illegally.

The Economic Gamble

The White House frames this as economic relief for American consumers and automakers. Press Secretary Karoline Leavitt argues that eliminating fuel efficiency standards will make cars cheaper and reduce regulatory burdens on manufacturers.

Environmental groups paint a starkly different picture. Peter Zalzal from the Environmental Defense Fund calculates that Americans will face $1.4 trillion in additional fuel costs from less efficient vehicles, plus up to 58,000 additional premature deaths and 37 million more asthma attacks from increased air pollution.

The automotive industry itself appears divided. While some manufacturers welcome reduced regulatory costs, others worry about global competitiveness. "Nobody else is going to want to buy American cars" if they're less fuel-efficient, warns Michael Gerrard, a climate law expert from Columbia University.

Unintended Consequences

The reversal creates a legal paradox that could backfire on the Trump administration. For years, the endangerment finding has been used to block state-level climate lawsuits and prevent stricter emissions standards at the local level. By eliminating this federal authority, the administration may inadvertently open the floodgates to litigation.

"The endangerment finding decision has blocked any number of lawsuits," notes Greenfield. "I would expect states and non-profit groups to bring suits, probably primarily in our state courts, to try to figure out where the contours of this new law are."

The timing is particularly striking given the devastating Los Angeles wildfires that climate scientists have linked to warming conditions. Former President Barack Obama, who rarely comments on sitting presidents' policies, called the reversal dangerous: "Without it, we'll be less safe, less healthy and less able to fight climate change — all so the fossil fuel industry can make even more money."

The Supreme Court Strategy

Legal experts believe the Trump administration wants this challenge to reach the Supreme Court before his term ends. If they win, the endangerment finding could be permanently eliminated, preventing future administrations from reinstating it without new legislation from Congress.

"This is really different as the EPA is exiting the space entirely and wants to do it on a permanent basis," explains Greenfield. "If they were to win that issue as they framed it before the Supreme Court, a new presidential administration could not change that position."

The strategy represents a fundamental shift from temporary policy reversals to permanent institutional change.