The Endangerment Finding is a formal recognition by the US Environmental Protection Agency that climate disruption poses a threat to human health and safety. It serves as the foundation for U.S. federal climate policy and the regulation of greenhouse gases—the chemical compounds that trap heat in Earth’s atmosphere and drive global heating.

In 2009, the EPA released the finding that:

elevated concentrations of the six greenhouse gases in the atmosphere—carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆)—endanger both the public health and the public welfare of current and future generations.

The language reflects the Preamble to the Constitution of the United States, which requires the federal government to

establish Justice… promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity…

In 2007, the Supreme Court found greenhouse gases are pollutants that must be regulated under the Clean Air Act and ordered the government to issue a finding of endangerment to inform future policy.

The Endangerment Finding was finalized 17 years after the U.S. agreed to urgently reduce global heating emissions under the 1992 United Nations Framework Convention on Climate Change. The Convention is a ratified treaty that is binding federal law under Article VI of the Constitution of the United States and had already committed the U.S. to reduce global heating emissions to 1990 levels by the year 2000. 

The Trump administration has been working to eliminate climate-related regulations, while the President faces allegations of open corruption, after he promised oil executives he would erase climate policies if they gave money to his 2024 campaign and other interests. The move to eliminate the Endangerment Finding is seen by both critics and allies as an attempt to eliminate the premise for U.S. national climate policy. 

Last year, a group of known climate science deniers was assembled by the Secretary of Energy, himself a fossil fuel executive, to write a report aimed at justifying the administration’s efforts to undo climate policy. That report was found to have been unlawfully crafted to misrepresent scientific findings. According to the Union of Concerned Scientists:

Now, a federal judge has ruled that the Climate Working Group (CWG) report was produced by a process that was so flawed as to be actually illegal—violating the Federal Advisory Committee Act (FACA). The illegality was so clear that the government did not attempt to contest it in court.

The Department of Energy’s violation of FACA is more than just a technicality. FACA is an important pillar of open governance, designed to prevent private interests from determining public policy behind closed doors.

The effect of eliminating the Endangerment Finding will not be the elimination of U.S. climate policy, however, or of related costs to industry. The U.S. moving more slowly to limit global climate disruption will only increase costs to all of society. Not investing in emissions reductions will ensure communities, states, businesses, and the federal government have to invest far more in response to disasters, risk reduction, and adaptation. Government agencies will also become more susceptible to litigation.

In July of last year, the International Court of Justice issued an Advisory Opinion on the climate responsibility of national governments. It found that the obligation to reduce risk and harm from industrial climate disruption applies to all governments, regardless of their national policies, and is embedded in the foundations of all law and in fundamental human rights, which no nation has any lawful authority to override or violate.

This means more people in more places can bring suit against governments that do not act in a timely, science-informed, and legally appropriate manner to eliminate or contain pollution that drives harmful and costly climate disruption. It also empowers judges at all levels to trace national obligations, local and national legal frameworks, and action or inaction by industry back to the foundations of modern law and jurisprudence. 

Going back to the George W. Bush administration, the EPA’s review of climate endangerment has been seen as intentionally conservative—looking only to quantify the most easily traceable and verifiable costs, leaving out cascading and compounding costs and ripple effects and discounting the direct and indirect costs of fossil fuel subsidies. The 2009 Endangerment Finding corrected some of the inadequacy of that approach, but it never provided the strict, clear math for a truly transformational overhaul of U.S. energy-related industries.

The First Amendment makes it illegal for Congress to abridge the right to pursue legal redress for harms caused (grievances). Without the Endangerment Finding providing a conservative basis for limited mandated climate-related upgrades to industrial processes, those businesses that do the most to drive dangerous climate change will face increased liability.

One possible perverse outcome of cancelling the Endangerment Finding could be polluting industries filing suit against the U.S. government for not creating a clear regulatory framework that justifies their own slow timelines for major climate-related innovation. Industry and investors could also see their risk and cost greatly increased, and use the Convention, scientific evidence, and the ICJ opinion to sue the government for inaction. 

This would have the effect of putting more taxpayer money at risk, even as the cost of responding to climate impacts—both gradual compounding impacts and shock events—rises rapidly to unaffordable levels. 

• Nearly 20% of all of the costs of major extreme weather disasters in the U.S. since 1980 have happened in the last 2 years.
• Two of the leading financial regulators in the US—the Financial Stability Oversight Council (FSOC) and the Commodity Futures Trading Commission (CFTC)—have found that unchecked climate change will destabilize the financial system and the wider US and global economies.

Climate endangerment is a geophysical reality. It cannot be wished away by policy memos written by Donald Trump or Lee Zeldin. The grave national security risks of unchecked climate disruption have been understood and reported in detail for decades. The 2010 Quadrennial Defense Review found climate change is an “accelerant of instability or conflict” and a “threat multiplier”. The future outlook is already dire and getting worse.

The 2023 State of the Climate report included this stark warning: 

By the end of this century, an estimated 3 to 6 billion individuals — approximately one-third to one-half of the global population — might find themselves confined beyond the livable region, encountering severe heat, limited food availability, and elevated mortality rates because of the effects of climate change (Lenton et al. 2023).

The 2025 State of the Climate report opens with this emergency alert: 

We are hurtling toward climate chaos. The planet’s vital signs are flashing red. The consequences of human-driven alterations of the climate are no longer future threats but are here now. This unfolding emergency stems from failed foresight, political inaction, unsustainable economic systems, and misinformation. Almost every corner of the biosphere is reeling from intensifying heat, storms, floods, droughts, or fires. The window to prevent the worst outcomes is rapidly closing.

An insurance law review published in the Yale Law Journal in December reported:

As losses mount, we can expect to see more insurance-company insolvencies, more unaffordable insurance price increases, and more insurers declining to write or renew insurance, all of which will negatively impact credit availability and asset values, which, in turn, will harm the real economy. A recent report from the U.S. Senate Budget Committee described the economic consequences of the insurance crisis as “2008 all over again,” except with more permanent results.

According to a Climate Value brief on Earth’s melting cryosphere:

Each day that emissions keep rising puts more strain on everyone going forward: faster transition needed, higher secondary cost per increment of pollution, higher cost of transition, greater risk of sudden market obsolescence, greater risk of fiscal collapse.

Today, the Guardian is reporting:

At just 1.3C of global heating in recent years, extreme weather is already taking lives and destroying livelihoods across the globe. At 3-4C, “the economy and society will cease to function as we know it”, scientists said last week, but a hothouse Earth would be even more fiery.

The costs to the American people are already grave and getting worse. Unless it is replaced by a stricter and more assertive pollution control standard, removal of the Endangerment Finding will cost American industry, taxpayers, and future generations, far more than simply acting to reduce risk and harm in line with the best available science.