WASHINGTON (AP) — The Trump administration is expected this week to revoke a scientific finding that has long served as the primary basis for U.S. initiatives to regulate greenhouse gas emissions and address climate change, according to an official from the White House.

The Environmental Protection Agency (EPA) plans to issue a final rule rescinding the endangerment finding established in 2009. This policy, formulated under President Obama, declared that carbon dioxide and other greenhouse gases pose a threat to public health and welfare.

The announcement was confirmed by a White House official who wished to remain anonymous due to the impending formal announcement. White House press secretary Karoline Leavitt stated, This week at the White House, President Trump will be taking the most significant deregulatory actions in history to further unleash American energy dominance and drive down costs.

The endangerment finding has provided the legal foundation for nearly all climate regulations under the Clean Air Act. It has justified regulations like auto emissions standards that are critical for safeguarding against increasingly severe climate threats, including deadly floods, extreme heat, and natural disasters.

Any actions taken to repeal these regulations are expected to face legal challenges, particularly from environmental groups who describe the shift as the most significant attack in U.S. history on federal efforts to combat climate change.

While an EPA spokesperson did not specify the timing of the finding's revocation, they indicated that a new rule was being finalized. Critics have described the Obama-era rule as a damaging decision, while proponents argue that ending it would lead to more pollution, increased health and fuel costs, and greater risks to public welfare.

Trump has historically referred to climate change as a hoax and previously issued an executive order mandating the EPA to assess the legality and applicability of the endangerment finding. Many conservatives and Republicans in Congress have long sought to eliminate what they consider economically detrimental rules aimed at limiting greenhouse gas emissions.

As significant legal battles loom, experts warn that reversing the endangerment finding would suppress essential climate protections supported by established scientific evidence.

In light of the anticipated change, University of Pennsylvania climatologist Michael Mann remarked, They can no longer deny climate change is happening, so instead they’re pretending it’s not a threat, despite the overwhelming scientific evidence that it is, perhaps the greatest threat that we face today.