THE Trump administration revoked on Thursday a scientific finding that has been the central basis for United States action to regulate greenhouse gas emissions and fight climate change.

The ruling by the Environmental Protection Agency (EPA) rescinds a 2009 government declaration, known as the endangerment finding, that determined carbon dioxide and other greenhouse gases threaten public health and welfare. 

The finding is the legal underpinning of nearly all climate regulations under the Clean Air Act for motor vehicles, power plants and other pollution sources that are heating the planet.

The repeal eliminates all greenhouse gas emissions standards for cars and trucks and could unleash a broader undoing of climate regulations on stationary sources such as power plants and oil and gas facilities, experts say. 

Mr Trump called the move “the single largest deregulatory action in American history, by far” and “one of the greatest scams in history,” claiming falsely that it “had no basis in fact” or law.

Environmental groups described the move as the single biggest attack in US history against federal authority to address climate change. 

“This action will only lead to more climate pollution and that will lead to higher costs and real harms for American families,” said Environmental Defence Fund president Fred Krupp.