The U.S. Environmental Protection Agency plans to repeal all greenhouse gas emission standards for light-duty, medium-duty, and heavy-duty vehicles and engines in the coming days after it removes the scientific finding that justified those rules,

The Trump administration wants to reverse a 2009 EPA finding that greenhouse gases endanger people. The finding is the basis for much of the United States' climate change regulations.

On paper, the endangerment finding states that greenhouse gases like methane and carbon dioxide pose a risk to the public’s health and well-being. That may sound obvious enough. But in practice, it’s one of the agency’s most important decisions.