“At issue is what’s known as the endangerment finding, a 2009 scientific conclusion that greenhouse gas emissions pose a danger to Americans’ health and welfare.”

Trump Repeals Key Greenhouse Gas Finding, Erasing EPA’s Power to Fight Climate Change

“That 2009 determination is called the endangerment finding, and most people have never heard of it. But it has played an enormous role in environmental regulations affecting cars, power plants and more. [...] The finding simply states that carbon dioxide, methane and four other greenhouse gases threaten human health, both now and in the future.”

What to Know About the E.P.A.’s Big Attack on Climate Regulation

“The endangerment finding was a 2009 scientific conclusion that greenhouse gas emissions pose a danger to Americans’ health and welfare.”

With Latest Rollback, the U.S. Essentially Has No Clean-Car Rules

“In 2009, President Barack Obama’s Environmental Protection Agency declared exactly this — what scientists had been saying for decades — that carbon dioxide and other greenhouse gases harm the health of Americans.”

The U.S. Government Now Says Climate Change Doesn’t Harm Human Health

“In 2009, the endangerment rule found that greenhouse gases, such as carbon dioxide and methane, endanger human life.”

President Obama reacts to Trump rolling back environmental rule he established in 2009: ‘We’ll be less safe’