Legal experts say it's a marked departure from the agency’s historic purpose to protect human health and the environment. “It's an all out assault on climate regulation and environmental and public health protections,” says Michael Burger, director of the Sabin Center for Climate Change Law at Columbia University.

Former heads of the EPA warned that President Donald Trump's systematic deregulation is likely to cause serious harm and potentially put lives at risk.

The EPA administrator says he is rolling back dozens of environmental rules, including those crucial to California programs on climate change and electric vehicles, and closing offices that worked to lower pollution in poor communities.