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.

In a barrage of pronouncements Wednesday, the Trump administration said it would repeal dozens of the nation’s most significant environmental regulations. EPA Administrator Lee Zeldin described it as "the greatest day of deregulation our nation has seen.