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.

ABC News’ Stephanie Ramos talks to former EPA Administrator Gina McCarthy on the Trump administration’s rollback of clean air and water protections.

EPA Administrator Lee Zeldin outlined an aggressive plan to dismantle the "holy grail" of climate regulation, the endangerment finding

The former regulators' warning comes in the wake of the U.S. Environmental Protection Agency's announcement to roll back dozens of air and water protections.

Environmental Protection Agency administrator Lee Zeldin on Wednesday outlined plans for an aggressive rollback of environmental regulations.

Lee Zeldin said he's targeting 31 rules, including a scientific finding that has long been the central basis for U.S. action against climate change.