In a bid to stave off the dire effects of global warming on human health and the environment, the White House on Monday unveiled a new plan to slash carbon emissions from the power sector by 30 percent below 2005 levels by the year 2030.

“That’s like cancelling out annual carbon pollution from two-thirds of all cars and trucks in America,” Gina McCarthy, the administrator of the U.S. Environmental Protection Agency, said in announcing the new rules.