The head of the Environmental Protection Agency announced Wednesday the agency is proposing to scrap two major regulations that limit air pollution and planet-warming emissions from coal and gas-fired power plants.

WASHINGTON—The Environmental Protection Agency proposed Wednesday weakening air-pollution standards for mercury and eliminating carbon dioxide rules on power plants, reversing Biden-era policies as part of an overall effort to curtail the agency’s role in regulating climate change.

Lee Zeldin, the E.P.A. administrator, said erasing regulations would produce jobs and lower electricity costs. He called efforts to fight climate change “a cult.”