EPA proposes walking back on greenhouse gas, mercury regulations

US Environmental Protection Agency administrator Lee Zeldin on Wednesday announced two EPA proposals to roll back emission limits for power plants on greenhouse gases, mercury, and particulate matter. Under one proposed rule, the EPA would repeal all greenhouse gas (GHG) emission standards for fossil fuel–fired power plants, undoing standards instituted during the administrations of Barack Obama and Joe Biden for new and existing second proposal would undo Biden-era rules to tighten the Mercury and Air Toxics Standards (MATS) for power plants and return them to 2012 standards. The proposals come almost 3 months after Zeldin said the EPA is reviewing 31 regulatory actions for potential rollback.“Today is a historic day for the EPA,” Zeldin said during the announcement. “We are proposing to repeal Obama and Biden rules that have been criticized as regulating coal, oil, and gas out of existence.” The proposed changes will ensure that people in the US will have access to plentiful and cheap electricity, he said. “Today, EPA is taking an important step reclaiming sanity and sound policy illustrating that we can both protect the environment and grow the economy.”The proposed changes could impact the chemical industry and other sectors of the economy by reducing the price of power. “Ensuring affordable and reliable energy supplies drives down the costs of transportation, heating, utilities, farming, and manufacturing while boosting our national security,” the EPA says in a press release.When are GHG emissions ‘significant’? Under the Clean Air Act, the EPA is required to regulate industrial sources if