The Environmental Protection Agency is expected to formally repeal Biden-era carbon pollution limits on coal and gas power plants as early as Monday, a move that would strip away one of the federal government's key tools for curbing greenhouse gas emissions from the electricity sector. The rollback comes just as energy ministers from the world's largest economies gather in Houston for a G20 meeting, a juxtaposition that underscores how far the United States is drifting from global efforts to address climate change. Power plants remain among the largest sources of carbon pollution in the country, and the standards being scrapped were designed to push utilities toward cleaner technologies over time. Environmental advocates and public health experts have long warned that unchecked emissions from fossil fuel plants contribute to respiratory illness and accelerate warming that fuels extreme weather. The timing, alongside international energy diplomacy, raises questions about the administration's priorities as other nations debate how to speed the transition away from fossil fuels, while the U.S. moves to loosen protections that had been years in the making.