Canceled a requirement for oil and gas companies to report methane emissions.
Revised and partially repealed an Obama-era rule limiting methane emissions on public lands, including intentional venting and flaring from drilling operations.
Loosened a Clinton-era rule designed to limit toxic emissions from major industrial polluters
Stopped enforcing a 2015 rule that prohibited the use of hydrofluorocarbons, powerful greenhouse gases, in air-conditioners and refrigerators.
Repealed a requirement that state and regional authorities track tailpipe emissions from vehicles traveling on federal highways.
Reverted to a weaker 2009 pollution permitting program for new power plants and expansions.
Amended rules that govern how refineries monitor pollution in surrounding communities.
Directed agencies to stop using an Obama-era calculation of the “social cost of carbon” that rule makers used to estimate the long-term economic benefits of reducing carbon dioxide emissions.
Withdrew guidance that federal agencies include greenhouse gas emissions in environmental reviews. But several district courts have ruled that emissions must be included in such reviews.
Lifted a summertime ban on the use of E15, a gasoline blend made of 15 percent ethanol. (Burning gasoline with a higher concentration of ethanol in hot conditions increases smog.)
Proposed weakening Obama-era fuel-economy standards for cars and light trucks. The proposal also challenges California’s right to set its own more stringent standards, which other states can choose to follow.
Announced intent to withdraw the United States from the Paris climate agreement. (The process of withdrawing cannot be completed until 2020.)
Proposed repeal of the Clean Power Plan, which would have set strict limits on carbon emissions from coal- and gas-fired power plants. In April 2019, the E.P.A. sent a replacement plan, which would let states set their own rules, to the White House for budget review.
Proposed eliminating Obama-era restrictions that in effect required newly built coal power plants to capture carbon dioxide emissions.
Proposed a legal justification for weakening an Obama-era rule that limited mercury emissions from coal power plants.
Proposed revisions to standards for carbon dioxide emissions from new, modified and reconstructed power plants.
Began review of emissions rules for power plant start-ups, shutdowns and malfunctions. In April, the E.P.A. filed an order reversing a requirement that 36 states follow the emissions rule.
Proposed relaxing Obama-era requirements that companies monitor and repair methane leaks at oil and gas facilities.
Proposed changing rules aimed at cutting methane emissions from landfills. In May, 2019, a federal judge ruled against the E.P.A. for failing to enforce the existing law and gave the agency a fall deadline for finalizing state and federal rules. E.P.A. said it is reviewing the decision.
Announced a rewrite of an Obama-era rule meant to reduce air pollution in national parks and wilderness areas.
Weakened oversight of some state plans for reducing air pollution in national parks. (In Texas, the E.P.A. rejected an Obama-era plan that would have required the installation of equipment at some coal-burning power plants to reduce sulfur dioxide emissions.)
Proposed repealing leak-repair, maintenance and reporting requirements for large refrigeration and air conditioning systems containing hydrofluorocarbons.