A federal appeals court in Washington ruled Monday that the head of the Environmental Protection Agency overstepped his authority in trying to delay implementation of a new rule requiring oil and gas companies to monitor and reduce methane leaks.In a split decision — the first major legal setback for Scott Pruitt, the EPA administrator — the three-judge panel from the U.S. Court of Appeals for the District of Columbia Circuit ordered the environmental agency to move forward with the Obama-era requirement that aims to reduce planet-warming emissions from oil and gas operations.The ruling signals that President Donald Trump’s plans to erase his predecessor’s environmental record are likely to face an uphill battle in the courts.