President Trump on Tuesday plans to sign an executive order seeking to undo much of former President Barack Obama’s environmental legacy. Administration officials said Trump would tell the Environmental Protection Agency to start the legal process necessary to rewrite Obama’s Clean Power Plan, which aimed to cut carbon dioxide emissions from electricity by 32 percent by 2030. The sweeping order also would seek to lift a moratorium on federal coal leasing and end a requirement on federal officials to consider how their decisions impact climate change. The White House said Trump’s order would increase the nation’s “energy independence” and restore thousands of coal mining jobs. Harvard energy economist Robert Stavins said the impact on energy independence was overblown. “We don’t import coal,” he said.