A federal judge has reversed the Trump administration’s environmental approval for ConocoPhillips’ multibillion-dollar proposed Willow development on Alaska’s North Slope, throwing a significant roadblock in front of a project seen by analysts as a needed boost to the state’s flagging oil industry and tax revenue. U.S. District Court Judge Sharon Gleason, in a 110-page ruling on two related lawsuits Wednesday, said the Trump administration’s approval of the project under the National Environmental Policy Act was flawed because it failed to thoroughly analyze potential greenhouse gas pollution, and didn’t sufficiently consider legal protections for Teshekpuk Lake, an important subsistence area on...