The Obama administration’s final plan to cut power-plant emissions will be tougher than was proposed last year, a top White House official said, as a document emerged that showed the government will give states two additional years to comply. White House Chief of Staff Denis McDonough said the final rule to fight climate change will be released soon, and will have new provisions to boost solar, wind and other renewable energy. President Barack Obama would veto any bill aimed at stopping the plan that would cut carbon emissions, he said. “There really is no overstating how big this year is for climate change,” McDonough said Wednesday at a Washington forum on the issue hosted by the New Republic. “We will finalize a stronger rule.” McDonough, who didn’t answer questions, spoke a day after the Environmental Protection Agency posted a slide on its website showing milestones to implement the standard. […]