USA Today: President Obamas crackdown on greenhouse gas emissions from cars and power plants made the U.S. a leader at the United Nations climate summit. Now, with the whole world watching, he can give real meaning to the promise Paris offers without bumping into an intractable Congress. The president can accelerate and expand efforts to slash emissions of global warming pollutants in the natural gas and oil industries drilling and distribution systems and improve refinery efficiency. He can issue tougher...