WASHINGTON (Reuters) - U.S. President Donald Trump’s top economic adviser on Friday said the nation’s withdrawal from the Paris climate accord will help keep energy markets competitive, allowing for a potential comeback in coal prices and the U.S. coal industry. Speaking in an interview on CNBC, National Economic Council Director Gary Cohn said that despite competition from cheap natural gas, “at some point in the cycle, coal will be competitive again,” adding: “We need to keep our options available to have the cheapest available energy” on a global market. 