Climate Central: Amid low oil prices and growing political opposition in the U.S., TransCanada Corp. has asked the State Department to suspend its review of the companys permit application for its controversial Keystone XL Pipeline. The request could wind up delaying the construction of Keystone XL, which has been at the forefront of the debate over climate change in the U.S. The companys action comes as oil prices hover around $50 per barrel, Canadian tar sands development is slowing and Democratic presidential...