Globe and Mail: Canada's oil sands are one of the most carbon-intensive sources of crude in the world, and for American climate activists, the Keystone XL pipeline represents a "line in the sand" on climate policy. But greenhouse gas produced by the oil sands is a fraction of the amount spewed by U.S. coal-fired power plants. In 2010, the oil sands produced 48 million tons of carbon-dioxide emissions. Coal-fired power plants in the state of Wisconsin alone produced 43 million tons. No wonder Canadian politicians...