Globe and Mail: Alberta’s oil sands producers and their U.S. refiners face sharply higher costs to reduce greenhouse gas emissions under legislation approved by the U.S. House of Representatives and championed by U.S. President Barack Obama. The American Clean Energy and Security Act, if passed by the U.S. Senate, could also result in new tariffs on Canadian exporters of energy-intensive goods from cement to chemicals if Washington deems Ottawa’s climate-change regulations to be lacking. Under …