Reuters: Prime Minister Stephen Harper said on Friday he would ban exports of tar-like bitumen from Alberta’s oil sands to countries that do not match Canadian efforts to cut carbon emissions, a campaign promise that perplexed both the oil industry and environmentalists. The policy could affect Asian countries that are the target of a proposed Enbridge Inc pipeline that would move oil sands-derived crude to Canada’s West Coast to be shipped across the Pacific Ocean by tanker, Harper …