Oil sands fastest-growing source of greenhouse gases in Canada

Canada's annual heat-trapping greenhouse gases continue to level off or decline in most sectors of the economy, outside of Alberta's oilpatch, says the latest annual inventory report submitted by the Harper government to the United Nations.  But oil sands companies exploiting Alberta's natural bitumen deposits, which require large amounts of energy and water to extract heavy oil, continue to be the fastest growing source of greenhouse gases in the country