'The world's dirtiest oil': Satellite photos reveal the relentless expansion of Canada's controversial tar sands industry

The mine at Fort McMurray, on the banks of the Athabasca River, Alberta, had already been operating for 17 years of the first picture from a U.S. satellite. Today the Canadian tar sands are recognised as one of the world's largest oil reservoirs. The International Energy Agency (IEA) estimates the recoverable oil sands reserves at more than 170million barrels - more than any other nation except Saudi Arabia and Venezuela. Source