Canada's tar sand projects sprawl across 600 square kilometers of northeastern Alberta. Prime Minister Stephen Harper has called the industrial effort to extract oil from the deposits “an enterprise of epic proportions, akin to the building of the pyramids or China's Great Wall. Only bigger.”
As traditional oil and natural gas reserves become increasingly difficult to find, and as demand rises, energy companies are turning to unconventional resources that, like the tar sands, are harder and more costly to access. Production of tar sands–based oil, for instance, has tripled over the past decade, reaching 1.6 million barrels a day in 2011.