The Why Files The Why Files --

Tar sands: Heavy price for heavy oil?

End of oil, or oil from the ends of the Earth?

Largely hidden from view, one of the world's biggest industrial projects is cooking a tarry sand in Alberta, Canada, creating a heavy fluid that is converted through the addition of hydrogen or subtraction of carbon into a synthetic crude oil that can be piped to refineries.

Tar sand, AKA oil sand, bears some resemblance to paving asphalt and contains about 10 percent hydrocarbon, or bitumen.

Almost entirely courtesy of the oil sands, Canada is now second only to Saudi Arabia in economically useful oil reserves, with 175 billion barrels hidden mainly under Alberta's fens and forests.

Tar sand was called the "dirtiest oil in the world," and it could also be the most expensive. Nonetheless, over the last decade, the rising price of crude oil turned Alberta's oil sands into a gusher that was, by 2005, producing 1.3 percent of total world oil production.

Decline in the average summer flow
of the Athabasca River between 1970 and 2005:

Hectares of lost boreal forest ecosystems
from the Athabasca Tar Sands region in Alberta:

Area of oil sands in the boreal forests of Alberta:
140,000 km2

Area of England:
130,000 km2

Source (items 1, 3 &4): Unconventional Oil: Scraping the Bottom of the Barrel, WWF Report, Leaton, James, 2008; (item 2): Timoney, Kevin P. "Does the Alberta Tar Sands Industry Pollute? The Scientific Evidence". The Open Conservation Biology Journal, 2009, 3, 65-81.

Shallow deposits of oil sand are removed via strip mining, which has already obliterated 650 square kilometers of the thin, boreal forest. Deeper deposits are pulled from the ground using thousands of miles of underground pipes that deliver steam and remove the heated bitumen. Both processes, and the necessary "upgrading" step, use vast amounts of energy, and release large amounts of greenhouse gases.

Photo of forest at ground level with lake in foreground and a moose standing in the water
Canada's "boreal" forest is one of the largest intact forests in the world, which is home to one of the largest energy projects on the planet.

Alberta's engine

Still, the open pits and in situ mines support an enviable economic engine in Alberta, which pipes most of its synthetic crude to the American Midwest. The plans for greater production all entail major expansions to the Midwestern refineries and the connecting pipelines.

Chasing oil is an old tradition, and the petroleum industry has pulled crude oil from Texas, the Middle East, the North Sea, the Caspian Sea and the American Arctic. Although many of the shallow, easily refined deposits have been exhausted, rising demand is moving the action to difficult deposits, located in Central Asia, for example, or two miles below the Gulf of Mexico.

Bar chart showing number of barrels per day imported by the US from foreign countries
From graph by DOE
Canada is now America's largest source of imported oil; 46 percent of Canada's oil comes from the tar sands, but rapid growth in Alberta could raise that amount significantly. Alberta has an estimated 175 billion barrels of recoverable oil in its sands.

In the tar sands, the problem is less distance than the oil's tight association with those signature sands. Breaking that bond requires plenty of hot water, a key reason why the tar sands consumes enough natural gas to heat one-quarter of Canada's 12 million homes (see #1 in the bibliography).

Gallon per gallon, oil from the sands produces more greenhouse gases than any other large-scale commercial liquid fuel.

These drawbacks did not matter much as oil's price soared during the last decade, and daily production from Canada's tar sands jumped from 550,000 barrels in 2002 to 1.1 million barrels in 2008. The industry was planning to reach 3.0 million barrels per day by 2015.

The boom brought floods of workers and capital into Alberta, but when the price of oil plunged during last fall's recession, construction in the tar sands went dormant, and thousands of suddenly superfluous workers headed home.

When the price of oil rises, however, oil-sand operators are expected to dust off their massive growth plans, which means we still need to answer a simple question: Is oil sands development a good thing?

Large truck with crane scooping dark mud from a large plot of brown earth, green grass in background
Shallow oil sand is mined using buckets that hold 100 tons per load. Suncor's mine delivers about half a million tons of oil sand daily to the ore preparation plants.

Simple question, but complicated answer

The short answer is that it depends on your viewpoint: Income and jobs for Canada? Energy security for Canada and the United States? Environmental health for Canada's forests, air, water and native peoples? The health of the global atmosphere?

While the oil industry sees black gold in the sand, many environmentalists see a zone of darkness: a source of air and water pollution that scourges vast tracts of boreal forest, disturbs native cultures and ecosystems, and threatens to absorb capital that would be better spent developing renewable energy resources rather than a dirty fossil fuel.

Tar sands: Boom or bust?


Terry Devitt, editor; Steve Furay, project assistant; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive

©2017, University of Wisconsin, Board of Regents.