The Debate over the Environmental Impact of Tar Sands

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Tar sands, or oil sands, are a mixture of water, clay, sand and bitumen (a thick black oil). Through a complex, multi-step process, usable oil can be extracted from tar sands. Tar sand production begins with mining, usually strip or open pit, followed by a sequence of separation, upgrading and dilution of the extracted oil. Initially, the cost of this extraction process effectively eliminated the tar sands as a viable source of oil. But technological advances in the 1990s, coupled with the decreased availability of more easily accessed oil worldwide, has made tar sands a more attractive option to explore for meeting the world’s growing energy needs. 

The Tar Sands:


The Canadian tar sands, located in Alberta in western Canada, are one of the largest oil reserves in the world, with the ability to supply 100 billion barrels in total. However, accessing and extracting the oil is no simple task. For these tar sands to provide oil and have it exported out to be used, TransCanda, the company that owns the tar sands, needs to have access to a deep water port. This can be achieved in one of two ways, either via the Pacific Ocean or the Gulf of Mexico. For the first option to move forward, local Indian tribes would have to allow TransCanda to build across their land to the Pacific ocean. The alternative is a pipeline running through the United States to the Texas Gulf coast to access a deep water port there. The proposed Keystone XL Pipeline would do just this, stretching 1,700 miles through six states to the Texas Gulf coast.

The Keystone Oil Pipeline Debate

In a debate on PBS, Robert Bryce of the Manhattan Institute for Policy Research, an avid advocate for the pipeline, argues that the Keystone XL will offer a source for “cheap, abundant and reliable energy”. He believes that if the US does not take advantage of these Canadian reserves, another country will step in and reap the benefits while still imposing the same heavy environmental cost on the rest of the globe. His argument boils down to the economic benefits of the pipeline for the U.S., citing job creation as a strong incentive as well.

Bill McKibben, environmentalist and author, who is on the other side of the debate, agrees that the tar sands won’t stay in the ground forever, but makes the point that blocking the pipeline will stall their removal for five to ten years, allowing for the development of alternative fuel sources and slowing the progress of climate change.

There has also been debate over the exact environmental risks associated with the construction of the pipeline. The U.S. State Department just released an environmental review of the proposed pipeline with findings that indicates few environmental risks. The review points out that the carbon emissions implications of the pipeline depend on what alternative fuel the tar sands oil would be replacing. Additionally, the study finds that various strategies can be used by the industry to mitigate the environmental footprint of extraction of the tar sands.

Many environmental activists and scientists disagree with the study, listing the following potential environmental impacts that were not accounted for:

  1. Habitat destruction - Increasing tar sand production in Canada would result in the destruction of 740,000 acres of boreal forest, which is a significant carbon sink, but also home to many species, some of them endangered.
  2. Water contamination - If a pipeline were to rupture, which past experience indicates is likely, hundreds of gallons of oil would spill, contaminating drinking water and more habitat.  The Keystone pipeline runs over the Ogallala aquifer, which supplies drinking water to more than two million Americans.
  3. Process water and energy use - Processing requires several barrels of water for just one barrel of oil produced. Tar sand extraction is an especially resource intensive process.
  4. Global warming and greenhouse gas emissions - A report from Canada’s environmental ministry forecasts that tar sands output will double over the next decade, amounting to more than 1.8 million barrels a day. This level of production means that “greenhouse gas emissions from the oil and gas sector as a whole would rise by nearly one-third from 2005 levels by 2020”, assuming cleaner production methods.

Clearly there is still strong disagreement about the true environmental impact of this project. But regardless, the Keystone XL debate highlights the extensive trade-offs we will have to weigh and decisions we will have to make as a nation as the environmental crisis worsens over the next few decades.

Peter Lehner, Executive Director at the National Resource Defence Council writes, “Do you want America to create cars that can go twice as far on a gallon of gas, employ 150,000 workers to build it, and cut our oil use by more than 3 million barrels a day? Or do you want America to remain addicted to fossil fuels and to accelerate the climate change that will worsen storms, increase disease, and flood coastlines? Do you want the U.S. to become the middleman to enrich foreign oil companies?”