The tar sands (referred to as “oil sands” by the petroleum industry) are a thick mixture of bitumen and sand/clay. This mixture is extracted from beneath forests covering over 140,000 square kilometres of North-Eastern Alberta, an area roughly the size of Scotland.
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Bitumen close to the surface is extracted by open pit mining, where hundreds of feet of topsoil are scraped away by huge earth-moving equipment. Bitumen at greater depths cannot be extracted in this fashion. These depth deposits are injected with high-pressure steam that has been heated by natural gas. The steam separates the sand from the bitumen, which can then be pumped to the surface. Although this method does not leave ugly open excavations, large amounts of CO2 emissions from the natural gas leave a big carbon footprint rather than the smaller one caused by surface extraction.
Whichever method is used, large amounts of water, up to 7000 litres for one barrel of oil, are required to separate out the bitumen. For bitumen obtained from open pit mining, the water is piped into tailing ponds, permitting approximately 85% recovery. In the case of separation by steam, no such recovery is possible.
The Simple Fact is: mainly because of the tar sands, Alberta emits an incredible 71 tons CO2 per capita, compared with the Canadian average of 17 tons.
It is the amount of CO2 emissions that has prompted the persistent objection of Norwegian Grandparents to the tar sands. Their campaign opposing the tar sands should be a model for other Grandparents Associations.