Alberta's first oil sand mine, close to the Athabasca River, pictured in 1984
Alberta, Canada has the world’s largest oil sands deposit. The region has the capacity to produce 2.5 million barrels of oil per day—and in the process, as TreeHugger has explained before, extraction produces up to eight times the emissions of conventional oil and operators are allowed to use twice the amount of fresh water that all of Calgary uses in a year.
We know all that. But exactly how much has the industry grown over the last few decades? Satellite images from NASA's Earth Observatory show the expansion of mines in Canada between 1984 and 2011.
Above is the 1984 image—compare that with this recent image:
"By 2011, pit mines surrounded the Athabasca River."
As the images show, forest must be cleared for both in situ and surface mining. The mining and extraction process releases sulfur oxides, nitrogen oxides, hydrocarbons, and fine particulate matter into the atmosphere. Tailings ponds contain a number of toxins that can leak into the groundwater or the Athabasca River. The entire process, from mining and separating oil sands to producing crude oil, releases more greenhouse gases than other oil production methods.
The Observatory has images from years in between, as well, if you want to see the change over time.