Most of you are already aware of the damage caused by the burning and the extraction of oil (like the apprehended damage caused by extraction in the Arctic Wildlife Refuge, for example). But what about the famous Canadian tar sands? After only two years of digging for bitumen near Fort McMurray in Alberta, Shell has already dug up a pit that is as much as three miles wide and 200 feet deep. 400-ton trucks, said to be the largest in the world, are used to move around all that dirt, and it takes a lot of it since on average 2 tons of tar sand are required to make 1 barrel of oil.
The oil operation has been a boon for Fort McMurray and its people. But some observers are worried about the facility's impact on the environment.
After processing the sand to extract its oily component, the gigantic holes dug in the earth are refilled and planted with trees. But the refilled mine pits rarely match the original terrain, and replanting programs so far have resulted in forests that resemble Christmas tree farms.
So much for repairing the damage done.
But companies are now moving away from these huge pits; a new technique allows them to inject steam directly into the soil to melt the tar enough so that it can be pumped back to the surface.
Whatever the process used, it takes a great deal of energy to recover bitumen and turn it into oil. An enormous amount of greenhouse gases are released in the process.
In fact, making oil from tar sands produces two or three times more greenhouse gases than producing conventional oil.
How do they produce so much energy? With natural gas, of course. It is one of the main reasons why Canada has so much trouble meeting its obligations under the Kyoto treaty.
Because the cost of natural gas has quadrupled in recent times and with the coming of peak natural gas, the Canadian tar sands should become more and more expensive as time goes on (most companies there have already run way over their predicted costs), both in monetary and environmental costs.
Photos credit: Martin Kaste, NPR
::Canada Digs Oil Out of the Ground for U.S.