The extraction of the oil requires heat, and thus the burning of vast amounts of natural gas - effectively one barrel of gas to extract two of crude - and some estimate that Fort McMurray and the Athabasca oil sands will soon be Canada's biggest contributor to global warming; nearly as much as the whole of Denmark. This in an area that has already seen, according to David Schindler, professor of ecology at the University of Alberta, two degrees of warming in the past 40 years.
The oil sands excavations are changing the surface of the planet. The black mines can now be seen from space. In 10 years, estimates Schindler, they are "going to look like one huge open pit" the size of Florida. Acid rain is already killing trees and damaging foliage. The oil companies counter that they are replanting - grass for bison, 4.5m trees by Syncrude alone - but the muskeg (1,000-year-old peat bog and wooded fen, which traps snow melt and prevents flash floods, and is home to endangered woodland caribou) is irreplaceable.
Two barrels of water are required to extract one barrel of oil; every day as much water is taken from the Athabasca river as would serve a city of a million people.
To read the entire well-written article, which also the social costs of the extractions to the local economy, go to: Mud, Sweat, and Tears
Now get on your bikes and ride!