As soon as you accept that it is the total quantity of fossil fuels burned that will determine how much the climate changes, it starts getting disturbing when people talk about how massive the quantity of oil embedded in the Athabasca oil sands is:

Canada’s proved oil reserves are the second largest in the world. This represents about 13% of the world’s proved oil reserves. Based on current Canadian rates of production, it would take more than 150 years to extract these reserves. Organization of Petroleum Exporting Countries (OPEC) member countries collectively control 70% of the world’s oil reserves, and produce about 40% of world oil production.

The amount of oil in-place (not all in-place amounts will be economically recoverable) in Canada’s oil sands is estimated at 1.8 to 2.5 trillion barrels. For comparison, the 150 year cumulative total of world oil production-to-date is approximately 1 trillion barrels.

That’s a huge amount of climate change potential!