Who do think it is that has published that the largest oil reserves on Earth are in the oil sands, bitumen carbonates, and tight and shale oil formations of Alberta - not even taking into account the resources in Saskabush, BC, NWT, Mckenzie Delta, Beaufort Sea, and Arctic Islands?
The problem is excess GHG emissions limits, and lack of investment due to low oil prices that will continue as long as U.S. shale oil production continues unrestrained.