By the way, a study published last September estimates that climate change will cost Canada C$5 B/yr by 2015 and C$21-43 B/yr by 2050. With an estimated 5% chance the costs then are a least C$ 91 B.
All that oil ought to be able to pay for that.
They estimate Canadian GDP in 2050 will be C$5000 B in 2008 C-dollars. So C$43 B will be about 1% of GDP (sounds low compared to the Stern Report), and up to about 2%.
So while Canada will make trillions from selling their oil, and pay up to $100 billion a year to combat climate change. And they'll pay almost that much if they don't sell their oil. I'd say that pencils out, for them at least.