The problem is that what you refer to as "short term" is going to be generations.  Most people are very naive when it comes to just how much of modern society relies on petroleum.  If every thing and service around you that used petroleum suddenly disappeared, you would be standing in a pile of sticks., unable to go anywhere.   Canada can either extract our own petroleum and keep the wealth in the country or we can buy from foreign sources and send the money overseas.  But to believe that in 5 or 10 years petroleum consumption is going to drastically decrease is nonsense.  And considering that every level of government is spending more money than they are taking in, we better be able to get revenue somewhere.