According to CAPP statistics for the last 20 years, the price of gas has risen ~ 4 cents/liter per year and consumption has increased by 475,000,000 liters per year (about 1.3%/year).  The carbon tax proposed will be ~ 2.3 cents/liter per year for the next five years.  
Imagine what kind of carbon tax will be needed to actually decrease consumption with an increasing population- that will be the Liberal surprise after the next election.