The only really fair measure is per capita GHG emissions. In Alberta and SK, those stand at around 67 tonnes per person. In Ontario, around 14 tonnes, and in China around  7. (The US average is 19.9 tonnes per capita, a bit less than the Canadian average of 20.94.)  So, yes, if Canada is to have a credible voice in advocating for global reductions, it needs to do its fair share. (Even with our small population, we are in the list of the ten largest overall emitters.) That being said, a carbon tax might be a fairer and more transparent way of achieving cuts than a cap and trade system, particularly if the cost of carbon rises sufficiently to create a strong incentive to reduce emissions.