Yes, it's a cap and trade, which is different from a simple tax like BC's carbon tax. In Europe, some companies have to buy emissions permits, while others were given permits for free. So some companies were basically given money for nothing. It's a system that can be gamed by giving favourable treatment to favourable industries.
It should be no wonder then that when Canada does talk about pricing carbon, Harper et al. have said they would like to introduce a cap and trade scheme. They have already said basically that the Athabasca projects would get a free ride as an exempted industry.
Considering that they are the major growth industry for Canada, that AB pays bilions more into programs. I can see why. No sense shooting yourself in the wallet.