The criteria air pollutants that are considered to be toxic and the greenhouse gases are now listed under CEPA. They're scheduled under CEPA, which gives the federal government the authority to regulate them under CEPA.
Again, I'm a physician and my expertise is more on the health side, but as much as air pollution can be a provincial jurisdiction, my sense is that because these pollutants are scheduled under CEPA, the federal government has the jurisdiction to do something about air pollution broadly and nationally across Canada.