The federal government’s “backstop” carbon-pricing policy will apply in provinces and territories that haven’t implemented a sufficiently broad and stringent policy of their own. The backstop has two parts. The first is the levy on the carbon embedded in fossil fuels such as gasoline and diesel; this is pretty straightforward. The second is a separate pricing system for large industrial emitters; this is the complex part that needs some explanation. Despite the complexity, however, it is interesting to see that governments of all political stripes seem to be adopting similar ways of treating the economy’s large emitters.