the way that a carbon tax (market access fee) like this would work is that the americans would set a monthly fee for ottawa to pay washington that is proportional to the amount of carbon generated that month, from all sources.
total emissions. if canada seeks to lower it's market access fee, it will need to reduce it's carbon emissions. the fee should be paid by the state, not by individual polluters. this is intended as a state-to-state interaction, to force the government to (re-)implement better policies.
if canada doesn't pay the fee, the border gets shut until it does.
the americans should really do this for everybody, not just us.