There’s no way countries that are growing their economies the most will agree to stringent caps on carbon dioxide emissions based on historical levels. This historical-cap framework rewards the countries that have shrinking populations and manufacturing. Instead Canada (as also noted in today’s WSJ) and others are focusing on CO₂ intensity. E.g., how much CO₂ is produced per kwh of electricity generated or per barrel of oil pumped? These are measures that don’t hurt production and labor mobility. Some say they don’t have bite. But if a CO₂ reduction policy bites too much (pun intended)–especially in a way that caps economic growth–then the growing polluting countries will ignore it.