Yes, this is pretty high as far as tax is concerned, and unlikely to get introduced soon. However, it's still less than 50 cents a gallon. My point is that it's

Yes, this is pretty high as far as tax is concerned, and unlikely to get introduced soon. However, it's still less than 50 cents a gallon. My point is that it's highly unlikely that "couple of dollars per gallon" is "a reasonable carbon tax", because carbon tax so high will be greatly exceeding the actual cost of CO2 emissions. "Couple of dollars per gallon" means at least $2/gallon, so $220/tonne CO2. That's enough to cover direct air capture of CO2, which is hardly the most cost-effective way of carbon capture.