> At some point - it's simple. Just pass on a carbon tax on any good, regardless of which country it is created on. Taxed in the country of destination.
I don't think it's so simple, actually. My experience is that when people declare big sweeping "simple" solutions to global problems, those solutions tend to backfire and make things worse.
Determining how much CO2 was emitted during the production of any particular good is quite difficult to do. Are you going to parachute some UN Carbon Inspection Team to investigate the BOM for every manufactured good and add up some carbon tally? How will they know whether some wire was made in a solar powered factory or a coal powered factory? And what about the inputs to those factories, etc? And why would China allow such inspectors?
You will not be able to get that type of per-item granularity.
But you can get general info about countries. OK, what do you do with the general info? Apply the same tax on all goods, or just invent some hypothetical carbon burden for each good produced in a given country? That's a great strategy for getting producers to reclassify goods -- e.g. from passenger cars to personal utility vehicles, or for diverting goods from one country to another.
Moreover here, you've switched from trying to use the market to incentivize behavior to collective punishment of producers, where producers who use green energy sources are also forced to pay the tax.
But then why would other producers change behavior? Moreover by adding these extra tariff costs, you are going to be driving producers to look for even cheaper inputs, and that means more fossil fuels.
Moreover, that's just going to result in counter-tariffs and punishment in the reverse direction.
So you will be punching China and getting an equal punch back at you, and none of that will do anything to reduce CO2. All it will accomplish is a lot of punching in all directions -- e.g this is a tantrum-based approach to CO2 policy.