> And it would be unfair to penalise countries with large ports when much of the cargo they handle is being shipped onward to other destinations.

This takes us back to the point of the top-level comment, but I think it's also unfair to penalize countries with large factories, when much of the manufacturing output is being shipped to other destinations.

Carbon should be attributed back to the consumers that paid for it to be emitted, not the place where it was emitted. This is what a carbon tax would achieve, as companies would pass the tax on to consumers, who ultimately drive all this manufacturing activity.

The Brits don't get a free pass just because they paid people in poorer countries to emit carbon for them.

It seems fair to attribute ambitions to the country where they are physically made, because that’s the country regulating those emissions. If you don’t, you’re incentivizing a country to have lax emissions regulations by letting their choices impact someone else’s accounting.

I disagree that would be fair, and it certainly wouldn't achieve a good result.

If emissions are attributed the country where they are physically made, then it incentivizes rich countries to offshore all their manufacturing to poor countries - which is exactly what's happened here in the case of Britain.

If the choice is between poverty and low emissions, of course developing nations are going to have lax regulations.

There's always an incentive to offshore to where costs are lower. A carbon tax like you suggested at least prevents hiding the costs of CO2 emissions across national borders. This is fair to both consumers and producers but it is not going to be costless to developing nations. Developing nations will either need to match developed ones on energy supply cleanliness or see their export oriented cost competitiveness eroded. This is a good thing for all parties in the long run but it is also a real cost.