I think my comment was perhaps not clear about what should be taxed - if any form of local tax is applied (a direct tax or other administrative measures that ma

I think my comment was perhaps not clear about what should be taxed - if any form of local tax is applied (a direct tax or other administrative measures that make carbon extensive production more expensive) then imports should be comparably taxed. If economically significant markets implement this then it can have a real global effect. Implementing a local tax only makes the local markets only less competitive and will favor imports from countries that do not implement proper measures.