There's a problem between non-tariff measures and tariffs, with carbon taxing being too obviously a tariff measure. And you can't just throw in a tariff thanks

There's a problem between non-tariff measures and tariffs, with carbon taxing being too obviously a tariff measure. And you can't just throw in a tariff thanks to WTO rules, especially if it wouldn't apply to countries that do collect carbon tax - WTO requires that tariffs are applied the same to all countries except through certain bilateral trade treaties. Which is workable, but makes for considerable stumbling block in "quick apply" of carbon tax