Right, but then you should set up specific restrictions for very specific circumstances. E.g. if a company in China is using coal power (that would be below EU/

Right, but then you should set up specific restrictions for very specific circumstances. E.g. if a company in China is using coal power (that would be below EU/US standards of pollution), you apply extra "fair-market fees" to their imports. However, you also allow for "certification" - if a company proves they comply to the stricter laws, they don't need to pay the fee.