According to a World Bank paper:Since freer trade raises income, it directly contributes to increasing pollution levels via the scale effect.
[9] Negotiations took place in 2001 Doha, Qatar, towards the improvement of work related issues concerning the implementation of present agreements.
The result of which was ministers agreeing to a reduction or complete removal of tariff and non-tariff barriers to environmental goods and services such as catalytic converters and air filters to name a few.
`(t) The Administrator shall prepare, within one hundred and twenty days of the enactment of this section and yearly thereafter, a pollution control index for each of the top fifty countries identified by the Office of Trade and Investment of the Department of Commerce based on the value of exports to the United States from that country's attainment of pollution control standards in the areas of air, water, hazardous waste and solid waste as compared to the United States.
The Administrator shall analyze, in particular, the level of technology employed and actual costs incurred for pollution control in the major export sectors of each country in formulating the index.Environmental tariffs may result in the movement in production of goods to areas in which stricter environmental standards are enforced.
A disputed case relating to this policy was brought forth to the GATT/WTO, involving the U.S. and Canada over Canadian environmental regulations on beverage containers.