During the time of globalization and the rapid expansion of the international market, the US policymakers have come to realize the importance of what is happening in other countries. Before making any decision and submitting the final draft to Congress, the policymakers were concerned about the effects of the North American Free Trade Agreement on the environment.[9] National accounting systems that include environmental and natural resources could provide useful information during negotiations over the nations' commitments to restore or maintain natural capital.
Trade restrictions have not been used when a country's production and processing methods result in excessive discharges of pollutants (carbon, sulfur, nitrogen oxides, chlorofluorocarbons) across national boundaries. The difficulty comes in when determining the effects of trans-boundary pollutants on industry costs.
