A study analyzes the impact of NAFTA cross-border transportation on air pollution
14 March 2001
The North American Commission for Environmental Cooperation (CEC) has released a study on the environmental impacts of cross-border trade and transportation within NAFTA (North American Free Trade Agreement), with a particular focus on air pollution emissions. The study, based on analysis of five corridor segments (Vancouver-Seattle, Winnipeg-Fargo, Toronto-Detroit, San Antonio-Monterrey, and Tucson-Hermosillo), determines current and future commodity flows, freight vehicle traffic volumes, emissions in each of these corridor segments, and the impacts of several mitigation strategies.
The findings of the study can be summarized as follows:
- Currently, NAFTA trade contributes significantly to air pollution in all the corridors, particularly NOx and PM-10 emissions. Cross-border freight is responsible for 3% to 11% of all mobile source NOx emissions in the corridors and 5% to 16% of all mobile source PM-10 emissions. Truck idling associated with border crossing delay contributes significantly to CO emissions, particularly in corridors where border delay is problematic. As much as 6% of all trade-related CO emissions in the corridors are caused by truck idling.
- By 2020, due to the expected reductions in emission rates from truck diesel engines, total trade-related emissions of NOx and PM-10 will decline or remain constant compared to current levels, despite trade volumes that will grow by two to four times.
- Due to less stringent emission standards and slower engine turnover, the study expects an increase in NOx and PM-10 emissions from railway locomotives. In corridors with higher trade growth, NOx and PM-10 emissions from rail will increase 50% to 100% by 2020. In all corridors, because of the decline in truck emissions, rail will contribute a larger share of trade-related NOx and PM-10 emissions.
- Trade-related emissions of greenhouse gases (CO2) and CO will not be reduced under the new emission standards, and are therefore expected to rise substantially by 2020. Under the baseline 2020 growth scenario, CO2 emissions from NAFTA trade will increase by 2.4 to 4 times over their current levels in the five corridors.
The above conclusions strongly depend on the assumed growth rates for future truck and rail traffic.
According to the conclusions of the study, shifting freight from truck to rail would actually increase emissions. This finding has received a very positive response from the Canadian trucking industry.