West Coast Ports Make Lowest Carbon Footprint: Study

Asian imports to the U.S. interior that are carried on Trans-Pacific services to West Coast ports emit fewer greenhouse gas emissions per-TEU than containers moving to the same destinations via all-water services, according to a study performed for the Port of Seattle.

Since the Pacific Northwest ports are 300 to 800 nautical miles closer than California ports to key Asian export centers such as Shanghai, Hong Kong and Singapore, Seattle's carbon footprint is the lowest on the U.S. West Coast, according to the study performed by Herbert Engineering.

The study estimated the level of greenhouse gas emissions on container movements from the three Asian export centers to Chicago, Columbus, Ohio, and Memphis. In addition to measuring vessel emissions, the study also measured emissions from intermodal trains carrying the containers from seaports on all U.S. coasts to the interior cities.

Trans-Pacific services to West Coast ports are 5,000 to 6,000 nautical miles, or half the distances from the Asian ports to New York, Norfolk, Savannah and Houston. through the Panama and Suez canals, so the West Coast services have a much smaller carbon footprint.

Also, West Coast ports are able to accommodate large vessels of 8,000 to 12,500 TEU capacity, and that reduces the carbon emissions per-TEU compared to the 4,500 to 5,000-TEU capacity vessels that transit the size-constrained Panama Canal.

All large vessels can transit the Suez Canal, but the Suez route to the East Coast is about 2,000 miles longer than the Panama route.

However, rail service from East Coast ports to Chicago, Columbus and Memphis are about 1,000 miles, or half the rail distances from West Coast ports, offsetting somewhat the lower level of emissions from ocean vessels to West Coast ports. Also, carbon emissions from trains are higher than from vessels.

Nevertheless, the West Coast gateways are greener than East and Gulf Coast gateways when the total emissions from vessels and trains are included.

For example, carbon emissions per-TEU are 41 percent lower when moving a container from Shanghai to Chicago via Seattle on an 8,500-TEU ship than moving a container via the Panama Canal to New York on a 4,500-TEU vessel.

Contact Bill Mongelluzzo at bmongelluzzo@joc.com .