To compare the carbon footprint of a 40-foot container transported from Ontario, Canada, to Dallas, Texas, versus one shipped from Shenandoah, China, to the Port of Los Angeles, we need to consider several key factors that affect carbon emissions. These include the mode of transport (truck, rail, or ship), the distance traveled, and the efficiency of each transport mode.

This journey primarily involves overland transport by truck or rail. Here are the estimated distances:

• Truck Route: The distance from Ontario, Canada, to Dallas, Texas, is approximately 1,500 miles (2,414 km) by road.
• Rail Route: If transported by rail, the distance may vary slightly but would be close to the truck route.

The carbon emissions from trucking are higher compared to rail, but trucks are often more convenient for direct point-to-point delivery. Below are the approximate emissions per mode of transport:

• Truck emissions:
  The average carbon dioxide emissions for a fully loaded truck are about 161 grams of CO₂ per ton-mile.
  Assuming the 40-foot container weighs 20 tons (a common estimate for a fully loaded container), the total emissions would be:
  161 g/ton-mile×20 tons×1,500 miles=4,830,000 grams=4,830 kg (4.83 metric tons of CO₂)
• Rail emissions:
  Rail freight is significantly more efficient, with an average of 20 grams of CO₂ per ton-mile.
  The total emissions for rail transport would be:
  20 g/ton-mile×20 tons×1,500 miles=600,000 grams=600 kg (0.6 metric tons of CO₂)

So, the carbon footprint for the Ontario-to-Dallas route would be:

• 4.83 metric tons of CO₂ by truck
• 0.6 metric tons of CO₂ by rail

This journey involves shipping the container across the Pacific Ocean and then potentially trucking it from the Port of Los Angeles to its final destination.

A. Shipping Route (Ocean Transport)

• The distance from Shenandoah, China, to the Port of Los Angeles is approximately 6,500 nautical miles (7,480 miles or 12,040 km).
• Cargo ships emit 10-40 grams of CO₂ per ton-kilometer, depending on the efficiency of the vessel. We'll use the average estimate of 17 grams of CO₂ per ton-km.

The total emissions for ocean transport would be:

17 g/ton-km×20 tons×12,040 km=4,093,600 grams=4,094 kg (4.09 metric tons of CO₂)

B. Port of Los Angeles to Final Destination (Truck Transport)

• If the container is transported by truck from the Port of Los Angeles to a location in Los Angeles or within 100 miles, we can estimate this as an additional 100 miles by truck.

The carbon emissions for this leg would be:
161 g/ton-mile×20 tons×100 miles=322,000 grams=322 kg (0.32 metric tons of CO₂)

• 4.09 metric tons of CO₂ for ocean transport
• 0.32 metric tons of CO₂ for trucking

The total carbon footprint for the Shenandoah-to-Los Angeles route would be approximately:

• 4.41 metric tons of CO₂