Carbon footprint of transporting tofu and chicken to San Juan Island
The Beam Reach Marine Science and Sustainability School is based on San Juan Island in Washington State. Since the island is much smaller than the rest of North America, its inhabitants tend to depend on food items purchased from the mainland if those items cannot be produced on-island. These food items must be transported onto the island from the mainland.
Beam Reach as a school is concerned with reducing the impact that its activities may have on the environment; since feeding its students and employees is a necessary activity for the smooth running of the program, it is important to consider the costs of feeding said students and employees.
One factor included in the costs of feeding people is the impact of the transportation of the food from its source to San Juan Island. The cost to the environment can be considered in terms of the food item’s carbon footprint, or the amount of carbon dioxide (CO2) emitted to bring the food from its source to its final destination. For convenience, I will use Friday Harbor Labs as the food’s final destination because the students of Beam Reach bring back all food to the Labs before transporting it to the Gato Verde. The cost of transporting any food item of equal weight is the same if it is afterwards moved from the Labs to the boat. I have chosen to examine the differences in the carbon footprints of two different food items: tofu that Beam Reach has purchased from White Wave Foods Company to eat aboard the Gato Verde, and organically farmed chickens from Lacrover Farms on San Juan Island. Each item has many costs of transportation to consider. The tofu is made from soybeans which must be shipped to a factory, and after it is made, it must then be transported to its destination on San Juan. The chickens are fed with feed that does not come from the island, and because of the inefficiencies in converting biomass between trophic levels, they will produce less food by weight than they will eat during their lifetimes.
In order to consider the costs of producing tofu versus producing chicken, I will examine the differences in CO2 output for transporting the ingredients (soybeans versus chicken feed) and final products (tofu versus chicken) for five pounds of final product. I use this standard because tofu can be purchased in varying amounts, and one Lacrover chicken weighs approximately five pounds (Lacrampe and Hover, personal communication). I have used Google Maps to calculate the distances between sources and destinations of ingredients and products.
White Wave tofu is manufactured in Boulder, CO, but it is made with soybeans that are shipped from China (Roseboro 2007). The distance from Hong Kong to Los Angeles, two major shipping ports, is 11579.23 km. Soybeans will be transported by cargo ship, which on average, emits 40 grams of CO2 per tonne-kilometer (Tkm). Since production of soy requires about twice as many soybeans by weight as tofu produced, production of five pounds of tofu would require about 10 pounds of soybeans (Wang and Cavins 1989). Movement of 10 pounds of soybeans over a distance of 11579.23 km by cargo ship would be responsible for approximately 2315.846 grams of CO2 emitted into the atmosphere.
Once the soybeans reach Los Angeles, they are transported to Boulder, where they are processed to make tofu. The distance from LA to Boulder is about 1654.41 km, and an average heavy-duty truck emits about 90 g of CO2 per Tkm (US Department of Transportation 2002). The resultant carbon footprint of transporting 10 pounds of soybeans from LA to Boulder is about 744.49 grams CO2. After production, the tofu is shipped from Boulder to Anacortes by truck over a distance of about 2246.64 km, with a resulting output of 505.494 grams CO2. The tofu is then shipped by ferry to Friday Harbor (37.98 km), causing 3.798 g of CO2 output. To get the tofu from the town of Friday Harbor to the Friday Harbor Labs (1.77 km) by a light-duty vehicle whose carbon footprint is 275 g of CO2 per Tkm would produce 1.22 g CO2 (US Department of Transportation 2002). The total carbon footprint of getting five pounds of tofu from its source as soybeans to the Friday Harbor Labs is 3570.85 grams of CO2.
Chickens from Lacrover Farms eat organically grown feed that is shipped from Abbotsford, British Columbia to Anacortes by heavy duty truck. Each five-pound chicken requires about 16 pounds of feed over its lifetime (Lacrampe and Hover, personal communication). Over the 111 km from Abbotsford to Anacortes, the truck emits about 79.92 grams of CO2 for those 16 lb of chicken feed. The feed is then transported by ferry to Friday Harbor with a resultant 12.15 grams CO2 produced. From Friday Harbor, the feed moves to the Lacrover Farm by light-duty vehicle over a distance of 12.07 km, resulting in 26.55 grams of CO2 emissions. Once the chickens are fed, grown, and slaughtered, they may be transported to FHL, which is 12.71 km away. This transportation by light-duty car would cause 8.74 of CO2 emissions per five pounds of chicken. In total, getting five lb of chicken to FHL would be responsible for 127.36 grams of CO2 emissions.
According to these calculations, purchasing chickens from Lacrover instead of White Wave tofu would reduce our carbon footprint by about 3443.49 grams of CO2, about a 96% reduction in CO2 output.
For both of these food items, transportation over long distances is responsible for the huge amount of CO2 output. For the tofu, the transportation of soybeans from China to Colorado and then of finished tofu product from Colorado to San Juan Island has a massive impact; the transport of the chickens’ feed from British Columbia to the island has a much greater impact than the transport of the 5 lb of chicken itself.
The impact of both food items could be reduced drastically if the ingredients for each of these items were produced locally. If soybeans were locally grown and if there were a tofu factory on the island, the carbon footprint of tofu transportation would be minimal. The impact of raising the chickens would be reduced as well if their feed came from the island because most of the inefficiencies come from transporting about three times as many pounds of feed as chicken is produced. If both food items were produced on-island, the most efficiently produced product might well be the tofu because the plant matter from which it is made is at a lower trophic level than the chickens; unfortunately, this effect is hidden with the obvious costs of transportation from our current practice of buying food from the mainland.
While Beam Reach has chosen to become herbivorous to reduce its environmental impact by eliminating the trophic-level inefficiency of eating animals, the transportation of White Wave tofu seems to have a larger carbon footprint than the transportation of Lacrover chicken. The difference in the carbon footprint of these two food items illustrates the importance of eating locally. For Beam Reach to lessen its impact in a more comprehensive way, we should purchase more locally grown food. Such a practice (if combined with a vegetarian diet to reduce the need for buying animal feed) would greatly reduce the carbon footprint of our buying practices.
OECD Environmental Directorate, Environmental Policy Committee (June 1993), The Social Costs of Transport: Evaluation and Links with Internalisation Policies.
Roseboro, K. White Wave Tofu and other Big Companies Turning Away from Domestic Organic Soybean Farmers in Favor of Cheap Imports from China. The Organic and Non-GMO Report, February 2007.
US Department of Transportation. Bureau of Transportation Statistics. National Transportation Statistics 2002. BTS02-08. Washington, DC, U.S. Government Printing Office, December 2002.
Wang, H.L., and J.F. Cavins. 1989. Yield and Amino Acid Composition of Fractions Obtained During Tofu Production. Cereal Chemistry 66(5):359:361.