How does the location of production influence a product's carbon footprint? Transport to the consumption location is certainly one factor, but what is often overlooked is that the production emissions may vary depending on where it is done.
If the finished product (or the components/ingredients used in production) must be air-freighted, then it is a good bet that air transport distances will heavily influence the final carbon footprint -- this is particularly true for air-freighted food products, where transport emissions can far exceed production emissions. On the other hand, rail and ocean transport are quite benign from a carbon perspective, even with refrigeration added. Road transport can be a critical factor if the production emissions are relatively small -- as in the case of many fruits, vegetables and grains. In one analysis we did concerning transporting dry food ingredients (such as dry beans or grains) from China and the US mid-west to the US west coast, the Chinese imports had the lower carbon emissions. For ocean transport from China to the US, the critical transport links are actually the road segments on either end, and not the long ocean segment that first comes to mind.
If older technology is used in overseas production, for example, then the production emissions per unit product can easily be higher overseas. Even if the same state-of-the-art technology is used at the overseas location, the actual emissions will depend on the fuels and electricity sources used. Here are average CO2 emission factors for energy production in selected countries (2005 data from IEA):
- China: 2.95 t CO2/toe (metric tons of CO2 per 42 GJ)
- India: 2.14
- Brazil: 1.57
- Mexico: 2.21
- France: 1.41
- UK: 2.27
- US: 2.49
- Japan: 2.29
This shows a variation of more than 2x between the best (France) and the worst (China). One big reason: France uses nuclear plants for about 80% of its electricity, and China depends on conventional thermal power plants (dominated by coal) for 74% of its electricity. In Brazil, which is second best in the above list, hydro-power supplies 83% of the electricity.
A related note: Textile and apparel production in China is exacting a heavy environmental toll there. Chinese companies reportedly dump untreated waste water into lakes and rivers. Proper wastewater treatment will add to the product's carbon footprint (US average: 742 Kg of CO2-eq/million gallons of wastewater treated). Prices in the US may be artificially low because we are not paying the costs of pollution for imported products. A VP at Liz Claiborne says the environment is the new frontier after labor issues in overseas production.
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