What does 30 pounds of carbon dioxide emissions look like? If you said a pair of sneakers, you would be right.
According to a study released by MIT, the production of one pair of sneakers may produce the same emissions as powering a 100-watt lightbulb for a whole week. Unlike many other “less advanced” products (generally speaking, non-electronics) the manufacturing process in sneaker production is the major polluter, as opposed to material acquisition.
The reason, the research group found, can be traced to the energy use and location of the manufacturing plants. Many running shoes are made in China, where coal is the main electricity source, and is also used to power steam and other plant processes.
The complexity of a running shoe also contributes to the high emissions output. “In general, we found that if you have a product that has a relatively high number of parts and process steps, and that is relatively light [weight], then you want to make sure you don’t overlook manufacturing,” said Randolph Kirchain, principal research scientist in MIT’s Materials Systems Laboratory. According to the press release, there are 360 distinct steps in processing a sneaker, which is comprised of about 65 different parts.
The good news is that there are numerous ways to cut down emissions, now that the issue has been identified. The researchers suggest that scraps can be recycled, and parts of the shoe can be combined to eliminate energy-intensive steps, like cutting and welding. In addition some features can be printed directly onto the shoe, instead of being added as a separate piece of material.
“Understanding environmental footprint is resource intensive, Kirchain says. “The key is, you need to put your analytical effort into the areas that matter.”