A typical pair of running shoes is comprised of 360 parts, and a new study led by MIT researchers demonstrates how energy-intensive the assembly process is.
The majority of the roughly 25 billion pairs of running shoes sold globally each year are manufactured in China, which relies heavily on coal electricity.
Sewing, cutting, molding and heating the shoes requires excessive use of carbon-intensive energy. All in, a single pair of shoes generates about 30 pounds of carbon dioxide emissions which is equivalent, according to researchers, to keeping a 100-watt light bulb on for one week straight.
It's hoped that the findings will prompt shoe manufacturers to reduce the carbon footprint of their products.
The findings have been published in the Journal of Cleaner Production.