Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

A Sneaker’s Carbon Footprint

Manufacturing—not materials—is biggest source of emissions.

A typical pair of running shoes accounts for 30 pounds of carbon dioxide emissions, equivalent to keeping a 100-watt light bulb on for a week, according to a new MIT-led life-cycle assessment. 

feet in sneakers walking

You might assume that the best way to shrink the carbon footprint of any consumer product would be to make it out of more sustainable materials. But more than two-thirds of the carbon dioxide emissions can come from manufacturing processes, with less than a third from acquiring or extracting raw materials.

September/October MIT News cover
This story is part of the September/October 2013 Issue of the MIT News Magazine
See the rest of the issue
Subscribe

A team led by Randolph Kirchain and Elsa Olivetti of the Materials Systems Laboratory examined the steps involved in making running shoes. They found that a typical pair comprises 65 discrete parts requiring more than 360 processing steps, from sewing and cutting to injection molding, foaming, and heating. For these small, light components, such processes are energy-intensive—and, therefore, carbon-intensive—compared with the production of shoe materials, such as polyester and polyurethane. The team also determined that much of a sneaker’s carbon impact comes from powering manufacturing plants: a significant portion of the world’s shoe manufacturers are located in China, where coal is the dominant source of electricity.

The group’s results, Kirchain says, will help shoe designers identify ways to improve designs and reduce shoes’ carbon footprint. They may also help industries assess the carbon impact of other consumer products more efficiently. 

“Material substitution strategies alone may not be sufficient in reducing the environmental impact of products,” says Vikas Khanna, an assistant professor of civil and environmental engineering at the University of Pittsburgh, who did not participate in the research. “For example, switching to renewable material sources alone may not be sufficient for products that involve high manufacturing energy requirements.”

Technology is changing. Are you keeping up?
Discover the latest in emerging tech at EmTech MIT.

Learn more and register
Next in MIT News
Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.