Everyone loves a good TEDTalk. Here’s one of ours:
Shoe manufacturing accounts for one-fifth of the fashion industry’s carbon emissions according to Angel Chang, a womenswear designer in rural China. In her TED Talk, she says that sneakers alone generate 313 million metric tons of carbon dioxide every year, which is equivalent to the annual emissions of 66 million cars. Sneaker consumption is at an all-time high with Americans purchasing 3 pairs a year on average. To meet growing demand, roughly 23 billion shoes are produced every year, mostly in factories across China and Southeast Asia.
Why are sneakers so bad for the environment?
According to Chang, the heel, insole, midsole, and upper layer are usually made from synthetic textiles like polyester, nylon, latex, and polyurethane. Mining the fossil fuels that make up these materials emits tons of greenhouse gases. And processing those raw ingredients into synthetic textiles also uses a lot of energy, further compounding that pollution. Some sneaker tops are made from natural sources like leather, but tanning this material relies on chromium; a carcinogenic chemical that can damage freshwater ecosystems.
The outer soles of most shoes are made of rubber that’s gone through a process called vulcanization. This technique adds sulfur to superheated raw rubber to create a material that’s both elastic and sturdy.
Producing these materials accounts for 20% of a sneaker’s carbon footprint. But more than two-thirds of the shoe’s carbon impact comes from the next step: manufacturing. A typical sneaker consists of 65 discrete parts, each of which is produced by specialized machinery. This means it’s cheaper for factories to mass-produce each piece separately rather than manufacturing every part under one roof. But the transportation required to ship these pieces to one assembly plant emits even more CO2.
Once the components arrive at the assembly line, they undergo cutting, pouring, melting, baking, cooling, and gluing, before the final products can be stitched together. The assembly of a typical sneaker requires more than 360 steps, and accounts for the remaining 20% of a sneaker’s environmental impact.
Since the shoes are made of so many different materials, they’re almost impossible to break down into recyclable components. 20% of these shoes are incinerated, while the rest are tossed into landfills where they can take up to 1,000 years to degrade.
Chang asks, how can we balance our love of sneakers with the need for sustainability? She advises that designers should streamline design elements and focus on eco-friendly materials. Factories need to develop energy efficient manufacturing processes that consolidate steps and sneaker parts. And consumers should support companies using clean energy and ethical manufacturing processes. We can also buy fewer shoes, wear them for longer, and donate those we no longer need. So no matter what your style, we can all take steps towards a sustainable future.