Running has a bigger environmental impact as one might imagine. As a study has found, a new pair of running shoes typically generates 30lbs of carbon dioxide emissions, 68% of which generated during the manufacturing process. The production of the materials involved, including leather, nylon, synthetic rubber, plastic and viscose, also takes an environmental toll. Sneakers have a high carbon footprint as, unlike other types of shoes, they normally have many different parts. This involves steps like injection moulding, foaming, heating, cutting and sewing.
What are the environmental costs of the different fabrics used in producing sneakers?
Leather: leather tanning is environmentally costly, since it needs large amounts of water for treatment, and generates significant amounts of solid and liquid waste, which impacts soil and water health. It also involves using toxic chemicals and have metals, like hexavalent chromium, that have been linked to cancer in leather workers. Finally, most leather is cowhide, and the beef industry is the largest driver of deforestation globally and is responsible for 65% of greenhouse gas emissions from livestock. Alternative: The best thing to do is buy leather-free sneakers and choose leather alternatives, like Piñatex, made from pineapple leaves. Otherwise, opt for chrome-free leather or vegetable tanned leather.
Synthetic leather: used in the liner of most sneakers is more eco-friendly than leather, but it is normally made from plastics like polyutherane and PVC that contain harmful chemical ingredients and are not biodegradable. Alternative: Vegetable tanned leather, Piñatex, recycled PET or textiles such as hemp, jute, wool or organic cotton.
Synthetic rubber: mostly used in the soles. It is made from petroleum byproducts and are treated with chemical compounds. Manufacturing synthetic rubber uses energy and water and creates waste. Chemicals can also leach from the shoe as the sole wears down. Alternative: Look for natural or wild rubber, which can be cultivated to aid against deforestation.
Cotton: cotton accounts for 24 percent of global insecticide use and 11 percent of pesticides, even though less than 3 percent of farmland is planted with cotton. Alternative: choose organic cotton, which uses none of these synthetic chemicals and requires about half as much energy to produce as the conventional version (but requires more land).
More and more brands realize there is a future, or it is the only future, in producing environmentally friendly sneakers. Adidas teamed up with Parley for the Oceans and created sneakers made from plastic currently polluting the world's oceans. Around eight million metric tons of our plastic waste enters the oceans from land every year and by taking it out of our oceans is not only good for the oceans, but also provides a revenue boost to Adidas. According to adidas CEO Kasper Rorsted, Adidas sold 1 million pairs of these specific types of sneakers in 2017, translating to 11 millions plastic bottles from the ocean recycled into a highly profitable product. By 2020, Adidas wants all of their shoes to be made using recycled plastic, and their first change to sustainability has been a success.
Another example are the sneakers made out of kelp by the company Algiknit. This startup developed a new material, called bioyarn. The material is robust enough to be used in footwear, doesn’t dissolve in water, and can even by dyed. Algiknit´s view on the current sneaker industry: "it’s a bad idea to produce trainers that people might wear out in two years, but won’t biodegrade for decades or even centuries." They call this concept “just-in-time degradability.” The advantages of kelp are numerous: it’s sustainable and supports a circular economy and it acts like an air purifier for the ocean, filtering out waste and toxins, making it a great candidate for farming without adversely impacting the sea. It creates ecosystems for marine life to flourish and has the potential to provide additional income for workers in the fishing industry once demand grows. These seaweed sneakers are not yet on the market.
Also interesting to mention is the sneaker created by energy company NRG together with the product management firm 10xBeta. The “shoe without a footprint” looks more or less like any ordinary white sneaker. But around 75 percent of the shoe’s material is made from gaseous waste captured from power plants and turned into a polymer. But they aren’t for sale, there are only five pairs, and they were created to promote the Carbon XPrize, a four-year competition NRG is sponsoring to develop the most innovative products using carbon emissions.
In the meantime, what can you do to reduce your carbon footprint when it comes to sneakers?
1. Buy less, avoid fast fashion
2. Choose sneakers made of the alternative fabrics mentioned above