The tire industry has a durability problem, and electric vehicles could make matters worse, experts say.

Tire production is an emissions and resource intensive process. In 2019, U.S. tire factories reported releasing the equivalent of more than 12.7 million metric tons of heat-trapping carbon dioxide, according to an E&E News analysis of EPA data. That’s a bigger carbon footprint than Honduras, a nation of over 9.7 million people.

But tire problems don’t stop once they leave the factory.

Independent researchers have found that tires are the second most common source of microplastic pollution, behind only synthetic textiles. While some upstart groups are working on new approaches to reduce the emerging contaminant, sustainability efforts in the tire industry have primarily focused on improving tire recycling.

At the same time, consumers and governments are increasingly adopting electric vehicles due to their low emissions. But because electric vehicles are heavier than internal combustion vehicles and accelerate faster, they are harder on tires and produce more microplastics.

“They don’t have a solution yet,” said Emilia Jankowska, senior researcher at the environmental nonprofit Project Drawdown, of the quest for a sustainable tire. “These companies don’t really talk about it, because they just focus on reducing [carbon dioxide] emissions, which is a big deal. But they don’t also show the whole story. “

Jankowska, who is an expert in ocean plastics, was specifically referring to an announcement last week from two French companies.

Tiremaker Michelin and green chemistry start-up Carbios touted their joint efforts to produce and test recycled plastic tire fibers, calling the achievement “a major step towards the development of 100% sustainable tires.” If Michelin were to use these fibers in all the tires it produces, the tire maker could recycle nearly the equivalent of 3 billion plastic bottles per year, they said.

Earlier this year, Japanese tire maker Bridgestone Corp. and two small companies unveiled a new tire design that they say will last longer and reduce carbon emissions.

None of these innovations, however, appear to reduce the release of microplastics from tires, which are defined as pieces of plastic less than 5 millimeters in length. When these tiny pieces of plastic blow on the roads, they can be inhaled by people or wildlife. If they are washed away by rain, they can end up in rivers, lakes or oceans where they are eaten by fish.

Little is known at this point about the potential effects of microplastics on human health. But research published earlier this year in the journal Science linked small concentrations of a chemical from microplastics in tires to the death of some coho salmon in the Pacific Northwest.

Carbios addressed questions about microplastics to Michelin, which did not respond to requests for comment.

The United States Tire Manufacturers Association, a group that advocates on behalf of Michelin, Bridgestone and other tire manufacturers, said its “members are committed to sustainable practices in all aspects of their operations. activities and assume a shared responsibility to help achieve a more sustainable society, “but recognized microplastics are a challenge for the industry.

“There is no one-size-fits-all approach to mitigating” microplastics in tires, the association spokesperson Kim Kleine wrote in an email. “A multifaceted approach is needed.”

She suggested rebuilding American roads with “rubber modified asphalt” and green infrastructure such as bioswales – a much more difficult task than reformulating tires. These changes could reduce tire wear and catch microplastics that rub off before they can drain into waterways.

“It’s convenient for them,” said Ad Ragas, professor of environmental science at Radboud University in the Netherlands, of the proposed industry infrastructure review. “They always said, ‘We don’t see a good alternative for tire development, we see the solution in product mitigation. “”

Ragas was part of a team of researchers who, in 2017, estimated that tires were responsible for at least 5% of plastics in the ocean and 3% of particles in the atmosphere. Their article was published in the International Journal of Environmental and Public Health Research.

Other researchers and entrepreneurs are working on ways to catch microplastics before they hit the road or to revise the business model of manufacturing tires.

The Tire Collective, a business started by four master’s students from Imperial College London and the Royal College of Art, seeks to market an award-winning device that fits the back of a tire and sucks up particles that it releases.

Another London company, Enso, creates tires specifically for heavier electric vehicles, which the company would own and lease to its customers. Sustainable designs “will tread lightly on our planet by keeping rubber on the road and out of our air and our oceans,” says its website.

Ragas suggested that if autonomous vehicles became widely available, they could reduce emissions and microplastics associated with driving.

“Autonomous vehicles, you can make them in such a way that they use their brakes less and they don’t accelerate very fast because that wears out the tire,” he said.

Yet perhaps the best way to make tires more durable is the simplest, according to Jankowska, the ocean expert for Project Drawdown: “You just have to drive fewer miles”.

“I know it is very difficult to change the behavior of people,” Jankowska added. But it would be “the most powerful solution”.