In the context of Earth Day, not many people know the role played by tires to keep our planet safer and greener. Tires, indeed, are a little-known sustainability story just waiting to be told.
An enormous amount of research and development goes into each new tire, mainly focusing on passenger safety, better performance, and fuel efficiency of the vehicle. Passenger tires are getting lighter, stronger, quieter, more reactive to road conditions, less susceptible to wearing down, and less toxic.
Natural rubber from rubber trees gives tires a large amount of biogenic content, and synthetic rubber and carbon black are themselves constantly improving from a performance and environmental point of view. Other materials being used or piloted in tires include rice husk ash, the guayule shrub, Russian dandelion, and soybean oil. As tire manufacturers continue to find breakthroughs in their materials research, the industry has come together globally to run scientific testing on the effects of tire roadwear particles on the quality of air and water in the vicinity of roads. There is a continuous feedback loop between transparency around environmental impacts of tires and new research to make them more environmentally friendly.
Since a major environmental impact comes from the vehicle itself, a lot of the research is around finding the right mix between fuel efficiency of the tire (low rolling resistance) and performance. Tires with low rolling resistance and proper inflation can make a strong contribution to the fuel economy of the vehicle (and the wallet of the driver who can spend less on gas).
Tire manufacturers also focus on environmental impacts throughout the lifecycle of a tire, and down the supply chain. With rising global demand for tires, and therefore rubber, there is concern that the need for new rubber tree plantations is contributing to deforestation. Tire manufacturers and other stakeholders have come together to launch a global platform for sustainable natural rubber to address the many challenges of a complex and fragmented supply chain, including human rights and land rights of smallholders, in addition to the environmental issues around forest and biodiversity management.
Tire manufacturing processes are improving, with a focus on clean energy, emissions reductions, and saving and reusing water. As an example, Pirelli reached its global 2020 target on water savings two years in advance, and more than 40% of the company’s global electricity consumption comes from renewable energy.
The greatest environmental impact in the lifecycle of a tire occurs when it is in use on a vehicle. That’s why there is so much attention to reducing rolling resistance of tires, which improves the fuel economy of the whole vehicle, helping to lower CO2 emissions into the atmosphere. Consumers should do their part too: properly inflated tires are an important guarantee of better fuel economy.
Ultimately, tires wear out and need to be scrapped. What happens to them then? First of all, there is a lot of research around ways to extract materials out of scrap tires that could be used again to make new tires. This is a big challenge, because tires are vulcanized (baked in an oven, like a cake), and their ingredients are transformed in the process. Just as it is difficult to extract raw eggs from a baked cake, it is tough to extract raw materials from a tire. But stay tuned; progress is being made. In the meantime, new markets have been created where scrap tires have become a raw material themselves. One is rubber-modified asphalt. The properties of a tire add value to asphalt, helping it react better to water and temperature. Another market for scrap tires is tire-derived fuel, a product made from scrap tires and used mainly in high-energy cement kilns and pulp and paper mills. And there are many others. More than 80% of scrap tires in the United States find their way into end use markets such as these.
These results are a long way from the tire piles that used to exist in the 1980s – but there is still much work to be done. Sustainability should always be considered a journey.
Today, companies are aligning around common sustainability practices, like setting goals, reporting transparently, and working together to tackle the biggest problems, such as deforestation. Everyone can do their part, and Earth Day is a reminder that we must. We must learn to live balanced lives, in harmony with nature. We owe that to future generations.