motor vehicles

Repurposing used tires

April 29, 2025 By EarthWise Leave a Comment

Every year, millions of tires from cars and trucks end up in landfills. Just in the U.S., more than 270 million tires were scrapped in 2021 and more than 50 million of them ended up in landfills. Discarded tires take up huge amounts of space but, more importantly, create environmental hazards. They leach chemicals into the environment and are a serious fire hazard.

Some tires are chemically recycled via pyrolysis, which is a high-temperature process to decompose the materials in the tire. But that process introduces harmful byproducts like benzene and dioxins.

Researchers at the University of North Carolina Chapel Hill have introduced a new chemical method for breaking down rubber waste. The process transforms discarded rubber into valuable precursors for epoxy resins.

Rubber – either natural rubber or the synthetic kind used in tires – is made of polymers cross-linked together to form a tough, flexible, and durable material. These very desirable properties make it difficult to break down rubber.

The new research has led to a two-step chemical process that breaks down the rubber into functional materials that be used to produce epoxy resins. The method does not require extremely high temperatures, uses aqueous media, and takes only six hours. It represents an efficient, scalable solution for repurposing rubber waste which, even as many other aspects of motor vehicle are changing for the better, remains a continuing environmental problem associated with driving.

This new research marks a significant step towards greener recycling technologies.

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A Cleaner Future for Tires: Scientists Pioneer Chemical Process to Repurpose Rubber Waste

Photo, posted May 5, 2011, courtesy of TireZoo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildlife crossings

October 23, 2024 By EarthWise Leave a Comment

Every year, there are one to two million collisions between motor vehicles and large animals in the U.S. About 200 people are killed annually. Counting smaller vertebrates, around a million animals are killed by vehicles each day. Research has shown that global warming is triggering widespread species redistribution. As a result, more and more animals are on the move, changing their habitats to escape warming temperatures and climate extremes.

This situation has created renewed interest in creating wildlife crossings. These are various kinds of structures that allow animals to traverse human-made barriers like highways. They include such things as a grassy overpass that allows pronghorn to run across a highway in Wyoming and a long underpass that allows tigers to scamper beneath a highway in India.

In the U.S., there are more than 1,000 wildlife crossings and there are more being built all the time. Data shows that they are highly effective. A study of wildlife crossings on Highway 9 through the Blue River Valley in Colorado found that they reduced wildlife-vehicle collisions by nearly 90%.

Wildlife crossing structures can be expensive to build, costing between $500,000 and $6 million, but research has shown that the money saved by avoiding crashes can recoup these costs in just a few years along with the fact that they potentially save lives. Federal funding is largely distributed based on areas with the highest number of wildlife-vehicle collisions, which is crucial for addressing public safety issues. However, a recent study suggests that future proposals need to incorporate climate-driven changes in animal behavior and habitat.

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As Climate Changes Fuels Animal Movement, Will These Structures Still Help Species Cross the Road?

Photo, posted April 5, 2017, courtesy of Jeffrey Beall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Benefits Of A Zero-Emissions Boston | Earth Wise

May 25, 2020 By EarthWise Leave a Comment

Many countries, states, and cities around the world have set goals to become carbon neutral, typically by the year 2050. These goals are based on the desire to mitigate the effects of climate change that are steadily increasing as a result of the buildup of carbon dioxide in the atmosphere. But reducing emissions is not just a way to combat climate change, it can also be a major contributor to improved public health.

The City of Boston has set a goal to become carbon neutral by 2050. A new study by the School of Public Health at Boston University published in the journal Environmental Research Letters looked at the consequences of eliminating fossil fuel emissions in the greater Boston area.

According to their modeling, eliminating emissions would save 288 lives a year by reducing fatal and non-fatal cardiovascular and respiratory illnesses. The resulting decrease in medical costs and lost and reduced work could save $1.7 billion a year in Suffolk County and $2.4 billion a year for the entire 75-square-mile zone modeled in the study.

The study looked at the amounts of two air pollutants known to harm human health: PM2.5 (particulates with a diameter of less than 2.5 microns) and ozone. They compared the current levels of these pollutants to what would be present when contributions from motor vehicles, generators, rail, industry, oil- and gas-burning, shipping and boating, and residential wood fires were eliminated.

The study focused on the City of Boston’s climate action plan, but actions taken by Boston will not take place in a vacuum. Many cities across the region are taking similar actions. The overall results will come from the collective actions across New England.

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A Zero-Emissions Boston Could Save 288 Lives and $2.4 Billion Annually

Photo, posted August 31, 2019, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Polluted Air In the Womb

June 22, 2018 By EarthWise Leave a Comment

Air pollution is a major problem all around the world. In fact, exposure to polluted air is blamed for the premature deaths of an estimated 6.5 million people annually.

Reduced Emissions From Electricity Generation

February 28, 2017 By EarthWise

A recent report from the Energy Information Administration notes that for the first time in 40 years, carbon dioxide emissions from electricity generation are less than those from transportation. The reason is that power plants nationwide are abandoning the use of coal and turning to cleaner burning natural gas, as well as newer sources such as solar and wind power.