Utilizing Highway Borders for Innovative Carbon Capture

August 2, 2014

triangle land conservancy

Picture a typical American highway. Black pavement, brightly painted lines, and close-cropped grass bordering the edge of the road. While this is the classic version of the American highway system, scientists are pointing towards the cleared land on either side of the blacktop as potential carbon trapping goldmines.

“The land alongside the 4 million miles of U.S. public roadways, already being maintained by federal, state, and local governments, could be planted with vegetation that helps transfer carbon from the atmosphere into soil,” writes Marianne Lavelle for The Daily Climate. Along the roads in public lands, like U.S. National Parks and refuges, shrubs, grasses, and other plants already capture 7 million metric tons of carbon on an annual basis.

What does that mean in real terms? That much carbon equals the emissions of 5 million cars! Planting additional shrubbery along non-federal road systems could absorb emissions from another 2.6 million cars. While these numbers are impressive on their own, with more active management this roadside land could be optimized to capture even greater amounts of carbon.

Though planting trees along roadsides would not be feasible due to safety concerns, hardy grasses or woody shrubs would allow higher levels of carbon capture without affecting the safety of the drivers themselves. Even letting the grass grow longer – from 6 to 8 inches – would save both time and money, while continuing to increase carbon capture.

New Mexico has embarked on an ambitious project to do just that. “Testing different plantings and techniques over the past year, the state boosted carbon capture on roadsides to from 35 percent to 350 percent over areas that weren’t actively managed,” Lavelle continues. The state is now exploring expanding their budget by selling carbon credits from management practices along roadsides.

Moving forward into the 21st century, management techniques like utilizing “empty” space along roadsides across the country is a simple yet powerful way to reduce carbon released into the atmosphere. The additional benefits, such as providing wildlife habitat or gaining revenue from carbon credit programs, build an even stronger case for effectively planning project on these properties.

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