Scooters adding to greenhouse emissions

Those scooters you see ridden in downtown Oklahoma City and more and more metro areas might be harming the climate more than other forms of transportation according to one new study.

E and E News reports that electric scooters may emit more greenhouse gas emissions than competing modes of transportation, resulting in a larger environmental impact than advertised, according to a new study.

The study from North Carolina State University published in Environmental Research Letters on Friday is the first to examine the carbon dioxide emissions contributed by the scooters throughout their life cycle — from the point of manufacture until they’re discarded. The researchers also considered other air emissions, such as sulfur dioxide.

The study was spawned by a shared e-scooter program that began on campus last year, said Jeremiah Johnson, the North Carolina State assistant professor of environmental engineering who led the study.

“We noticed early on that the scooter companies were making claims about the environmental performance, using terms like ‘carbon-free,’ and saying these were Earth-friendly rides,” he said.

So Johnson and his team of students bought a Xiaomi scooter, took it apart and matched its components with emissions profiles from a global supply-chain database. They also calculated emissions from the end-of-day collection of the scooters, production of electricity and other sources.

The scooters, the team found, “consistently result in higher life cycle global warming impacts relative to the use of a bus with high ridership, an electric bicycle, or a bicycle” on a per-mile basis.

And riders tended not to use the e-scooters in place of a personal car or other more-polluting options, according to surveys carried out in Raleigh, N.C., and Portland, Ore.

“Claims of environmental benefits” stemming from the use of the scooters, the study said, “should be met with skepticism.”

Nearly half of the e-scooter riders in Raleigh, for example, would have walked or ridden a bicycle — options with zero or close to zero climate impact — compared with 34% who would have driven a personal car or hailed a ride.

“It’s really important that you’re displacing car ridership,” said Johnson. “If you’re displacing walking, e-scooters ultimately look poor from an environmental perspective.”

Half of the pollution associated with e-scooters came from their manufacture. Less than 5% was attributable to charging, meaning it made little difference whether the local grid derived its electricity from coal, solar or any other source, he added.

Whether or not e-scooters were preferable to one alternative — buses — could shift depending on whether ridership of the latter was low, and if the bus was fueled by diesel or electric propulsion, said Johnson.

Additionally, about 43% of the pollution associated with e-scooters descended from their collection at the end of the day, when contractors get in their cars and fan out across a city to gather up abandoned scooters and bring them back to recharging sites.

That opens some paths for solutions, the team concluded.

E-scooter companies could encourage contractors to use more fuel-efficient cars and centralize management to limit the miles traveled during collection, or find ways to extend the typical two-year lifetime of a scooter.

Cities, meanwhile, could let companies leave out the scooters overnight, allowing them to collect only those with drained batteries.

“I realize there’s a downside to leaving them on the street. But if it were an option, it would relieve some of the collection and redistribution burden,” said Johnson.