For a small carbon footprint, a bicycle might be a better choice than one of the battery-powered scooters littering many cities.

The rentable electric scooters that now pepper many cities have high environmental costs.

Companies that distribute shared e-scooters tout the environmental benefits of getting people out of cars and onto something that is battery powered and emissions free. To determine whether the scooters are in fact a ‘green’ form of transport, Jeremiah Johnson at North Carolina State University in Raleigh and his colleagues disassembled a scooter in the lab and calculated what it took to produce it.

Aluminium in the scooter frame and lithium in the battery must be mined, and all the vehicle’s components manufactured. Those steps accounted for about half of the greenhouse gases an e-scooter is responsible for over its lifetime. Almost as significant were the environmental costs of collecting discarded scooters and transporting them to charging stations — a task usually performed by scooter-company employees driving personal vehicles.

Using an e-scooter is more carbon intensive than walking or biking. The scooters are environmentally friendly only when people use them for trips they would otherwise take in cars.