E-scooter sharing services have sprung up in cities across North America and continental Europe. These services allow anybody to use an app to locate and hire an e-scooter for a single journey, then abandon the vehicle at their destination, typically without having to locate a docking station.
While e-scooters have been presented as an environmentally friendly alternative to private vehicle, ride sharing and even public transport, this study suggests that they are not as green as they may first appear.
“E-scooter companies tout themselves as having little or no carbon footprint, which is a bold statement,” said Professor Jeremiah Johnson, an author of the study and expert in civil, construction and environmental engineering at North Caroline State University. “We wanted to look broadly at the environmental impacts of shared e-scooters and how that compares to other local transportation options.”
Johnson and his colleagues examined the emissions associated with four aspects of each e-scooter’s life cycle: production of materials and components required to build each scooter; manufacturing; shipping to city of use, and maintaining the scooters (regular collection, charging and redistribution). These aspects were compared to similar aspects in the life cycle of cars, buses, electric mopeds and bicycles.
They examined four types of environmental impact as a result of these aspects: climate change; nutrient loading in water; respiratory health complications linked to air pollution, and acidification.
According to Johnson: “A lot of what we found is pretty complicated, but a few things were clear: biking – even with an electric bike – is almost always more environmentally friendly than using a shared e-scooter. The sole possible exception is for people who use pay-to-ride bike-share programs. These companies use cars and trucks to redistribute the bicycles in their service area, which can sometimes make them less environmentally friendly than using an e-scooter.”
Unsurprisingly, the researchers also found that driving a car is almost always less environmentally friendly than using a shared e-scooter. They also found, more unexpectedly, that taking the bus on a route with high ridership tends to also be more environmentally friendly than hiring an e-scooter.
The largest environmental impact of the e-scooters is not the electricity used to charge them (which accounts for approximately five per cent of their overall impact) but from using other vehicles to collect and redistribute them and the emissions associated with manufacturing the scooter. Consequently, e-scooters have a less negative impact on the environment if they remain in service for longer and if less driving is required to collect and redistribute them.
“There are a lot of factors to consider, but e-scooters are environmentally friendly compared to some modes of transport,” said Johnson. “And there are things that companies and local governments can do to further reduce their impacts. For example, allowing – or encouraging – companies to collect scooters only when they hit a battery depletion threshold would reduce a scooter’s impact, because you wouldn’t be collecting scooters that don’t need re-charging.”
They additionally surveyed e-scooter riders to find what type of transportation they would use if they had not used an e-scooter. They found that approximately half (49 per cent) of riders would have walked or cycled instead, while 34 per cent would have used a car, 11 per cent would have taken a bus, and seven per cent would not have made the journey at all. These findings were similar to the results of a larger-scale survey conducted in Portland, Oregon.
In July, more than 50 scooters were removed from the Willamette River in Portland. The scooters are likely to have ended up at the bottom of the river deliberately as a result of vandalism.
The introduction of thousands of shared e-scooters to cities before regulatory framework can be laid out has resulted in backlash from residents and local governments, who complain of scooters being frequently abandoned in anti-social ways (such as blocking pavements), being driven on pavements and being ridden without a protective helmet. In July, television presenter Emily Hartridge became the first person to die in an e-scooter accident in the UK.
At time of writing, riding e-scooters on roads and pavements remains illegal in the UK.