If you live in a big city, chances are you’ve seen scores of electric scooters take over the sidewalks. Rideshare companies promote them as a greener alternative to cars that residents can use to get around—a claim that is rather easy to assume as true. After all, these e-scooters don’t spew any emissions. But are these e-scooters as “earth-friendly” as they claim to be? Unfortunately, the answer is no.

Researchers at North Carolina State University set out to determine how much harm to the climate results from each portion of a scooter’s “life cycle”. They found that most of the harm comes from manufacturing the device, which is typically done in China. One scooter alone contains 13 pounds of aluminum, a 2.5-pound lithium-ion battery, an electric motor, and various plastic and steel parts. Once the scooters are manufactured, they also need to be transported to cities, which is typically done by — you guessed it — cars.

Then there’s the question of how these e-scooters get charged. Each night, after the scooters have been parked on the curb, the companies behind them pay contractors (known as “Juicers” or “Chargers”) to drive around the city and gather them, transport them to be charged, and then reposition them in places where they’ll likely be picked up in the morning.

When the researchers tallied up all the greenhouse gas emissions that go into making and moving the scooters around, they found that scooters typically produce more emissions than a standard bus with high ridership, an electric moped, an electric bicycle, a regular bicycle, or a good old carbon-free walk.

The researchers also note some important survey results from Raleigh, North Carolina. If there were no scooter option available, almost half of scooter riders say they would have biked or walked instead—which tells us that e-scooter rides are actually replacing forms of transportation that are far more eco-friendly.