One of the advertisements used by companies that rent electric scooters in some large cities – including Milan – is that these means of transport are less polluting than others. Since they are electric they actually do not emit carbon dioxide (CO2), unlike most cars, buses and mopeds. However, when calculating the impact that something will have in terms of greenhouse gas emissions (the so-called “carbon footprint”), not only direct emissions are considered, but also those necessary for the production of the object in question and its functioning. According to a study by the State University of North Carolina, when you consider these factors, electric scooters are less environmentally friendly than the means of transportation that people would use in their place if they were not there.
The authors of the study, published in July in the scientific journal Environmental Research Letters, estimated the total emissions produced by the use of electric scooters starting from those necessary to produce the individual components of a scooter. For this they first disassembled a Xiaomi M365 scooter, one of the most common, and calculated how many greenhouse gases are released into the atmosphere to produce it using the database on the environmental impact of the production of objects of the Swiss NGO Ecoinvent, the most complete in international level. This is the factor that matters most in the entire estimate of the environmental impact of scooters: it is equal to 50 percent of the total.
They then looked at the emissions required to transport the scooters from China (the country where they are mostly produced) to the United States and those produced in charging the scooters. In fact, each company has its own recharging staff, called “juicer” or “charger”, who collect the unloaded scooters from the streets to charge them at home and, once they have been recharged, put them back on the streets: since they often do it using a automobile must be taken into account. The contribution of these transports is equal to 43 per cent of the total environmental impact of the scooters, while that due to the transport from China to the United States is negligible, which is why it matters little that the account was made thinking of the scooters available in Raleigh. the capital of North Carolina.
Finally, the researchers estimated the emissions due to the production of the electricity that powers them; they are a very small part of the total, 4.7 percent. So assuming that an electric scooter can be used for a period of time between six months and two years – they should remain in circulation and functional for two years, but the cases of theft and vandalism are so frequent that they have prompted researchers to imagine that can also be used for much less time – it has been calculated that on average it has an environmental impact of around 126 grams of greenhouse gases per kilometer per passenger. It is greater than the impact of a single passenger on a bus, if the bus is crowded, and the impact of an electric bicycle but, understandably, much less than the impact of a car.
Simultaneously with the analysis of the emissions produced to ensure that an electric scooter is rentable, the researchers surveyed 61 users of rental services in Raleigh to understand what means of transport they would use if there were no scooters. More than half of the people who took part in the survey said they would cycle or walk, two non-polluting options. Only 34 percent said they would use a car or chauffeur-driven car rental service like Uber, which tends to be more polluting; 11 per cent said they would take a bus, 7 per cent said they wouldn't make that kind of commute.
The conclusion of the North Carolina researchers is that if the percentage of people using electric scooters instead of cars were higher, they could be considered an ecological alternative, but for the moment this is not the case. Lime, a leading electric scooter rental company, responded to the study by saying it's based on some assumptions that aren't always valid and incomplete data that make the results unreliable.
According to the researchers, however, scooter rental services could become more environmentally friendly if theft and vandalism cases decrease and, above all, if a more efficient system is put in place to recharge them. For example, if the chargers could remotely “book” the scooters to load, they would collect them all in the same area and optimize their movements. And if they were incentivized to use low-polluting means of transport to do so, emissions could be reduced even more. The fact remains that with the current Italian traffic rules for scooters, introduced in June by the Ministry of Transport, the limitations to the areas in which they can be used could still make them uncompetitive.
