In July the time had come again: environmentalists put on wetsuits to dive in the Rhine, secured to two ropes, on the banks of the old town in Cologne – and to salvage e-scooters.
The divers fished 20 of the electrically powered scooters out of the Rhine, although a parking ban on the bank was actually supposed to prevent this.
Environmentalists had fished more than 100 e-scooters out of the river last year.
Maximilian Sachsen
Editor in Business
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It is reports like this that make many people doubt the benefits of e-scooters for the environment.
At the time of their introduction, e-scooters were a beacon of hope for the mobility revolution.
They should bridge the notorious "last mile" - i.e. the way from the train station to the apartment - and thus also make local public transport more attractive.
New study evaluates data from 4,000 people
A new study by the Fraunhofer Institute for Systems and Innovation Research (Fraunhofer ISI) on behalf of the e-scooter rental company Lime now comes to the conclusion: Shared e-scooters and e-bikes can help to reduce greenhouse gas emissions.
To do this, the Fraunhofer researchers evaluated survey data from more than 4,000 people in six major cities who use Lime e-scooters.
People from Berlin, Düsseldorf, Paris, Stockholm, Seattle and Melbourne took part.
In a questionnaire, they answered, among other things, what means of transport they would have used for a trip if no e-scooters or e-bikes had been available.
The researchers then compared the lifecycle CO2 emissions of the e-scooters to the lifecycle CO2 emissions of the modes of transport that people would otherwise have used, and adjusted the data to reflect the specifics of each city.
Since these are estimates, the calculations may be subject to inaccuracies.
CO2 savings like 1000 tree seedlings
The e-scooters had the greatest effects in Melbourne, mainly because the electricity used for e-cars and public transport is produced there with significantly more CO2 than in Europe.
According to Fraunhofer calculations, the people in Melbourne saved around 42.4 grams of CO2 per kilometer compared to the means of transport otherwise used.
But the researchers also calculated savings of 22.1 grams of CO2 per kilometer in Düsseldorf, in Paris and Stockholm it was 20.7 grams of CO2 per kilometer in each case, and in Berlin it was still 14.8 grams.
Over a period of one month in late spring 2022, the savings in Dusseldorf corresponded to 4 tons of CO2 and in Paris to 66 tons.
In order to absorb so much CO2, 1,000 tree seedlings would have to grow for ten years, the authors of the study write.
However: e-scooter rental companies usually have significantly more customers in spring and summer than in winter.
Therefore, the CO2 savings are likely to fluctuate strongly seasonally.
It depends on the reason for use
The e-scooters have the greatest climate effect when they replace taxi services.
There, the scooters save an average of almost 700 grams of CO2 equivalents per trip in all cities examined.
According to Fraunhofer calculations, a ride on an e-scooter saves more than 300 grams of CO2 as an alternative to private cars.
The study authors write that switching from such “highly emitting means of transport” to shared e-bikes or e-scooters is “quite substantial” in terms of reducing emissions.
However, the use of e-scooters can also lead to an increase in CO2 emissions, for example if this replaces footpaths or a ride with a private e-bike or if the ride would otherwise not have taken place.
Various surveys indicate that such "fun trips" are quite common.
A representative survey by the ADAC in July showed that every seventh driving pleasure is the most important reason for using the e-scooter.
Twelve percent of those surveyed saw e-scooters primarily as an alternative to walking.
Nevertheless, the increase in greenhouse gas emissions from such substitutions is usually lower than the savings from shifting away from car use, the researchers write.
This also has to do with the fact that the providers have made their scooters more and more robust in recent years.
The first generation e-scooters only lasted a few months, new models can stay on the road for three years or much longer with regular maintenance.
As a result, according to Fraunhofer calculations, greenhouse gas pollution has fallen by more than 80 percent from the first generation to the current one.
E-bikes perform worse
Many e-scooter rental companies now also offer e-bikes for hire.
These performed worse in the study than the e-scooters.
While the rental bikes in Düsseldorf still saved 20.4 grams of CO2 per kilometer driven, emissions in Berlin even increased by 13 grams per kilometer.
The authors of the study explain this by saying that shared e-bikes are rarely used as a replacement for motorized vehicles, the theft rates are higher and the intensity of use is lower than with e-scooters.
The emissions of private e-bikes over their life cycle, on the other hand, are significantly lower.
In order to improve the climate impact of e-scooters and e-bikes, the industry should further extend the lifespan of the vehicles, promote decarbonization in production and work towards a shift from taxi services and private cars to more climate-friendly alternatives through partnerships, demands Claus Doll, mobility expert from Fraunhofer ISI and co-author of the study.
In addition, providers and city planners would have to ensure a better link between the rental offers and public transport.