Shared e-scooters reduce carbon emissions, Fraunhofer ISI reveals

Andrew Savage, Vice President for Sustainability at Lime

A new study from leading German research institute Fraunhofer ISI finds that shared e-scooters help to reduce carbon emissions within city transportation networks. Fraunhofer researchers surveyed Lime riders in spring 2022 across six cities globally, including Stockholm, Paris, Melbourne, Berlin, Seattle, and Dusseldorf, asking what mode they would have taken on their most recent trip if an e-scooter or e-bike were not available – often called “MODESHIFT.”

What did MODESHIFT’s data offer Lime?

This mode shift data was then fused with a lifecycle analysis of Lime’s latest Gen4 e-bikes and e-scooters, measuring the service’s carbon footprint from cradle to grave. This research followed the methods used in previous studies in France, Germany, and Switzerland.

As in these studies, the researchers looked at what modes are replaced when a rider chooses to use a Lime e-scooter or e-bike. Based on the lifespan emissions associated with Lime’s vehicles and the modes that are being replaced, Fraunhofer calculated whether that trip reduced carbon emissions (e.g. an e-scooter trip replacing a car trip) or increased carbon emissions (e.g. an e-scooter trip replacing a walking trip).

Fraunhofer then added up those differences across all of the rides taken in a city and for a particular micromobility mode to calculate the net impact of shared e-scooters. In each city studied, researchers found that e-scooters reduce more carbon emissions than they emit.

To date, research on the carbon emissions impact of e-scooters has been mixed, with some earlier studies finding that e-scooters were a net-contributor of carbon emissions. However, previous research used lifecycle emissions data from older generations of e-scooter hardware and operational practices, and therefore failed to capture the current state of the industry.

Over the past three years, shared micromobility companies like Lime have made substantial improvements in new hardware and operational practices, such as longer-lasting vehicles with modular design, swappable batteries and electric operational vehicles.

The most recent lifecycle analysis of Lime’s Gen4 e-scooter, conducted by global sustainability consultancy Anthesis, found the company’s lowest carbon impact yet–producing just 19.7g CO2/passenger km traveled in Paris and 25.5g CO2/passenger km in Dusseldorf. In the five years since Lime began operating shared e-scooters and e-bikes, it has consistently improved its lifecycle emissions, resulting in a 84% drop in CO2/passenger km traveled.

What has Lime done to decarbonize its service?

  • Extending the lifespan of e-scooters by making them modular, more durable, and fully repairable, resulting in less waste and fewer new hardware orders.
  • Introducing swappable batteries, as well as larger batteries to reduce operational impacts and increase vehicle availability for riders.
  • Transitioning operations fleet to electric vehicles, including electric vans and e-cargo bikes.
  • Powering all warehouses and facilities on 100% renewable energy

As a result, today’s Gen4 Lime e-bikes and e-scooters are less carbon intensive than public buses, subways, electric vehicles and many other common means of transport.

“These findings show how far shared micromobility has come in our work to decarbonize transportation,” said Andrew Savage, VP for Sustainability at Lime. “They demonstrate to city policymakers the role shared e-scooters can play as an integral part of a lower-carbon urban future. Our work is just beginning and we will continue to be relentless in decarbonizing our service to help meet the urgent threat of climate change,” Andrew Savage added.

What were the additional findings of the report?

The report found that greatest carbon savings from mode shift occurs when riders choose e-scooters instead of a taxi. Through Lime’s partnership with Uber, riders can book a Lime e-scooter or e-bike through the Uber app, encouraging even greater mode shift. Riders who booked Lime e-scooters via the Uber app were not surveyed by the Fraunhofer researchers, making it likely the carbon savings of Lime’s service is greater than what this report details.

The report’s findings demonstrate the impact of Lime’s carbon reduction efforts and Ride Green commitments, first laid out in 2020. Aligned with the company’s mission to build a future where transportation is shared, affordable and carbon-free, Lime set an industry-first science-based target across the entire business, including its up & downstream emissions.

This target was independently-validated by the Science Based Targets Initiative (SBTi), becoming the only validated target in micromobility across Scope 1, 2 and 3 emissions. Lime’s validated target & path to be net zero by 2030, without the use of carbon offsets, is consistent with the Paris Accord goal of limiting climate warming to 1.5C. Lime’s 2021 carbon inventory demonstrated a 64% reduction of emissions from its baseline year of 2019.