Scooting Around: Are Shared E-Scooters Good Or Bad For The Environment?

The shared e-scooters floating around Paris may have emitted 12 000 tonnes of additional greenhouse gases over the course of one year, according to a new study. Are the popular micro-vehicles good fun, but not good for the climate?

by Anne de Bortoli

The sudden arrival of massive numbers of shared electric scooters in many cities around the world since 2017 has triggered considerable resentment from other users of our urban space. The skepticism is shared by governments and local authorities – some of whom have banned e-scooters outright, as is the case in London and many university campuses in the United States.

Others have targeted e-scooters with specific regulations. France added a new section to the Code de la route that covers motorised micro-vehicles. The city of Paris will allow only three selected companies to operate in the city, which will be partly chosen on environmental criteria.

But assessing the hoped-for environmental benefits of e-scooters turned out to be a headache for public authorities. The first scientific assessment was not published until the summer of 2019 and was too narrow to draw general conclusions about their environmental effect: it only estimated the environmental impact of using a free-floating e-scooter over an average of one kilometre in US cities.

Change to the system

Yet e-scooters are disrupting the long-established patterns of urban mobility and should not be looked at in isolation. They are not just something additional, they are bringing real change to the system: by replacing trips with cars, bicycles or on foot, but also by inducing people to take an e-scooter when previously they would not have bothered to move.

The environmental question, therefore, should be addressed in these terms: have shared e-scooters reduced the overall environmental impact of human mobility so far? If the answer is yes, how can we exploit these benefits even further? If it is no, should there be any room for e-scooters in a sustainable mobility system?

What’s in a lifetime?

At the University of Patras, we took up the challenge. Using a cutting-edge method developed in-house, we were able to calculate how CO2 and other greenhouse gas emissions for the entire mobility system of Paris over a whole year were affected by the usage of shared e-scooters

The model reflects how people switch from other transport options to shared e-scooters as well as the new trips these trigger, information that was gleaned from a dedicated survey. It also uses a so-called life cycle assessment, which takes account not only of direct emissions during operation but the entirety of emissions over the life cycle of the elements that make up the transport system, including infrastructure and vehicles.

This is crucial. The operation of shared vehicles is comparatively energy efficient, and much of the environmental impact stems from manufacturing, maintenance, and disposal. The model also anticipates changes that are likely to occur in relevant industries – for instance a change in the carbon intensity of the electricity consumed – to calculate environmental performance.

In the (carbon) balance

The result of the modelling exercise was perhaps unexpected: Parisian e-scooters (shared ones, that is) generated 12 000 tonnes of additional greenhouse gases in the city over one year ─ that is equivalent to the annual emissions produced by a French town of 15 000 inhabitants.

Three reasons lie behind this negative carbon balance.

First, the production of e-scooters is not very environmentally-friendly. Production accounts for a full third of the Parisian e-scooters’ marginal environmental impact, that is to say of the absolute values of the GHG savings and extra-emissions due to shared e-scooters. This is notably due to the carbon-intensive production of the aluminum used for the vehicle frame and because of the lithium-ion battery.

Second, servicing the e-scooters causes considerable emissions. Standard vans with internal combustion engines are used to collect the e-scooters, charge them and then drop them again across the city. This support also makes up one third of the Parisian e-scooters’ marginal emissions due to shared e-scooters.

Finally, e-scooter trips often replace low-carbon trips. This is due to 60% of modal shifts coming from massive electrified public transport – the Metro, the RER light trains, the trams, 13% from walking, and 9% from cycling. These transport modes present a lower carbon footprint than the shared e-scooter: respectively 8, 9, 20, 2 and 36 gCO2eq per passenger-kilometre traveled, compared to 108 g for the e-scooter.

Strike ‘em?

So should e-scooters be struck from the list of solutions for green mobility? In fact, things are not quite that simple. Their environmental impact depends on three factors: firstly, their entire life cycle emissions (and how operators manage these), the specific mobility patterns of the cities in which they operate (and the shares of transport modes e-scooters replace); and, finally, the carbon intensity of the electricity they consume.

The carbon footprint for a shared e-scooter roaming Paris is 50 grams of CO2eq per kilometre, if servicing impacts are excluded – which is about as much as that of a shared bicycle. And if the e-scooter’s lifetime mileage increases to 5 200 kilometres instead of 3 750 (our base case scenario in the model), the emissions fall to 30 gCO2eq per kilometre traveled: in Paris, this is one quarter of a diesel bus, one seventh of a private car, and one tenth of a taxi’s emissions per passenger-kilometre traveled.

Operators thus have their work cut out: they need to simultaneously green manufacture of e-scooters, improve their durability and recyclability, and drastically enhance their servicing process. In the case of Paris, the last point is necessary to get a positive impact of the shared e-scooters.

Each city has a unique mobility system with specific environmental impacts and different user behaviors, and these factors shape the impact e-scooters have on the overall system. The results of our analysis thus cannot be simply transferred to other cities, and even less to other countries. But  an extra analysis we did on the impact of the electricity carbon intensity does suggest that, beyond the case of Paris or similar cities, shared e-scooters have a good potential to make urban mobility greener, once the three main factors that make their current carbon balance negative – at least in Paris – have been addressed. Whether that promise materialises in different contexts will need to be examined in well-tailored, case-by-case studies.

Watch the life cycle

What are our conclusions and recommendations? First, the environmental performance of transport options must be assessed for the complete life cycle to ensure shared vehicles are really green(er). Conventional wisdom assumes that using more shared vehicles reduces the environmental footprint, but our somewhat counter-intuitive results show that servicing and shorter lifespans can in fact lead to higher overall emissions.

Secondly, proper assessments of transport modes needs (good) data. Operators should therefore be required, as a licensing condition, to share their data with the public authorities ─ vehicle components and energy consumption, as well as statistics on servicing, lifetime mileage, maintenance schemes and recycling. For our study, we contacted the thirteen e-scooter operators in Paris in the summer of 2019 ─ only one answered, and finally did not share any data.

Finally, e-scooters and other micro-vehicles have a role to play in a green mobility system ─ even  where their eco-balance is less good than other modes. E-scooters can help overcome the first/last mile problem that keeps many people from using public transport because the closest metro station is too far to walk to.

The availability of shared e-scooters can also trigger a ripple effect: the experience could nudge people to buy their own personal e-scooter, which will likely be used much longer and thus with a much lower life cycle emissions ─ we estimate them as low as 12 gCO2eq/km for a life-cycle use of 15 000 km.

Let’s not forget that mobility systems are dynamic. Thus, environmental assessments need to be updated regularly, especially when new services enter the mix and change somewhat established patterns. And it is a safe bet that the current pandemic is changing mobility habits drastically, possibly for good.

Anne de Bortoli is the ITF Young Researcher of the Year 2020. This blog summarises the findings of her winning paper, which she wrote while at the University of Patras, Greece, and currently under peer review for an international journal. Anne is now an eco-design researcher with Eurovia, the road construction subsidiary of the VINCI Group.

“Gender is One of the Most Robust Determinants of Transport Choice”

What has gender got to do with transport? A lot, but few people know it. That needs to change, was the message from a consultation on gender and transport organised by the ITF with 34 transport stakeholders.

Mary Crass at ITF Summit 2019

Mary Crass, the ITF’s Head of Institutional Relations and Summit sat down with Emma Latham Jones to discuss female representation in the transport industry, women’s personal safety and how gender influences travel behaviour.

ELJ: Is it still necessary to focus on women in transport in 2020?

MC: Without a doubt! Women represent the largest share of public transport users around the world. In France, for instance, two-thirds of passengers on public transport networks are women. A study that we’ve recently done here at the ITF reveals that gender is often a more robust determinant of modal choice than age or income. So it’s really significant, especially since transport services and policies are still not gender neutral.

ELJ: If gender is so important to journey decisions, why is it so often overlooked?

MC: Data collection and analysis very often do not include gender to reflect differences in travel behavior. This means that transport policy is potentially not accounting for 50% of travelers’ needs. It’s a huge missed opportunity for transport authorities, planners and operators to ignore the specific trip patterns and access needs of women— a market that represents over half of public transport clients. Clearly, gender needs to be better taken into transport policy consideration.

ELJ: Are travel policies not gender neutral because women are not well represented in the transport sector?

MC: I think this certainly plays a part. The transport labour force remains heavily male-dominated. Only 22% of transport employees in the European Union are female. In the Asia-Pacific region, women are typically found in fewer than 20% of transport jobs. There are relatively few women working as operators, drivers, engineers, and similar positions. A survey of ITF member countries also found that only 13 out of 60 member countries currently have female transport ministers. As a result, women’s voices in decision-making are under-represented across all levels, which leads to a lack of incentive for transport services to respond to the particular needs of women as users. It also contributes to the fact that gender considerations are largely ignored in transport data collection and analysis, and therefore in policy decisions. We need to change this to ensure that the voice of women is heard in public transport decisions.

ELJ: Does this mean female representation in the transport industry is a priority of the ITF?

MC: Absolutely – the lTF is working alongside its members and stakeholder organisations to better understand the questions related to gender in transport, both on a travel-behaviour level and in terms of representation in the sector. Our consultation on women in transport just now in January brought together 34 stakeholders to explore these questions. We hold this consultation annually, and our understanding of the importance of a gender-diverse transport sector is advancing year to year. We greatly appreciate the insights of our partners and we feed the findings to our summit in Leipzig in May. There we’ll examine how innovation in the sector is impacting women, in terms of their travel and mobility choices.

ELJ: How else does the ITF support women in transport?

MC: We’re looking at gender in transport within the context of inclusive transport and we examine the question from three different angles: travel behavior, safety and security, and representation in the sector. We look at how the gender balance in the industry can be more effectively pursued by understanding the distinctions between how men and women navigate the transport system as users – and how they evolve as workers and professionals serving transport operations and activities.

ELJ: I am a young woman, and sometimes on public transport I find myself concerned about my personal safety. How do issues like these influence women’s decisions and their lives more broadly?

MC: Women are more likely than men to be dependent on public transport. Yet they face personal security challenges that hinder and often deter them from using transit systems. As a result, women’s access to jobs, services and amenities is severely compromised. A Reuters survey of 16 major cities worldwide found that women in Latin American cities faced the highest rates of harassment, with about 60% of women reporting physical harassment on public transit systems. Even under conditions where infrastructure is considered to be safe, women’s perception of that security can influence their willingness to use collective means of transport. Simple, low-hanging fruit can go a long way to improve perceptions of security – including better lighting, clear signage and presence of security personnel. Our work has shown that if women do not feel safe and secure using transport, they will switch to taxis or private vehicles faster than men. So ignoring gender impacts of transport infrastructure and operations is a disservice to the sustainability agenda as well.

ELJ: February 11 is International Day of Women and Girls in Science. How can we increase the number of women in transport related science, technology and engineering roles?

MC: If we look at this question from the perspective of education and training, then I’d say employment in the transport sector needs to have greater visibility in higher education. Too often, opportunities in the transport sector for women are not properly understood.

ELJ: What about the more practical aspect of being a woman in a male-dominated sector?

MC: For operational jobs in the sector – driving vehicles for instance – the conditions of employment need to ensure that the needs of both genders are met. Too often required clothing, equipment and even facilities are not appropriate for women in the sector. This can be rectified by ensuring that upstream purchasing and planning of the worker environment take into consideration the presence of women in these jobs.

Thank you so much for your time, Mary.

Mary Crass is Head of Institutional Relations and Summit for the International Transport Forum. She is responsible for the ITF’s relations with member countries, international organisations and associations, and the Annual Summit of the International Transport Forum. The next Summit will be held from 27-29 May 2020 on the topic of “Transport Innovation for Sustainable Development” in Leipzig, Germany.

Why Flight Shaming Will Not Take Off

Exploding demand for air travel, low ticket prices and the simple ease of flying make it hard for the flight shaming movement to develop truly global momentum

By Emma Latham-Jones

Since 2017, there has been a surge in the number of northern European campaigners boycotting air travel for leisure. But this so-called flygskam (“flight shaming”) movement is up against the lure of low prices for air tickets, the sheer convenience of flying and a rapidly growing number of air travelers particularly in the newly prosperous Asian countries.

Flygskam has arisen from a broader concern that man-made climate change poses a serious threat to people’s livelihoods around the globe. Rising temperatures cause droughts, rising sea levels threaten low-lying regions, and ever more extreme weather leads to severe disruptions.

International aviation is responsible for only 2% of all man-made CO2 emissions. But this does not take into account the warming impact of aircrafts’ non-CO2 emissions. Planes also emit other substances such as contrails, aerosols, nitrogen oxides and particle emissions that are a major contributor to the warming impact of aircraft. Scientists have shown that non-CO2 emissions occurring at high altitudes have a much stronger climate impact than those produced by other modes of transport.

A record number or air travellers

Since 2010, international flights (measured in passenger-kilometres) have increased by 61%.  In 2018, a record 4.3 billion airline passengers were counted, up 6.1% from the year before. Between now and 2050, demand for air travel could again triple, according to the most recent projections by the International Transport Forum.

Global demand for air travel is set to quadruple over the next 30 years

If airlines were treated as a country, they would already now be among the ten biggest greenhouse gas emitters ahead of Brazil, Mexico and the UK, the Union of Concerned Scientists notes. “Even trying to stabilise aviation CO2 emissions at today’s level is challenging”, explains Andreas W. Schäfer, Professor of Energy and Transport at University College London and Director of the Air Transportation Systems Laboratory. “This is due to the strong growth of the sector, its capital intensity, the comparatively limited number of mitigation options and longtime constants—half of the aircraft introduced today will still be operating at mid-century.”

Of all transport-related CO2 emissions, aviation contributes over 10%. And transport’s carbon footprint has grown faster than that of any other sector over the past 50 years. The main reason is the rapidly growing demand for mobility – not least for air travel. In 2017, an average person flew once every 22 months – twice as frequently as in the year 2000.

Flygskam gains momentum

Flygskam was originally championed by Swedish singer Staffan Lindberg and Olympic athlete Bjorn Ferry and gained momentum thanks to social media and the so-called “Greta Thunberg effect”: The Swedish teenage climate activist made her – widely publicised – trip to the 2019 World Economic Forum in Davos entirely by train.

Rather than flying, climate activist Greta Thunberg took a train to Davos and a boat to New York

This gave birth to tagskryt (“train-bragging”), soon popularised by a Facebook group in which Swedes share stories of, and tips from, their journeys via train. The group now has 14.6K followers. Greta Thunberg has since moved to on to another emissions-free transport mode, sailing across the Atlantic to New York for the United Nations’ Climate Action Summit on a sleek hydrofoil yacht, the Malizia II.

Could Flygskam kick-start change in behavior on a scale big enough to counteract the predicted boom in global air travel?  Three main reasons make this seem doubtful.

Lack of alternatives

First, the lack of more sustainable alternatives for many flight routes. Europe and East Asia have well-developed high speed rail network. All bar two of the 20 countries with the best high-speed rail links are in Europe and East Asia. Among the extensive high-speed rail networks in Europe there are now many international links across orders. In these regions, travellers can fairly easily switch from air to rail, certainly for shorter flights. Indeed, Japan’s high-speed Shinkansen train has a greater market share than air transport on domestic routes under 600 kilometres.

Europe has a densely-woven network of high-speed rail lines

The picture in other parts of the world looks much less positive. In North America, the United States have no train line that is entirely high speed. The Acela Express that links New York and Washington, D.C., has an average speed of 106 km/h, less than half the speed of most high-speed trains. California is building a high-speed rail system, but its first phase won’t be completed until 2029.

The fastest train from San Francisco to Los Angeles takes 9 hours and 18 minutes. Any of more than one dozen airlines gets you there in 90 minutes. And “even where there is good alternative infrastructure, high-speed rail often simply cannot compete with the low prices and convenience of short-haul flights,” explains Jagoda Egeland, Aviation Policy Lead at the International Transport Forum.

No Chinese word for flygskam

A second reason why flight shaming may not take off is the soaring demand for air travel in Asia. There simply is no sign that newly prosperous Chinese, Indonesians or Uzbeks intend to forgo the pleasures of flying to Paris or Phuket.

The Asia-Pacific recorded the biggest numbers of overall aviation passengers in 2017, with 1.5 billion passengers and a 36.3% market share. The region also saw the highest year-over-year increase in traffic and had the five busiest international airline routes.  The Asia-Pacific region “will account for up to half of total annual increase in air traffic by 2020,” predicted Shukor Yusof, an aviation expert at Endau Analytics, in a conversation with Deutsche Welle.

China is the engine of much of this demand growth. The 400 million members of its relatively new middle class have an increasing thirst for exploring the world. Within the next decade, China will overtake the USA as the largest aviation market in the world. But currently there isn’t a word for flygskam in Chinese.

Passengers check in at an airport in China

Biofuels against flight shaming

A final factor that may contain flygskam are biofuels. Significantly, Northern Europe, where flight shaming originated, is now pushing hard towards making the fuel mix used for air travel less objectionable. The Swedish government has set a tax on avfuel – previously untaxed – and is contemplating to require 30% biofuels to be blended into kerosene by 2030.

Norway already requires 0.5% biofuel for airlines operating in the country and also targets 30% by 2030. The International Civil Aviation Organization (ICAO) also calls for a significant proportion of conventional aviation fuels to be substituted with sustainable aviation fuels by 2050 in its  2050 Vision for Sustainable Aviation Fuels

The problem is that scaling up the production of biofuels may be difficult, and that growing more of the organic matter required for biofuels can actually increase greenhouse gas emissions. Which is why offsetting emissions is important. The ICAO’s 192 member countries agreed a global deal called CORSIA in 2016 that committed aviation to achieving carbon-neutral growth from 2020 and to halve net emissions levels by 2050 compared to 2005. Any rise in international aviation emissions above 2020 levels will be offset, mostly through planting trees. While some of the largest environmental NGOs argue that the carbon stored in trees or biological carbon is not equivalent to fossil carbon, this may still help travellers to feel less guilt about flying.

Will short-haul flights be electric a couple of decades from now?

Electricity plus efficiency

Electrification of aircraft is another hotly pursued aviation innovation since explorers Bertrand Picard and André Borschberg demonstrated the viability of the concept with their circumnavigation of the globe in their solar-powered “Solar Impulse 2” aircraft in 2016. Electric aircraft are now being introduced by airlines in the US and in Canada. Norway has made the electrification of short-haul aviation by 2040 its official policy target.

This would have a truly drastic effect: Electrification of short-haul flights and more stringent carbon pricing would cut  CO2 emissions from domestic aviation by as much as 81% and those of (mostly longer-haul) international aviation by 19% by 2050, according to the ITF’s Transport Outlook 2019.

In the meantime, upgrades that increase the efficiency of conventional engines will likely continue, and the question of life-cycle emissions is also being addressed: The Advisory Council for Aeronautics Research in Europe has set itself some challenging environmental goals that include ensuring all aircraft are designed and manufactured to be recyclable.

Cancelled out

Ultimately, flight shaming remains a concept that has traction mostly in European countries with already environmentally engaged citizens. The idea is unlikely to make a difference to consumers’ travel behaviour across the globe, as it is not catching on in some of the world’s largest aviation markets and is easily cancelled out by exploding demand for air travel.

However, the aviation industry is taking note of the movement. Airlines fear reputational damage and are keen to find ways to ensure their services will be less obvious targets for being branded as “shameful” by climate activists – and they are even willing to forgo some business: In reaction to flygskam, Dutch airline KLM recently launched a platform called “Fly Responsibly”: The website invites passengers to compensate for their travel CO2 – and also highlights that getting to Brussels from Amsterdam is faster by train than by plane.


Emma Latham-Jones is a Young Associate at the International Transport Forum at the OECD.