Most of the planet’s emissions are produced by cities and their populations: in the coming years urban mobility will have to play a greater role in reducing them. From hydrogen buses and smart traffic lights, to reimagined town plans and data-driven cycle routes, cities around the world are already finding ways to become greener and easier places to live and work.
Over half of the world's population live in cities. Increasingly, however, urban denizens feel that cities are falling short of their expectations for smarter ways to get around, while creating less emissions. A recent survey of more than 10 000 people in 58 cities revealed the scale of the discontent: one-third of respondents said they were considering leaving their city. Over a third (38%) were concerned about how long they spent commuting, and nearly half (42%) said pollution was pushing them away.
Cities make an outsize contribution to global climate change. Despite covering less than 1% of the surface of the earth, urban areas contribute over 70% of global emissions according to the IPCC. However, cities can turn their size into an advantage, mobilising residents, businesses and other key stakeholders around coherent and fast-paced carbon reduction programmes. And as 10% of total greenhouse gas emissions come from only 100 of the world’s biggest cities, a small number of local governments have a great deal of power to help the planet meet global emission goals.
Making urban transport greener
Cities around the world are finding ways to use mobility infrastructure to become greener. One important route is by moving public transport to renewable energy sources. “We just finished working on a business plan to turn a traditional diesel bus service into one that runs on hydrogen,” says Julien Henault, Senior Manager, Mazars. “That wasn't possible ten years ago because the technology wasn't up to the task, but it is now.” Cities from the around the world are acting as laboratories for new and green public transport solutions: “Innovative cable car solutions in La Paz, Bolivia and Ecatepec, Mexico, and Vienna’s experiment with an autonomous and electric public bus transport system in the Seestadt district, will likely have a lasting impact on the future of green mobility in these cities,” says Michael Dessulemoustier-Bovekercke, Partner, Mazars.
These individual modes can be bundled on a city level, proposing mobility as a unified (and more sustainable) service rather than a set of separate options. “One of the first communities to introduce Mobility as a Service (MaaS) was Helsinki,” adds Dessulemoustier-Bovekercke. “All public and private transport was bundled on one app that proposed the optimal multimodal route to passengers.”
Investment and aggregation
Henault emphasises the need for investment in green technologies to extend the renewable reach: “The regulatory environments in many countries, such as Britain and France, already make green urban transport an attractive prospect for investment, but the priority now is to leverage the investment.”
Cities can also reduce emissions and improve mobility by managing and monitoring transport systems’ energy use. “Traffic, street lighting, parking, electric vehicle mobility and other services can be integrated into one Open Data Platform,” explains Michael Michaelides, Director, Energy, infrastructure & environment, Mazars. “These platforms aggregate the data and make it available for public administrators, energy and transport providers, businesses and citizens’ groups to form their own solutions.” This allows citizens to make decisions about how to travel across the city based on detailed carbon footprint data.
Designing greener cities
Above all, Michaelides argues that the biggest ‘wins’ in terms of carbon reduction could come from designing cities in ways that helps residents to use less energy. “A great deal of cities’ carbon emissions occur because so many people need to commute,” he says, “but cities don't need to be designed that way. New models are emerging.” He points to transit oriented developments (TODs) as a possible solution: a concentrated mix of commercial, residential, office buildings and entertainment within a half mile radius of a transit station. “This allows people to work, shop, live, and spend their recreation time near the station, so they can walk or cycle almost everywhere they need to go.”
Whereas a traditional rail hub might be similar to an airport detached from the surrounding businesses and ringed by parking areas, a TOD is directly embedded in the city. “Instead of walking off the platform to the car to drive home, passengers can walk directly into an office block or shopping centre,” he explains. “This not only reduces emissions, it also creates a safer environment for bikes and pedestrians.” With concern over climate change and congestion growing, TODs are likely to form a model for the future of city design. “One of the ways we will reduce emissions is by changing behaviour, to use resources in a more sober way,” says Henault. “Anything that nudges people to do that can be part of the solution.”
Experimenting with greener urban infrastructure
Cities can also adopt artificial intelligence and other technologies to reduce travel time and emissions. Engineers at Carnegie Mellon University and Pittsburgh City Authority have developed an AI system to enable traffic signals to communicate with each other; the experiment has reduced average travel time by up to 25%.
Similar systems can reduce bus travel time. Copenhagen, for example, has installed intelligent traffic lights that prioritise bikes and buses over cars, reducing bus travel time by up to 20% and lowering emissions as a result.
Streets that collect data can also be used to assess demand for new initiatives such as cycle routes: video sensors with artificial intelligence in twenty London locations assess cycle and pavement traffic and use the data to help policymakers decide where to build new cycle routes.
Innovation and experimentation
These kinds of initiatives will require city officials, venture capital funds, academic institutes, start-ups and others working together to ensure trust is built into how data is gathered and used.
If city authorities can inspire technologists, entrepreneurs, campaigners, and citizens to contribute ideas and innovations, there is no reason why they cannot show how sustainable mobility can truly be. “Integrated multi-stakeholder collaborations like the Smarter Together project, supported by EU Horizon 2020, suggest that the right balance can be found between innovative technologies, citizen engagement and institutional governance to deliver smart and inclusive solutions,” says Dessulemoustier-Bovekercke.
Covid-19 has shown that radical change in how we move around our cities is not only possible but might also be overdue. The sudden shifts in working, shopping, and spending more time at home or within walking distance, have radically reduced emissions. While nobody expects these changes to be permanent, 2020 has demonstrated that collective policy and individual decisions can reduce aggregate emissions. In doing so, they help draw the blueprints for greener cities and a more sustainable planet.