How Urban Mobility Can Help Cities Limit Climate Change

Our approach prioritizes not only sustainability, but controls for factors like accessibility, affordability, investment costs, convenience, and efficiency. We used sophisticated modelling, introducing factors to account for different scenarios and the fact that people cannot change overnight. Commuters who travel, say 10 miles, to their office cannot feasibly be asked to walk or bike instead of driving.

And while every city needs a unique strategy, there are common threads that most should weave into their plans, like electrifying fleets, reducing personal car usage, or promoting shared mobility.

Decreasing car use and gasoline vehicles can accomplish much of the task for cities, according to our research. An increase in shared and active mobility, like bike-sharing and walking, and incentivizing public transit use can compensate for lower car use to some extent and bring cities closer to their goal.

However, it’s close to impossible for some cities to achieve their Paris Agreement targets by 2030 without drastic measures like stark and sudden shifts in commuter behavior. The research examines where those changes are needed and what they would have to be for each city.

But the scope of exactly how far those solutions will reach in lowering emissions varies widely depending on how car-dependent or holistic a city’s mobility network is. That underscores the need for individualized plans, even between cities grouped in the following categories.

Even cities with strong mobility networks need to adapt

These cities, like London, New York, and Paris, have ambitious climate action plans but will still fall just short of closing their emissions gap, if no additional measures are introduced. They boast strong public transport networks, and have more multimodality available, like ride-hailing and micromobility. And yet, commuters still typically rely on traditional modes, like personal car use, because of gaps in first- and last-mile transportation. Authorities for the leading cities need to commit to even further action.

Take San Francisco, for example. It’s the leading city in our research – almost closing its mobility emissions gap without employing any optimization scenarios. However, the Bay Area city falls just short of reaching its global warming target based on city action plans despite an expected 20% decline in carbon emissions by 2030. San Francisco is estimated to reach 1.6°C in 2030 with current city plans and needs an additional 11% emissions drop on top of those plans to meet the Paris Agreement.

That small gap gives San Francisco a wide array of feasible options for city leaders to act on. Pursuing more multimodality would be relatively simple, requiring solutions like more car-free areas and public transit infrastructure, more electrification largely means accelerating the electrification of car and bus fleets. The latter is already a goal in the city’s Electric Mobility Implementation Plan.

But modal shifts can only do so much in some cities. Take Hong Kong and Singapore, both boast top-tier public transit systems but are reliant on carbon-intensive energy grids. Without sharp reductions of energy emissions, Hong Kong and Singapore would need to reduce mobility demand by building denser housing or a implementing a “15-minute city” urban planning design. Both cities should consider reducing energy emissions and electrifying public and private transport.

Cities dependent on cars must confront their legacies

Commuters in sprawling cities, like Dubai and Los Angeles, rely heavily on personal cars. Trips are often over long distances, and a lack of other transportation modes — namely, mass transit and micromobility for first- and last-miles — makes it difficult to meet climate commitments.

Better public transit options can greatly help Los Angeles, for example, but the city is spread over a wide area, which makes it challenging to provide services with enough station density. City officials should explore increasing the appeal of buses with more affordable fares and more frequent and expansive routes.

Los Angeles is far from closing its emissions gap, and the city’s current plans would only reduce emissions by 9% by 2030, requiring an additional cut of 54% on top of those current commitments to meet a 1.5-degree goal. And mobility demand in Los Angeles – a city notorious for its gridlock traffic – is expected to grow by 8% by 2030, which puts it further from one of the city’s potential levers: significantly reducing overall mobility demand. Los Angeles can reduce demand for personal car use by limiting parking spaces and establishing congestion pricing and low-emission zones where only clean-energy vehicles are allowed. Other methods for reducing travel demand include incentivizing hybrid or remote work and building “15-minute city” concepts, in which necessities like healthcare, work, and education are within a 15-minute walk or bike ride.

And while California banned the sale of new-gasoline-powered cars by 2035, Los Angeles needs to be more proactive in phasing them out. More than 90% of distance traveled in Los Angeles was made by car in 2022, and roughly 90% of those vehicles are gasoline or diesel-powered. Aggressive pushes for electrification will go a long way for a city with historically high levels of car ownership.

Cities in developing economies need investment to jumpstart sustainable mobility

Emerging cities, like Lagos, are typically located in developing countries with low government investment in infrastructure, resulting in weak public transport networks and shared mobility support.

Both mobility demand and forecasted emissions are expected to increase by roughly 50% in Lagos by 2030, meaning the Nigerian city would need to decrease its emissions by an additional 53% on top of current commitments. That wide veer away from meeting Paris Agreement targets is mostly driven by the popularity of gasoline-powered cars and buses.

Reducing that mobility demand isn’t a realistic option for Lagos given its rapid social and economic growth. In theory, Lagos could invest heavily in decarbonizing its power grid and electrifying public transport to meet the Paris Agreement target. This path would require not only domestic investment, but billions of dollars in urgent and immediate international support as well.

Reaching a 1.5-degree target will take everyone

A sustainable future is still in reach but realizing that vision will require everyone to work together, from mobility providers and governments to consumers. The Oliver Wyman Forum designed these modal mixes to account for new technologies and solutions that enable more equitable, affordable, and sustainable mobility – particularly for parts of our society that are heavily reliant on personal cars and carbon-intensive power grids.

Commuters need to reflect on how they travel and what their carbon footprint is, and make greener choices. City governments must double down on sustainable infrastructure and incentives to shift the modal mix in line with their emissions targets, while providers work to unfold the full potential of their services without cannibalizing ridership from public transport. With transit accounting for such a large percentage of global emissions, cities must act now on their urban mobility networks.

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