Takeaways from IPCC’s Sixth Assessment Report for Transportation

On March 20, 2023, the Intergovernmental Panel on Climate Change (IPCC) provided a major update on the state of climate science and ways forward in its synthesis of the Sixth Assessment Report (AR6).

Here’s what the world’s top authority on climate says about climate action and transportation:

#1. Climate change is probably humankind’s biggest unfolding catastrophe.1 It multiplies the most problematic existing societal challenges and it exacerbates inequalities. Pretty much no one is left unscathed.

#2. We can head off continued warming and prepare for the unavoidable by making major coordinated commitments–which is manageable.2

#3. In fact, climate action is an opportunity for abundance.3 The solutions called for are largely centered in creating more inclusive, affordable, healthy, and joyous communities that make people better off. Sustainable and equitable development worth doing even without the benefits of decarbonization. 

#4. Rising to the challenge means rapid, broad, and deep decarbonization of our energy supply plus five principal “demand-side” areas: Food, buildings, industry, electrification, and land transportation.4 Emissions in all areas need to rapidly peak, decline, and move to nearly zero by 2050-2070.

#5. Decarbonization of transportation needs to include three major transformations:

  • Energy-Efficient Mobility Systems:5 Improving per-passenger energy productivity through development of systems to prioritize the widespread use of transit and other shared vehicles, vehicles right-sized for their purpose, and active transportation (e.g. bicycling and walking), meanwhile decreasing the distance between where people and things need to travel. Methods include safe streets for people outside of vehicles, more advanced public and community-based shared transportation, redesign of transportation for accessibility rather than car flow, inclusive housing, and inclusive use of public spaces. 
  • Resource-Efficient Electrification:6 Electrifying nearly every vehicle with wheels and a motor, while stewarding resources to create the most decarbonization for the materials employed. Methods include switching internal combustion engines with electric powertrains of existing vehicles in every class (e.g. cars, buses, and trucks), using the superior technology of battery-electric systems to advance new classes of highly-efficient small vehicles in urban areas (e.g. scooters and neighborhood electric vehicles), and creating new capabilities for active transportation (e.g. e-bikes). 
  • Rigorous Demand Management:7 Creating economic incentives to reward climate-compatible travel and contain the impact of vehicles and behaviors that are in conflict with decarbonization. Methods include programs of incentives for users making everyday travel choices and capital purchases (e.g. expanded use of transportation demand management or “TDM” initiatives), structural reforms (e.g. reorganizing subsidies to move beyond car-centric planning to interoperable multimodal systems, as well as ensuring public agencies have sufficient capacity and resources to conduct such work), and new creativity in public engagement (e.g., entrepreneurship to enhance user experiences, communication, and education).

#6. Everyone has a job to do.8 Climate action around transportation requires comprehensive support for activities as varied as public policy design, advocacy, organizing, technology deployment, education, applied research, and more. Those who have influence over urban areas and financial investments taking place are especially important. Leadership is contagious.

#7. Everything we can still do matters.9 Each increment of warming avoided can make an enormous difference.


1  From the IPCC’s published Headline Statements (Headlines), Summary for Policymakers (SPM), and Longer Report (LR). As of March 22, the full volume has not yet been published. Additional detail is available in the three reports the synthesis is based on, especially the 2022 report on Mitigation.

2  Climate change is a threat to human well-being and planetary health. (Headlines C.1). Climate change has reduced food security and affected water security, hindering efforts to meet Sustainable Development Goals (SPM A.2.4). Continued emissions will further affect all major climate system components, and many changes will be irreversible on centennial to millennial time scales and become larger with increasing global warming. Without urgent, effective, and equitable mitigation and adaptation actions, climate change increasingly threatens ecosystems, biodiversity, and the livelihoods, health and wellbeing of current and future generations. (C.1.3)

3 There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all. (Headlines C.1) All global modelled pathways that limit warming to 1.5°C (>50%) with no or limited overshoot, and those that limit warming to 2°C (>67%), involve rapid and deep and, in most cases, immediate greenhouse gas emissions reductions in all sectors this decade. (SPM B.6). Low-cost decarbonization opportunities abound. (SPM Figure SPM.7.a)

4  Negative decarbonization opportunities abound. (SPM Figure SPM.7.a). Deep, rapid and sustained mitigation and accelerated implementation of adaptation actions in this decade would reduce projected losses and damages for humans and ecosystems (very high confidence), and deliver many co-benefits, especially for air quality and health (C.2) Mitigation options often have synergies with other aspects of sustainable development, but some options can also have trade-offs. There are potential synergies between sustainable development and, for instance, energy efficiency and renewable energy. Similarly, depending on the context, biological CDR methods like reforestation, improved forest management, soil carbon sequestration, peatland restoration and coastal blue carbon management can enhance biodiversity and ecosystem functions, employment and local livelihoods. However, afforestation or production of biomass crops can have adverse socio-economic and environmental impacts, including on biodiversity, food and water security, local livelihoods and the rights of Indigenous Peoples, especially if implemented at large scales and where land tenure is insecure. Modeled pathways that assume using resources more efficiently or that shift global development towards sustainability include fewer challenges, such as less dependence on CDR and pressure on land and biodiversity (B.6.4)

5  Rapid and far-reaching transitions across all sectors and systems are necessary to achieve deep and sustained emissions reductions and secure a liveable and sustainable future for all. (Headlines C.3) All global modeled pathways that limit warming to 1.5°C (>50%) with no or limited overshoot, and those that limit warming to 2°C (>67%), involve rapid and deep and, in most cases, immediate greenhouse gas emissions reductions in all sectors this decade. Global net zero CO2 emissions are reached for these pathway categories, in the early 2050s and around the early 2070s, respectively. (Headlines B.6)

6 SPM Figure SPM.7.a

7 Urban systems are critical for achieving deep emissions reductions and advancing climate resilient development. Key adaptation and mitigation elements in cities include considering climate change impacts and risks (e.g. through climate services) in the design and planning of settlements and infrastructure; land use planning to achieve compact urban form, co-location of jobs and housing; supporting public transport and active mobility. (SPM C.3.4) Public transportation with bikes and rightsizing motor vehicles are among top 20 key modeled areas of mitigation, and the 5th (nearly tied with 4th) and 3rd-highest sources of mitigation that are cost-negative. (SPM Figure SPM.7.b) Urban systems are critical for achieving deep emissions reductions and advancing climate resilient development, particularly when this involves integrated planning that incorporates physical, natural and social infrastructure (high confidence). Deep emissions reductions and integrated adaptation actions are advanced by: integrated, inclusive land use planning and decision-making; compact urban form by co-locating jobs and housing; reducing or changing urban energy and material consumption; electrification in combination with low emissions sources; improved water and waste management infrastructure; and enhancing carbon uptake and storage in the urban environment (LR 4.5.3)

8 Electric vehicles powered by low-GHG emissions electricity have large potential to reduce land-based transport…The environmental footprint of battery production and growing concerns about critical minerals can be addressed by material and supply diversification strategies, energy and material efficiency improvements, and circular material flows. (SPM C.3.3)

9 Reducing industry GHG emissions entails coordinated action throughout value chains to promote all mitigation options, including demand management, energy and materials efficiency, circular material flows, as well as abatement technologies and transformational changes in production processes. (SPM C.3.3) The systemic change required to achieve rapid and deep emissions reductions and transformative adaptation to climate change is unprecedented in terms of scale, but not necessarily in terms of speed. Systems transitions include: deployment of low- or zero-emission technologies; reducing and changing demand through infrastructure design and access, socio-cultural and behavioral changes, and increased technological efficiency and adoption; social protection, climate services or other services; and protecting and restoring ecosystems. Feasible, effective, and low-cost options for mitigation and adaptation are already available. (SPM C.3.1) Electrification load brings significant new impacts that need to be reduced (SPM Figure SPM.7.b) Transport-related GHG emissions can be reduced by demand-side options and low-GHG emissions technologies. Changes in urban form, reallocation of street space for cycling and walking, digitalisation (e.g., teleworking) and programs that encourage changes in consumer behavior (e.g. transport, pricing) can reduce demand for transport services and support the shift to more energy efficient transport modes. (LR 4.5.3) Approaches that align goals and actions across sectors provide opportunities for multiple and large-scale benefits and avoided damages in the near-term. Such measures can also achieve greater benefits through cascading effects across sectors (medium confidence). For example, the feasibility of using land for both agriculture and centralized solar production can increase when such options are combined (high confidence). Similarly, integrated transport and energy infrastructure planning and operations can together reduce the environmental, social, and economic impacts of decarbonizing the transport and energy sectors (high confidence). (4.9) 

10 Urban systems are critical for achieving deep emissions reductions and advancing climate resilient development.  SPM (C.3.4) Finance, technology and international cooperation are critical enablers for accelerated climate action. (SPM C.7) 

11  There are gaps between projected emissions from implemented policies and those from NDCs and finance flows fall short of the levels needed to meet climate goals across all sectors and regions. (Headlines A.4). Every increment of global warming will intensify multiple and concurrent hazards. (Headlines B.1)

12  Climate change is a threat to human well-being and planetary health. There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all. Climate resilient development integrates adaptation and mitigation to advance sustainable development for all, and is enabled by increased international cooperation including improved access to adequate financial resources, particularly for vulnerable regions, sectors and groups, and inclusive governance and coordinated policies. The choices and actions implemented in this decade will have impacts now and for thousands of years (SMP C.1). Delayed mitigation and adaptation action would lock-in high-emissions infrastructure, raise risks of stranded assets and cost-escalation, reduce feasibility, and increase losses and damages (high confidence). Near-term actions involve high up-front investments and potentially disruptive changes that can be lessened by a range of enabling policies. (C.2)

U.S. Launches Blueprint to Decarbonize Transportation, Mobility First

When the U.S. passed its most important climate legislation ever, the Investment Reduction Act (IRA), it didn’t tackle transportation very squarely. Not in the sense of what climate science authorities, such as the Intergovernmental Panel on Climate Change (IPCC), say is the path to deep decarbonization, a sequence known as “Avoid-Shift-Improve.”

What passing the IRA did do was show a recipe for making climate policy in the U.S. Which is to create things people care about, and use the chance to generate popular support and hopefully win constituents for even more reform.

US federal agencies have launched a new framework, The US National Blueprint for Transportation Decarbonization: A Joint Strategy to Transform Transportation, which aims to do that for transportation.

The blueprint composes, for the first time, a national policy on transportation decarbonization that is holistic according to climate science and speaks to modern politics.

The framework brings key agencies together to chart a path to do the following:

  1. Increase convenience by implementing system-level and design solutions. This means, in part, making communities more walkable and building more housing near the places where people need to go.
  2. Improve efficiency through mode shift and more efficient vehicles. This includes making public transportation work better and become more relevant.
  3. Transition to clean options by deploying zero-emission vehicles. Electrification of everything.

The blueprint suggests, correctly, that status-quo transportation policy costs people money, time, and freedom that they could potentially have back. And it shows a way forward that is about making people’s lives better through more mobility options, especially those who transportation to date has left out.

It also agrees with the findings of IPCC and others in asserting that decarbonization through transportation requires a set of solutions—in particular, mobility and electrification—that need to work together. And hence, a commitment to transportation decarbonization means advocacy for any one solution requires being thoughtful about the wider strategy.

The framework needs funding, which theoretically could come in part from current subsidies that prop up car dependence and work against the many opportunities to create abundance through transportation highlighted in the blueprint. It also needs reciprocity from states, municipalities, and elsewhere.

With the new Blueprint for Transportation Decarbonization, leaders who want a modern way to structure investments for transportation climate action have a good framework translated for the U.S. to support and build with.

Transportation Questions for Climate Action

To bring climate pollution under control, we need to reshape transportation, especially the way we get around on the ground.

Namely, we have to evolve from a mono-modal system that is extraordinarily energy-intensive because it requires one tool for almost every job–the private car, typically carrying one person–towards a system that is resource-efficient.

No question a big part of resource efficiency is more efficient motors with cleaner energy sources. That means electrifying more or less every motor vehicle, and then some.

But just as important, and what we need to wake up about, is making the system architecture into one that is multimodal. An architecture that provides a diversity of travel choices giving people multiple good options. That ferrets out subsidies working against the most economic travel tool for the job in order to give the most climate-compatible modes a level playing field. That multiplies the possibilities through “geometric efficiency”–by designing and redesigning communities to give people more amenities near where they live.

This system we need is one that is designed to first avoid the need for physical travel and next to let people frictionlessly shift to the most efficient and convenient mode for the trip. See figure for a summary of these strategies, together “avoid/shift,” in context.

Avoid-Shift-Improve Framework from SLOCAT (reference at bottom)

Four questions will shape how and when we get to the multimodal, resource-efficient system that we need–and hence whether transportation leaders will do their part in delivering a safe climate:

  1. How do we give the movements for bicycle/pedestrian and transit development the high status climate science and literature on equity say they deserve?
  2. How can transportation electrification and “avoid/shift” climate strategies work harmoniously towards a holistic transportation decarbonization agenda?
  3. What’s it going to take to get public agencies take serious climate action, which requires–according to the most authoritative science–a revolution in mobility options on top of electrification?
  4. How can resource-limited local governments rapidly take it the next level for combined transportation decarbonization, equity, and resilience?
  5. How do we overcome carbon lock-in in the transportation system making change difficult and spark new action?

There’s a lot packed in here. How we pay for things (and quietly subsidize the status quo). The role of emerging technology. Paths to diffusion of technology and solutions that already exist but at small scale. How to be more appropriately imaginative. And a lot more.

In the coming months, watch this space for materials and some perspectives to explore them. The goal is to better understand the profound untapped value mobility offers the climate movement and what we can do about it. As well as the potentially untapped popular support for initiatives that give people time, money, and freedom back once we get the flywheel really moving.


IPCC (April 2022). Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel.

Litman, Todd (2022). Evaluating Transportation Equity Guidance for Incorporating Distributional Impacts in Transport Planning. Victoria Transport Policy Institute.

SLOCAT: Partnership on Sustainable, Low Carbon Transport (2021). Transport and Climate Change Global Status Report — 2nd Edition.

Unruh, Greg (2002). Escaping Carbon Lock-in. Energy Policy.

Why “More” Mobility?

More Mobility is about the possibility of more from mobility. 

More freedom and joy in how we get around. 

A higher standard of care and dignity for the large number of people our transportation system is leaving behind. Both travelers and those living where travelers are moving through.

Better shared results between public transportation departments and other crucial public domains that transportation affects and is affected by. 

Greater accessibility to what we need.

Transportation that costs less money, less time, and less harm.

This is what we need more of. Not because of the climate crisis, but despite it. Yet, what we need to do to get more serious about climate action is exactly what we need to do to make more happen.

These are big statements–and they are what More Mobility is about. More, with footnotes, soon. 🙂

Climate Action Requires Mobility-First Transportation Action Says IPCC

Earlier this year, the world’s top authority on climate science, the Intergovernmental Panel on Climate Change (IPCC), gave an update on our best chances to minimize further climate damage and keep humankind as safe as possible.1

Here are some of the conclusions about transportation from the 3000-page report, which deals with every main aspect of decarbonization:

#1. The path to decarbonizing transportation is mobility first, with support from technology. Most of what needs to happen to decarbonize transportation is about reducing demand with a focus on transportation on the ground. More specifically, to pursue an Avoid-Shift-Improve (ASI) framework, a sequence of advancing policies and investments that first help to avoid travel, next shift travel to more efficient modes, and finally, improve to vehicle equipment, which a category that includes electrification.

#2. Mobility-led transportation climate action is crucial for decarbonization and we’re not going to get the job done without it. There are no modeled solutions to a safe climate that do not involve a mobility-centered transformation of transportation. And unfortunately, we are not only off track, but without assertive action, unfolding technologies and status quo public management could lead climate pollution from transportation to significantly increase. The good news is there’s strong evidence from leadership around the world showing the way that gives local communities a lot of flexibility and chances to create co-benefits.

#3. Transportation is full of no-regrets investment opportunities that governments should be pursuing no matter what. Transportation is a treasure trove of low- and negative- cost decarbonization that shouldn’t require a lot of hemming and hawwing. And the agenda for serious transportation action–which is centered in designing public environments for more human-centered mobility that gives people more choices–can be a powerful agenda for well-being and equity.

#4. The upside of what transportation can do for climate action is enormous and transcends the models. In addition to analysis showing the minimum work needed around transportation, there is also evidence that transportation climate investments have the potential to create accelerated, outside-the-box change that exceed modeled expectations. Transportation, because it is so integral to our daily lives, is part of  economic and cultural processes that can create extraordinary change quickly while making our lives better.  We can cultivate the conditions to make this happen.

#5. Our best chances of success are in integrated solutions. We need mobility and electrification, and electrification could both hinder or help mobility. Advocates for particular solutions can be the most helpful by keeping the whole ASI framework in mind.

To wrap it up, any serious general climate action strategy needs to have a major focus on transportation that puts weight behind creating high-performing, technology-enabled multimodal system that gives people meaningful choices for safely and conveniently getting around.

And those responsible for transportation or decisions that affect transportation—including zoning, parking, other land use planning, economic development, schools, destination marking and management, and enforcement—need to play a coordinated role in making it happen.

1 IPCC (April 2022). Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel. Also, watch for original briefings and analysis on IPCC 2022 to come.

Welcome to the More Mobility Blog

Welcome to the blog of More Mobility!

This space is for policymakers, practitioners, investors, and grant-makers contemplating how to unlock more at the nexus of transportation and climate action.

The aim is short, slightly wonky discussion on ideas that inspire More Mobility (see the about page), original More Mobility resources focused on decisions and action, and world developments (e.g. studies, events, etc.)

The geographical is North America, mostly the U.S., with possible material specifically on Colorado and California.

Through the end of 2022, posts will come at least every two weeks, with the possibility of bonus material.

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