Updated September 10, 2022

In April 2022, the world’s authoritative scientific body on climate change, Intergovernmental Panel on Climate Change (IPCC), gave a major update on the state of climate science.1 Here’s what is said about space-efficient, multimodal systems:2

Meeting climate mitigation goals requires transforming transportation as we know it (TS-67). This transformation entails that we significantly step down demand for energy from transportation and improve energy efficiency at the system level, especially on on-road modes (10-13). This required shift is in addition to electrification and other transportation technologies, which are needed, but not by themselves sufficient (10-12).  

The main solution area for reducing transportation energy demand is enhancing infrastructure for walking, bicycling, and transit in ways that reduce car-dependence, while increasing compact land use (TS-67 and 10-15). This area, “high-functioning multimodal systems” for shorthand, gives cities a chance to reduce transportation energy consumption by 25%, and is the most quantifiable way to decarbonize on-road transportation shown by evidence (TS-67 and 10-15).

High-functioning multimodal systems are created with  three core  methods: (1) Building out infrastructure for both a plush active transportation fabric (associated with 50% less climate pollution per capita vs an automobile fabric) and a plush transit fabric (associated with 25% less climate pollution), (2) Improving space utilization by increasing population and employment density, and (3) Optimizing the “spatial form” by growing continuity within urban spaces and developing more localized, “mixed use” development that can reduce the distance between where people live, work, and pursue leisure. (10-14, 10-22).

These strategies are synergistic; using them together multiplies gains. The possibilities of high-functioning multimodal systems not only offer the chance to reduce energy demand by orders of magnitude, but decouple transport emissions from economic growth (10-13).

In addition to building and developing components of the system, the change requires a paradigm shift towards a system architecture that prioritizes high-accessibility transportation solutions which minimizes the amount of mobility required to meet people’s needs, and that favors transit and active transport modes (10-12).  

It also requires deliberate demand management strategies, especially with local legislative and creative initiatives such as bike-to-work campaigns, free transport passes, parking charges, or eliminating car benefits (TS-69).

The targeted transformation is associated with profoundly improved economics.  These economics support a lower cost of transportation to both individuals and at the subnational government level. They also offer fundamentally new mobility services that are both less expensive for the same output and can give access to people that cars were not suitable for, such as elderly, children, and disabled. As such, benefits as a climate strategy include both support for a just transition and the provision of concrete improvements that support adoption and growth.

High-functioning multimodal systems, as described here, rest within a large scope of demand management opportunities that can lead to further decarbonization. They also can and should support technology strategies, including electrification and targeted mobility innovations, that are additionally are crucial and can create synergies.

Feedback is welcome in the comments below or at the contact page. Updates will made as needed and documented.

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.

2. This is an abbreviated take for the non-specialist.

unlock transportation climate action

Success! You're on the list.