Addressing the climate crisis requires major changes in our cars, trucks and fuels, but ensuring that all people share equitably in the benefits and burdens of the transportation systems requires more profound change, that centers people rather than technology. My colleagues and I at UCS have been working with an advisory committee to understand what is required to decarbonize our economy while centering people. We recently released a report outlining a transformative climate action framework that puts people at the center of our clean energy transition, rooted in three core principles:
- Effectively address the climate crisis;
- Advance equity and justice; and
- Drive systemic, not just incremental, change.
Transportation is about connecting people to the things they need, and we need to do better.
Our approach to transforming transportation mirrors our approach to transforming the broader energy system. Our fundamental guiding principle is that the transformation must not only drive down climate emissions but must provide equitable access and mobility. Through a modeling exercise using tools developed by Evolved Energy Research, we explore the magnitude and pace of technological change needed to drive down transportation carbon emissions. The modeling is informative, and it makes clear that to address the climate crisis, we must quickly replace the cars, trucks and fuels we use today with electric vehicles (EVs) and low carbon fuels. But energy models cannot capture the broader economic and societal implications critical to advancing people-centered, multidimensional solutions, and clean technology alone will not provide transportation justice.
We need a transportation system that improves people’s access to jobs, education, healthcare, food, and other destinations, which shouldn’t always need to involve a trip in a private car, but all too often does. With investments in transit, housing and neighborhoods we can improve people’s lives, increase mobility options, and reduce the need (and associated costs and pollution) to own and maintain a car. Reducing the need to drive or own a car offers many benefits even when what powers those cars is clean, including reducing the amount of renewable power, hydrogen and clean fuel we need to power them and the materials needed to build them. When developing plans for transportation investments, it is especially important to center communities that have not only been poorly served, but have borne the brunt of the pollution, displacement, violence and disinvestment that have so often been built into our transportation system.
As part of our analysis we explored the implications of a transition away from reliance on low occupancy passenger cars for most travel, and toward a more multi-modal future, where people drive less and walk, bike, and use transit more. Not surprisingly, less driving means less energy needed to power EVs, and less infrastructure required to generate and transmit all that additional power. Our “Low Energy Demand” scenario. which explored a 40 percent reduction in driving, a 20 percent reduction in goods movement and flying, and a doubling of transit (all relative to business-as-usual projections). We found an 8 percent reduction in liquid transportation fuel use, and a 30 percent reduction in electricity and 34 percent reduction in hydrogen use for transportation in 2050 compared to our primary scenario.
Electrify transportation as quickly as possible.
We can do a lot to make our transportation work better for everyone and reduce pollution by increasing access to different mobility options and reducing the overall need for driving. But there’s no getting around it: the big pollution problems in transportation, both for climate and air quality, come from burning petroleum-based fuels like gasoline, diesel, and jet fuel. Reducing pollution means reducing petroleum use, by making all cars and trucks as efficient as possible and rapidly transitioning to zero-emission vehicles, powered by both batteries and hydrogen fuel cells. Completing the transition of all NEW light duty passenger cars and trucks to zero emissions technology by 2035, and all NEW medium and heavy-duty vehicles by 2040 will cut liquid transportation fuel use by 50% before 2040 and by more than 80% by 2050.
Meeting the growing demand for electricity while also cleaning up electricity generation is a major challenge and an important opportunity, explored further in the report as well as one of my colleague’s accompanying blogs. Electric vehicles can help support the transition to a grid powered by renewable energy by taking advantage of the flexibility in charging schedule that most battery EV drivers have. Within the window of time the vehicle is typically parked and could be charging, the charging can be scheduled to coincide with times of higher renewable power generation from wind and solar energy. Hydrogen fuel producers can similarly schedule hydrogen production to match times of greater renewable energy production so that fuel cell EVs are fueled with renewably-generated hydrogen. Even with such strategies to pair charging and hydrogen production loads with existing renewable energy production, the infrastructure required for increased renewable power generation and transmission to meet demand from transportation electrification is substantial, and measures that reduce total driving can reduce the scale of the challenge. Scaling up EV manufacturing responsibly will also require focused efforts to address critical materials used for battery manufacturing and increase battery reuse and recycling.
Turning over the fleet
While quickly transitioning to EVs is critical, combustion fueled cars will be around for many years, even after all new sales are zero emissions. The charts above illustrate the share of gasoline, diesel, battery and fuel cell vehicles in terms of both sales and the stock of vehicles in use. Gasoline and diesel vehicles sold between now and 2035, while becoming a smaller and smaller share of all new vehicles sold, will stay on the road until 2040 and beyond. Because of this lag, it is important to make sure that all gasoline and diesel vehicles continue to improve and emit as few climate change and other air pollutants as possible.
Beyond the overall share of EVs sold and on the road, equitable transportation electrification must prioritize an equitable distribution of benefits. EVs offer many benefits, both lower fuel and operating costs for those who own or drive them, and reduced air pollution for the communities in which they operate. Policy support for EV sales should be targeted to overcome barriers of low and moderate-income drivers so that they are not among the last drivers able to adopt EVs and to ensure air quality improvements prioritize communities overburdened by pollution from gasoline and diesel use.
Decarbonize the remaining liquid fuel
After implementing the changes described above to reduce unnecessary driving and minimize the use of petroleum fuels in our passenger vehicles, buses and heavy-trucks, what’s left? While zero emission technologies are advancing rapidly, there are many places where replacing liquid fuels will remain a big challenge — especially for aviation. Thus we also need strategies to develop cleaner liquid fuels, that replace petroleum and reduce emissions associated with both fuel production and use.
Our modeling suggests that increased efficiency and electrification can cut liquid fuels demand by more than 80 percent by 2050, which still leaves an important challenge to minimize pollution from the liquid fuels we continue to use. There are three major potential sources of liquid fuels to meet this remaining demand.
- Biofuels are currently the main alternative to petroleum, accounting for about 10 percent of gasoline and 5 percent of diesel. While resources to produce biofuels are limited, they can play a key role in helping to decarbonize and reduce pollution from liquid transportation fuels. By improving the farming practices used to produce biofuel feedstocks and by reducing pollution from biofuel production technology, biofuels could sustainably supply half or more of the liquid fuels needed in 2050. Biofuel production levels should be carefully calibrated against resource availability and competing uses of crops and land. At a reasonable scale, biofuels can be a productive part of the agricultural system, but if consumption exceeds sustainable production levels it can increase food prices, expand the footprint of agriculture or both.
- Electrofuels made from hydrogen produced from electricity and carbon extracted from the air, offer the promise of using renewable power to produce drop-in liquid fuels. However, since it take a lot more energy to make a liquid fuel than to directly power an EV, this solution only makes sense for applications where electrification is not feasible.
- Petroleum with decarbonization: Our analysis also found that the global warming pollution from limited remaining petroleum use could be managed by removing carbon from the atmosphere in a process called carbon removal. However, carbon removal is an expensive and problematic last resort that should be minimized and does not address the non-carbon impacts of continued petroleum use. Given the uncertainty about whether biofuels and electrofuels can be successfully commercialized at the scale required to fully replace petroleum transportation fuels, it is possible that a small amount of petroleum-based liquid fuel, less than 10% of today’s levels, may still be in use by mid-century. So we need policies to manage this shrinking industry, to minimize pollution and harm to the climate, to protect fence-line communities, and to provide a fair transition to workers in these industries.
The precise mix of biofuels, electrofuels and petroleum-based fuels that can meet potential remaining liquid transportation fuel demand in 2050 and fit within carbon constraints is highly uncertain and depends on both technology development and policy choices. In our primary scenario biofuels, electrofuels, and petroleum account for 53 percent, 7 percent and 40 percent of 2050 liquid fuel use respectively in 2050. It is also important to protect fence line communities impacted by production of transportation fuels. Fuel production should be pursued in a responsible and mutually beneficial manner, with robust community involvement, or else it could harm adjacent communities, as has so often been the legacy of the petroleum industry. It is technically possible to meet remaining liquid fuel demand and decarbonize with either biofuels, electrofuels or petroleum coupled with carbon removal, or some mix of the three. But it is hard to see how to all three strategies can be completely avoided. Rather than betting entirely on a single option, prudence in the face of uncertainty suggests pursuing responsible development of both biofuels and electrofuels, while mitigating pollution and other harm from declining petroleum extraction and refining to the maximum extent possible.
The road ahead for equitable mobility
Decarbonizing transportation is a major technical challenge, but beyond technology, transportation connects people to opportunity and to one another. Meeting people’s needs for mobility and mobility justice requires much more than just technical solutions. Investing in solutions to move people and goods in a safe, just and equitable manner can improve the quality of life for everyone and address the harms the transportation system has caused. These solutions and investments should focus especially on communities that have been most harmed by the transportation system, from Black neighborhoods cut in half or simply erased by interstate highway construction, to the fence line communities near oil fields or refineries. Replacing petroleum with renewable electricity is a major opportunity to reduce pollution and support good jobs and can coordinate with development of a reliable distributed energy system. And even as improved efficiency and transportation electrification cut liquid fuel use, we should build up the capacity to supply the remaining liquid fuel demand in the least polluting and most responsible way possible, with a mix of sustainable biofuels, innovative electrofuels, and carefully managed residual petroleum use.
Ensuring that all people have equitable access to safe and clean personal mobility means doing more than tackling the technological challenges. We must also ensure that transportation policies and investments respond to the voices and center the needs of communities that have borne the brunt of the pollution, displacement, violence and disinvestment that have so often been built into our transportation system. By putting people at the center of our clean transportation transition, we can create the equitable non-polluting transportation system we need.
 In addition to biofuels and electrofuels, some related technologies rely on a combination of the two, combining biological sources of carbon with hydrogen produced from renewable electricity to produce low emissions fuels.