Studies Show that a Transition to Low-Carbon Transportation Is Possible

The conclusion of the Frontier Group paper – that strategies to transform transportation in the United States can lead to dramatic cuts in greenhouse gas emissions – is one that has been shared by other analyses, evaluating a variety of pathways to decarbonization. Among them:

1. The Institute for Transportation and Development Policy estimated in 2014 that the United States could reduce urban passenger transportation emissions by nearly 60 percent below current levels by 2050 under a “high shift” scenario that includes expanded use of public transportation, bicycling and walking, as well as a reduction in growth of vehicle travel.

Michael A. Replogle and Lewis M. Fulton, Institute for Transportation and Development Policy, A Global High Shift Scenario: Impacts and Potential for More Public transport, Walking and Cycling with Lower Car Use, September 2014, archived at

2. The National Renewable Energy Laboratory found that a combination of strategies – including improved vehicle economy, fuel switching and reductions in travel growth – could cut transportation-sector carbon dioxide emissions by 80 percent.

For summary, see U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Transportation Energy Futures, March 2013, archived at

3. The Rocky Mountain Institute found that adopting advanced vehicles and using them more efficiently could reduce U.S. transportation energy use by two-thirds compared with forecast levels and eliminate oil consumption by 2050, even at increased levels of overall driving.

Rocky Mountain Institute, Reinventing Fire: Projected Decline in U.S. Transportation Sector Fuel Use,2010-2050, accessed 1 February 2016, archived at

4. Energy and Environmental Economics, working with two U.S. national laboratories, evaluated four scenarios for deep reductions in U.S. greenhouse gas emissions, each of which yielded a 75 percent or greater reduction in transportation sector emissions. Emission reductions were achieved by improvements in vehicle fuel economy and fuel switching to electricity and hydrogen fuel.

James Williams, et al.,Pathways to Deep Decarbonization in the United States, prepared for Sustainable Development Solutions Network and the Institute for Sustainable Development and International Relations, 2014, archived at

5.The Transportation and Climate Initiative of the Georgetown Climate Center found in 2015 that a series of public policy initiatives in northeastern states, coupled with existing state and federal policies, could reduce transportation carbon dioxide emissions by up to 39 percent by 2030, consistent with a trajectory to achieve 80 percent emission reductions from transportation in the region by 2050.

Gabe Pacyniak, et al., Georgetown Climate Center, Reducing Greenhouse Gas Emissions from Transportation: Opportunities in the Northeast and Mid-Atlantic, November 2015.

6. A 2015 analysis by researchers at Lawrence Berkeley National Laboratory estimated that a transition to a network of shared autonomous taxis, powered by low-emission electricity, and rightsized to meet demand, could reduce per-vehicle greenhouse gas emissions by 87 to 94 percent by 2030 compared with conventional gasoline-powered cars.

Jeffery B. Greenblatt and Samveg Saxena, “Autonomous Taxis Could Greatly Reduce Greenhouse Gas Emissions of U.S. Light-duty Vehicles,” Nature Climate Change, 5: 860-863, 2015, DOI: 10.1038/nclimate2685.

Each of these studies evaluated a different pathway for cutting transportation greenhouse gas emissions. Some relied on technological advances, others on changes in land-use and travel behavior. But the end conclusion is the same: America has the technical and policy know-how to achieve large-scale reductions in carbon dioxide emissions from transportation – and to do it within a time frame sufficient to make a difference.

Last modified: May 29, 2016