Transportation Decarbonization White Paper

The transportation sector is the fastest-growing contributor to global CO2 emissions. In the United States, individual ground transportation generates over 80 percent of transportation sector emissions and accounts for about 30 percent of overall energy related CO2 emissions. The economic and health impacts of these emissions are not evenly distributed, with low income communities and communities of color disproportionately affected by the environmental costs of transportation systems. Equitably decarbonizing transportation is an urgent and complex policy priority that is critical to achieving local and international climate goals. 

Sector-wide transportation decarbonization will require a suite of policies, long term investments, and technology developments—from decarbonizing the electric grid to increasing green hydrogen production for fuel cell vehicles. However, these technological and structural changes alone will not be enough to meet decarbonization targets in the United States. In the short term, there is an urgent need to identify policies that shift individual transit away from conventional gas powered vehicles and toward low or zero-carbon transport options such as public transport, electric vehicles, or biking. By embedding randomized evaluation into transportation decarbonization policies, researchers and policymakers can strengthen the evidence base on the behavioral mechanisms that underpin transportation decarbonization and generate actionable learnings for other jurisdictions.  

This paper presents the results of systematic literature review and meta analysis of rigorous empirical evidence on ground transportation decarbonization in North America. The research team conducted an extensive keyword search across 45 journals in the economic, transportation, and environmental space. Based on literature review findings, conversations with policymakers, and a review of local climate action plans, this paper identifies gaps where academic research and local priorities are not aligned and presents three recommendations for researchers and governments to leverage randomized evaluation to identify high-impact, equitable, and cost-effective transportation decarbonization policies. For more information on J-PAL North America’s work in decarbonization, visit the J-PAL North America Evidence for Climate Action Project webpage.