Cities can achieve 20% of abatement potential as primary policy architects. Cities can achieve 80% of abatement potential as critical implementers and strategic partners.

A National Renewable Energy Laboratory (NREL) study finds that commonly implemented city actions in the United States could reduce emissions by 210–480 million metric tons of carbon dioxide (mmtCO2) per year by 2035. That’s 3%–7% of 2013 U.S. greenhouse gas emissions. 

For the study — called Estimating the National Carbon Abatement Potential of City Policies: A Data-Driven Approach — NREL used a unique new dataset of energy use in more than 23,400 cities. 

Study Result

NREL estimates national carbon dioxide (CO2) technical abatement potential and economic impacts of city CO2 reduction actions under different scenarios from 2020 to 2035. These ranges reflect estimates from a “moderate” abatement scenario based on conservative assumptions and a “high” abatement scenario based on the most optimistic assumptions from policy impact literature. See Figure 1. 

What is Technical Abatement Potential?

Abatement potential refers to the quantity of CO2 emissions that could be avoided by the implementation of a policy.

Abatement potential in this study is calculated as the difference between projected CO2 emissions in 2035 with and without the policy.

Technical abatement potential does not account for the economic or political feasibility of policies; however, this study models commonly implemented city actions that have already demonstrated some degree of economic and political feasibility.

Figure 1: Preliminary estimated national annual CO2 abatement potential in 2035 of six U.S. city policy areas (mtCO2/year).

NREL’s analysis includes city actions where the city is the primary policy architect. Additional city actions outside the scope of this report, such as community choice aggregation (city-level purchasing of renewable energy), zero energy districts, and multi-level governance strategies, could significantly augment the carbon abatement contributions of city actions toward national climate targets. The estimated national abatement potential of the city actions analyzed in this report equates to about 15%–35% of the remaining carbon abatement necessary to achieve the U.S. climate change target, which was established during the 2015 Paris Climate Conference (COP21) (Figure 2).

Figure 2. Carbon abatement potential of common city actions in the context of U.S. COP21 targets (high abatement potential scenario)

Figure 2. Carbon abatement potential of common city actions in the context of U.S. COP21 targets (high abatement potential scenario).

The results of the study show regional variation in the impact of specific policy areas. In general, they suggest cities in colder northern climates have the potential for higher CO2 abatement through building energy policies, while more temperate coastal cities might have higher potential CO2 abatement through transportation and renewable energy policies. See Figure 3. 

Figure 3. The estimated CO2 abatement potential of building energy codes is about 50% higher in Midwestern cities than other cities.

Figure 3. The estimated CO2 abatement potential of building energy codes is about 50% higher in Midwestern cities than other cities.

Key Considerations from the Study

Based on the study, some key considerations for cities prioritizing CO2 reduction actions include:

  • The CO2 abatement potential of different policy areas varies regionally and according to unique city characteristics. Every city’s CO2 abatement pathway will vary based on its own set of energy use characteristics.
  • The preliminary results shown represent the CO2 abatement potential of city-led actions; however, cities may achieve greater CO2 reductions in partnership with state and federal authorities.

Study Assumptions and Methodology

The abatement potential estimates are founded on literature-based assumptions applied to a dataset of energy use in 23,400 cities compiled for the U.S. Department of Energy’s City Energy Profile Tool.

For example, NREL estimated the CO2 abatement potential of building energy code policies as a function of a:

  • Building energy use baseline
  • Policy-driven change in building code energy realization rates
  • CO2 intensity of the local grid

Other Data and Information Sources

For this study, NREL also cites the following data and information sources: