Resources for the Future (RFF) has released its first assessment—called a “carbon score”—of key federal climate policies and their effects on US emissions. This carbon score sets a baseline for future assessments by RFF’s Carbon Scoring Project.
Last year, Resources for the Future (RFF) announced the kickoff of our Carbon Scoring Project. The goals of the project are to provide timely, nonpartisan, and transparent “carbon scores” for key legislation and other policies that could have substantial implications for greenhouse gas emissions. These carbon scores are analogous to the “budget scores” that assess the fiscal effects of legislation, which are provided by the nonpartisan Congressional Budget Office and have informed federal lawmaking for decades. Given the importance of climate change, understanding the effects on emissions of existing and potential policies, alongside the fiscal implications of those policies, can help in judging progress toward meeting national climate commitments and achieving a net-zero future. (For more about the project, see our kickoff blog post and accompanying op-ed.)
Today, we are putting forward an initial carbon score on a new, fully interactive platform. This initial carbon score provides RFF’s updated assessment of the Inflation Reduction Act and other recent federal regulations and will serve as our baseline against which additional carbon scores in 2024 will be generated.
Prior to producing this assessment, we interviewed an array of stakeholders to understand the metrics that they wished to see in a carbon score. Our baseline carbon score provides the primary metrics for emissions that we would expect an effort sponsored by Congress to include, such as the annual and cumulative effects of policy options on emissions through 2040, along with comparisons to milestones for US climate goals and alternative pathways to decarbonization. We also assess the health effects of policies by region, provide metrics that can track outcomes in the power and transportation sectors, and evaluate the benefits and costs of various policy options.
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A top-level result from this initial carbon score is that the Inflation Reduction Act is projected to continue providing positive benefits and put the US economy on a trajectory that is consistent with a path to achieving net-zero emissions by midcentury, though emissions reductions increasingly fall short of this trajectory as we approach 2040. We find less rapid deployment of renewable energy resources in this carbon score than in our previous modeling of the Inflation Reduction Act, which we primarily attribute to downward-adjusted projections of prices for natural gas.
Our Approach to Carbon Scoring
The Carbon Scoring Project aims to assess emissions throughout the economy, including energy emissions (e.g., burning fossil fuels) and non-energy emissions (e.g., emissions from land use change). In our initial carbon score, we focus on energy-related emissions from the four sectors of the US economy that pollute the most: power, industry, transportation, and buildings.
We use RFF’s in-house models to project emissions from the power and transportation sectors: for the power sector, we use the Haiku model to simulate changes in power generation, and for the transportation sector, we use Vehicle Market Model to project household purchases of light-duty vehicles. We rely on outputs from the Annual Energy Outlook 2023 report, published by the US Energy Information Administration, to project emissions from the buildings, industrial, and transportation sectors (excluding emissions from light-duty vehicles in the transportation sector). Specifically, we incorporate emissions and electricity demand from these sectors in our projections, allowing us to account for both the effects on emissions of recent policies such as the Inflation Reduction Act and increased electricity demand from electrification in these sectors. Additionally, we quantify the health effects of reduced air pollution from the power sector with the Estimating Air Pollution Social Impact Using Regression model that was developed by the US Environmental Protection Agency.
All results for all scenarios that we examine are downloadable via the interactive data tool for the Carbon Scoring Project, per our commitment to transparency. The source code for the Haiku model is openly available, and we are working to make the data sets on which our models rely publicly available for future carbon scores, as well.
What’s Next?
Now that we’ve established this carbon score as our baseline, we’ll move on to assess two additional actions from the Environmental Protection Agency that are expected to be consequential in their respective sectors of the economy. The first is the updated greenhouse gas emissions standards for light-duty vehicles. The second is the suite of updated regulations under the Clean Air Act for fossil fuel–fired power plants; we will focus on the new regulations for greenhouse gases under Section 111(d) of the Clean Air Act.
Future carbon scores will expand in their coverage and detail as we continue to build our process for carbon scoring. We plan to assess the distribution of the impacts of policies across households using RFF’s Social Welfare Incidence Model (SWIM), which calculates the effects of reduced air pollution among households, notes changes in energy costs, and compares various approaches to financing a given policy. RFF’s Carbon and Land Use Model (CALM) is ready to be deployed to understand the effects of land use policies on non-energy emissions. Efforts also are underway at RFF to develop models for medium- and heavy-duty vehicles and decarbonization in the industrial sector. We plan to incorporate these models in future carbon scores as the models come online.
In short, we’re excited about taking this step forward and the steps to come as we continue to develop our process and capabilities for evaluating the effects of federal policy on climate change.
