Abstract
Carbon dioxide and non-greenhouse gas air pollutants are emitted from many of the same sources. Decarbonization actions thus typically yield air pollutant emission reductions, resulting in significant air quality benefits. Although several studies have highlighted this connection, including in the context of net zero carbon emission targets, substantial uncertainty remains regarding how alternative technological pathways to this goal will affect the spatial distribution and magnitude of air pollutants. Comprehensive multi-model and multi-scenario analyzes are needed to explore the relative impacts of alternative pathways. Our study begins to address this gap by leveraging the results from the recent Energy Modeling Forum 37 inter-model comparison exercise on U.S. decarbonization pathways. Comparing the results of the six teams who submitted air pollutant emissions suggests that strategies that target net zero U.S. carbon emissions would yield significant reductions in many air pollutants, and that this finding is generally robust across pathways. However, some energy sources, such as biomass and fossil fuels with carbon capture, will emit air pollutants and can potentially influence the magnitude, spatial distribution, and even sign of localized air pollutant emission changes. In the second part of this analysis, a simplified air quality and health impacts screening model is used to evaluate the air quality impacts in 2035 of sectoral emission changes from the three models that provided sectoral detail. Relative to a reference scenario, a net zero pathway is estimated to reduce fine particulate matter concentrations across the contiguous U.S., with health benefits from reduced mortality ranging from $65 billion to $250 billion in 2035 alone (2023$s). These benefits would be expected to grow over time as the net zero trajectory becomes more stringent. Both the magnitude of potential benefits and the substantial variation of the projections across models underscore the need for an EMF-like inter-model comparison exercise focused on air quality.
| Original language | English |
|---|---|
| Article number | 100165 |
| Journal | Energy and Climate Change |
| Volume | 5 |
| DOIs | |
| State | Published - Dec 2024 |
Funding
Many additional parties have contributed to this work, including: the five modeling teams that submitted air pollutant results to the EMF 37 database (EPA-TIMES, EPS, FECM-NEMS, GCAM, MARKAL-NETL); the three teams that provided sectoral results at our request (EPS, GCAM, WITCH); Morgan Browning of the U.S. EPA, who provided quality assurance for the EMF 37 data submissions; and John Weyant of Stanford Univ., Jim McFarland of the U.S. EPA, and the rest of the EMF 37 steering committee, who perceived the utility of this study and supported its development. DM acknowledges support from the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy. SS acknowledges support from the U.S. Department of Energy Office of Fossil Energy and Carbon Management. LS and JE acknowledge support from the European Union's Horizon Europe research and innovation programme under grant agreement No 101056891 (CAPABLE). The views expressed in this manuscript are those of the authors and do not necessarily represent the views or policies of their respective institutions, including the U.S Environmental Protection Agency, ORNL/UT-Battelle, and the U.S. Department of Energy. Many additional parties have contributed to this work, including: the five modeling teams that submitted air pollutant results to the EMF 37 database (EPA-TIMES, EPS, FECM-NEMS, GCAM, MARKAL-NETL); the three teams that provided sectoral results at our request (EPS, GCAM, WITCH); Morgan Browning of the U.S. EPA, who provided quality assurance for the EMF 37 data submissions; and John Weyant of Stanford Univ. Jim McFarland of the U.S. EPA, and the rest of the EMF 37 steering committee, who perceived the utility of this study and supported its development. DM acknowledges support from the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy. SS acknowledges support from the U.S. Department of Energy Office of Fossil Energy and Carbon Management. CBC and AOM were supported by the Smith College Strickler Fund. The views expressed in this manuscript are those of the authors and do not necessarily represent the views or policies of their respective institutions, including the U.S Environmental Protection Agency, ORNL/UT-Battelle, and the U.S. Department of Energy.
| Funders | Funder number |
|---|---|
| Laboratory Directed Research and Development Program | |
| Office of Fossil Energy and Carbon Management | |
| Oak Ridge National Laboratory | |
| European Physical Society | |
| U.S. Department of Energy | |
| EPA-TIMES | |
| U.S. Environmental Protection Agency | |
| Smith College Strickler Fund | |
| European Union's Horizon Europe research and innovation programme | 101056891 |
Keywords
- Air pollutants
- Air quality
- Climate
- Decarbonization
- Emissions
- Health co-benefits
