Evaluating Air Quality and Climate Mitigation Pathways

Climate-oriented energy system changes are often associated with air quality “co-benefits,” where efforts to reduce carbon emissions also reduce emissions of reactive pollutants with adverse health impacts. These co-benefits arise because carbon dioxide is often co-emitted with nitrogen oxides (NOx), sulfur dioxide (SO2) or other pollutants. Despite the air quality co-benefits of carbon reductions, there is not necessarily a reduction of carbon emissions from air quality management strategies. With funding from ExxonMobil Technology and Engineering Company, our team is evaluating how policies to address air quality can be designed to achieve climate benefits and vice versa.

Objectives

We are developing a modeling framework that integrates energy and atmospheric models to different air quality regulation and climate mitigation scenarios for the 2025–2050 period. We will compare energy pathways to understand how to achieve air quality goals, climate goals, and combined goals for both air quality targets and carbon reductions.

By integrating the EPA’s Community Multiscale Air Quality (CMAQ) model and the Global Change Analysis Model for the United States (GCAM-USA) model, our team will:

• Estimate emission reductions required to attain hypothetical national air quality standards
• Evaluate how the energy system responds when required to meet air quality targets.
• Evaluate how energy system pathways differ under different policy scenarios: 1) air quality constraints only, 2) climate-based constraints only, and 3) combined air quality and climate constraints.

Outcomes

The integration of these models will provide a high-impact toolbox to identify strategies that maximize combined air quality and climate benefits per dollar invested.