In December 2025, four Nelson Institute Center for Sustainability and the Global Environment (SAGE) affiliates published an analysis on how clean air regulation can be designed to achieve both climate and health goals. Paul Meier and Tracey Holloway, along with environment and resources MS students Xinran Wu and Cecilia Orth, suggest through their study that decarbonization does more than just curb climate change — it can drive substantial improvements in air quality.
For decades, the United States has improved air quality by reducing nitrogen oxides (NOX) and volatile organic compounds (VOCs), even though carbon dioxide (CO2) emissions have not fallen much. This study asks a simple question. What if efforts to fight climate change also helped clean the air?
To explore this, researchers looked at how the country could meet a stricter ozone standard proposed by the U.S. Environmental Protection Agency (EPA). They compared two approaches over a 15-year period: traditional pollution controls and larger energy changes — like switching to electric vehicles, cleaner fuels, and renewable electricity.
They found that in some regions, switching to cleaner energy alone could meet most air quality goals while cutting CO2 emissions by more than half. Adding traditional pollution controls on top of clean energy changes helped meet the remaining targets. In contrast, relying only on older pollution-control technologies led to smaller improvements and could even slightly increase CO2 emissions.
The results point to a clear conclusion. Moving toward cleaner energy can be one of the most effective ways to improve air quality and address climate change at the same time.
