Climate change eroding ozone control

New research from the Massachusetts Institute of Technology reveals that rising global temperatures will make it more difficult to control ground-level ozone.

It’s air pollutant responsible for respiratory illness, cardiovascular diseas and thousands of premature deaths annually.

The study, published in Environmental Science and Technology, suggests that as the Earth warms, conventional strategies to reduce ozone levels may lose effectiveness in key regions.

“Future air quality planning should consider how climate change affects the chemistry of air pollution,” said lead author Emmie Le Roy, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “We may need steeper cuts in nitrogen oxide emissions to achieve the same air quality goals.”

Ground-level ozone forms through complex chemical reactions involving nitrogen oxides (NOx), volatile organic compounds and sunlight.

The team used an advanced modelling approach that captured meteorological changes, such as temperature and wind, under different climate scenarios for the years 2080–2095, compared with data from 2000–2015.

In regions like eastern North America and Western Europe, where natural NOx emissions from soil rise with temperature, reducing industrial emissions will yield smaller air quality improvements.

Conversely, in northeast Asia, emissions reductions are projected to be more impactful.

The study underlines the importance of incorporating real climate variability into air quality planning. “Average climate isn’t the only thing that matters,” said Le Roy. “One high ozone day… could mean we don’t meet our air quality target.”

The findings offer policymakers clearer guidance as they navigate the dual challenge of mitigating climate change and protecting public health.