Air pollution and a warming climate are compounding threats to the lungs, straining health systems and deepening existing inequities
Air pollution remains one of the leading environmental risk factors for respiratory disease. Fine particulate matter (PM2.5), ground-level ozone, nitrogen oxides, and volatile organic compounds from transport, fossil fuel combustion, industry, agriculture, and household products can inflame the respiratory tract, reduce lung function, and worsen conditions such as asthma and chronic obstructive pulmonary disease (COPD).
Estimated global deaths associated with PM2.5 exposure, 2019
In 2019, PM2.5 exposure was associated with an estimated 6.7 million deaths globally, highlighting the significant health burden of poor air quality. Climate change further amplifies these risks through higher temperatures that promote ozone formation, reduce pollutant dispersion, and increase the frequency and severity of wildfires.
Climate change is also altering environmental conditions that affect respiratory health. Longer and more intense pollen seasons are increasing allergic respiratory illnesses, while changing weather patterns introduce new aeroallergens to previously unaffected regions. Heatwaves, droughts, and floods can further increase mold exposure, trigger asthma outbreaks, and worsen air quality. These changes are associated with declining lung function, increased emergency visits and hospitalizations, and higher mortality among people with respiratory diseases.
Children, older adults, pregnant women, people with asthma or chronic lung disease, outdoor workers, and those with weakened immune systems are particularly vulnerable. Children face greater risks because their lungs and immune systems are still developing and they breathe more rapidly than adults. However, increasing wildfire smoke, urban pollution, and PM2.5 exposure make respiratory health a broader public health concern, disproportionately affecting communities already facing health and social inequities.
Protecting respiratory health requires coordinated climate, health, and environmental action. Reducing fossil fuel emissions, strengthening air quality standards, expanding urban green spaces, improving early warning systems, and investing in climate-resilient health systems can deliver immediate health benefits while reducing climate risks. Aligning national air quality standards with WHO Air Quality Guidelines, as advocated by the European Respiratory Society, can simultaneously improve respiratory health and advance climate mitigation. These health co-benefits demonstrate that reducing greenhouse gas emissions can also reduce respiratory disease and improve quality of life.
As climate negotiations shift from commitments toward implementation, COP31 presents an opportunity to place health more firmly at the center of climate action. Integrating respiratory health into climate adaptation, mitigation, and financing strategies can strengthen policy coherence and ensure climate investments deliver measurable health benefits.
Adjunct Professor, Georgetown University
