New Delhi: Climate change could significantly worsen air quality across large parts of North America by the end of the century, exposing millions more people to unhealthy levels of pollution during summer months, according to a new study published by researchers from the University of Waterloo.
The research warns that rising temperatures, changing weather patterns and increased atmospheric instability could reverse decades of progress made in improving air quality, posing serious health risks to vulnerable populations.
According to the study, nearly 100 million Americans could be exposed to unhealthy summer air by 2100, compared to around 14 million people in 2000. Researchers found that climate change is likely to increase the frequency and intensity of air quality alerts, particularly during warmer months.
Air pollution is already considered one of the leading environmental causes of premature deaths worldwide. Exposure to polluted air has been linked to lung cancer, respiratory infections, cardiovascular diseases and several chronic health conditions.
The researchers noted that even countries with relatively cleaner air, such as Canada, experience significant health and economic impacts from air pollution. More than 17,000 premature deaths and economic losses exceeding $140 billion annually have been linked to poor air quality in Canada alone.
Scientists explain that climate change affects air quality in several ways. Rising temperatures can accelerate chemical reactions that create harmful pollutants, while changing wind patterns and rainfall can allow pollutants to accumulate in the atmosphere for longer periods.
The study used models of the global economy, climate systems, atmospheric conditions and public health to assess future risks. Findings suggest that health risks associated with air pollution could double for sensitive groups if current trends continue.
Researchers warned that climate change may undermine many of the air quality improvements achieved through environmental regulations over the past five decades.
Certain populations are expected to face a higher burden from worsening air quality. These include children, older adults, pregnant women and people with existing health conditions such as heart disease, lung disorders, diabetes and cancer.
Outdoor workers and individuals who regularly engage in physical activity outdoors are also considered particularly vulnerable.
The study found that people aged over 65 and young adults between 18 and 35 years could gain significant health benefits by reducing exposure during air quality alert periods. However, researchers noted that many people remain unaware of air quality warnings or lack the resources needed to protect themselves.
The researchers acknowledged that their projections may actually underestimate future pollution levels because the study did not fully account for the growing impact of wildfires.
Climate change is increasing the frequency and intensity of wildfires across North America, producing massive amounts of fine particulate matter, one of the most dangerous forms of air pollution. The devastating wildfire season of 2023 caused several Canadian and American cities to experience record-breaking pollution levels.
Experts believe future wildfire activity could further worsen air quality beyond current projections.
The study concludes that reducing greenhouse gas emissions remains one of the most effective ways to prevent severe air pollution in the future. Researchers argue that policies aimed at limiting climate change could stabilise air quality by mid-century and prevent many pollution-related health risks.
They also recommend improving building ventilation, air filtration systems and access to clean indoor spaces as long-term adaptation measures. As climate change continues to reshape environmental conditions, experts say both pollution control and climate action will be essential to protect public health in the decades ahead.