According to new US research, warmer temperatures caused by climate change could cause an increase in ground-level ozone by 2050. According to the study, elevated ozone levels in the atmosphere may deteriorate air quality, possibly harming the lungs and inflaming the respiratory system.

James East, a PhD student at North Carolina State University and the first author of the study, said, "Climate change affects ozone formation through a complex set of factors, but warmer temperatures are correlated with increases in ozone in polluted areas."

The ozone layer in the Earth's atmosphere is known to protect people from harmful sun radiation, but ozone gas on the ground is often formed when air pollutants, including volatile organic compounds (VOCs) and nitrogen oxides, interact. These pollutants are released as gases from solids and liquids like paints, pesticides, cleaning supplies, building materials, and furnishings. When fuel is burned, nitrogen oxides are produced. Indoors versus outdoors, volatile organic compounds (VOCs) can have both immediate and long-term health impacts.

The study, published in the journal Earth's Future, suggests that areas with higher pollution levels will likely see more ozone as temperatures rise. East noted, "Climate change is expected to increase naturally occurring VOC emissions in some parts of the US, such as the Southeast, making the problem worse."

While previous studies have shown that climate change increases ozone pollution, this research addresses the uncertainty about what this increase could look like in the US. The researchers examined how much the increased levels of ozone would exceed air quality standards and how this might change by 2050.

In an extreme situation with elevated carbon dioxide levels, there is a possibility of an increase in ozone above 2.3 parts per billion. The levels could rise by 0.3 parts per billion in the best-case scenario. This would mean more days of poor air quality for many parts of the country.

In practical terms, our study finds that between 5 million and 13 million additional people will be exposed to dangerously high levels of ozone in 2050," East said.

The findings also suggest that current efforts to reduce emissions might not be enough to meet ozone standards for many parts of the US, especially those already struggling with air quality.

"Right now, state and federal governments are trying to manage ozone levels by reducing emissions of air pollutants," said Fernando Garcia Menendez, NC State associate professor of environmental engineering and corresponding author of the study. "This work suggests that the current emissions reduction efforts may be less effective for helping meet ozone standards for many parts of the country, particularly those that are already struggling to meet air quality standards."

Garcia Menendez added, "Atmospheric chemistry is complex, and climate change affects the rate of chemical reactions, the amount of ozone precursors present, and how long the ozone will linger in the environment." The team built on various existing models and used statistical tools to account for the wide array of variables impacting ozone pollution in the future.

In order to support policy decisions, such as the EPA's current review of the ozone air quality standard, the researchers believe that this study will provide vital information. The Canadian Natural Sciences and Engineering Research Council provided funding for the project.

(Inputs from various sources)

(Rehash/ Susmita Bhandary/MSM)