Climate change could raise ozone levels, cause serious respiratory issues, study finds

New Delhi: Warmer temperatures, driven by climate change, could spike ozone levels on ground by 2050, a new research in the US has found.

According to researchers, the increased ozone in the air could worsen air quality, potentially affecting lungs and causing inflammation in the breathing tract.

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

While the ozone layer in the Earth's atmosphere is known to protect people from harmful radiations from the Sun, the ozone gas on ground is often formed when air pollutants, including volatile organic compounds (VOCs) and nitrogen oxides, interact. The gas can also naturally occur.

VOCs are released as gases from solids and liquids, such as paints, pesticides, cleaning supplies, building materials and furnishings, among others. Levels of VOCs have been consistently shown to be higher indoors than outdoors and have adverse short-term and long-term effects on health. Nitrogen oxides are formed when fuel is burned.

The findings, published in the journal Earth's Future, suggest that areas already having higher levels of air pollution will likely see ozone levels rise as average temperatures go up, East said.

"What's more, climate change is expected to increase naturally occurring VOC emissions in some parts of the US, such as the Southeast, exacerbating the challenge," the author said.

While previous studies have established climate change to increase ozone pollution, the researchers said they have addressed the uncertainty around what this increase could look like in the US.

They looked at how far the increased levels of ozone would overshoot the air quality standards and how that might change by 2050.

In the worst case scenario, where carbon dioxide levels are high, ozone levels could go up by more than 2.3 parts per billion, whereas in the best scenario, the levels could go up by 0.3 parts per billion, the researchers found, which they said 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 directed at reducing emissions are less effective for helping meet ozone standards for many parts of the country (US), especially those already struggling to meet the air quality standards, the researchers said.