Industrial emissions are one of the precursors to ozone formation. Credit: Sumaira Abdulali/CC BY 4.0
A long-term study in India using satellite and ground-based data has revealed increasing trends in tropospheric or ground-level ozone, a major component of smog1.
Tropospheric ozone is the third most important greenhouse gas after carbon dioxide and methane. High concentrations can cause breathing problems, premature death in humans, and damage plant growth.
Scientists at the Indian Institute of Technology Kharagpur analyzed seasonal and year-to-year variability, long-term trends and radiative forcing of ozone from 2005 to 2020.
Peninsular India showed the highest trend and the northwest the lowest. Seasonally, the highest trend was during the monsoon, while the pre-monsoon had the lowest trend.
“The enhanced ozone can warm our climate up to 0.2 °C to 0.5 °C depending on the region,” says Jayanarayanan Kuttippurath.
Ozone is a secondary pollutant formed as a byproduct of chemical reactions that occur when nitrogen oxides (NOx) and volatile compounds (VOCs) interact with sunlight.
Natural sources such as lightning, biomass burning, biogenic emissions, and anthropogenic sources such as industrial emissions and vehicle exhaust pollution are precursors to ozone formation.
The study warns that ozone pollution in India could shoot up because of population growth, climate change, and anthropogenic emissions. Policy measures are needed to control air pollution, which would reduce tropospheric ozone levels.
