Understanding Surface Ozone Pollution in Summer

As winter ends, the focus shifts from PM2.5 and PM10 particles, which dominate winter air quality discussions, to ozone pollution, particularly in summer.

Surface Ozone: A Summer Challenge

• Ozone is a hazardous pollutant and potent greenhouse gas.
• It poses significant health risks and impacts agricultural productivity.
• The threat is increasing with climate change and extreme weather events.

Formation of Surface Ozone

• Oxides of nitrogen and volatile organic compounds (VOCs) react under sunlight to form ozone.
• VOCs arise from human activities like vehicular emissions and industrial sources, as well as naturally from certain trees.
• Biogenic volatile organic compounds (BVOCs) are emitted by specific trees during high temperatures and sunlight.

Ozone in Lutyens’ Delhi

• Lutyens’ Delhi has many high BVOC-emitting trees such as ficus species, Phyllanthus sp, and Bauhinia sp.
• The area experiences high ozone levels during summer, with substantial spikes in 2019.

Factors Influencing Ozone Levels

• Temperature: Higher temperatures lead to increased BVOC emissions and ozone formation.
• Climate Patterns: Transition from La Niña to El Niño can intensify these effects by altering atmospheric conditions.

Implications and Mitigation

• Climate Penalty: Climate change exacerbates the frequency and severity of high-ozone days.
• Urban Planning: Integration of vegetation-sensitive planning is crucial for ozone mitigation.
• Policy Approach: Emphasizes science-based policymaking, airshed approaches over city-centric plans, and decisive emissions reductions.

In conclusion, addressing surface ozone pollution requires integrated strategies that align climate mitigation with air quality improvement efforts.