Better Air Quality Conference 2026: Daily Update from Pre-Event Session Building Momentum on Tropospheric Ozone – 10 March 2026

10 March 2026,  Bangkok - Ahead of the Better Air Quality (BAQ) Conference 2026, the Clean Air Fund, Climate and Clean Air Coalition, and the Super Pollutant Action Alliance convened a pre-event session on “Opportunities to address tropospheric ozone alongside fine particulate matter in Asia.” 

The message from experts across the region was clear: while many countries have made progress in reducing fine particulate matter, tropospheric ozone is emerging as one of the next major challenges for clean air, climate, public health, and economies. 

Tropospheric ozone forms when pollutants from vehicles, industry, and other sources react in sunlight. It damages lungs, reduces crop yields, and contributes to climate warming. 

Research highlighted during the session indicates that around 500,000 deaths globally each year are linked to long-term exposure to tropospheric ozone, yet it remains under-recognised in many air quality policies. 

Speakers shared experiences from across Asia and beyond, highlighting the need for: 

• Monitoring and emissions data, particularly for tropospheric ozone precursor pollutants 
• Integrated strategies that address tropospheric ozone alongside fine particulate matter 
• Regional cooperation, since air pollution crosses borders 
• Clear communication linking tropospheric ozone to health, climate, and food security 

Speakers shared experiences and lessons from several countries: 

Thailand  

Highlighted national efforts to control tropospheric ozone and fine particulate matter through emission inventories, modelling, and vehicle pollution policies, while noting challenges from rapid growth in the vehicle population. 
 

China  

Shared insights from its air quality policies that have significantly reduced fine particulate matter. The experience underscored the need for balanced control of tropospheric ozone precursor pollutants, while ongoing electrification of transport and nitrogen oxide reductions are expected to contribute to future declines in tropospheric ozone. 
 

Japan  

Emphasized the importance of long-term monitoring systems and regional collaboration, noting that air pollution can travel across borders and affect air quality beyond national boundaries. 

Perspectives from India, Indonesia, and Mexico among the participants engaging in the dialogue highlighted the importance of sustained monitoring, improved emissions data, and integrating tropospheric ozone into broader clean air strategies, as well as opportunities to share knowledge and best practices. 

This discussion marks the beginning of a broader effort to bring greater global attention and coordinated action on tropospheric ozone and PM2.5 for integrated climate and clean air action and benefits. We look forward to continuing this conversation with partners across governments, cities, organisations, and other stakeholders as momentum grows.