6^thWebinar: Air Pollution Impacts on Health, Ecosystem and Climate Linkages in South Asia

Webinar Series on Air Quality Management: Science and Investment for Sustainable Development
in Malé Declaration Member Countries

31 August 2026Webinar

The Regional Resource Centre for Asia and the Pacific at the Asian Institute of Technology (AIT RRC.AP), supporting the South Asia Co-operative Environment Programme (SACEP), the Secretariat of Malé Declaration, organized the 6th Webinar in the Series on 31 August 2026 under the topic “Air Pollution Impacts on Health, Ecosystem and Climate Linkages in South Asia”. The webinar brought together 93 participants (42 male and 51 female) from countries across South Asia and Southeast Asia, as well as China, South Korea, Mongolia, Ethiopia, Qatar, and Turkmenistan. Participants represented government agencies, the private sector, academia, and students, reflecting a diverse group of stakeholders interested in air pollution, climate change, health, and ecosystem issues.

The webinar highlighted the close links between air pollution, climate change, human health and ecosystems in South Asia. The presentations covered the impacts of ground-level ozone on crops and ecosystems, the combined effects of air pollution and climate change on human health and ecosystems, and the climate and air pollution challenges being faced by Bhutan and the Himalayan region. A key message from the discussions was that air pollution and climate change cannot be addressed separately, as their impacts are closely connected.

The webinar also emphasized the need for better impact monitoring and regional data, stronger research, evidence-based decision-making, integrated mitigation and adaptation, and regional cooperation. The Malé Declaration was highlighted as an important platform to strengthen the link between science and policy and support coordinated action across South Asia.

Opening Session

Dr. Vanisa Surapipith, Head of the Air Pollution Cluster, AIT RRC.AP, welcomed participants and introduced the webinar as the sixth session of the Malé Declaration Webinar Series. She briefly presented the background and evolution of the Malé Declaration since 1998, including its work on capacity building, air pollution impact assessment, institutional arrangements and policy development. She also highlighted ongoing efforts to revitalize the Malé Declaration and strengthen regional cooperation in South Asia. She then introduced the three presentations, which examined air pollution impacts on ecosystems, the combined impacts of climate change and air pollution on health and ecosystems in South Asian cities, and climate change and air pollution impacts from the perspective of Bhutan and the Himalayan region.

Presentations Session

Air Pollution Impacts on Ecosystem: Research and Evidence-based Decision Support for South Asia by Prof. Lisa Emberson, Environment & Geography Department, University of York, U.K

Prof. Lisa Emberson focused on tropospheric or ground-level ozone, noting that it is increasingly moving up the policy agenda as a super pollutant. She explained that ozone affects human health, climate and ecosystems, so controlling it can bring multiple benefits. She showed that ozone can damage crops, forests and semi-natural vegetation, including reducing crop yields and pasture quality.

She explained that crops differ in their sensitivity to ozone. Soybeans and wheat appear relatively sensitive, while rice and maize are somewhat less sensitive, and cultivars also vary in sensitivity. She highlighted a major knowledge gap in Asia, where most ozone monitoring is conducted in cities, while much less is known about ozone concentrations and ecosystem impacts in rural areas.

Prof. Emberson highlighted South Asia as a hotspot for ozone damage. Drawing on an India case study, she reported an average wheat yield loss of around 14%, equivalent to about 15 million metric tonnes of production loss, with wider implications for producers, consumers and government. She also noted that ozone impacts can be of similar importance to nutrient and heat stress, while available evidence suggests that ozone exposure affecting vegetation may be increasing in some parts of Asia.

She concluded that there are opportunities to mitigate and adapt by reducing ozone precursor emissions such as methane, selecting more tolerant crop varieties and adjusting crop management. She stressed that ozone affects not only crop yield, but also grain nutritional quality, forest biomass and carbon sequestration, making it important for food security, ecosystems and climate.

Climate Change and Air Pollution Synergistic Impacts on Health and Ecosystems in South Asian Cities by Dr. Pallavi Saxena, Hindu College, University of Delhi, India

Dr. Pallavi Saxena discussed the synergistic approach of climate change and air pollution and their combined impacts on human health and forest ecosystems in South Asian cities. She explained that there is a climate penalty for air quality, where rising temperatures and vegetation stress can influence the formation of secondary pollutants such as tropospheric ozone and secondary organic aerosols. These interactions can contribute to photochemical smog, atmospheric brown clouds and further climate warming.

Drawing on her research from India, she presented examples of Thar Desert dust storms and forest-fire activity to demonstrate how climate-related extreme events can affect regional air quality. She also discussed the impacts of ozone and particulate matter on vegetation, including changes in plant physiology, plant signalling, reproductive processes and plant pollinator interactions. She emphasized that climate change and air pollution can create multiple stresses on ecosystems, affecting plant growth, productivity and ecosystem health.

On human health, she highlighted the combined risks of air pollution and climate change, including respiratory and cardiovascular diseases, heat stress, low birth weight and preterm birth. She briefly shared a study showing reductions in air pollutants and associated health risks during the COVID-19 lockdown, as well as a study on high winter PM2.5 exposure among university students in Delhi. She also identified residential biomass burning, crop-residue burning, industries and transport as major contributing sectors, and highlighted the Indo-Gangetic Plain as an important shared airshed and food producing region where these pressures can also affect food security.

Dr. Saxena concluded that South Asian countries need to address climate and air pollution linkages together. She highlighted regional airshed management, a shared regional air quality monitoring network, transboundary cooperation, data harmonization, SLCP reduction and nature-based solutions such as green roofs, green walls and urban green spaces. She described green infrastructure as a cost-effective approach that can support air quality improvement, climate mitigation and health benefits at the same time.

Trend of Environmental Conservation, Climate Change, and Air Quality in Bhutan by Dr. Om Katel, Department of Environment & Climate Studies, Royal University of Bhutan, Bhutan

Dr. Om Katel presented Bhutan's experience in linking environmental conservation, climate change and air pollution. He explained that Bhutan's conservation approach is strongly rooted in traditional ecological knowledge and Buddhist principles of harmony with nature. These values have shaped national policies, including the constitutional requirement to maintain at least 60% forest cover at all times to come, together with the broader development philosophy of Gross National Happiness.

Despite its extensive forest cover, Dr. Katel stressed that Bhutan remains highly vulnerable to climate change. He highlighted rising temperatures, changing rainfall patterns, glacier retreat and increasing glacial-lake risks, with implications for downstream communities, hydropower, agriculture, water resources and food security. He also noted that forests provide important climate and ecosystem benefits, but increasing forest-fire activity can in turn worsen air quality.

On air pollution, Dr. Katel noted that concerns have increased with urbanization, particularly for PM2.5, black carbon and other aerosols. He highlighted the importance of transboundary pollution, explaining that a substantial share of pollution affecting Bhutan comes from outside the country. He also stressed that Bhutan is still short of data and needs stronger monitoring and research to better understand the links among air pollution, climate change and the Himalayan environment.

Q&A Highlights

The Q&A session included questions raised verbally, questions submitted through webinar registration form and provided through webinar chat and Q&A boxes. The discussion mainly focused on ozone impacts, research and monitoring needs in South Asia, communication of scientific evidence, and climate-related disaster risks.

Research capacity on ozone impacts: Participants asked how South Asia could strengthen research and involve students and researchers. Prof. Emberson explained that work could follow two main approaches: experimental studies and modelling/risk assessment. Important gaps include understanding ozone concentrations in rural areas and how different crops and cultivars respond. She suggested that a coordinated experimental programme, together with training in crop modelling and risk assessment, would be particularly useful for the region. The CCAC AQMx initiative was also mentioned as a useful resource for assessing ecosystem impacts under different levels of available data and capacity.
Impacts of ozone on human health and biodiversity: In response to questions from the chat box, Prof. Emberson confirmed that ground-level ozone has substantial human health impacts, particularly on the respiratory system. She noted, however, that PM2.5 accounts for a much larger number of premature deaths than ozone. Ozone can also affect terrestrial biodiversity, for example by changing the balance of grasses and legumes in grasslands. Direct impacts on marine biodiversity are considered unlikely because ozone reacts and degrades on contact with seawater.
Ground-level ozone and stratospheric ozone: The discussion clarified an important distinction between stratospheric ozone, which is associated with the Montreal Protocol, and tropospheric or ground-level ozone, which is an air pollutant that directly affects human health and vegetation. Ground-level ozone can be controlled by reducing its precursor emissions, including NOₓ, VOCs, methane and CO.
Ozone data and monitoring in South Asia: Prof. Emberson noted that current modelling provides reasonable confidence in ozone concentrations across South Asia, allowing medium-confidence estimates of risks to crops and vegetation. However, these assessments would be much stronger with more rural ozone observations, particularly across areas such as the Indo-Gangetic Plain. She emphasized that rural ozone concentrations remain an important knowledge gap for assessing impacts on agriculture and ecosystems.
• Communicating ozone impacts and supporting action: The discussion highlighted the need to communicate ozone impacts beyond the air-pollution community by linking them with agriculture, forests, biodiversity, carbon sequestration and other policy interests. Prof. Emberson also suggested that demonstrating the economic costs of not tackling ozone could help make investment in monitoring and risk assessment more convincing. She noted that evidence remains particularly limited for ozone impacts on tropical forests.
Glacier retreat and disaster risk in Bhutan: A question to Dr. Om Katel asked what Bhutan could learn from the recent catastrophic flash-flood in Nepal in the context of glacier retreat and accelerated cryosphere loss. He emphasized the importance of early-warning systems, real-time upstream-to-downstream information, hazard and risk assessment, mapping, and careful planning of development along river basins. He also referred to the potential role of forests and nature-based solutions in reducing risks.
Using research and data for decision-making: Dr. Katel added that research findings are sometimes not sufficiently considered in decision-making. He stressed the need to generate quality data, examine data critically and use scientific evidence to make informed decisions, particularly when addressing climate-related disasters.

Concluding Remarks

Prof. Johan Kuylenstierna, Stockholm Environment Institute (SEI), York, U.K.

Prof. Johan Kuylenstierna reflected that air pollution remains a serious problem in South Asia and is clearly a regional and transboundary issue. He stressed that, alongside national action, regional cooperation is an absolute necessity. He highlighted the serious impacts on human health, crops, forests and biodiversity, particularly from PM2.5 and tropospheric ozone. A key message from the presentations was that we cannot really separate air pollution and climate change, as both are important for the future development of the region.

Prof. Kuylenstierna emphasized the need for more data and evidence from the region, particularly on ecosystem impacts, to help policymakers understand the scale of the problem. He noted that impacts on crops and ecosystems should also be connected to their economic impacts, livelihoods and food availability. He highlighted the Malé Declaration as an opportunity to make a closer linkage between the research and the policy.

Prof. Kuylenstierna also stressed that climate change and air pollution are linked through issues such as secondary aerosols, monsoon changes, black carbon, glacier melting and forest fires, requiring both mitigation and adaptation. He stressed the benefits of addressing air pollution and climate change in an integrated way. For example, shifting from private cars to public transport, particularly electric buses, can reduce congestion and air pollution, while active mobility can also bring health benefits. He pointed to Bhutan's use of renewable electricity for mobility and cooking as a good example that could be shared across the region. He concluded that the region needs to link the science to the decision making and use the Malé Declaration to bring science and policy together, supported by stronger evidence, knowledge and resources

Concluding Remarks by Prof. Johan Kuylenstierna

Concluding Sessions

Dr. Vanisa Surapipith thanked the speakers and participants for their contributions and closed the webinar. She informed participants that the webinar recording would be made available following confirmation from the speakers and presentation materials would be shared with registered participants upon speakers' approval. Participants were also encouraged to complete the post-webinar evaluation form and continue engaging in future activities under the Malé Declaration Webinar Series.

​​6thWebinar: Air Pollution Impacts on Health, Ecosystem and Climate Linkages in South Asia

Webinar Series on Air Quality Management: Science and Investment for Sustainable Developmentin Malé Declaration Member Countries