IIT Madras Research Maps Human Influence on Aerosol Levels and Coastal Climate

An international study led by IIT Madras has uncovered the significant impact of human activities on aerosols and climate patterns in India’s coastal regions.

IIT Madras Research Maps Human Influence on Aerosol Levels

An international study led by the Indian Institute of Technology (IIT) Madras has revealed critical insights into aerosols, tiny airborne particles that play a key role in cloud formation and precipitation. Conducted between March and July 2020, the research highlights the strong influence of human activities on cloud-forming aerosols, known as ‘Cloud Condensation Nuclei’ (CCN), across India’s coastal regions. The findings carry significant implications, as they provide robust empirical data to refine climate models, reduce uncertainties, and improve the accuracy of future climate predictions.

The research also found that anthropogenic organic matter was the dominant factor in the growth of these new particles, challenging the common belief that organic particles inhibit cloud formation. While it is true that organic particles can create surface films that affect cloud droplet formation, this study found that a significant increase in the number of organic particles can actually promote cloud formation.

The findings has been published in the American Chemical Society's ES&T Air Journal (https://doi.org/10.1021/acsestair.5c00180) in a paper co-authored by Prof. Sachin S. Gunthe, Coordinator, Center for Atmospheric and Climate Sciences, IIT Madras, Aishwarya Singh, a former PhD student at IIT Madras who is now a post-doctoral researcher at the Max Planck Institute for Chemistry in Mainz, Germany, Prof. R. Ravikrishna, faculty, IIT Madras, and other National and International researchers.

Highlighting the importance of such research, Dr. M. Ravichandran, Secretary, Ministry of Earth Sciences, Government of India and a renowned climate scientist who was not part of this research, said, “Aerosol-cloud interactions are intrinsically complicated, and these findings underscore that human activities can dramatically influence underlying processes. This is critical information for negotiating future atmospheric dynamics.”

Elaborating on this research, lead researcher and atmospheric scientist Prof. Sachin S. Gunthe, also a faculty in the Environmental Engineering Division, Department of Civil Engineering, IIT Madras, said, “Our research reveals that anthropogenic emissions strongly influence aerosol behaviour, particularly in how they form clouds. These findings challenge existing models and propose new avenues for understanding how human activities shape climate patterns.”

Further, Aishwarya Singh, a former PhD student at IIT Madras who is now a post-doctoral researcher at the Max Planck Institute for Chemistry in Mainz, Germany, said, “We witnessed firsthand how the drastic reduction in air pollutants during the lockdown provided a unique ‘natural experiment’. Our observations show that a cleaner atmosphere can be highly sensitive to new emissions, altering the aerosol-cloud interactions significantly, which can have a profound impact on climate predictions.”

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