IIT-M study reveals impact of human activity on cloud formation along India’s coastal regions

New Delhi, Aug 26 (PTI) A study has found that human activities were a dominant factor in the growth of aerosols along India's coastal regions, challenging the common belief that organic particles inhibit cloud formation.

Researchers from the Indian Institute of Technology (IIT), Madras and Max Planck Institute for Chemistry, Germany, said that while organic particles can create surface films that affect cloud droplet formation, the study found that a significant increase in the number of organic particles can actually promote cloud formation.

The study has unveiled the profound influence of human activities on cloud-forming aerosols, also called ‘Cloud Condensation Nuclei’ (CCN), along India’s coastal regions, they said.

This is a critical area of research that continues to generate uncertainties in climate change predictions. The findings were published in the prestigious American Chemical Society's ES&T Air Journal.

Highlighting the importance of such research, M Ravichandran, Secretary, Ministry of Earth Sciences, 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," said Ravichandran, a renowned climate scientist who was not part of the research.

According to officials, the research challenges common beliefs about the role of organic aerosols and provides critical data to reduce uncertainties in global climate models.

The research team at IIT-Madras observed a startling 80-250 per cent increase in CCN concentrations following the COVID-19 lockdown.

This surge, as clearly shown by the study, resulted from more frequent new particle formation (NPF), a process where aerosol particles are formed from gases through complex chemical processes in the atmosphere, post-lockdown, as human-caused emissions slowly rebounded.

Sachin S Gunthe, Professor, 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.” 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.

"In coastal India, for instance, an increase in these organic particles led to a rise in cloud condensation nuclei (CCN), which are essential for cloud development. Despite their relatively lower ability to attract water compared to inorganic particles, the sheer number of organic particles allowed them to contribute effectively to cloud formation.

"This means that even particles we thought might hinder cloud growth can, under certain conditions, play a crucial role in creating clouds, ultimately influencing weather patterns and climate," Gunthe said. PTI GJS GJS SKY SKY