An unprecedented triple-dip La-Nina event, extended by climate change, triggered a peculiar trend in the 2022-23 winter season where air quality improved in north India while peninsular India recorded an increase in pollution levels, according to a new study released on February 18.

• The study by a team of scientists led by Gufran Beig, Chair Professor, National Institute of Advanced Studies, emphasised that besides local emissions, rapidly changing climate is a significant factor affecting air quality.
• Published in the Elsevier Journal, the study reveals that the air quality worsened in peninsular Indian cities in the 2022-23 winter season but improved in the northern part of India, contrary to the trends seen in recent decades.
• Among the north Indian cities, Ghaziabad registered the most significant improvement with a reduction of 33%, followed by Rohtak (30%) and Noida (28%).
• Delhi, being the most critical and landlocked city, showed an improvement of around 10%.
• On the contrary, Mumbai recorded the highest deterioration with a 30% increase in PM2.5 levels, followed by other peninsular Indian cities like Coimbatore (28%), Bengaluru (20%), Chennai (12%), etc.