Rare 'triple-dip' La Nina behind unusual air quality trend in India in 2022-23, says study
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 Sunday. The three consecutive years of La Nina conditions (2020-23) — a rare «triple-dip» phenomenon — had widespread impacts on the ocean and climate across the globe.
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 percent, followed by Rohtak (30 percent) and Noida (28 percent). Delhi, being the most critical and landlocked city, showed an improvement of around 10 percent.
On the contrary, Mumbai recorded the highest deterioration with a 30 percent increase in PM2.5 levels, followed by other peninsular Indian cities like Coimbatore (28 percent), Bengaluru (20 percent), Chennai (12 percent), etc.
Many North Indian cities almost reached the 5-year-long target set under the National Clean Air Programme in no time. What caused this had been a puzzle, the researchers said.
«The winter of 2022-23
