Mumbai tops the charts for road traffic CO2 emissions

India Dec 14, 2025

Mumbai just ranked highest among Indian cities for road traffic carbon emissions per kilometer, according to a new study.
Researchers from India and France looked at 15 major cities and found that Mumbai's crowded roads—packed with about 10 vehicles per km—are pumping out 5-6 tons of CO2 for every kilometer driven.

What else did the study find?

Other big cities like Chandigarh, Chennai, and Pune aren't far behind in vehicle density or emissions, while Delhi's total output is still huge even if its per-kilometer numbers are mid-range.
The study also points out that high levels of nitrogen oxides and carbon monoxide from all this traffic are making air quality worse, highlighting how urgent it is to rethink urban transport if we want cleaner city air.