Calcutta is the bus-burning capital of the world. This mode of “protest” not only inconveniences millions and destroys public property worth crores but also affects the city’s climate.

“On an average, eight to 10 public vehicles are burnt in the city every year, unheard of even in cities like Karachi, Dhaka and Manila. The environmental cost of burning vehicles is huge,” says environment expert S.M. Ghosh.

Joyashree Roy, a climate expert and economics teacher from Jadavpur University associated with Intergovernmental Panel on Climate Change, says large quantities of pollutants are released when a vehicle is torched on the streets.

According to experts, burning a bus can significantly affect the health of the people, especially the aged and the children, in the surrounding areas.

“Over 200 litres of diesel and other oil burn along with other combustible materials, releasing about 400kg of carbon dioxide and about 40kg of carbon monoxide, when a bus is torched. The dark colour of the smoke that comes out indicates presence of significant amounts of unburnt fuel and particulate matter,” says Siddhartha Dutta, the pro vice-chancellor of Jadavpur University and environment expert.

Particulate matters containing black carbon contribute to the formation of brown haze and other climatic irregularities.

“Burning of the paint on the bus releases toxic and cancer-causing substances like poly-aromatic hydrocarbons and volatile organic compounds,” says Anjali Srivastava, the regional in-charge of the National Environmental Engineering Research Institute, a central body working for the environment.

But do the political leaders, and the goons they lead, care?