Errr...rapid expansion of the population, high pollution levels, concretisation of the city, lack of an enforceable planning permissions protocol, decline in green spaces and trees, over-reliance on cars, diesel-powered buses and two-wheelers, and a lack of a proper coordinated environmental policy by city and state governments. Did I leave anything out?
Every South Indians know that if cyclone starts in Chennai it will affect the Bangalore also but unfortunately North Indians don't know even how many areas in Bangalore also