To what extent should the blame for vehicular air pollution be shared by manufacturers, consumers, and government

The three groups of people may be blamed for the vehicular air pollution in respect to the following reasons:

(1) manufacturers may be blamed for not exerting effort in devising or developing vehicles that would cause lesser pollution,

(2) consumers may be blamed by choosing convenience over the environment, when one is a walking distance from the destination, one should walk or take the public transportation instead, and

(3) government may be blamed for not devising laws that would address the given problem.