Global warming is the order of the day! Chimneys, emissions, smog, exhaust are in every news item all over the world. China and the US are two key culprits, among others.
How come nobody has ever objected to the number of buses, tourist coaches, taxis, and domestic cars being left with their engines running forever? This happens all over the world! One sees big squares located at touristic points with a great number of coaches and none of the engines is switched off. One of the reasons is the airconditioning, which is kept running for the comfort of passengers. Great! One does not have to be a genius to gauge the immense value for the atmosphere were this habit to be abolished. Not to mention the great savings on fuel!
International laws should be passed making it illegal to leave engines running. Heavy fines and the possibility of having vehicles impounded would go a long way to alleviate the further castigation of our poor atmosphere!