America’s air is cleaner and water purer due to pollution controls and our contribution to global warming is less due to natural gas replacing coal and some renewable energy.
Compared to the largest cities in the world, America is a paragon of pure air. Even Riverside, California, has clearer skies compared to cities of Asia and the Middle East.
Iran, India and Pakistan dominate the list of most polluted cities. Some of the most polluted cities, due to mostly auto, but also industrial pollution, are: