Exhaust from combustion engines is the number one cause of air pollution.  Pakistan is the number one country with the most pollution. I thought it would definitely be China but China isn't even in the top 10. Air pollution is causing global warming. What we can do to try and stop global warming is the little things, like plant trees, use energy efficient light bulbs, and/or use your bike more rather than your car. Global warming is warming the Earth up by greenhouse gases trapping the Suns heat. Air pollution can damage trees, lakes, animals, and etc. Trees are very Important because what they do is release oxygen and suck in carbon dioxide. Pollutants like ground level ozone can trigger respiratory problems, especially for people with asthma. If we keep doing these things that cause air pollution soon our Earth will not be in proper living conditions so we need to spread the word and try our best to stop polluting our one and only Earth