Air pollution is caused by gases, dust, and fumes released into the atmosphere from various sources like vehicles, factories, and smoking. It is a global problem, with some of the worst air pollution found in large cities in China and Southern California. Air pollution harms both human and environmental health, leading to respiratory diseases in people and melting ice caps, rising sea levels, and weakened plants. Some solutions to air pollution include using public transportation instead of cars, recycling materials, and developing clean energy technologies.