Burning fossil fuels, the major cause of global warming

Burning fossil fuels, the major cause of global warming, also causes air pollution. Exhaust gasesfrom factories, cars, other vehicles contain greenhouse that trap heat in our atmosphere. As well as making Earth warmer, some of these gases can create smog and acid rain.

Smog masks A traffic officer, in Kolkata, India, wears a face mask to protect himself from air pollution. Smog causes more than 1.6 million deaths worldwide each year

How smog is created

Smog is formed when exhaust gases from cars and factories react with oxygen in the air, warmed by high temperatures and ultraviolet rays from the Sun. This creates a thick cloud of nitrogen dioxide, ozone, and other harmful gases, Which can irritate or even permanently damage the lungs.

Mexico City Less than 30 years ago, Mexico City was considered one of the cleanest cities in the world. It is now one of the most polluted. A thick layer of smog covers the city, and the volcanoes that dot the horizon can no longer be seen.

Heat island effect

Concrete buildings and sidewalks trap heat during the day, leaving cities and towns several degrees warmer than surrounding country areas in the evenings. This is called the heat island effect. The increased heat in cities and towns also leads to higher levels of air pollution.

Children are three times more likely to develop asthma if they live in a smoggy area.