Acid rain first became a problem in the Industrial Revolution, but it is getting worse today.
1________ from large cities, especially from power stations, enters the 2_________ and then falls as acid rain. It 3_________ forests and can kill life in rivers and 4_______________. We can see the effects of acid rain in eastern Canada, Scandinavia and central Europe.
The Greenhouse Effect
The Greenhouse Effect describes the situation when the air around 5_________ gets warmer because of gases which trap heat. This is a problem because if 6_______ rise by 1oC, the sea level will rise by over 25cm and many cities will be in danger.