The above image is a Spruce forest damaged by acid rain.
Burning fossil fuel results in the formation of air pollutants like
carbon dioxide, and
These gases dissolve in water and clouds forming "nitric oxide" and "sulphuric acid". These water falls down as "acid rain". It is very harmful. When it falls on buildings and statutes they damage them extensively. Some lakes too have become acidic due to dissolved acidic vapors thereby fish and birds which relied on it have died. The acid rain speeds up the rusting of iron, erodes marble, limestone and even concrete. It kills plants and reduces soil fertility.These kinds of rain is prominent near the east coast of America and near Europe.