Rainfall Acidity

Rainfall is naturally acidic due to the presence of carbon dioxide in the atmosphere which combines with rainwater to form weak carbonic acid. However, the combustion of fossil fuels produces waste gases such as sulphur dioxide, oxides of nitrogen and to a lesser extent, chloride. These pollutants can be converted, through a series of complex chemical reactions, into sulphuric acid, nitric acid or hydrochloric acid, increasing the acidity of the rain or other type of precipitation, such as snow and hail.

Carbon dioxide + Water à Carbonic acid (weak)

Sulphur dioxide + Water à Sulphuric acid

Nitrogen oxides + Water à Nitric acid