Dark clouds

A very beautiful metaphor, the opportunity to explain to children the phenomenon of acid rain. Acid rain is one of the consequences of air pollution from the use of sulfur-rich fossil fuels such as oil, coal and natural gas; Factories, heating and road traffic are the main causes. The disastrous effects for biodiversity are numerous. The increased acidity of soils and rivers endangers many animals and plants lose the mineral nutrients necessary for their development.