Europe's temperate forests have been under attack from polluted air and acid rain. This was first noticed by the Germans and is known as 'forest death' or Waldsterben. Acid Rain as its name suggests is rainfall that carries and deposits an acid made from sulphur dioxide and nitrogen oxide. It is not as strong as sulphuric acid or even vinegar. The acidity is measured on a pH scale .
Acid rain is part of a cycle involving industry, people and traffic.
These gases rise into the air from chimneys or vehicle exhausts. These gases can fall as dry deposits often close to the factory. People can find dusty deposits on washing hung out to dry. The pollution can also mix with rain clouds. The clouds may be carried long distances in weather systems, so the rain can fall in countries a long way from the factory making the pollution.