ABSTRACT
Acidifi cation caused by human activity is most commonly associated with atmospheric pollution arising from anthropogenically derived sulphur (S) and nitrogen (N), so-called ‘acid rain’, a term fi rst used in England about 150 years ago when a Scottish chemist found that local rainfall in Manchester was unusually acidic. Smith (1852) suspected a connection with sulphur dioxide (SO2) from local coal-burning factories, and commented on the eff ects the deposits had on buildings and vegetation. e eff ects of acidifi cation on lake and river ecology in Sweden pushed the issue onto the international agenda in the 1960s and the long-range atmospheric transportation of pollutants from other countries, including Britain, was eventually accepted as a major cause. e eff ects of this deposition on various aspects of aquatic, terrestrial and built environments are still the subject of some controversy, and will form the greater part of this chapter. However, in more recent times another form of atmospheric pollution has been highlighted as a much wider issue of human-induced acidifi cation: the global decline in pH of the ocean surface due to its absorption of CO2.
