Climate Change : Glossary

There are 65 documents in this section.

  • Petrochemicals

    22 August 2000

    Chemicals derived from oil and natural gas - for example, ethylene, propylene, toluene - which act as feedstocks for the manufacture of products such as plastics, pesticides, fertilisers, antiseptics and pharmaceuticals. Petrochemicals play a very important role in modern society, but they also create pollution problems. Plastics are a major component of solid waste, for example, fertilisers contribute to eutrophication of lakes and rivers and pesticide residues in food and water present health problems.

  • Ultraviolet radiation

    22 August 2000

    High energy, short-wave radiation lying between visible light and X-rays in the electromagnetic spectrum. It is usually divided into ultraviolet-A (UV-A) with wavelengths of 320-400 nanometres (nm), ultraviolet-B (UV-B) with wavelengths of 280-320nm and ultraviolet-C (UV-C) with wavelengths of 200-280nm. Ultraviolet rays are an important component of solar radiation. At normal levels it is an important germicide and is essential for the synthesis of Vitamin D in humans. At elevated levels, it causes sunburn and skin cancer, and can produce changes in the genetic make-up of organisms. It also has a role in the formation of photochemical smog. Most of the UV radiation which reaches the earth from the sun is absorbed by the ozone layer in the stratosphere. Thinning of the ozone layer, however, has increased the proportion of ultraviolet radiation - particularly UV-B - reaching the earth's surface, giving rise to fears of an increasing incidence of skin cancer and other radiation-related problems.

  • WHO (World Health Organisation)

    22 August 2000

    A UN agency created in 1948 to deal with global health issues and to achieve as high a level of physical, mental and social well-being as possible for peoples of the world. It is involved in a variety of environemental studies, including the impact of climate change and ozone depletion on health, in conjunction with other agencies such as the World Meteorological Organisation (WMO) and the United Nations Environment Program(UNEP).

  • CFC's (Chlorofluorocarbons)

    21 August 2000

    A group of chemicals containing chlorine (Cl), fluorine (F) and carbon (C), sometimes referred to by their trade name Freon. These synthetic compounds were used extensively for refrigeration and aerosol sprays until it was realized that they destroy ozone (they are also very powerful greenhouse gases) and have a very long lifetime once in the atmosphere (more than 100 years). The Montreal Protocol agreement of 1987 has resulted in the scaling down of CFC production and use in industrialised countries.

  • El Niño/Southern Oscillation (ENSO)

    21 August 2000

    El Niño is the name originally given by local inhabitants to a weak warm ocean current flowing along the coast of Ecuador and Peru. ENSO is an extensive, intense, atmospheric and oceanic phenomenon affecting the tropical Pacific Ocean. It is associated with major anomalies in atmospheric circulation and rainfall patterns. El Niño occurs irregularly, but approximately every four years on average. ENSO events have impacts on fisheries, bird life and mainland weather.