EDA3046 EXAM PREP summary.

Define the following concepts: Environment - The surroundings or conditions in which a person, animal, or plant lives or operates. Environmental education - Environmental edcuation is a process during which values are discovered and concepts explained in order to develop skills and attitudes pertaining to an appreciation of the relationship between man, his culture and his biophysical environment. Environmental education also includes the practice of decision-making and the formulation of a personal code of conduct on matters affecting the quality of the environment. Ecology - Ecology is the interaction between living organisms and their environment, as well as the interrelationship between living organisms. Health hazards - Hazard to the health of those exposed to it or Any agent or activity posing a potential hazard to health (the free dictionary) Biodiversity - The variety among living organisms and the ecological communities they inhabit. Overpopulation - Having too many people living in an area or city. Urbanisation - is the physical growth of urban areas as a result of global change. Desertification - is the degradation of land in drylands. Deforestation - To clear an area of forest or trees. Pollution - The presence in the air, soil, or water of a substance with unpleasant or harmful effects CHAPTER 1 – Environmental Issues + Risks 1. The population is exploding, particularly in developing countries. Also, the greenhouse effect gone crazy is resulting in the temperature rising by .5 degrees C. Severe carbon emissions from burning forests in further contribute to this problem. Finally, the number of endangered species has escalated. 1.2. BIODIVERSITY Biodiversity is the term used to describe the richness and vast variety of forms of life on earth. It describes the variety of life in an area, including the number of different species, the genetic wealth within each species, the interrelations between them and the natural areas where they occur. Biodiversity is often defined as the variety among living organisms and the ecological communities they inhabit. 1.3. WASTE, LITTERING + RECYCLING We live in a throw-away society. 3 kinds of waste * biodegrable (2 weeks to 5 months) *combustible – plastic + rubber (10 – 30 years when exposed to the sun) * noncombustible – metal (80 – 100 years) More than 90% of all rubbish is disposed on land. Only 30% of waste is recycled. Landfills take very long to decompose because of no exposure to the sun or air. Recycling is a better option but is a difficult process. 1.4. GREENHOUSE EFFECT + GLOBAL WARMING Carbon dioxide, methane, CFCs, ozone and nitrous oxide all contribute. It is unknown exactly how the greenhouse effect could change our lives because it is difficult to do conclusive study. A doubling of C02 could result in the temperature rising between 1 and 5 degrees. Clouds [automatic feedback to counteract effects of C02) and oceans [full of C02] are known to influence the GHE but it is difficult to factor into the global circulation model. 1.5. HOLE IN THE OZONE LAYER Ozone layer is in the stratosphere – 20 – 50 km above earth. Ozone is made of three oxygen molecules. When O2 reacts with UV rays it creates ozone. This layer protects the earth from harmful UV radiation that would make life on earth almost impossible. In 1985 a hole the size of SA was discovered above Antarctica. This means that the density of ozone had declined significantly. Chlorine based compounds such as CFCs which rise high into the atmosphere and then destroy ozone molecules are the main cause of the hole. In 1988 40 countries signed the Montreal Protocal which pledged to reduce CFCs by 50% by 1999. CFCs live very long so the ozone layer is not expected to stabilize till 2060. CFCs in the atmosphere are still increasing by 4% every year. One CFC molecule can destroy up to 100 000 ozone molecules. 1.6. FACING A NUCLEAR WINTER In 1986 in Chernobyl a nuclear reactor exploded [Level 7 disaster]. More than 9 tons of nuclear material were released into the atmosphere causing a cloud to cover parts of Europe. Many people died from the radiation. The radioactivity in that area would last for 100 years and the peak of cancers resulting from the incident was estimated to be reached in 2005. A major nuclear war would cause firestorms that would send a similar cloud of dust