CAPF-AC (Assistant Commandant) Exam Study Material : Environment & Ecology - Global Environmental Problem
CAPF-AC (Assistant Commandant) Exam Study Material : Environment & Ecology - Global Environmental Problem
Environment & Ecology
Global Environmental Problem
Global Warming
In recent past, global observations have provided clear evidence of climatic changes resulting from anthropogenic activities. According to a report from World Watch Institute (1992), the earth’s surface was warmest in 1990. Six of seven warmest years on record have occurred since 1980. Observations on temperature at many places of the world over the last century show an average increase of about 0.5°K. This is supported by palaeo-climatic evidence gathered from deep-sea ice-cores from Arctic and Antarctic regions. While the primary cause of an increase in global temperature in the past has been increasing concentration of CO2, fossil fuel burning, extensive deforestation, rapid increase in chlorofluorocarbons (CFCs) has further complicated the global environmental problems.
The minor gaseous constituents more commonly known as trace gases or greenhouse gases (GHGs) like CO2, Clog, CH4, N2O, NOx, O3 CFCs etc., though occur in traces but play a surprisingly dominant role in regulating the entire earth’s atmosphere.
Greenhouse Effect
These gases act as the glass pans of a greenhouse which allow solar radiations to pass through and heat the surface of the earth but do not allow the heat radiated from the ground to pass through thereby trapping it in the process. This heat trapping phenomenon is known as green house effect.
Environmental Effects of Global Warming
According to Stockholm Environment Institute, all natural ecosystems can tolerate a rise by 0.1°C of temperature per decade. However, further rise in temperature has been calculated to pose serious environmental consequences.
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Many species particularly plants would be unable to migrate to new and some suitable habitats, leading to rapid loss of biological diversity and natural resources of economic importance.
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The increase in temperature will cause more frequent storms to many parts of the world, including regions that have experienced no such activity earlier.
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Rainfall and monsoon patterns could shift dramatically as the planet warms. Some regions of the world could dry out while others could receive too much rains - flooding rivers and increasing soil erosion.
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An increase in temperature shall cause the oceans to expand. Rising sealevels shall flood many highly productive areas of the world like Bangladesh, Egypt, Indonesia, China and India.
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Glaciers and ice-caps shall melt contributing further in the rise’ of sealevel.