Answer» - Global warming is rise in mean temperature of lower atmosphere and earth’s surface.
- Causes – increase in quantity of radioactively active green house gases CO2, CH4, N2O, CFCs. They allow heat waves to reach surface and prevents their escape.
- They are produced by combustion of fossil fuels, biomass [CO2]; burning of nitrogen rich fuels [N2O]; paddy fields, fermentation in cattle and wet lands [CH4]; refrigerators, aerosols, drying, cleaning [CFCs].
- Effects: Heating of earth surface [mean temperature is increased] Climatic changes e.g.: El Nino effect.
- Increased melting of polar ice caps and Himalayan snow caps. Increased sea levels and coastal areas will submerge.
- Measures – Decreased use of fossil fuels, improve efficiency of energy usage, Reduce deforestation, plant trees Control of man made sources of green house gases like vehicles, aerosol sprays.
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