31.Today, concentration of green house gases is high because of A. Use of refrigerator B. Increased combustion of oil and coal C. Deforestation D. All the above
Option D. The various greenhouse gases are carbon dioxide, methane, chlorofluorocarbons (CFCs), and nitrogen oxide. Other minor contributors are water vapours and ozone. The rise in carbon dioxide concentration is due to large scale deforestation (for grazing land, cropping land or urban settlements), change in land use pattern and large scale combustion of fossil fuels. Methane is produced by incomplete biomass combustion, incomplete decomposition mostly by anaerobic methanogens. CFCs are inert propellants used in aerosol cans and jet fuel, refrigerants in air conditioner and refrigerators.
