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GLOBAL WARMING. The greenhouse effect is the name applied to the process which causes the surface of the Earth to be warmer than it would have been in the absence of an atmosphere. Global warming or the enhanced greenhouse effect
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GLOBAL WARMING
The greenhouse effect is the name applied to the process which causes the surface of the Earth to be warmer than it would have been in the absence of an atmosphere. Global warming or the enhanced greenhouse effect is the name given to an expected increase in the magnitude of the greenhouse effect, whereby the surface of the Earth will amost inevitably become hotter than it is now.
About 70% of the sun's energy is radiated back into space. But some of the infrared radiation is trapped by greenhouse gases and warms the atmosphere,
Water vapour accounts for 98% of the natural Greenhouse effect. Water vapour has lower ‘radiative forcing’ properties than some other atmospheric gases such as carbondioxide, methane and nitrous oxide which are naturally present in the atmosphere in small quantities. Since the Industrial Revolution the proportion of these gases has increased significantly.
N2O CFCs CO2 CH4 1 Carbon Dioxide > fossil fuels, vehicle emissions, forest clearance 2 Methane > rice cultivation, biomass burning, digestive fermentation, termites, sewage, landfill, natural gas production 3 CFCs > aerosol propellants, refrigerants, foaming agents 4 Nitrous oxide > nitrogen fertilisers, industrial pollution
CONCENTRATION CHANGES SINCE 1750 Carbon Dioxide: 280 ppm 360 ppm (+30%) Methane: 0.70 ppm 1.80 ppm (+145%) Methane c25 x effect of CO2 CFCS (chlorofluorocarbons) recent significant decrease due to concern about OZONE LAYER BUT CFCs c10,000 x effect of CO2