4. TABLE /DATA OF STUDY /INFORMATION IN VARIOUS FORMS Atmospheric lifetime and GWP relative to CO 2 at different time horizon for various greenhouse gases. Gas name Chemical formula Lifetime (years) Global warming potential (GWP) for given time horizon 20-yr 100-yr 500-yr Carbon dioxide CO 2 See above 1 1 1 Methane CH 4 12 72 25 7.6 Nitrous oxide N 2 O 114 289 298 153 CFC-12 CCl 2 F 2 100 11 000 10 900 5 200 HCFC-22 CHClF 2 12 5 160 1 810 549 Tetrafluoromethane CF 4 50 000 5 210 7 390 11 200 Hexafluoroethane C 2 F 6 10 000 8 630 12 200 18 200 Sulphur hexafluoride SF 6 3 200 16 300 22 800 32 600 Nitrogen trifluoride NF 3 740 12 300 17 200 20 700
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8. REFERENCE SOURCE Anthropogenic sources (human activity) mostly related to burning different kinds of fuel : -"Stationary Sources" include smoke stacks of power plants , manufacturing facilities (factories) and waste incinerators, as well as furnaces and other types of fuel-burning heating devices -"Mobile Sources" include motor vehicles , marine vessels, aircraft and the effect of sound etc. -Chemicals , dust and controlled burn practices in agriculture and forestry management. Controlled or prescribed burning is a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement. Fire is a natural part of both forest and grassland ecology and controlled fire can be a tool for foresters. Controlled burning stimulates the germination of some desirable forest trees, thus renewing the forest. -Fumes from paint , hair spray , varnish , aerosol sprays and other solvents
![[object Object],[object Object],P roblems of The Greenhouse Effect The greenhouse effect causes trouble by raising the temperature of the planet. The actual rise is not very much, but the Earth's ecosystem is very fragile, and small changes can have large effects.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)