Greenhouse Gases

GHGs are the atmospheric constitutes which are transparent to (incoming) short wave radiation & have the property of absorbing (outgoing) long wave radiation & and

• Short wave radiation: 0.15-4 μ (solar radiation)
• Long wave radiation: 4-100 μ (terrestrial radiation, nocturnal radiation)

 It means they reradiate the long wave radiation back to the surface. CO2, Water vapor, CO4, CO, Sulphur, Nitrous oxides (N2O), chlorofluoro carbons & chlorofluoromethanes are the major GHGs.

In this process, earth atmosphere warms up & its temperature rises. It is known as greenhouse (GH) effects. Many GHGs occur naturally, such as water vapor, CO2, CO4, (N2O). Others such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), & sulfur hexafluoride (SF6) result exclusively from human industrial processes.

Human activities also add significantly to the level of naturally occurring greenhouse gases. CO2 is released into atmosphere by burning of solid waste, wood & wood products, & fossil fuels (oil, natural gas, & coal).

N2O emissions occur during various agricultural & industrial processes, & when solid waste or fossil fuels are burned. CH4 is emitted when organic waste decomposes under anaerobic condition, whether in landfills or in connection with livestock farming. CH4 emissions also occur during production & transport of fossil fuels.

N2O absorbs 270 times more heat per molecule than CO2 & CH4 absorbs 21 times more heat per molecule than CO2 .