Question

How do methane and CFCs contribute to the Greenhouse Effect?

Answer 1

Greenhouse effect:-

• The greenhouse effect describes how the natural gases in the earth's atmosphere reduce the amount of heat escaping from the earth into the atmosphere.
• These gases in the earth's atmosphere which can trap heat are known as greenhouse gases.
• When the number of greenhouse gases present in the atmosphere increases, it results in a phenomenon known as global warming (an increase in the overall temperature of the earth's atmosphere).

Methane (${\mathrm{CH}}_4$):-

• Methane is released from landfills, swamps, volcanoes, methane-oxidizing bacteria, burning of coal and natural gases, livestock farming, and rice cultivation.
• Methane can absorb radiation between 3 to 5 micrometers and 7 to 8.5 micrometers.
• It is the second most abundant greenhouse gas and it is 25 times more potent than ${\mathrm{CO}}_2$ in trapping heat from the Earth’s surface.
• However, methane is shorter-lived than ${\mathrm{CO}}_2$ and controlling its concentration can contribute to major reductions in greenhouse gas.

Chlorofluorocarbon$\left(\mathrm{CFC}\right)$:-

• The compounds that contain only Carbon, Fluorine, and Chlorine are known as Chlorofluorocarbons(CFCs).
• Major sources of CFCs include coolants inside refrigerators and air conditioners, and solvents for industrial purposes.
• CFCs destroy the earth's protective ozone layer that protects the earth from harmful ultraviolet rays generated from the sun.
• CFCs also warm the lower atmosphere of the earth, changing the global climate.
• CFCs pass through the troposphere into the stratosphere where they photo dissociate to produce Chlorine radicals$\underset{\mathrm{Dichlorodifluoromethane}}{{\mathrm{CCl}}_2{\mathrm{F}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Chlorodifluoromethyl}\mathrm{radical}}{{\mathrm{CClF}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}\mathrm{radical}}{\mathrm{Cl}\bullet \left(\mathrm{g}\right)}$
• It destroys Ozone and inhibits the formation of new Ozone by reacting with every single Oxygen atom that is needed to produce Ozone.
• The destruction of the Ozone causes the harmful UV rays to pass through the stratosphere into the troposphere to the surface of the earth.