Question

In column I, a list of gases known to have a greenhouse effect is given. Relate them to their main source listed in column II.

	Column I		Column II
A.	Nitrous Oxide	1.	Secondary pollutant from car exhausts
B.	Chlorofluorocarbons (CFCs)	2.	Combustion of fossil fuels, wood
C.	Methane	3.	Refrigerators, aerosols, sprays
D.	Carbon dioxide	4.	Cattle excreta

• A. A – 3, B − 4, C − 1 , D − 2
• B. A – 1, B − 3, C − 4, D − 2
• C. A − 4, B − 2, C − 1 , D − 3
• D. A – 3, B − 2, C − 4, D − 1

Answer 1

The correct option is B A – 1, B − 3, C − 4, D − 2

Nitrogen oxides are mainly produced by the combustion of fossil fuels in vehicles. Especially diesel powered vehicles and power plants. Methane is a gas that is 25 times more potent than carbon dioxide in warming the atmosphere. It is released into the atmosphere primarily by two sources, which are the livestock animals through their rotting excreta and garbage dumped by humans.The main source of chlorofluorocarbons (CFCs) are refrigerators and aerosol propellants. The major greenhouse gas CO₂, largely results from natural processes like respiration and from the burning of fossil fuels like coal, oil, wood, gas etc.