Question

Which gas plays a major role in global warming?
A. Carbon monoxide
B. Nitrogen
C. Carbon dioxide
D. Sulphur dioxide

Answer 1

The increase in the release of greenhouse gases leads to global warming which is due to trapped radiations in the atmosphere. Some greenhouse gases are released due to the natural activities and some due to human activities (anthropogenic activities).

Complete answer:
> The gases which lead to global warming are known as greenhouse gases (GHGs). The primary greenhouse gases are – water vapour, carbon dioxide, methane, fluorinated hydrocarbons, and nitrous oxide. They help in keeping the temperature of the earth appropriate for living beings as without them temperature of earth would be -18°C. Since the industrialisation the amount of carbon dioxide has drastically increased in our atmosphere and this leads to increase in temperature of the atmosphere to such a point that the polar ice caps began to melt.
> Main reasons for increase in the carbon dioxide emission are increased burning of natural gas, fossil fuels, petroleum, increased deforestation (Plants are being cut on a very large scale so the $CO_2$ can’t be utilised). Along with carbon dioxide, methane emissions have also increased due to several agricultural activities.

Hence, the correct answer is option (C).

Additional information:
> Fluorinated gases like chlorofluorocarbons, sulphur hexafluoride, perfluorocarbons, hydrochlorofluorocarbons and nitrogen trifluoride are anthropogenic greenhouse gases. They also play a very potent role in the stratospheric ozone and have a very high global warming potential. They are released from automobiles, refrigerators, spray foam insulation, and air conditioners
> Large amounts of methane is released from rice fields.

Note: The concentration of greenhouse gases in the atmosphere is measured in parts per million, parts per billion and parts per trillion. Though they are present in small quantities but they can remain as such in the atmosphere for thousands of years.