Major anthropogenic greenhouse gas focus – UGC NET Question

Carbon dioxide is the most significant anthropogenic greenhouse gas in terms of total emissions. It is released in large quantities through burning coal,oil and natural gas and through deforestation. Its long atmospheric lifetime and high volume make it the main driver of human induced climate change. Therefore carbon dioxide best fits the description in the question.

Option A:
Oxygen is a major component of the atmosphere but it is not a greenhouse gas. It does not trap outgoing infrared radiation in the way greenhouse gases do. Hence it cannot be the primary greenhouse gas mentioned in the stem.

Option B:
Nitrogen makes up the largest fraction of Earth’s atmosphere. However it is largely inert and does not act as a greenhouse gas in its diatomic form. Therefore it is not responsible for the described warming effect.

Option C:
Ozone in the troposphere acts as a greenhouse gas and pollutant,but its concentration is much lower than that of carbon dioxide. It is important locally but is not the primary anthropogenic greenhouse gas globally. Thus it is not the best answer here.

Option D:
Carbon dioxide is produced by combustion processes in power plants,industry and transport as well as by land use changes. It accumulates in the atmosphere and enhances the greenhouse effect. This makes it the central gas referred to in the question.