Previous Year Question
Which of the following gases is responsible for global warming?
Correct Answer: C
Detailed Solution
The expected answer to this PYQ is Greenhouse Gas. Greenhouse gases absorb and re-emit part of the infrared radiation emitted by the Earth, producing the greenhouse effect. When their atmospheric concentrations increase because of human activities, they contribute to an increase in global average temperature. According to the IPCC, major anthropogenic greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases.
“Greenhouse gas” is a category of gases rather than the name of a single gas. Moreover, according to PNGRB, Piped Natural Gas (PNG) consists primarily of methane (CH4), and methane itself is a potent greenhouse gas. Therefore, methane emissions associated with natural gas can also contribute to global warming.
Thus, for the given examination options, the answer is (C) Greenhouse Gas, while the scientifically precise understanding is that specific greenhouse gases such as CO2, CH4, N2O and fluorinated gases contribute to global warming.