Question

How many of the following are the greenhouse gases?

$C{O}_2$, $C{H}_4$, $N_{2}O$, Chlorofluorocarbons (CFCs), DDT.

• A. 2
• B. 3
• C. 5
• D. 4

Answer 1

The correct option is D 4

Greenhouse gases absorb long wave radiations like infrared radiations. They cause global warming by trapping the sun's heat and stopping it from leaking back into space.

Global warming is the long-term heating of Earth's climate due to human activities (burning of fossil fuels and deforestation) which will increase the level of greenhouse gases in Earth's atmosphere.

$C{O}_2$, $C{H}_4$, $N_{2}O$ and CFC (chlorofluorocarbons) are greenhouse gases. Hence option d is correct.

Carbon dioxide (60%) contributes maximum to the greenhouse effect on Earth. Methane (20%), nitrous oxide (6%), chlorofluorocarbons (14%) are also potent greenhouse gases, but their contribution to global warming is less compared to carbon dioxide.


DDT is not a greenhouse gas. DDT is used in agriculture as an insecticide. However, due to its negative impact on the environment the compound has been banned in many countries.