Question

The greenhouse effect is caused by:
i) Accumulation of $O_2$ in the atmosphere
ii) Depletion of $O_3$ layer
iii) Accumulation of $C{O}_2$ in the atmosphere

• A. i and ii
• B. i only
• C. i and iii
• D. iii only

Answer 1

Answer: (D)

Greenhouse effect:

• The progressive heating up of the surface of the Earth is called the greenhouse effect or global warming.

• $C{O}_2$ and $H_{2}O$ block a part of the heat emitted by the Earth and reflect it back. Due to this, the Earth's surface gets heated up.

• 50% of $C{O}_2$ content of air can increase the surface temperature of the Earth by $3^{o}C$.

• In addition to $C{O}_2$, the other greenhouse gases are $CFC$ (17%), $O_3$ (18%), $NO$ (4%) and water vapour (2%).