Consider the following statements :
Statement-I :
The atmosphere is heated more by incoming solar radiation than by terrestrial radiation.
Statement-II :
Carbon dioxide and other greenhouse gases in the atmosphere are good absorbers of long wave radiation.
Which one of the following is correct in respect of the above statements ?
Show answer
Answer: D. Statement I is wrong: the atmosphere is heated mainly by terrestrial (long-wave) radiation given off by the Earth, not directly by incoming short-wave solar radiation, which mostly passes through it. Statement II is correct: carbon dioxide and other greenhouse gases absorb long-wave radiation well. So I is incorrect and II is correct.
Watch for: It feels natural that the Sun heats the air directly, but the air is mostly transparent to sunlight and is warmed by the Earth's surface.
Why the other options are wrong
- A. Wrong because Statement I is false; the atmosphere is heated more from below by terrestrial radiation.
- B. Wrong because Statement I is false, so both cannot be correct.
- C. Wrong because Statement I is the false one and Statement II is true.
Source to check: NCERT Class 11 Fundamentals of Physical Geography, Chapter 8 'Solar Radiation, Heat Balance and Temperature'
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.