Q. 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?
(a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
(b) Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
(c) Statement-I is correct, but Statement-II is incorrect
(d) Statement-I is incorrect, but Statement-II is correct
Correct answer: (d) Statement-I is incorrect, but Statement-II is correct
Question from UPSC Prelims 2024 GS Paper
Explanation :
1. Statement I claims: “The atmosphere is heated more by incoming solar radiation than by terrestrial radiation”
– This is actually incorrect
– The atmosphere is heated primarily by terrestrial (long-wave) radiation and other processes like conduction and convection
– Most solar (short-wave) radiation passes through the atmosphere and heats the Earth’s surface instead
2. Statement II claims: “Carbon dioxide and other greenhouse gases in the atmosphere are good absorbers of long wave radiation”
– This is correct
– Greenhouse gases like CO2, water vapor, and methane effectively absorb long-wave (infrared) radiation emitted by Earth’s surface
– This is a key mechanism in the greenhouse effect
