Consider the following statements :
- 1.High clouds primarily reflect solar radiation and cool the surface of the Earth.
- 2.Low clouds have a high absorption of infrared radiation emanating from the Earth’s surface and thus cause warming effect.
Which of the statements given above is/are correct ?
Show answer
Answer: D. Statement 1 is wrong: high, thin clouds let sunlight through but trap outgoing infrared heat, so they mainly warm the surface. Statement 2 is wrong: low, thick clouds mainly reflect sunlight back to space and cool the surface. The two statements have the roles swapped. So neither.
Watch for: The effects are simply swapped between high and low clouds.
Why the other options are wrong
- A. Wrong because high clouds mainly warm, not cool.
- B. Wrong because low clouds mainly cool, not warm.
- C. Wrong because both statements reverse the actual roles.
Source to check: NASA Earth Observatory, 'Clouds and Radiation'; IPCC AR6 WG1, Chapter 7 (cloud feedbacks)
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.