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?
Answer & explanation
Answer: (d) Neither 1 nor 2
Both statements swap the roles of the two cloud types. It is low, thick clouds that mainly bounce sunlight back and cool the surface, while high, thin clouds let sunlight through but hold back part of the Earth's outgoing heat and so warm the surface.
- ✗ 1. Reflection of sunlight (the cooling effect) is the main job of low, thick clouds. High, thin clouds such as cirrus mostly transmit incoming solar radiation.
- ✗ 2. The warming effect comes from high, thin clouds, which trap some of the infrared radiation leaving the Earth and send it back down. Low clouds are dominated by the cooling effect.
Remember · Low, thick clouds cool the surface (they reflect sunlight); high, thin clouds warm it (they trap outgoing infrared). Deep convective clouds are roughly neutral.
Sources
- NASA Earth Observatory, Clouds and Radiation ↗ “Low, thick clouds primarily reflect solar radiation and cool the surface of the Earth. High, thin clouds primarily transmit incoming solar radiation; at the same time, they trap some of the outgoing infrared radiation emitted by the Earth and radiate it back downward, thereby warming the surface of the Earth.”
Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·