निम्नलिखित कथनों पर विचार कीजिए :
- कथन-I: पार्थिव विकिरण की तुलना में आगामी (इनकमिंग) सौर विकिरण से वायुमंडल अधिक गर्म हो जाता है ।
- कथन-II: वायुमंडल में कार्बन डाइऑक्साइड और अन्य ग्रीनहाउस गैसें दीर्घ तरंग विकिरण के अच्छे अवशोषक हैं ।
उपर्युक्त कथनों के संबंध में, निम्नलिखित में से कौन-सा सही है ?
Read this question in English
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
उत्तर और व्याख्या · explanation in English
Answer: (d) कथन-I सही नहीं है, किंतु कथन-II सही है
The atmosphere lets most short-wave sunlight pass through; the Earth's surface absorbs it and then radiates long-wave (terrestrial) energy, which carbon dioxide and other greenhouse gases absorb. So the air is heated mainly from below by the Earth, not directly by the Sun: Statement-I is wrong, Statement-II is right.
- ✗ Statement-I The atmosphere is largely transparent to incoming short-wave solar radiation. It is heated indirectly, from below, by the long-wave radiation the warmed Earth gives out.
- ✓ Statement-II Terrestrial radiation is long-wave, and carbon dioxide and the other greenhouse gases absorb it well. This is the basis of the greenhouse effect.
Remember · Sun heats the ground (short wave); the ground heats the air (long wave, terrestrial radiation). Greenhouse gases trap that long-wave energy.
📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 8 (practise this chapter) · Class 11 Fundamentals of Physical Geography, Ch 8 (practise this chapter)
Sources
- NCERT Class 11 · Fundamentals of Physical Geography, Chapter 8 “The long wave radiation is absorbed by the atmospheric gases particularly by carbon dioxide and the other green house gases. Thus, the atmosphere is indirectly heated by the earth's radiation.”
- NCERT Class 11 · Fundamentals of Physical Geography, Chapter 8 “The atmosphere is largely transparent to short wave solar radiation.”
Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·