Q. Consider the following statements:

I. Without the atmosphere, temperature would be well below freezing point everywhere on the Earth's surface.
II. Heat absorbed and trapped by the atmosphere maintains our planet's average temperature.
III. Atmosphere's gases, like carbon dioxide, are particularly good at absorbing and trapping radiation.

Which of the statements given above are correct?
(a) I and III only
(b) I and II only
(c) I, II and III
(d) II and III only

49. निम्नलिखित कथनों पर विचार कीजिए:
I. वायुमंडल के बिना भूपृष्ठ पर सर्वत्र तापमान हिमांक के बहुत नीचे होता है।
II. वायुमंडल के द्वारा अवशोषित और पाशित (ट्रैप्ड) ऊष्मा हमारे ग्रह के औसत तापमान को बनाए रखती है।
III. वायुमंडल की कार्बन डाइऑक्साइड जैसी गैसें विकिरण को अवशोषित और पाशित करने के लिए विशेष रूप से उत्तम हैं।

उपर्युक्त कथनों में कौन-कौन से सही हैं?
(a) केवल I और III
(b) केवल I और II
(c) I, II और III
(d) केवल II और III

Answer: D

Explanation:

Statement I is not correct: The atmosphere is a vital layer of gases that surrounds the Earth, making life possible in several crucial ways. It provides the air we breathe, protects us from the Sun’s harmful ultraviolet (UV) radiation, traps heat to maintain a habitable temperature, and moderates extreme temperature fluctuations between day and night. Without this protective envelope, Earth’s average surface temperature would drop well below freezing.

Statement II is correct: Instead, the heat absorbed and trapped by our atmosphere keeps our planet's average surface temperature at a balmy 15°C (59°F). The atmosphere acts as a blanket, absorbing and trapping heat from the sun. This process, known as the greenhouse effect, helps maintain the Earth's average temperature within a range that supports life. Gases like water vapor, carbon dioxide, and methane play a key role in this process.

Statement III is correct: Gases such as carbon dioxide, methane, and water vapor are known as greenhouse gases because they are particularly effective at absorbing and trapping infrared radiation. This property allows them to retain heat within the Earth's atmosphere, contributing to the greenhouse effect and maintaining the planet's temperature.

Source:

https://geo.libretexts.org/Bookshelves/Geology/Book%3A_An_Introduction_to_Geology_(Johnson_Affolter_Inkenbrandt_and_Mosher)/15%3A_Global_Climate_Change/15.02%3A_Earths_Temperature

https://scied.ucar.edu/learning-zone/atmosphere/what-is-atmosphere