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
Ans-d
Explanation
The atmosphere functions as a protective blanket of air enveloping the Earth, effectively retaining the heat necessary to maintain a livable environment—often referred to as Goldilocks’ planet. Within the atmosphere, certain gases, such as carbon dioxide and water vapor, are capable of absorbing the sun’s infrared radiation. This process helps to prevent surface temperatures from plummeting during the night, when the sun is absent.
Additionally, the atmosphere regulates the amount of solar energy that reaches the Earth’s surface. This is why regions with thicker layers of atmosphere, such as the poles, receive less solar energy, despite receiving the same radiation as equatorial regions.
Without the atmosphere, surface temperatures on Earth would experience extreme fluctuations, reaching up to 100 degrees Celsius during the day and dropping to near freezing at night, similar to the conditions observed on the moon. This freezing impact would be particularly pronounced in areas where sunlight strikes at an angle, such as the poles and temperate regions, while equatorial regions may still experience temperatures above freezing, as evidenced by the north and south poles of the moon.
Hence statement 1 is incorrect
Consequently, the assertion in statement I is incorrect. Conversely, the greenhouse effect describes the mechanism by which certain gases trap heat close to the Earth’s surface, contributing to a warmer temperature than would otherwise exist.
Hence, statement 2 is correct.
Greenhouse gases include carbon dioxide, methane, ozone, nitrous oxide, chlorofluorocarbons, and water vapor.
Hence, statement 3 is correct.
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