Question

Which one of the following statements is TRUE for Greenhouse Gas (GHG) in the atmosphere?

• A. GHG absorbs the incoming short wavelength solar radiation to the earth surface, and allows the long wavelength radiation coming from the earth surface to pass through
• B. GHG allows the incoming long wavelength solar radiation to pass through to the earth surface, and absorbs the short wavelength radiation coming from the earth surface
• C. GHG allows the incoming long wavelength solar radiation to pass through to the earth surface, and allows the short wavelength radiation coming from the earth surface to pass through
• D. GHG allows the incoming short wavelength solar radiation to pass through to the earth surface, and absorbs the long wavelength radiation coming from the earth surface

Hint:

Remember: Shortwave radiation from the sun enters freely, but greenhouse gases trap longwave infrared radiation re-emitted by the earth. This is the basis of the greenhouse effect.

Answer 1

The Correct Option is D

Step 1: Understand incoming solar radiation.
The sun emits mostly short wavelength radiation (visible and UV) that passes through the earth's atmosphere easily.

Step 2: Understand earth's re-radiation.
The earth's surface re-emits energy in the form of long wavelength infrared radiation.

Step 3: Role of GHG.
Greenhouse gases are transparent to shortwave radiation but absorb longwave infrared radiation, trapping heat in the atmosphere. This leads to the greenhouse effect.

Step 4: Match with options.
Only option (D) correctly states: "GHG allows incoming short wavelength solar radiation to pass through to the earth surface, and absorbs the long wavelength radiation coming from the earth surface."
\[ \boxed{\text{Correct Statement: Option (D)}} \]