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: D. Neither statement is correct (both reverse the actual cloud-radiation effects). Clouds have TWO competing radiative effects on Earth's climate: - ALBEDO EFFECT: clouds REFLECT incoming solar (shortwave) radiation back to space, cooling the surface. - GREENHOUSE EFFECT: clouds ABSORB and re-emit outgoing infrared (longwave) radiation from the Earth's surface, warming the surface. Statement 1 is WRONG. HIGH CLOUDS (cirrus, ~6-13 km altitude) are THIN and ICY. They have LOW albedo (poor reflectors of solar radiation), but they EFFICIENTLY ABSORB OUTGOING INFRARED radiation from the Earth's surface. Net effect: they WARM the surface (greenhouse-dominant), NOT cool it. Statement 2 is WRONG. LOW CLOUDS (stratus, cumulus, ~0-2 km) are THICK and DENSE WITH WATER DROPLETS. They strongly REFLECT INCOMING SOLAR RADIATION (high albedo). Their absorption of infrared is offset because their cloud-top temperature is close to the surface temperature, so they re-emit at nearly the same energy. Net effect: low clouds COOL the surface (albedo-dominant), NOT warm it. In summary the statements have it BACKWARDS: - High clouds = warming - Low clouds = cooling Source: NCERT Class 11 Fundamentals of Physical Geography / IPCC AR6 Working Group I (cloud radiative forcing).