From insolation, __% is reflected by clouds

• A. 8%
• B. 17%
• C. 25%
• D. 52%

Answer: (B)

Clouds have a big impact on the Earth’s energy balance by reflecting sunlight back into space, which is what albedo measures. On average, clouds reflect about one-sixth of the Sun’s energy that reaches Earth, roughly 17 percent. This reflection reduces the amount of solar energy absorbed at the surface and helps regulate daytime warming. The exact amount varies with cloud type, thickness, altitude, and how much of the sky is covered. While some estimates can differ, 17% sits with the commonly cited average for cloud reflection; numbers as low as 8% would understate cloud reflectivity, while 25% or 52% would imply much higher cloud albedo than is typical on a global scale.