What term describes the fraction of insolation reflected by Earth?

What term describes the fraction of insolation reflected by Earth?

• A. Insolation
• B. Albedo
• C. Greenhouse Effect
• D. Heat

Answer: (B)

Albedo describes the fraction of incoming solar radiation that Earth's surfaces, clouds, and atmosphere reflect back into space. It directly measures how reflective the planet is. Insolation is the incoming sunlight itself, so it’s about how much energy arrives, not how much is reflected. The greenhouse effect relates to trapping heat in the atmosphere, not reflectivity. Heat is energy transfer, not a reflection fraction. Earth’s average albedo is about 0.3, meaning roughly 30% of the sunlight is reflected while about 70% is absorbed.

Albedo describes the fraction of incoming solar radiation that Earth's surfaces, clouds, and atmosphere reflect back into space. It directly measures how reflective the planet is. Insolation is the incoming sunlight itself, so it’s about how much energy arrives, not how much is reflected. The greenhouse effect relates to trapping heat in the atmosphere, not reflectivity. Heat is energy transfer, not a reflection fraction. Earth’s average albedo is about 0.3, meaning roughly 30% of the sunlight is reflected while about 70% is absorbed.