Final answer:
Albedo is the percentage of received energy reflected by a surface, with Earth's albedo being about 30%. It is crucial for understanding climate as it influences how much sunlight is absorbed or reflected. It is factored in with the solar constant and emissivity to estimate Earth's temperature without greenhouse effects.
Step-by-step explanation:
Albedo is b. the percentage of received energy that is reflected by any surface. It measures the reflectivity of surfaces or objects, with a higher albedo indicating a higher reflectivity. Earth's albedo is about 30%, meaning it reflects 30% of the solar radiation that hits it, while absorbing the rest. This concept is important in understanding Earth's climate system, as changes in albedo can influence the planet's temperature by affecting how much solar energy is absorbed versus reflected.
The solar constant is approximately 1,360 W/m², indicating the rate at which solar energy reaches the top of Earth's atmosphere. Earth's surface and atmosphere reflect around 29.3% of this incident solar radiation, which is accounted for in its albedo. The energy that is not reflected is absorbed, contributing to warming the planet's land, water, and atmosphere. The emissivity of Earth, which relates to how well it radiates energy, plays a key role in Earth's temperature balance as well. Without considering the greenhouse effect, the planet's temperature can be estimated using the solar constant, Earth's albedo, and the Stefan-Boltzmann law.