Albedo

Albedo tells you how much incoming sunlight a surface sends back to space or to the atmosphere instead of absorbing. It is defined as the ratio of reflected radiation to incident radiation, so it has no units and must fall between 0 and 1 for a single surface under the same lighting conditions. A higher albedo means less solar energy is absorbed, which helps explain why bright surfaces stay cooler than dark ones.

Use this when comparing how different Earth surfaces affect heating, such as ice, vegetation, soil, water, rooftops, or deserts. It is also useful in climate and energy studies when estimating how changes in land cover influence local temperature and the planet’s energy balance.

• Using absorbed radiation in the numerator instead of reflected radiation
• Forgetting that albedo is a ratio, so the answer should be a decimal or percentage with no units
• Mixing up reflected and incident radiation, especially when comparing different surfaces or time periods