Final answer:
Albedo is the measured index of the reflectivity of a surface, signifying the percentage of incident light that is reflected back. It is a critical factor in determining the amount of energy absorbed by Earth's surface, influencing climatic changes and surface temperatures.
Step-by-step explanation:
Albedo is a measured index of the reflectivity of a surface or object. It represents the ratio of the intensity of the reflected light to the intensity of the incident light, often expressed as a percentage. For example, Earth has an albedo of about 30%, which means that 70% of the sunlight that reaches it is absorbed, whereas the remaining 30% is reflected. Surfaces with higher albedo, such as snow and clouds, reflect more sunlight and tend to stay cooler, whereas surfaces with lower albedo, like oceans and forests, absorb more sunlight, leading to warmer temperatures.
Alterations in reflectivity, or albedo, directly affect the amount of energy that enters Earth's system. When the albedo of the Earth's surface is decreased due to pollutants like soot or dust, the surface absorbs more solar radiation, contributing to a rise in temperatures. This concept is essential in understanding climate dynamics and the impacts of human activities on the global environment.