What is light pollution?

Light pollution refers to excessive or misdirected artificial light that disrupts the natural darkness of the night sky. The correct answer highlights the specific aspect of light pollution where outdoor lighting is improperly directed upwards into the sky, contributing to a phenomenon known as skyglow. This can obscure the visibility of stars and celestial bodies, negatively impacting astronomy, wildlife, and human circadian rhythms.

While other aspects of light usage in urban settings contribute to the overall experience of light pollution, such as the excessive illumination of public spaces or the creation of unwanted shadows, they do not capture the essence of light pollution as effectively as the improper direction of outdoor lighting into the sky. The issue of excessively lighting urban areas also pertains to light pollution but lacks the specific focus on the impact of directing light skyward, which is central to defining light pollution. Thus, the emphasis on the direction of lighting illustrates its role in contributing to the broader environmental effects associated with light pollution.