What percentage of people are affected by light pollution?

Light pollution significantly affects a vast portion of the global population. The statistic indicating that approximately 80% of people live under light-polluted skies is derived from various studies that analyze urbanization and artificial lighting's spread. As cities expand and more artificial lights are used for public safety, commerce, and recreation, the natural night sky becomes obscured. This phenomenon impacts not only astronomical observations but also ecosystems and human health, emphasizing the extent of its reach. The choice of 80% reflects a broad consensus in environmental studies regarding the prevalence of light pollution in contemporary settings, particularly in urban and suburban areas where artificial lighting is most concentrated.