Satellite observations indicate that the United States ranks highest worldwide in total nighttime illumination, followed by China, India, Canada, and Brazil. This intense brightness reflects widespread urbanization, infrastructure growth, and extensive electricity access, establishing the US as the most luminous country after dark.
Between 2014 and 2022, the US experienced a 6 percent overall increase in nighttime brightness, although this growth varied regionally. The West Coast saw notable brightening driven by population expansion and booming technology sectors. Conversely, parts of the East Coast and Midwest exhibited dimming trends, influenced by population migration away from traditional urban centers, declines in manufacturing areas, and the implementation of energy-saving lighting programs in cities such as Washington, DC, and Chicago.
China and India, occupying the second and third positions globally, also contributed significantly to the global rise in nighttime light. Worldwide, brightness levels grew by 16 percent during the same period, but this increase was uneven. Emerging economies in sub-Saharan Africa and Southeast Asia experienced remarkable brightening as rural electrification and urban development extended electricity to previously unlit areas. Countries including Somalia, Burundi, Cambodia, Ghana, Guinea, and Rwanda saw rapid gains in illumination.
In contrast, certain regions witnessed reductions in nighttime light. Nations like Ukraine, Lebanon, Yemen, and Afghanistan suffered substantial dimming due to conflict and infrastructure breakdowns, while prolonged economic difficulties led to declines in Haiti and Venezuela. Europe recorded a 4 percent net decrease in brightness, largely attributed to the adoption of energy-efficient LED streetlights, dark-sky preservation initiatives, and government policies aimed at minimizing light pollution. France was highlighted as a global leader in these efforts.
The research, published in the journal Nature and based on analysis of over one million daily satellite images processed by NASA, underscores the dynamic nature of Earth’s nightscape, which continuously expands, contracts, and shifts. While nighttime light serves as an indicator of human development and electrification, experts caution that increasing artificial illumination can disrupt ecosystems, affect animal migration patterns, and interfere with human circadian rhythms.
