Recent maps reflecting changes in artificial light across the globe reveal patterns of brightening and dimming influenced by various factors, according to an analysis of NASA’s Black Marble data.
The study, covering the period from 2014 to 2022, shows that the world’s nighttime illumination has not uniformly increased; instead, it demonstrates complex fluctuations tied to industrial developments, construction activities, and energy policies.
NASA’s Black Marble product, which utilizes data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi-NPP, NOAA-20, and NOAA-21 satellites, generates records of nighttime lights at different time scales. The VIIRS day-night band detects light across various wavelengths, allowing researchers to identify signals such as urban illumination and reflected moonlight.
Maps created from this data indicate that global radiance increased by 34 percent from 2014 to 2022, although this increase obscures significant areas of dimming. Notably, urban areas on the U.S. West Coast saw brightness growth due to population increases, while many East Coast locations experienced dimming attributed to the adoption of energy-efficient LEDs and shifts in the economy.
The study highlights that nighttime light intensity surged in China and northern India alongside urban expansion. Conversely, cities like Paris, along with broader regions in France (33 percent dimming), the UK (22 percent dimming), and the Netherlands (21 percent dimming), recorded reduced light pollution. A marked decrease in lighting across Europe in 2022 also correlated with an energy crisis that followed the outbreak of the Russia-Ukraine conflict.
Source: science.nasa.gov.
