An analysis of nearly a decade of nighttime imagery from NASA’s Black Marble product reveals a world where patterns of light are more nuanced than simple growth, displaying a patchwork of brightening and dimming across the inhabited globe. Utilizing data collected from the VIIRS sensors on the Suomi-NPP, NOAA-20, and NOAA-21 satellites, researchers examined nighttime light patterns from approximately 2014 to 2023, detecting signals ranging from city lights to auroras through specialized filtering techniques. While global radiance increased by 34 percent during the study period, this surge obscures significant regional dimming, with areas like Paris experiencing a 33 percent reduction in light pollution alongside surges in China and northern India. These changes reflect not only urban development but also the impact of events like the Russia-Ukraine conflict and the widespread adoption of energy-efficient LEDs. European nights dimmed sharply during a regional energy crisis that followed the outbreak of the Russia-Ukraine conflict.
The VIIRS day-night band’s ability to differentiate between city lights, moonlight, and auroras was critical to this detailed analysis, allowing scientists to move beyond a basic assessment. Yellow and gold areas indicate where brightness increased during the study period, while purple areas denote regions experiencing a reduction in light output. For example, while West Coast cities in the U. S. grew brighter with population increases, much of the East Coast experienced dimming, attributed to the increased use of energy-efficient LEDs and broader economic restructuring.
VIIRS Sensors Track Global Radiance and Dimming Patterns
These instruments, aboard the Suomi-NPP, NOAA-20, and NOAA-21 satellites, detect nighttime light ranging from green to near-infrared, but do not merely register lights on or off. They employ filtering techniques to distinguish between city lights, reflected moonlight, and even auroras, allowing for a nuanced assessment of human activity and its impact on the Earth’s radiance. A recent analysis of NASA’s Black Marble data, spanning from 2014 to 2023, demonstrates that these patterns are more than a gradual increase in artificial light. Researchers discovered flickering patterns linked to specific events, such as industrial booms and busts, construction projects, and even temporary blackouts, alongside longer-term shifts driven by policy changes.
Internationally, nighttime light surged in China and northern India alongside urban development, while LEDs and conservation measures coincided with reduced light pollution in Paris and throughout France, a 33 percent dimming, the UK, 22 percent dimming, and the Netherlands, 21 percent dimming. European nights dimmed sharply during a regional energy crisis following the outbreak of the Russia-Ukraine conflict.
Such “bidirectional changes” often happen side by side.
Regional Shifts: LEDs and Conflict Impact European Nights
Across Europe, a distinct dimming trend emerged, particularly noticeable in France, the UK, and the Netherlands. Researchers found that France experienced a 33 percent dimming, while the UK and the Netherlands saw reductions of 22 and 21 percent respectively, coinciding with the widespread adoption of LEDs and energy conservation measures. However, the most dramatic shifts occurred during 2022, when a regional energy crisis following the outbreak of the Russia-Ukraine conflict caused a sharp decline in nighttime illumination across the continent. The researchers noted this, highlighting the complex interplay of factors influencing light emissions.
