Global trends in population exposure to outdoor artificial light at night and future projections

The population exposed to light emissions increased from 4.3 billion in 2000 to 6.3 billion in 2020.

• 88% of the growth in exposure occurred in areas with medium to high light emissions, primarily suburban and urban regions.
• 73% of the increase in exposure to high light emissions, mostly found in urban areas, is linked to population growth and migration.
• For medium light emissions, predominantly in suburban areas, 63% of the increase in exposure is associated with rising radiance.
• By 2050, nearly 70% of the projected growth in exposure will be in medium to high light emission areas.
• Potential increased disease burden and actions to mitigate light growth may be necessary.

AI simplified