Night Sky Getting 10% Brighter Each Year as Light Pollution Grows Worldwide

The night sky is growing 10 percent brighter every year, with 80 percent of people now living under light-polluted skies, according to recent findings. While visiting the International Dark Sky Places network in the Oregon outback—a protected region spanning 2.5 million acres—observers noted that artificial lighting continues to disrupt natural darkness even in remote areas.

Impacts on Wildlife and Humans

Artificial lights severely affect animals that rely on the moon for navigation, such as baby sea turtles, moths, lightning bugs, frogs, and migrating birds. Research also shows that light pollution breaks the relationship between plants and pollinators, alters the timing of tree flowering, and disrupts circadian rhythms in both animals and humans.

Existing Regulations

Some communities have already taken steps to control outdoor lighting. Flagstaff, Arizona, introduced outdoor lighting rules in 1958 and became the first recognized Dark Sky City in 2001, regulating the amount, type, and direction of light used. Meanwhile, New York state is considering a Dark Skies Protection Act to add similar restrictions.

Space-Based Threats

Ground-level rules cannot address light pollution originating from space. More than 11,000 Starlink satellites are currently in orbit, and some companies plan to launch satellites that provide artificial sunlight on demand. Space objects currently do not require environmental reviews even when they affect life on Earth.

Context

Light pollution is caused primarily by unshielded or excessive outdoor lighting from street lamps, buildings, and parking lots left lit overnight. Preserving natural darkness involves practical measures like targeting lights downward, using warmer tones, and ensuring bulbs are only as bright as necessary for safety.