What Light Pollution Does to Living Things
Artificial light at night is expanding constantly, disrupting ecosystems and human biological rhythms. Simple solutions can balance safety and comfort with respect for living systems.
Seeing the Milky Way has become a rare privilege. Artificial lighting from streetlamps, signs and illuminated offices has pushed true darkness out of most inhabited areas, with very real consequences for living organisms.
When night disappears
Wildlife deprived of darkness
Billions of years of evolution have tuned organisms to the day-night cycle. Artificial light disrupts that clock. Disoriented nocturnal insects exhaust themselves around streetlights, worsening their major decline and affecting pollination and food webs.
Migratory birds stray from their routes, bats abandon hunting grounds, and newly hatched sea turtles move towards cities instead of the ocean.
We also sleep less well
In humans, exposure to light at night, particularly blue wavelengths, disrupts melatonin production and sleep quality, with cascading effects on health.
It is one of the simplest forms of pollution to reduce: in many cases, all that is needed is to switch the light off.
Giving residents the stars back
Turning off signs and offices at night, directing fixtures towards the ground, using warm colours and suitable intensities, and introducing overnight switch-offs are all immediate, economical measures that can restore the night sky.
- More than 8 people in 10 live under a night sky affected by light pollution.
- Insects, migratory birds and human sleep cycles are directly disrupted.
- It is one of the least expensive forms of pollution to reduce: often, the solution is simply to switch off.