“Dark night skies are essential to the rhythms of life on Earth,” according to the National Park Service. All living things need cycles of light and dark.

For thousands of years, dark skies pervaded but since man’s invention of artificial light, light pollution has limited truly dark skies to rare, extremely rural areas.

Light pollution affects the health of both plants and animals that rely on natural cues visible only in true dark, according to the Park Service.

Further, the large amounts of energy needed to illuminate the night contributes to climate change.

Did you know most people in the world live under light-polluted skies, with only 20% able to see the Milky Way at night?

Humans have brought light into places and times at which it does not naturally occur and the intensity, color temperature, and direction of artificial lights have unintended impacts on the environment, the Park Service notes.

A growing body of research points to measurable adverse effects of light pollution on wildlife, plant development, human health, and energy consumption.

The light pollution doesn’t have to originate within the affected area. The Park Service has documented effects from light sources 200 miles away.

According to the Maine Audubon, a few of the effects on nature include:

• Some animals mistake artificial lights for moonlight.

• Some are disoriented by artificial lights.

• Man-made lights automatically favor diurnal species, and can lead to conflicts between them and their nocturnal counterparts.

• The problem of predation also disproportionately hurts nocturnal species, which have evolved to hide. Exposed to lights, they are more likely to get eaten.

• When man-made light extends the day into night, nocturnal mammals – among them beavers, bats and most rodents – have less time (and surface area) to scavenge for food.