Preserving the night benefits everyone!

Benefits for human health

The entire biosphere is affected by light pollution, and humans are no exception. A number of studies have shown the considerable degree to which artificial light impacts human health, both physical and psychological.

While blue light is emitted naturally during the day by the sun, our nighttime environment should be virtually devoid of it. However, with the use of screens (cellphones and TV) as well as inadequate lighting, more and more people are unfortunately exposed to blue light. When exposed to blue light, the retina sends a signal to the nervous system, suppressing the secretion of melatonin. This can delay the onset of sleep by several hours since this essential hormone is, in a way, in charge of your biological clock.

We also know that melatonin is a powerful natural antioxidant. Numerous studies have established a link between nighttime exposure to light and an increased risk of developing breast or prostate cancer.

Benefits for biodiversity

By reducing light pollution, we can help protect biodiversity. In the plant world, artificial light influences growth as well as resistance to disease and insects. In the animal kingdom, the negative impacts are even more numerous, and affect insects, mammals, amphibians, and birds alike.

Some disturbances caused by night lighting are clearly visible. Consider, for example, the clouds of insects that swarm around light sources, a behavior that often leads to their death by exhaustion or predators.

Other impacts, while more subtle, are potentially much more serious, including the modification of the relationship between plants and pollinators or between prey and predators. By changing the apparent duration of day and night, artificial light desynchronizes the natural biological rhythm and periods of activity of species. It is not only the quantity and duration of the light that is at cause; the color and spectral composition also have a significant impact.

All living species have adapted to interact among themselves in the natural environment. The search for food, territory, shelter, or a mate hinges on a delicate balance between each species, and when one of them is advantaged or disadvantaged by artificial light, the health of the entire ecosystem suffers. After all, night accounts for half of all one’s life!

Benefits for the economy

Inappropriate lighting, lighting when it’s not needed, unnecessary lights, lights that are directed into the sky… there are numerous sources of wasteful light, and the potential savings related to light pollution are enormous.

While energy is relatively cheap in Québec, by adopting better lighting practices, the savings could top $45 million a year!

Benefits for astronomy

Humans have always been fascinated by the starry skies. In fact, it is thought that the Babylonians—who lived millennia before our time—were the first to discover the existence of the planets Mercury, Venus, Mars, Jupiter, and Saturn when they plotted the movement of the stars in the sky, observing that these five bright celestial objects did not move at the same speed as the others. It was also by observing the night sky that scientists developed the first theories about the shape of the Earth and its position within the solar system.

In the 21st century, the increase in light pollution constitutes the greatest threat to astronomy research, and has even resulted in some observatories having to close down altogether. While many astronomers are forced to travel tens and sometimes hundreds of kilometers to observe the wonders of the deep sky, some urban dwellers who never leave the city could spend their entire lives never having the opportunity to marvel at the Mily Way.

By preserving the night sky, we can help further scientific advances and allow current and future generations to contemplate one of the oldest spectacles in the universe!