A Third of the World’s Population Can’t See Stars at Night

Laura Goldman | Precis Wayne Lazarides

Living on the western foreshores in Sydney is unique. Rarely is it possible to live in one of the world’s major metropolises and still be close to nature.

Unfortunately, nature does not always want to be close to us. And so if we truly love where we live, for what it currently is, then we need to understand how to coexist with our natural environment and how to protect and maintain the fragile balance we currently enjoy.

The Australian bush at night is dark, or at least it is supposed to be. Nocturnal Insects, birds and animals like it that way. Importantly, they have adapted to wake, hunt and eat, navigate, reproduce and function in the dark.

And getting used to the dark hasn’t happened overnight. Evolution takes time, a long time, about 1,000,000 years give or take a millennium or two…

“Across a broad range of species, the research found that for a major change to persist and for changes to accumulate, it took about one million years.” Source: Phys.org (http://phys.org/news/2011-08-fast-evolutionary-million-years.html)

So nature will find it tough to adapt “overnight” to our artificial light sources. In fact, research by Travis Longcore and Catherine Rich has shown that the opposite is happening, and that artificial light is having a profound and adverse impact on ecosystems.

It can disturb development, activity patterns, and hormone-regulated processes, such as the internal clock mechanism.

Probably the best-known effect, however, is that many species are attracted to, and disoriented by, sources of artificial light, a phenomenon called positive phototaxis. Apart from insects, birds that migrate during the night are especially affected. This may cause direct mortality, or may have indirect negative effects through the depletion of their energy reserves.

Artificial light impacts on wildlife by:

  • Causing disorientation or creating unnatural stimulus.
  • Disadvantaging prey and benefiting some predators
  • Disrupting reproduction
  • Either increasing or decreasing the completion between species

How can we help?

A few simple techniques can help significantly - especially in the western foreshores.


1. Is the light needed?

  • Only light what’s necessary.
  • We live in an environment where visitors and residents are prepared for darkness.
  • In addition, under many circumstances, removing existing lights is an option because they were not needed.


2. Selective Direction of Lighting

  • Try to direct lighting only where required.
  • Use lights that are “full cut-off,” which is defined as a light that emits virtually no light upward and very little light in the 10° angle below the horizon. Depending on where the light is located, additional shielding may be necessary to keep light from spilling into sensitive habitats such as a wetland or forest. Even lights that are directed downward may still cause adverse effects for ecosystems
  • The shotgun approach where light escapes or is shone in all directions should be avoided and eliminate where possible.

3. Light intensity

If an existing light is shielded properly, often less light is just as effective because it is all going where it is desired.

Outside, in the Western Foreshores, being a natural habitat for Nocturnal animals, intensity should be kept low so that the contrasts between lit and unlit areas are minimized. Interestingly this actually improves visibility. Allowing the human eye to keep some of its adaptation to the dark.

ie: When lights are very bright, the eye adapts to this brightness and all else appears as dark shadows. Alternatively, when light is reduced - closer to ambient conditions, you are able to see more that is not directly illuminated by the light.

4. Duration

Rarely do lights need to be on from dusk to dawn.

Consider setting a timer to turn off after a certain hour or by putting the light on a motion sensor .

Good practices such as turning lights out when they are not needed could go a long way to reducing light pollution, not to mention reducing energy useage and saving money.

5. Spectrum

Although all light has some effects on wildlife and habitats, certain spectra are more damaging. Full spectrum light, which has blue and ultraviolet wavelengths, should not be used. Tthe presence of the blue light sends an environmental signal of "it's daytime".

Ultraviolet light is highly attractive to insects and it should be avoided as well.

For further information Read:http://www.actionbioscience.org/environment/longcore_rich.html

A Third of the World’s Population Can’t See Stars at Night

Light pollution is a side effect of industrial civilization, according to the International Dark-Sky Association (IDA), a nonprofit working to protect the night sky. Among the contributors to this type of pollution are building lighting, factories, streetlights and illuminated sports venues.

The country with the worst light pollution in the world is Singapore, where the entire population “lives under skies so bright that the eye cannot fully dark-adapt to night vision,” according to the study. Several Middle Eastern countries are among the most light-polluted, including Kuwait (98 percent of its population is affected), Qatar (97 percent) and the United Arab Emirates (93 percent).

If you want to look up and see the constellations, your best bet is gazing at the night sky over African countries like Chad, the Central African Republic and Madagascar.

Light Pollution Doesn’t Just Block Our View of Stars

Along with preventing us from enjoying starry nights, light pollution has other, more sinister, effects. Called “artificial skyglow,” the lack of darkness negatively impacts our behavior, is dangerous for wildlife and causes wasteful energy spending.

  • Human physiology and behavior: Artificial light messes up our natural circadian rhythm, the physical, mental and behavioral changes that occur during a 24-hour period in response to light and darkness. It also increases our production of the stress hormone cortisol, according to a 2007 study that examined the role of artificial light in cancer and other diseases.
  • Wildlife: Animals – especially nocturnal ones — can become disoriented when exposed to artificial light. It’s a reason why millions of migrating birds are killed every year. “Predators use light to hunt, and prey species use darkness as cover,” research scientist Christopher Kyba told the IDA. “Near cities, cloudy skies are now hundreds, or even thousands of times brighter than they were 200 years ago. We are only beginning to learn what a drastic effect this has had on nocturnal ecology.”
  • Wasteful energy: “The fact is that much outdoor lighting used at night is inefficient, overly bright, poorly targeted, improperly shielded and, in many cases, completely unnecessary,” says the IDA. Instead of illuminating objects and areas, the light is wasted when it spills into the sky.

While artificial lighting may seem to have some benefits, such as preventing crime and making night driving safer, a study last year found that streetlights have no significant impact on public safety.

What can be done to reduce light pollution? Quite a bit, fortunately. Unlike other types of pollution, it is relatively easy to eliminate. For starters, each of us can do our part by only using lighting when needed, and only using energy-efficient light bulbs.

“Many people either don’t know or don’t understand a lot about light pollution and the negative impacts of artificial light at night,” says the IDA. “By being an ambassador and explaining the issues to others you will help bring awareness to this growing problem and inspire more people to take the necessary steps to protect our natural night sky.”


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