In this project we are going to discuss the subject ‘light pollution’. We will discuss the following topics:
- What is light pollution
- Causes light pollution
- Effects of light pollution on individual organisms
- Types of light pollution
- Effect on astronomy
- What will happen if all dark places would be gone
We weren’t familiar with the topic, which made it exciting for us to do. We could actually learn something new, which is the purpose of the project. We spent a lot of time in the mediatheek looking for information. When we knew something about light pollution, we could start writing. We have spent a lot of time working on our project. We think that we did a good job at doing the project. We do believe that there is a solution to the problem, as long as we all try. Everything can help, even the smaller things. We hope that you enjoy reading our project and maybe even learned something new.
What is light pollution?
A basic evolutionary fact is that we humans are diurnal (active mainly during the day) species. Humans have eyes that are adapted to living in the sun’s light. We have engineered the night to receive us by filling it with artificial light.This engineering is almost the same like damming a river. It has benefits, but also consequences. These consequences are light pollution.
Light pollution (aka: photopollution or luminous pollution) occurs at night and is obtrusive (bothering), misdirected, inappropriate, or excessive artificial light. Components of light pollution are: Urban Sky Glow, which is the brightening of the night sky over inhabited areas; Light Trespass, when light falls where it is not intended or needed to fall; Glare, visual discomfort caused by excessive brightness and high levels can decrease visibility.; Clutter, light sources which are bright and excessive. These light sources can be found in over-lit urban areas.
It is the brightening of the night sky and it diminishes the view of stars and planets.
Causes light pollution
Light pollution is pollution caused by misplaced artificial light and reflections such as outdoor light which scatters in the atmosphere and reflects back to the ground.
The light allows a fraction of light to go up in the sky. This leads to sky glow. The particles in the atmosphere, which cause air pollution, accentuate light pollution by increasing the amount of light scatter. It has been proven that around one-third of the energy used for the outdoor lighting is reflected into the outer space, where it is wasted, because it doesn’t serve any useful purpose. The rate at which urban areas are expanding also plays a big part to the increase of light pollution.
Effects of light pollution on individual organisms
The most common effect of light pollution is that it interferes with biological cycles and activities. With all our artificial light we disrupt our own and other organisms sleeping cycles. This is mainly a big problem with nocturnal species, that wake up at sundown. Because of the artificial lighting, the are more exposed to predators so they have less time to find food. Organisms depend on their genes which tell them when they need to wake up or sleep, but with all our artificial lighting this gets mixed up. Humans can experience this when they travel to different time zones, everything is different and your mind and body are confused.
A lot of different animals are affected by light pollution. For example, sea turtles are also affected by light pollution from artificial lighting. Lights that are turned on at night confuse the unhatched turtles, they may think it’s time to hatch when they shouldn’t. If they hatch to early, or during the wrong part of the day, the chances of survival will become a lot smaller. With the artificial lighting by the beaches or on the roads, instead of crawling to the sea they might crawl to the roads.
Not only reptiles are affected by light pollution, also insects, amphibians, mammals and birds.
Insects that are attracted to light like flies will fly around street lights during the night and they will stay in one place, this makes them vulnerable to nocturnal predators. Since they fly around the lights the opportunities to mate are reduced which leads to population reduction. Overall the number of insects will be reduced over the years.
Amphibians are also affected by light pollution, even if they don’t live in an urban city, because light pollution isn’t only causing problem in the areas with a large amount of light, areas around it are also affected. Amphibians get really confused by light pollution because they don’t know when it’s nighttime with all the artificial lighting. Since they eat at night to avoid predators, they become an easier prey because they don’t know when they need to get food.
Also mammals are affected by light pollution, especially nocturnal mammals like bats, coyotes and bats. They are so affected by light pollution because there is too much light at night to find food. It becomes more difficult to find a breeding site, which leads to less reproduction opportunities, and the population of the species will shrink.
Birds that migrate at night rely on the light that is reflected by the moon and stars to find their way through the dark. They get confused and could get stuck in an urban area, because they were caught off their guard by all the lights. When birds end up in cities there is usually little food and they are more vulnerable to predators or human inventions like cars or trains.
Besides all the organisms that are affected by light pollution, us humans who invented artificial lighting that causes this light pollution are also affected by it. Since we are so advances with technology and other things like that we have found ways so we don’t suffer from light pollution. But we can’t completely solve it with our inventions like curtains. Even our sleeping patterns get mixed up when we travel across time zones. Our natural sleep rhythm get’s affected by light pollution too.
Us humans have a hormone called melatonin. This hormone helps us sleep and creates a natural rhythm for sleep. Light pollution and artificial lighting disturbs the natural rhythm and decreases the amount of melatonin in our body. Which leads to broken nights and a bad sleeping patterns.
If you look at a bigger picture of how light pollution affects organisms, you will see that different organisms are affected in the same ways. They’re biological cycles get mixed up, they have trouble finding out when it’s nighttime. Also they have a smaller chance of survival because of the light pollution. All the consequences to these organisms are bad and disrupt the natural rhythms.
Types of light pollution
Urban Sky-glow: Sky glow exists in large cities. It is the ‘glow’ which you can see over many cities and towns in the evening. Urban Sky Glow is the brightening of the night sky. It is caused when artificial light escapes from misdirected and badly designed light sources into the atmosphere. It is scattered by particles (pollen, bacteria, dust, spores, mineral particles) or by water droplets while it travels through the atmosphere. The light gets reflected and masks the background stars and cases a hazy glow over the night sky. This type of light pollution is a concern to astronomers, because it creates a hazy glow over the night sky. Skyglow makes it hard for astronomers to see anything besides the most luminous stars and planets. Skyglow also caused behavioral disorders in many species of animals. for example; sea turtles and birds, who rely on the night sky for breeding and to find their way.
In heavily polluted areas Urban Sky-glow is worse. It will always exist if the air quality is poor.
Clutter: Light clutter is the excessive groupings of light. These groupings of light may cause confusion, distraction from objects, and possibly cause accidents. Clutter light pollution is caused by things like street lights, these can be dangerous to the people driving since the drivers can be distracted by these lights.
Glare: Glare is a visual sensation that is cause by excessive and uncontrolled brightness. Glare from street-lights, car-yard and security lights can shine directly into the eyes and cause discomfort. This makes it hard for the eye to adjust effectively to changing levels of illumination, so compromising night vision. there are three forms of glare:
Discomfort glare: The sensation of annoyance or pain induced by overly bright sources. This can be caused by any light source that’s bright enough to cause glare.
Disability glare: The reduction in visibility caused by intense light sources in the field of view. This can be caused by any light source that’s bright enough to cause glare
Blinding glare: When there is a light source that’s so bright that it can cause a moment of blindness, the amount of time the blindness lasts depends on the brightness of the light source.
Light trespass: Light trespass is unwanted and uncontrolled light that shines outside the area that it is designated to illuminate. It causes discomfort, distraction, annoyance, or a reduction in visibility, and wastes energy and money.
These are several characteristics of nighttime lighting that can cause Light trespass:
Spill light: The light that illuminates surfaces beyond the property line.
Brightness: The presence of bright sources which are in a person’s field of view which can cause discomfort glare, disability glare or blinding glare.
Effect on astronomy
Astronomy is very sensitive to light pollution. Light pollution interferes with our visibility due to sky glow. Sky glow is unshielded light that is send in all directions. Sky glow, mostly caused by big cities, makes it hard to see dim objects in the sky at night, such as nebulae, stars and galaxies. Sky glow reduces the contrast between the sky and between the stars and galaxies, which makes it even harder to see dim objects.
Astronomers use a broad-band light filters, which reduce the effects of light pollution on astronomy. The broad-band light filters do that by filtering out spectral lines and so alter the view of dim objects. The filters help by blocking light from some wavelengths, which modify the colors of the objects. But the broad-band filters can only affect certain object types. They affect nebulae, but have little effect on galaxies and stars. The visibility of objects such as nebulae and galaxies is affected more than stars, due to their. Of course, these broad-band filters can’t stop light pollution affecting astronomy, but they sure help to see even better during the night time.
What will happen if all dark places are gone?
Most of us live in an area where it is not dark enough for our brains to recognize it as night. Humans and other species have evolved to be in tune with cycles of day and night, so if we would destroy our night, the following problems will occur everywhere.
Light pollution is bad for our health, it can cause cancer, so if all the dark places would be gone there would be higher nighttime lighting levels, which will cause a big increase of cancer patients.
Light pollution is a disturbance to animals, animals are, just like we are, evolved to be in tune with cycles of day and night. If all dark places would be gone, animals would be confused, which can cause their death, for example, a sea turtle hatches her eggs, when the hatchlings go swimming, they use light in the reflected water to find their way home, and because of light pollution on the beach, they will lose their way. Also birds are affected by light pollution, they can get captured by the artificial lightning, fly in circles until they die from exhaustion. Many more animals are affected by light pollution, they become an easy prey for predators which has an unknown effect on the ecosystem.
Astronauts and astronomers have already complained that the streetlight interferes with their equipment. If all the dark places would be gone, we could not see anything in space which will stop us from discovering and learning more from space. Light pollution also alters our view of the sky and stars.
It is a waste of energy, about 30 percent of the nightlight is a waste. The total amount of electrical energy can illuminate over 11 million homes and power over 777.000 cars.
It is bad for the environment, this is because out nightlight causes 12 million tons of carbon dioxide to go into the atmosphere which ruins it. Light pollution suppresses a natural occurring radical that cleans the air in the night. Light pollution increases the chemicals for ozone pollution by 5 percent.
How can we reduce light pollution? (solutions):
We can reduce the light pollution by, for example save more energy at home, turn off the light that’s not needed, by doing this, we can reduce the light pollution together. Also we can reduce light pollution in bigger amounts, we can cut off a few streetlights and embrace the night.
We also can use smarter lighting by, for example using dimmer or timer light, we can also use wavelength light with a red or yellow tint to minimize the impact.
We can also reduce excessive lighting, for example the billboards in Las Vegas can be turned off or can be made smaller, we can also turn off lights of big buildings, while nobody is doing something, for example a football stadium or the Eiffel Tower.
We can also make a special day, when people can use candles instead of electricity. We can shield our outdoor lightning too.
One of the most effective solutions would be to shine lights down instead of upwards on streets. In that way we could efficiently use the light, and shine it at the place where it is most needed, which is the ground.
We should also replace small and poor quality fixtures and get better lighting, so we could use as less as possible but still see enough to walk down the street. We could also use efficient sources around businesses and houses.
Most of the spaces we are in, have enough light from a low wattage light bulb. And when you do need higher wattage light bulbs,you should make sure that the bulb is shielded, so that no light is wasted.
Of course not for everyone making a change is easy, mostly because we all have our personal habits, for example, most people like to have a late night snack or some people have to go to the bathroom in the middle of the night. Even those people can make a change by installing a dimmer so they can use as little light as possible, or they can install a light sensor, so that the light will only go on when you walk passed the sensor.
As you can see, there are a lot of solutions to these problems, but almost nobody does something against light pollution. If we work harder and together, we can reduce light pollution and get the night back. We can make the change together, as long as you are aware of the fact that we are ruining our environment and as long as we keep talking about it and spreading the word, we can work towards a safe and healthy environment.
There is already a movement called The Dark-Side Movement, which consists of astronomers who try to show people that light pollution is bad and want it to decrease.
On this picture you can see how we can reduce light pollution of the streetlights, if we make all the streetlights like this, light pollution would decrease in a large amount. Beside this, there are many more ways to use light in a better way.
So, light pollution is the artificial light which is wasted. There are a lot of bad consequences, but most people have never heard of it and some of the people who do know it, don’t think it’s a big problem, we think this has to change because it is a very bad thing even though some people say it isn’t. But there are a lot of people that are trying to fight light pollution. They want to protect human health and wildlife. Countries are starting to realize the big effects and problems light pollution is causing. They are starting to look for solutions that will make a big difference. Many scientists are trying to find good solutions to this problem. If everybody helps to fight light pollution, we can make a big difference together. We think that it’s not that hard to turn off some lights and use better lightning. People who care about themselves should care more.
- Globe at night – what is light pollution? http://www.globeatnight.org/light-pollution.php
- Gizmag – http://www.gizmag.com/led-streetlamp/27246/
- Wikipedia – https://en.wikipedia.org/wiki/Light_pollution
- Light pollution and the law – http://www.britastro.org/dark-skies/law.html
- Light pollution – International Dark Sky Association – http://darksky.org/light-pollution/
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