Look at the stars! How many of them can you see? Five, fifteen, fifty or five hundred? Even more? If you can see at least a few dozen, you are the lucky one. Many people living on the Earth have even never seen the Milky Way. How is it possible? I think that almost everybody has sometimes heard about light pollution. That’s the reason. Do you think that the only one effect of light pollution is that you cannot see the stars? You are wrong.
Light pollution affects everyone’s quality of life. It disturbs our sleep and our biorhythm and may even contribute to the development of cancer. Light pollution has influence not only on us, people, but also on our environment, forests, plants, insects, and animals. Light pollution is widespread in Asia, Europe, and North America. Unfortunately, it remains largely overlooked and unregulated in many countries. Many politicians don’t realize that regulations restricting lighting are advantageous not only because of decreasing level of light pollution but also because of energy saving.
All plants and animals depend on Earth’s daily cycle of light and dark rhythm. This rhythm governs reproduction, nourishment, sleep and protection from predators. Light pollution affects a wide variety of living organism. It can even influence ecological balance. Artificial light affects the population of many organisms, it could have an impact on the population of those organisms, and it can even threaten biodiversity.
You can ask how light pollution affects for example birds. They sing at unnatural hours in the presence of artificial light. Long artificial days allow longer feeding and it can influence migration schedules. The consequence is that birds start their migration too early or too late and they can miss ideal climate conditions for nesting. Many birds migrate or hunt at night, they are navigated by moonlight and starlight. They can wander off course and toward the dangerous nighttime landscapes of cities and all because of light pollution. They die colliding with needlessly illuminated buildings and towers.
Light pollution may also contribute to the global decline of amphibians because many amphibians are nocturnally active or have biological rhythms regulated by light.
How can light pollution influence forests?
The natural cycle of day and night has an impact even on plants and trees. Light pollution can cause that plants don’t respond to the change of seasons. Light pollution can also affect the regeneration of tropical rainforests. It has an influence on the recovery of deforested rainforests.
Light pollution disrupts the behavior of fruit-eating bats. These bats are important because they eat fruits and disperse seeds. Bats can help trees and plants recolonize the deforested land. Artificial light can cause the extinction of bats. Light pollution can have adverse consequences for forest regeneration in the tropics. Deforested ecosystems rely on seed-dispersers and bats are the most important seed dispersers in tropical rainforests. Bats are an important source not only dispersing seeds but also a source of pollination. They disperse a lot of seeds through seed-rich feces known as “seed rain” across the rainforest. Fruit-eating bats are so important because only a few another animals than bats disperse seeds into open habitats. Bats are more likely to feed in dark conditions than in artificial light. Human expansion and light pollution cause that bats die or they don’t spend time in those areas. Throughout South America and parts of Central America, the bats encourage the growth of hundreds of plant species. In many tropical countries in these areas, light pollution is increasing rapidly as human populations grow. It can have negative impacts on biodiversity and consequent effects on land erosion.
Why is this kind of pollution different? In a certain sense, light pollution has a big advantage. From all kinds of pollution, light pollution is perhaps the most easily remedied. Unlike losing a species to extinction or topsoil to erosion, the night sky is 100% recoverable.
The main cause of light pollution is bad lighting design. Almost 30% of outdoor lighting is wasted due to poor design. It allows artificial light to shine outward and upward into the sky, instead of focusing it downward. Already simple changes in lighting design can cause immediate changes in the amount of light pollution and energy savings immediately. Many people don’t realize that light costs lots of money, also the state uses millions of money to generate electric power. Unfortunately, the reduction of light pollution from widespread street lighting may prove more difficult to achieve. Through that, you can make small steps to the reduction of light pollution at your own home. The solution is to choose outdoor light fixtures that are shielded and turn off any unnecessary outdoor lights. Turn off all decorative and unnecessary light as much as possible. And one of the most important things, educate other people about dangers of light pollution!