How Light Wreaks Havok Worldwide
Image 1 – Milky Way lighting up the sky in Tasmania, Australia far from the reach of artificial light sources Image Source: Caleb White
According to space.com, there are over 100 billion stars in the galaxy. Imagine looking up to the night sky, and witnessing the masses located millions of kilometers away, shining bright in one corner of the infinity above. Interestingly enough, over 80% of the world cannot see the stars at night (Light Pollution). Sounds crazy, but it’s true. Moreover, according to National Geographic, 99% of Americans and Europeans cannot look up and see one of the world’s natural phenomena’s – celestial objects.
The United Nations has 17 goals to meet by 2030. These goals, known as the Sustainable Development Goals (SDGs), are targets that the world must reach in order to support the human population on the planet Earth. Light pollution is connected to multiple of these Sustainable Development Goals, such as SDG 3: Good Health and Well Being and SDG 15: Life on Land. It is also one of the leading causes of the prohibition of the viewing of celestial objects. All pollution is an effect of industrial civilization, and light pollution is no exception to this. Light pollution is derived from the light in buildings, outside buildings, advertising signs, commercial properties, sporting venues, etc. It comes from the unshielded lights on the street and a room without the curtains shut. It even comes from a phone or computer screen at night. A common assumption is that light pollution only affects the ability to see the stars at night, however, light pollution has a significant impact on human health and wildlife, but there are methods that individuals and government systems can use to solve this growing problem.
Human Health
Image 2 – Light from the city of Los Angeles seen miles away Image Source: Matthew Cooksey
Despite the numerous beliefs that light pollution merely affects one’s ability to view celestial objects at night, research and study show that light pollution can also cause major issues with an individual’s health and can even result in being more susceptible to breast cancer (Heydt).
Melatonin is a hormone that is released from the pineal gland in the center of the brain and is produced when there is no light. Melatonin not only induces sleep but also has antioxidant properties, boosts the immune system, lowers cholesterol, and helps the thyroid, pancreas, ovaries, testicles, and adrenal glands (Human Health).
The production of melatonin is directly affected by the body’s circadian rhythm. The human body has a biological 12-hour day/12-hour night clock known as the circadian rhythm, also found in other living organisms such as birds and plants (The Overuse & Misuse). Light pollution directly impacts the body’s circadian rhythm, which can quite often result in sleep deprivation, fatigue, headaches, stress, anxiety, and depression (Human Health). It has been shown to have a connection to forms of cancer such as breast cancer (Light Pollution), showing the importance of this rhythm and therefore the importance of lowering or dimming lights at night.
Image 3 – Bustling city in Hong Kong with intense light usage is suffering from light pollution Image Source: Saad Chaudry
The production of melatonin, in turn, affects the human body’s estrogen levels- a hormone that stimulates the reproduction or multiplication of cells in breasts (EcoCancers). However, excess of this hormone could promote high multiplication of cells that could have cancer, resulting in breast cancer (Artificial Light is). In 1987, Richard G. Stevens of Pacific Northwest Laboratory in Richland, Walsh suggested that exposure to light at night could increase the body’s total dose of estrogen, which would increase the risk of getting breast cancer. However, dimming or decreasing the amount of light exuded at night would not only help with the body’s circadian rhythm but potentially lower the risk of becoming a breast cancer patient. He also suggested that if researched further, this could help identify the origins of cancer growth within a patient, along with possible cures (EcoCancers).
Wildlife in Danger
Not only does light pollution impact the body’s circadian rhythm, melatonin production, and susceptibility to breast cancer, but it also impacts the livelihood and health of wildlife, including sea turtles, moths, flowers, trees, and wallabies.
Sea turtles are very well known to be beautiful, yet endangered specimens. However, more than plastic bags and straws are threats to the angelic sea creatures. Upon hatching, sea turtles instinctively crawl towards the brightest light source, and of course, in previous years, it would be the moon hanging over the ocean, that the hatchling would then crawl towards and arrive safely in the ocean. However, in more recent times, sea turtles have been crawling towards the bustling and bright city lights, and instead of being greeted by the tide, they have been dying due to dehydration and predators at night (International Dark-Sky Association).
Image 4 – Lights from Rossini, Switzerland blocking out most of the stars in the night sky, the light trespassing to dark areas of the map as well Image Source: Jan Huber
Aside from sea turtles, light pollution also impacts the well-being of trees. Exposure to light affects and alters the trees’ photoperiodic, daylight responses and reaction, causing some plants to bloom too early, too late, or not at all entirely. For example, Deciduous trees in the north drop leaves and stop growing in the autumn months, however, when exposed to artificial light for prolonged periods of time, they grow late into autumn, only to grow weak and damaged in the winter (Heydt). Trees such as birch and sycamore act in a similar manner, proving that the effects of light pollution are more varied than initially expected.
Image 5 – An unshielded streetlamp in Frankfurt, Deutschland exhibiting a lot of light glare Image Source: Justus Menke
Recent studies have also shown that light pollution has impacted the relationship between flowers and pollinators. Eva Knop, an ecologist at the University of Bern in Switzerland, recently conducted a study involving nighttime pollinators. The result of the said study pointed toward flowers in lit meadows having 62% fewer nocturnal pollinators than those in dark meadows. Even common flowers such as the cabbage thistle were impacted by this, and because over 80% of the flowers need a pollinator to reproduce, plants such as the cabbage thistle were also shown to have 13% fewer seeds produced. If this were to continue, it would lead to catastrophic impacts on ecosystems worldwide.
Even more so, pollinators such as moths were also shown to be impacted in terms of reproduction because of light pollution. In a study conducted by ecologist Roy van Grunsven of Wageningen University in the Netherlands, when exposed to artificial lights at night, female moths were shown to produce 30-60% fewer mating pheromones. These pheromones are hormones that help attract males to the females to mate, however, due to the lack of producing this hormone, two-thirds of the largest moth species’ population has been in decline in the United Kingdom (Nighttime Light Pollution). Since moths are nocturnal pollinators, a decline in their population and pregnancy will inevitably lead to less and less pollination occurring at night, resulting in fewer flowers and plant reproduction, leaving the environment in ruin.
Furthermore, light pollution has been impacting tammar wallabies’ mating cycles, leaving those exposed to light to be out of sync with ideal birthing conditions. Tammar wallabies who were exposed to nighttime lighting were more common to give birth 30 to 250 days later than usual in comparison to wallabies 6km away, with the moon as the only light source (Milius). Zoologist Kylie Robert thinks that one of the main causes of this could be the lack of melatonin the wallabies produce, as they are exposed to up to ten times the amount of light that bush wallabies are exposed to.
Solutions
Despite the majority failing to recognize light pollution as a proper, growing issue in our world, it is a complicated topic with a complicated solution. Whilst individuals’ help does help, the growing issue that is light pollution will not be “solved” without a large group of people being able to help work towards a darker sky (The Overuse & Misuse). Due to the fact that there is no actual solution for light pollution, it is quite hard to “solve”. However, there are still ways for individuals to help bring light emissions down in individual communities.
Some ways to move towards resolving light pollution are properly shielding outdoor lighting. There are three main types of light pollution, glare, clutter, and light trespass. Glare is excessive brightness emitting from a light source, which can harm one’s eyes. Clutter is the excessive grouping of light sources; this can be seen from satellite images as cities with large populations tend to have brighter pinpoints on the map. Light trespass – perhaps the most evasive form of light pollution – is when light extends into unwanted areas (Light Pollution IDA). Most outdoor lighting is either too bright or shielded in a way that allows “wasted energy” to be sent into the sky (Light Pollution). Making sure that outdoor lighting is properly shielded is essential to helping lower light emissions, as it is the main cause of light pollution (The Overuse & Misuse).
Image 6 – Light clutter seen over the Gulf of Mexico, United States of America from satellite Image Source: NASA
Whilst individuals can help, it is considerably better to step towards resolving light pollution if larger groups of people work together to lower the light clutter in a community. In a study led by Dr Christopher Kyba of the GFZ German Research Center for Geosciences, with help from NASA and NOAA, 5 years’ worth of satellite images showed that artificial lighting at night increased at a rate of around 2 percent per year, and these increases were seen worldwide. This challenged the assumption that having a higher energy efficiency led to decreasing energy consumption as whilst the energy efficiency of outdoor lighting was increasing worldwide, from the ongoing switch to LED lighting, the amount of outdoor lighting being put up had increased, leaving gross profits made from switching to LED lights lower than expected (Global Light Pollution). Despite this, efforts to help with light pollution are still very important, in order to try and reverse this issue. Whilst solutions are quite simple, many people still neglect them, leading to this increase. Ways individuals can help resolve light pollution include turning off unnecessary outdoor lighting, closing blinds or curtains to keep light inside buildings, and dimming lighting (The Overuse & Misuse).
Overall, light pollution does more than prohibit one’s view of the natural night sky, but in fact, influences human health, and wildlife behavioral trends, and whilst this is quite commonly brushed over, there are reasons and ways people should and can help solve this issue. Even though the issue is glossed over or completely ignored, it is important that everyone should try to reduce the individuals’ amount of light emitted into the sky, just as one would with plastic waste and carbon footprints. Even simple things such as turning off porch lights, closing curtains, and turning off or dimming unnecessary lighting help, and hopefully, individuals can work together as a community to help meet the Sustainable Development Goals that relate to the issue of light pollution.
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