An Analysis on How Artificial Light at Night May Impact the Sustainable Development Goals 2030 and Human Health
Article information
Abstract
This study addresses the relationship between Sustainable Development Goals (SDGs) 2030 and artificial light at night (ALAN). In this research paper, different types of SDGs by the United Nations are discussed regarding the effects of ALAN on different goals. In addition, different policies associated with ALAN around the world are examined, and literature reviews are discussed. With this analysis and additional stakeholder discussions, several suggestions are introduced to create a better environment. Regarding different sustainable goals, we observe a trade-off between SDGs and ALAN. It is necessary to discuss different stakeholders, to minimize the negative impact of light pollution and make better policies for the world. One cannot attain SDGs 2030 without considering ALAN. We hope this paper will be helpful to create better policies for sustainable development.
INTRODUCTION
Ever since the invention of the artificial light bulb 150 years ago, artificial lights have played a significant role in human civilization, culture, and development. The new form of light, artificial light, brightened and made safe previously dark streets, extended waking hours into the evening, and for the first time introduced power into houses. This radiance has increased in recent years but at a cost. They also have a significant impact on the United Nations Sustaintable Developement Goals (SDGs, https://www.undp.org/sustainable-development-goals). Human health, life underwater, life on land, increased energy use, biodiversity consequences, and how the glare from night lighting may continue to rise throughout the world [1].
One of the less-discussed types of pollution is light pollution. It uses artificial lights to overnight towns and skies at night. At night, light pollution occurs when an artificial light source sends light in an unintended direction. There are several varieties of light pollution, including glare, a disruptive light that shines horizontally, and light trespass, which is a light that shines vertically. The undesired reflection of light onto neighbouring locations and skyglow, a halo above populated areas caused by light particle scattering [2].
Whatever form light pollution takes can have a unified yet damaging effect. The nighttime rhythm of wildlife, particularly sea turtles, has been interrupted. The instinct of a turtle hatchling to follow the moon’s light to the sea is disrupted by the light of inland cities, and many never make it to the sea. It also has adverse effects on bats, which rely on darkness for hunting their prey, and it disrupts almost all nocturnal animal life cycles.
Light pollution has a negative impact on human health. Excess light can damage photoreceptor cells in the retina, causing vision loss [3]. Artificial light in the evening disturbs natural sleep cycles and produces sleep deprivation, leading to a variety of health issues, including cancer [4]. Additional carbon emissions are also produced because of light pollution. Hundreds of billions of dollars’ worth of coal or oil are consumed each year to provide power wasted on unneeded illumination.
Over the last decade, the usage of artificial light at night (ALAN) has expanded significantly because of population expansion, urbanization, and exaggerated access to energy and reasonable illumination. This has altered the nighttime setting and created fashionable urban lifestyles, leading to light pollution that obscures the night sky and raises issues regarding the harmful effects of night light on our health and the environment. Furthermore, artificial lighting edges humanity since, in contrast to a typical day for an energetic species like humans, it permits us to increase our activities at night and will increase our sense of security [5].
SUSTAINABLE DEVELOPMENT GOALS AND ARTIFICIAL LIGHT AT NIGHT
SDG3: Good health and well-being
Since the invention of the electric bulb, we have used light as an energy source, and it also tells us about the country’s development. Little did we know that ALAN will also be in pollution. As we usually tend to say, light pollution is extremely harmful and affects human health. Endogenous time unit sound property has evolved in many all-life forms that have daily physical oscillations over three billion years. This permits you to ascertain the sunrise and sunset prior to time.
This physiological rhythmicity is maintained for exactly 24 hours on the daily cycle of sunlight and darkness. However, there is scant light throughout the day to revive human endogenous time unit rhythmicity, and there is an excessive amount of light at nighttime to observe true darkness, inflicting circadian disruption and moving the wake/sleep cycle, core body temperature, internal secretion regulation and release, and organic phenomenon patterns throughout the body. These situations become more common as societies modernize (i.e., become electric). Many tantalizing clues to capacity mechanisms, in addition to epidemiological findings, assist an etiological function for electric powered lights in infection pathogenesis. These encompass suppression of melatonin, expression of the circadian gene, and the hyperlink among circadian rhythmicity and metabolism withinside the moiety stricken by the uptake and distribution of heme iron [6].
The boom in anthropogenic synthetic mild at night in a well-timed way of “improvement for humanity” maybe related to the outbreak of human coronavirus (HCoV). Bats, a nocturnal herbal reservoir for lots Coronaviridae, strongly suffer from ALAN because of their addiction and habitat destruction. Most bat species are “threatened” or “endangered” on the International Union for Conservation of Nature list. The nightlight should disrupt the timing of the “virus-host” by exerting selective strain that could result in mutation within the virus genome and immoderate viral spread. Khan et al. [7] proposed techniques to mitigate the effect of ALAN.
Light at night also harms the mental health of adolescence and sleep patterns. The study by a group of researchers at the American Medical Association states that in a nationally representative cross-sectional survey of American teens, higher levels of outdoor ALAN, measured by satellite, were associated with bedtime hours in the last hours of the week; those in the lower night-light quartile reported the longest nocturnal sleep times [8]. ALAN also has a potential risk of prostate cancer in men and breast cancer in women [9].
Biologists are searching for mild options to hold sea turtles that have been harmed via way of means of synthetic lighting, in addition to gaining knowledge of greater approximately mild pollutants and their consequences on the environment. Light pollutants, like noise pollutants, are a type of strength waste that has poor results and lowers environmental quality. Light is conveyed via way of means of electromagnetic waves generated via means of energy generated via means of burning fossil fuels. Therefore, there may be a connection between mild pollutants and air pollutants from fossil gasoline electricity plants [10].
Humans are stressed by high levels of brightness and/or changes in the light environment, especially when they are unanticipated. Changes in pineal melatonin levels can also influence metabolic rate. Circadian rhythm disruption can cause metabolic changes, which can lead to obesity and/or diabetes, which has become a pandemic.
In terms of cancer consequences, chronic ALAN exposure linked to lifestyle may also be linked to breast and prostate cancer. Circadian misalignment might manifest as a disease in its early stages. In fact, ALAN is regarded as a “modernized” phenomenon that has the potential to produce a slew of “modernized” health issues. Other variables, such as smoking, food, and air pollution, contribute to the development or worsening of these disorders. Nonetheless, given its recognized impact, ALAN could be deemed a significant risk factor.
SDG7: Affordable and clean energy
The SDG7 is directly related to the generation and consumption of electricity which is being used throughout the world. It encourages the stakeholders to improve the quality continue the research and development in the required sector. Since the electric bulb, the sector has not seen much innovation in society’s progress. SDG7 also focuses on investments in the renewable sector, but that is not enough. The light bulb, which has evolved from the tungsten bulb to compact fluorescent light bulbs and now the light-emitting diode (LED) bulbs, these innovations determined only energy-saving aspects of the light bulbs.
We also must focus on the amount of glare the light creates and innovate warmer colored lights. The SDG7 emphasizes the communities and the stakeholders how to innovate and find new ways of technological innovations in the lighting industry. Moreover, little is thought of approximately the long-term cumulative outcomes of ALAN and other environmental adjustments, including weather change. More studies are wanted however, the existing information base is already enough to justify moves aimed toward decreasing ALAN [11].
Light pollution is never considered a short-term effect on different biodiversity through outdoor lighting techniques. Still, it has long-term effects on different human organs, animals, and especially climate change [11]. Investigators have given the following high-level policy recommendations for effective legislation:
• No light should be directed directly towards or above the horizontal by luminaires.
• Outside the region to be lighted, do not squander downward light flux.
• Avoid using too much illumination.
• When the space is not in use, turn off the lights.
• Aim for no increase in total installed flux.
• Short wavelength ‘blue’ light is severely restricted.
The SDG7 motivates the countries to possess a paradigm shift from non-renewable sources of energy to renewable sources of energy generation, merely to boost the energy standard. Responsible production is linked with responsible consumption, towards which the countries should proceed for the sustainability of lighting techniques. The amount of ALAN we use is directly related to the amount of energy we consume. According to the United Nations SDGs, “energy contributes around 60% of the global greenhouse gases and has a direct impact on the climate change, and around 3 billion people are dependent on coal and animal wastes for their daily household.”
The energy we use has a severe impact on climate change as most of the developing countries are dependent on coal for their energy production. A study conducted by three scientists of the Reserve Bank of India found that night light is directly related to the country’s development but at a cost. Energy waste has significant economic and environmental implications. Outdoor lighting consumes around 120 terawatt-hours of energy per year in the United States alone, primarily to brighten roadways and parking stations [5]. That is enough energy to meet the whole power demand of New York city for two years! According to the International Dark-Sky Association (IDA), at least 30% of all outdoor lighting in the United States is wasted, primarily by lights that are not protected. This equates to $3.3 billion and the emission of 21 million tons of CO2 every year. We would have to plant 875 million trees per year to counteract all that CO2 [12].
SDG11: Sustainable cities and communities?
In many Asian and Pacific nations, cities account for more than 80% of GDP and are engines of economic growth that have lifted millions of people out of poverty. According to United Nations Environmental Programme, rural-to-urban migration is speeding up because of this economic expansion. Asia’s cities will welcome another 1.1 billion people in the next two decades as the impoverished flock to greater prospects. Approximately 700 million people live in slums in cities today. Many cities have already faced environmental deterioration, traffic congestion, poor urban infrastructure, and a lack of essential services like water supply, sanitation, and waste management. Cities’ environmental footprints are concerning, as they may jeopardize the natural resources needed to maintain economic development and poverty reduction rates [12].
Today’s largest urban issue confronting Asia and the Pacific is maintaining economic growth while constructing sustainable, liveable cities for everybody. The influx of people to the cities creates a huge energy demand, but cleaner alternatives are few in operation considering the developing countries. The demand for smart cities shapes the world’s future while considering the smart cities the outdoor lighting facilities. The cities are flooded with high-intensity outdoor lighting as it is considered one of the aspects of the city’s development. It gives a sense of safety and allows citizens to utilize the nighttime for higher productivity. Little did we know that the impact of ALAN is economic, social, and environmental factors are immense.
The outdoor ALAN around the coastal areas is creating a risk in marine and coastal habitat, diverting the routes of sea turtles [10]. The migrating birds are also affected by the glare of the outdoor lighting as they lose their way. The glare disrupts the normal cycle of the migrating birds and creates an illusion of nature that does not exist. Bats at night are also affected by the glare during outdoor lighting, which has been linked to the outbreak of COVID-19. The reduction of carbon footprint is of huge importance to substantially reduce the speed of climate change, but the increase in globalization has forced the outdoor ALAN to increase exponentially [7,12].
In our ongoing study, we investigate the correlation between night light and socio-economic indicators using empirical data from the Philippines to provide additional evidence about the usefulness of night light in the context of developing countries. There are assumptions that social and economic activities at night need light and that the intensity of night lighting and the areas it covers correspond with socio-economic indicators of economic development [13].
The 2030 Agenda for Sustainable Development, ratified in September 2015 by the United Nations General Assembly, stresses the importance of geo-information and earth observation in monitoring progress towards the SDGs. The data revolution for the SDGs is supplementing traditional sources of official statistics with more innovative sources. Earth observation and advanced data processing and analysis provide an unprecedented opportunity to make quantum leaps in the country’s ability to pursue all facets of sustainable development [13].
It considers the crucial importance of integrating data and emerging technologies into new areas such as placeable objects to produce high-quality and timely information with more detail, greater frequency, and the ability to break down development indicators. Furthermore, effective monitoring of 232 indicators will provide management tools to implement development strategies and report progress towards the SDG targets, as the reporting on progress toward the goals requires the use of several types of data that go beyond traditional socio-economic data and can be used by countries to assess their development policies [14].
Appear LP (DAAC) is a user-friendly tool for accessing and transforming spatial data from a range of federal data repositories. Users can employ geographic, temporal, band, and plane characteristics to get a subset of spatial geosp datasets. When you request an area extraction, you will be directed to the extract area samples page, where you can select a set of parameters for extracting data from that area [15].
Nocturnal light can also be used to calculate the distribution of the human population in the absence of a proper census. A histogram graph is used to display the distribution of variable data values for a selected region over a period. An average time series of the area is used to display the values of the data variables by comparing the data values determined for each selected region in each time step [13,15].
In 2015, the United Nations adopted the 17 SDGs, a collective framework for peace and prosperity for humanity and, therefore the planet within the future. The SDGs have deep ambitions to finish economic conditions and different deprivation, acknowledge the requirement to boost health and education, scale back inequality, stimulate economic growth, and combat climate change. To achieve this, we need to use renewable and carbon-free energy sources, prepare for natural disasters and extreme weather, develop sustainable transportation alternatives, provide adequate housing for residents, and much more [16].
Greater than half of the earth’s population has lived in urban areas since 2007, and that number is anticipated to climb to 60% by 2030. It is important to think about how cities contribute to the wider landscape. Local particularities play an important role in defining order, and the view in the Global South is very different from the prevailing framework for urban development [17].
Unplanned populated areas are related to accumulated CO2 emissions and dangerous pollution and pose a significant health risk. Creating cities safer and additional property means making certain access to reasonable and safe housing, rising settlement conditions, water, sanitation, and energy infrastructure, investment publicly transports, and making inexperienced areas that contribute to productivity, physical and mental health [18].
Cities are nice to visit, but it is about prioritizing the local needs of the inhabitants to create beautiful places to visit. Open spaces and trading venues are vital to the informal economy that many people depend on for a living. Equal access to public spaces helps to increase the output and physical and mental health [18].
SDG12: Responsible consumption and production
More and more customers and consumers want to know how we design our production processes and business activities socially, sustainably, and fairly. We can play an active role in carrying out our responsibilities by integrating human rights principles into our rules, systems, and processes. The 2019 OSRAM Guidelines on Human Rights, based on the United Nations Guiding Principles, can help us in this regard.
The SDGs came in legislation in 2015 by United Nations member states to end poverty, reduce inequality, and build a peaceful and prosperous society by 2030. The 2030 Agenda for Sustainable Development recognizes the important role of sustainable consumption and production (SCP) in its introduction section, including SDG as one of the 17 SDGs and related goals as part of several other SDGs. The SCP target, SDG12, aims to ensure SCP patterns by 2030 and comprises 11 targets, 3 implementation methods, and support for 13 indicators [16].
Objective 12.2 aims to realize sustainable management associated with degreed economical use of natural resources, reflective the necessity to mitigate the impact of human societies on natural systems. Overall, these indicators may be accustomed to monitor changes in national economies and pressures on the world from completely different perspectives. The definitions of indicators for sustainable resource use and limits are given wherever knowledge is available [18].
SCP is about doing more with less. It decouples economic growth from environmental degradation, increases resource efficiency, and promotes a sustainable lifestyle. Natural resource management must be long-term, and the use and consumption of these resources must be efficient.
The SDGs reduce inequality, promote economic growth, and ensure universal social protection. Reducing inequality is an objective, but the primary reason is to reduce poverty, raise living standards for the poor and ensure that economic growth benefits everyone. Decent work and economic growth aim to create a fair and productive economic environment for all people.
The aim is to ensure that economic activities do not harm the environment, natural resources, cultural heritage, and human health. The United Nations SDGs pledges to take care of biodiversity, ecosystems, and the marine environment. They also aim to increase the resilience of coastal communities to the impacts of climate change and reduce the impact of excess nutrients and organic substances on marine ecosystems.
The aim is to protect the planet’s biodiversity, combat desertification, stop and reverse land degradation, promote sustainable forest management and stop or reverse biodiversity loss.
SDG13: Climate action
Plants and animals depend upon the daily cycle of sunshine and darkness, which regulate rhythms that manage vital behaviours like reproduction, nutrition, sleep, and protection against predator’s lightweight pollution changes the nocturnal animal atmosphere and turns night into day. Furthermore, scientific proof suggests that artificial light will have negative and even deadly effects on several creatures at night, together with amphibians, birds, mammals, insects, and plants [19].
Light pollution has the potential to disrupt animal migration patterns, modify animal interaction, alter predator-prey relationships, and inflict physiological harm. It also competes with starlight in the night sky for city inhabitants, upsets astronomical observatories, affects ecosystems, and has significant health impacts, like other forms of pollution. In addition to disrupting ecosystems, light pollution poses a major threat to certain nocturnal animals, as it has a deleterious impact on plant and animal health [20].
Light pollution, like noise pollution, is a sort of energy waste that has negative consequences and lowers environmental quality. Indoor and outdoor lighting, billboards, and outdoor lighting such as parking spots, buildings, industries, streetlamps, and illuminated sports facilities are all sources of light pollution [21].
Light transmits electromagnetic waves that generate electricity, which in flip is generated with the aid of using burning fossil fuels, so it may be stated that there is a hyperlink among mild pollutants and air pollutants from emissions from fossil fuels. Control of mild pollutants can assist in keeping gas costs, lessening air pollutants, and alleviating the instant troubles because of immoderate mild [22].
Other articles have described how ALAN affects bats and scatter seeds from fruit trees. Although light pollution does not directly affect plant cycles as described above, it can affect plants by interfering with the life cycle of pollinators and other animals that interact with them.
Recent studies on lightweight pollution as a driver of insect decline say surroundings loss, chemical use, invasive species, and temperature change all play a job in insect decline, however artificial light at midnight is very vital and infrequently overlooked lightweight disturbs chemical action in insects, birds, and alternative animals. In addition, studies have shown that light pollution influences animal behaviour, like migratory patterns, waking and sleeping habits, and habitat formation [23].
Many insects are killed when they encounter light sources, the primary food source for birds and other animals attracted to artificial light. Birds also suffer, which is why many towns have adopted lighting schemes that switch lights off during bird migration. In addition, because of light pollution, sea turtles and birds that migrate by night become confused, lost, and die.
According to a website (https://www.darksky.org/light-pollution/light-pollution-solutions/), the IDA aims to prevent darkness from light pollution. Ruskin Hartley, executive director of the organization, said in a statement that the switch to LED lighting had contributed to increased light pollution. The organisation believes that the increased and widespread use of artificial light affects the environment, our health and safety, as well as energy consumption.
The Sierra Club includes in the definition that anthropogenic light is wasteful and misdirected, has negative environmental impacts, is used as a form of violence, harms health, safety, and other human rights, interferes with our view of the natural night sky, and separates us from our cosmic environment, including our home-kept Milky Way. While the Sierra Club recognizes that artificial light can bring desirable benefits to society, such as extended social hours at night, its excessive and inappropriate control and use can cause significant harm [24].
Since 2010, the medical literature has exploded with studies investigating mild outcomes on man or woman species, from birds and fish to bushes and humans. Artificial mild adjustments in the ecosystem such as migration and duplication of animals, the increase of tree leaves, chicken nests and flights, pollination, human sleep, and plenty more. Holker is a trained fish ecologist; he studies changes in urban fish populations and finds that light and temperature are two of the most important behavioural triggers for life in water [25-27].
Professor Gaston is a scientific adviser to a future ground-breaking natural history series called Earth’s Night Colours. In his opinion piece, he proposed 10 reasons why artificial light should be the focus of global research in the 21st century. Climate change and night lighting seem to benefit certain species in certain places, he says, and the clear message from this study is to reduce lighting as much as possible [28].
Since the introduction of ALAN by Longcore and Rich in 2004 as a human-induced disturbance as an established environmental disturbance, several studies have grown in the last decade documenting the effects on the environment and human health. This research underscores the ubiquity of ALAN effects throughout a wide variety of biomes, ecosystems, species, and behaviours. By measuring the organic reactions that arise while the depth and spectrum of synthetic mild is encountered withinside the environment, the worldwide distribution of nocturnal lights manner it’s far probably to have had far-attaining results on marine, freshwater, and terrestrial habitats across the world [28].
SDG14: Life below water
Excessive and inappropriate use of artificial light outside, known as light pollution, impacts human health, animal behaviour, and our capacity to see stars and other celestial objects. Artificial light disrupts land ecosystems and impacts human health at night. With the extinction of stars in the night sky, more than a third of civilization would be unable to see the Milky Way, and light pollution will become a concern that reaches much deeper into the ocean floor [29].
The mild ALAN form towns and ships repel or draws many fish species, pollutes coral reefs, and disrupts the circadian rhythm of woodland lice and sandy beaches. Light additionally disrupts photosynthesis in insects, birds, and different animals. Recent research on mild pollutants as a driving force of insect decline say habitat loss, pesticide use, invasive species, and weather extrude all play a position in insect decline; however, synthetic mild at night-time is vital to overlook [30].
Ecological mild pollutants are described because the presence of synthetic mild ALAN (intensity, irradiance, illuminance, spectral composition, polarization, and time) that does not correspond to herbal night-time mild has terrible ecological effects [31]. The environmental impacts touch a good type of species, communities, and ecosystems and therefore the impacts extend well on the far side [31], however lightweight pollution is known as a possible threat to multifariousness. This suggests that light pollution from coastal cities affects ecosystems below the seabed.
Experts from the University of Plymouth have found that artificial light used for everyday street lighting penetrates marine zones in coastal cities and poses a significant threat to coastal species. While cities and communities along the coasts continue to grow, more than three-quarters of the seabed around them are exposed to harmful light pollution, the researchers said. Although Plymouth, with its 240,000 inhabitants, is a relatively small city, the impact of this light pollution will inevitably be several orders of magnitude higher than that of coastal cities (https://www.sustainability-times.com/environmental-protection/light-pollution-even-affects-seafloor-ecosystems-at-coastal-cities/).
The results provide evidence that artificial light caused by skylit cities causes significant pollution of seabed habitats at the bottom of the sea. The scientists have found that it is not only terrestrial life forms that we screw up when we turn off the light, but also that light enters the high seas and prevents marine life from settling, writes Kate Wheel of Science. As scientists begin to understand how light affects underwater ecosystems, they need much more research to figure out exactly how it does so [32].
Cloud cover amplifies the unfold of celestial glowing, which is thought to influence urban areas [26], disrupting the migrations of birds, amphipods, and crustaceans in cloudy conditions, also as probably temperature regions and regions close to the equator. Artificial glow extends the geographical influence on the far side native direct light-weighting to many kilometres, suggesting that the results on marine organisms are widespread and wish to be quantified. Satellite mental imagery has proven valuable in quantifying the exposure of coastal areas to night-time lighting and marine organisms whose life histories are in water and biogeographical region habitats might provide expertise artificial light that satellite sensing technologies cannot detect [32].
The survival, reproduction, physiology, and movement of marine fish, corals, birds, turtles, and other vertebrates are all affected by ALAN. For example, corals associate their spawning events with monthly and annual fluctuations in moonlight intensity. Likewise, zooplankton, tropical corals, and temperate marine organisms react to artificial light like illuminating streetlights along the water at depths of 70–100 m [32].
The results show that most of the sea surface is exposed to all the colours from red to blue, artificial light under cloudy or clear conditions. Of course, researchers will have to experiment with a range of exposures, but the study by Davies et al. [33] was at the upper end of the artificial light-scale experienced by marine environments.
The good news is that researchers know now how light affects the behaviour of different species, and designers will be able to configure LEDs to emit a light spectrum less harmful for other organisms and provide people with light when needed, Longcore said. Davies says he and his colleagues were the first to quantify how light pollution from coastal cities reaches the seabed. They found that up to three quarters of Plymouth Sound and Tamar Estuary seabed are bathed in artificial light, some of which are bright enough to affect ecosystems [28].
According to Raz Tamir, a light pollution researcher at Tel Aviv University, showed that estuaries tend to contain sediment clouds that were not involved in the new study. In addition, an expansion of phytoplankton coincided with an urban study, reducing the amount of light reaching the seafloor. Berge, who researches the effects of light pollution on marine species near the Arctic Circle, was not involved in the new study [30].
Indeed, new scientific findings about the health impacts of artificial light have persuaded the American Medical Association to support initiatives to reduce light pollution and pursue study into the potential dangers of night-time light exposure. This article will examine recent skimmer-style research on how light pollution affects many marine organisms and marine ecosystems. For example, numerous studies have documented that adult sea turtles avoid nesting near lighted beaches and that artificial light attracts freshly hatched sea turtles into the ocean, resulting in increased mortality, increased predatory fishing, dehydration, and energy expenditure [34].
Blue light has been shown to suppress melatonin levels in people. LEDs, the low-cost, energy-efficient light bulbs that have become popular for lighting homes and industrial cities, emit blue light. In research, light pollution has altered animal behavior, including migration patterns, waking, sleeping habits, and habitat formation [35].
Animals and plants on the planet, including humans, have adapted to the seasonal day-night cycles, but the glow of artificial light has damaged many places on Earth. In the last century, with the introduction and spread of electricity, the problem of artificial night lighting has become ubiquitous. While some animals have benefited from lighting, many have suffered from its effects for over a hundred years, and there has not been enough time to adapt to the changes [36].
SDG15: Life on land
You may help monitor light pollution by participating in citizen science programmes throughout the world at night and capturing as many measurements as possible from various locations. A global database can be utilised to compare patterns over time with other animal data sets to see the influence of light pollution on other animals [20].
The Florida Fish and Wildlife Conservation Commission has its own page on the effects of light pollution on diverse biological organisms. Skykeepers.org in California is a page dedicated to ecological light pollution, with further information and reports on the effects of light on the overnight environment [10].
Light pollution can disrupt animal migration patterns, alter animal interaction, modify the relationship between predators and prey, and cause physiological damage. In addition, light pollution interrupts the naturally dark sky cycle and increases the glare over the sky at night in many regions of the world beyond the natural level. It also competes with starlight for city dwellers in the night sky, disrupts astronomical observatories, and disrupts ecosystems with adverse health effects like other forms of pollution [37].
Built-in exterior and interior lighting, advertising, outdoor illumination in car parks, offices, and industries, and street lamps that illuminate sports facilities are all causes of light pollution. Excessive, misdirected, and intrusive use of light and the use of light that disrupts natural circumstances all contribute to light pollution [38]. Light pollution is a prominent side effect of urbanisation that puts people’s health at risk, disturbing ecosystems, and degrading the aesthetic surroundings. Because it disrupts natural light cycles and species responses, light impacts the ecosystem. Insects, birds, and another creatures’ photosynthesis is also hampered [38]. Although there is a large body of literature on the effects of artificially manipulated light conditions on plants in the 17th and 18th centuries, it is well understood that light at night, especially of short duration and low intensity, has physiological consequences [39]. Artificial light is present at night in many natural and near-natural ecosystems at a level that is compatible with the causes and physiological effects on plants [40].
Growing awareness of the effects of disturbance of the natural light cycle on animals and plant-animal interactions, studies have shown that light pollution affects animal behaviour such as migratory patterns, waking and sleeping habits, and habitat formation [40].
Artificial light disrupts the body’s normal cycles in both humans and animals. For example, circadian rhythms are disrupted by nocturnal light, which alters physiological processes in living organisms. Because birds are particularly vulnerable, many cities have implemented lighting schemes that turn off construction lights while birds migrate [37].
Plants and animals rely on the daily cycle of light and darkness to regulate life-sustaining behaviours [19] like reproduction, nourishment, sleep, and predator defence. The natural light-dark cycle on our planet gives clues to all living beings concerning these activities. Light glare in wetlands disrupts amphibian breeding at night and reduces populations [41].
According to scientific research, artificial illumination can have detrimental and even fatal impacts on all kinds of organisms at night, including amphibians, birds, mammals, insects, and plants. On the other hand, artificial lighting benefits humanity in the following ways: during a regular day, artificial lighting allows energetic species like humans to extend their activities into the night, increasing our sense of security [37].
Animals and plants on the planet have adapted to regular seasonal day-night cycles, including humans, but many places on Earth have been interrupted by the light produced by artificial light. While some animals have benefited from lighting, many have suffered from its effects for over a hundred years, and there has not been enough time to adapt to the changes. In the last century, the problem of artificial night lighting has become ubiquitous with the advent and spread of electricity.
Melatonin is a hormone that is produced in response to light and affects animal physiology. Melatonin production is decreased when people are exposed to light while sleeping [42]. Since melatonin is an antioxidant and removes free radicals, disturbing melatonin expression by ALAN can increase the risk of cancer. Changes in the light regime (day-night cycle) caused by light pollution cause the natural expression of melatonin to be disrupted [42].
In general, the most common measure of light pollution is to alter or disrupt the timing of necessary biological activities. Half of the lives of nocturnal species that start their daily activities before sunset are restricted by our ALAN, they are exposed to predators and the time it takes them to find food, shelter, mating, and reproduction is shortened. The assumption that every other living organism on the planet will adapt to our established lighting plan for commercial reasons is either ignorant or crazy [43].
Day and night, light and darkness, have shaped and governed the life of land for hundreds of millions of years. In the presence of artificial light, no one has ever reported on the impact of human activity on the environment [44].
GOVERNMENT POLICIES AND ANALYSIS
Stakeholder involvement
Billions of years ago, light and darkness on Earth depended on the sun, moon, and stars. The first use of controlled lighting occurred about a million years ago when early humans lit fires to provide warmth, food preparation, and safety [45].
People began to think about the consequences of their easy use, and some countries began to legislate against it. Artificial light was first used about 100 years ago when people relied on candles, gas, and oil for their lighting. The invention of electricity made it easier for us to stick to light [46].
Excessive illumination and energy waste can have major health and environmental repercussions. Many states have passed legislation that governs outdoor lighting. Manufacturers have created and produced light bulbs and equipment that save energy and prevent light pollution. People who are asked to use outdoor lighting when required should ensure that it is shielded from direct sunlight and that it is kept dark at night by closing windows, blinds, and curtains [47]. The damage caused by light pollution has been understood only since the last two decades, writes Verlyn Klinkenborg for National Geographic. For much of Earth’s history, the wonders of its star world were only seen in the dim light of night. Not so long ago, the unpolluted night sky was full of a vast world of celestial light that awed man from the very beginning [46,47].
Increased urbanisation, along with excessive and inefficient use of light, has resulted in the pollution that obscures the view of stars and causes a slew of other issues. In regions that should provide and safeguard natural habitats for wildlife, light pollution has had an impact [35]. The increasing and widespread use of ALAN affects not only our view of the universe but also our environment, our security, our energy consumption, and our health. Many US parks are taking new measures to preserve the remaining dark skies we have. The National Park Service has made it a mission to keep the night sky gloomy [35].
In the nocturnal environment, light pollution is well known as the presence of manmade artificial light. Excessive, erroneous, and intrusive use of light exacerbates light pollution, and this use affects natural circumstances. For city inhabitants, it is comparable to starlight in the night sky, upsets astronomical observatories, affects ecosystems, and has poor health impacts, like other forms of pollution [48]. Astronomers are not alone in suffering from light pollution but have documented harmful effects on sea turtles, birds, bats, corals, and hundreds of other species. The effects of light pollution are dwarfing but are increasingly in the spotlight as cities, regulators, and conservation groups seek solutions. The areas where significant improvements are taking place are driven by a new technology of cheaper, more energy-saving lights [49].
Under the supervision of Fabio Falchi of the Institute of Light Pollution Science and Technology in Italy, the research team used image data of National Oceanic and Atmospheric Administration and National Aeronautics and Space Administration’s Suomi satellites in a polar orbit to create the map and calibrate the data with thousands of ground measurements. The international team and its map of artificial brightness of the sky in North America represent the ratio of natural brightness of the night sky [50].
We discovered that 83% of the world’s population and more than 99% of Americans and Europeans live under light-polluted skies, with artificial sky brightness reaching 14 mcd/m2 at its peak. Light pollution affects almost 23% of the world’s land surfaces above 75° N (60° S), 88% of Europe, and half of the United States at night. More than a third of humanity, including 60% of Europeans and 80% of North Americans, cannot see the Milky Way due to light pollution [38].
The Central African Republic and Madagascar, which are the most affected by light pollution and the entirety of Greenland, have clear skies. The light-emitting country is Singapore, where nearly the whole population lives under a sky so brilliant that the eyes can darken and adapt to night vision [38]. The light from our streetlights and house lights is reflected into the sky, where it bounces and scatters particles and moisture drop in the atmosphere, creating an artificial glow in the sky—one of the key factors contributing to light pollution.
The artificial brightness of the sky in Europe would double if sodium lamps were replaced by cold white LED lighting, leading to an increase in blue light emissions, according to a new study. For Chan Yuk Lung, who manages an astronomy club at Queens College, a high school with a rooftop observatory on Causeway Bay in Hong Kong, one of the city’s brightest areas, light pollution is exaggerated. Modern filters and telescopes, he says, save the problem because light refracts particles [51].
It has inspired astronomers, artists, musicians, and poets alike. Still, the Milky Way for much of humanity has become a distant memory, suggesting a new global atlas of light pollution. It is no longer visible to more than a third of our population [52].
Who initiated the resistance on the issue of light pollution in the world?
The increasing and widespread use of ALAN not only affects our view of the universe but also affects our environment, our security, our energy consumption, and our health. The focus in the present manuscript is on dim light at night (DLAN) (IDA, 2009), which, despite its impact on human and wildlife health, shows little sign of moderation [53,54].
Artificial light under dark settings is referred to as light pollution. It competes with starlight in the night sky for city inhabitants, upsets astronomical observatories, and disrupts ecosystems, all of which have negative health consequences. Typical natural light intensity ranges from 103,000 lux on a sunny day to 0.1 lux with the moon on a cloudy night, while the degree of muted light at night (DLAN) of only 5 lux has biological effects [49,55].
The good news is that light pollution can be decreased by covering light, employing light where it is needed, reducing the amount of energy used by using energy-efficient light bulbs and using light bulbs with the right spectral power distribution for the job. You may help monitor light pollution by participating in citizen research programs throughout the world at night and capturing as many measurements as possible from various locations.
The study revealed that 97.8% of the Turkish population lives under light pollution, and 49.9% will never be able to see the Milky Way. As part of the project, the Municipality of Bursa measured light pollution in the city in 1,021 different places, where 90% of the population live, collaborating with the Bursa Amateur Astronomy Foundation, and produced a map of light pollution. In addition, the global database is being compared to other animal data sets to discover how light pollution impacts them over time.
Light pollution (the presence of unnatural light at night) covers 18.7% of US landmass, and the intensity detected in space, and spatial extent grew by 2.2% a year from 2012 to 2016 [54].
Turtles and birds are not the only animals affected by artificial nocturnal lighting. Some people find that less bright light makes it easier to see in unlit areas and our eyes adapt better to the darkness.
Bright city lights distract migratory birds and disorient them, causing them to collide with tall buildings. It is estimated that 985 million birds are killed in this way each year in the United States alone. Artificial light also hinders insect courtship and mating, and car lights cause hundreds of billions of insect deaths in Germany each year alone.
Artificial light destroys the natural rhythm of human and animal bodies. Nocturnal light interrupts sleep, disrupts circadian rhythms (the internal 24-hour time that controls day and night) and influences the daily processes of living organisms. For example, some of us wake up at night when we have a power failure, shadowed by the electric light coming in through our windows.
Two-thirds of the US population and more than half of the European population have lost their ability to see the Milky Way with the naked eye, according to a report on global light pollution [56]. In addition, approximately 63% of the world’s population, as well as 99% of the populations of the European Union and the United States (excluding Alaska and Hawaii), live in locations where the night sky is too bright to surpass the International Astronomical Union’s light pollution threshold (artificial brightness of the sky greater than 10% of natural brightness at 45°). Many jurisdictions have implemented rules regulating outdoor lighting to save energy and prevent light pollution, and manufacturers design and build extremely efficient light sources.
French lawmakers introduced a law in 2013 requiring shops and office buildings to turn off their signs after the hour their last employees leave. In addition, individuals are recommended to only use outside lighting when necessary and to shield it from direct sunlight by closing windows, blinds, and curtains at night to keep the light out. This area has significant improvements, driven by a new wave of cheaper and more energy-efficient light bulbs [57].
Policy measures to control light pollution in different countries
Large swaths of the United States, Europe, the Middle East, and Asia are illuminated, while some isolated areas, such as Russia, Sudan, and the Amazon, are completely black. Yet, the residents of these villages and regions are the only ones aware of the need to reduce light pollution for the environment [35,58].
Waste of energy and excessive lighting can seriously affect humans and the environment. Many governments have implemented regulations regulating outdoor lighting to save energy and prevent light pollution, and manufacturers are inventing and producing extremely efficient light sources. In addition, most states have passed so-called dark-sky laws that promote energy savings, public safety, aesthetic interests, and astronomical research capacities [47].
People who are urged to use outdoor lighting, when necessary, should ensure that it is shielded from direct sunlight from the sky and close windows, blinds, and curtains at night to keep the light out. However, there are times and places where outdoor lighting can brighten dark activities; for example, many of us burn down porches with spotlighting because it gives a sense of safety [59].
In fact, there is little data supporting the idea that outdoor light reduces crime. The procrastination that darker, dimmer lighting leads to increased crime or reduces security at night is not supported by data from Chicago’s West Garfield Park, where poorly lit lanes have led to an increase in reported crime [49].
According to Falchi et al. [5], LEDs increase the known and possible unknown impacts of light pollution on humans and the ecosystem by a factor of five. Despite their claims of being energy efficient and colour accurate, most LEDs installed today are brighter than the old luminaires they replace, contributing to increased light pollution. New lighting technologies and their ability to control and steer computers make LEDs an important tool for reducing light pollution, but they can also make things worse [60].
Like many other human innovations, artificial light has negative consequences for other animals. Insects, birds, and other creatures’ photosynthesis is disrupted by light. Habitat loss, pesticide use, invasive species, and climate change all play a role in insect decrease, but night artificial light is particularly crucial and often underestimated, according to recent studies on light pollution as a driver of insect decline [61].
The core of a glowing stone emits 5–7 cd light, but unlike electric light, it emits no light. Therefore, the ambient glow from the centre is not a source of light pollution and does not contribute to a bright night sky [61].
When we turn off our indoor lights, most of our outside lights remain unprotected, allowing light to enter the sky, our eyes, and our neighbours’ “bedrooms.” Our best hope of controlling artificial light is to shield our bulbs by installing or retrofitting lamps that direct the light to its intended destination. Given the prevalence of light in southern Europe in recent decades and the consideration of switching to blue-and-white LED lighting in recent years, the new Croatian law is an important step in reducing the significant threat posed by dark skies.
The proposed national law in Croatia corresponds to the best practices supported by the IDA, including the requirements regarding shielding, colour temperature and outdoor lighting. The new requirements not only bring the Croatian law with best practices for reducing light pollution but also provide a robust inspection and enforcement system that other national legislation tends to lack. The proposed law is in the process of being used as a template for other lighting policies in Europe, particularly regarding enforcement [62].
Other laws mandate the use of low-illuminance, low-watt lighting, set time limits for the use of specific lights, and incorporate the Illuminating Engineering Society’s (IES) principles into state legislation. For example, as discussed by Martin and Taylor [47], the UK has expanded existing air pollution laws to include light pollution. China and Korea are among the countries that have introduced preventive measures against light pollution through urban ordinances. In August 2008, Puerto Rico signed a light pollution control and prevention plan to protect the Bay of Puerto Rico and other delicate ecosystems and the country’s ecotourism industry [63].
The current study provides a comparative analysis of Seoul’s light pollution regulations, regional laws about light pollution and preventive measures in China, given the social similarities between China and Korea, which may have led to similar trends in artificial lighting [63]. Many cities on Long Island, according to Susan Long, a founding member of the Dark Sky Society of Long Island, a New York-based advocacy group, include guidelines that indicate which types of luminaires are best protected against light pollution, how energy-efficient building permit decisions are made, and how local planning departments should consult with the organisation on guidelines for better outdoor lighting solutions when planning new sites or developing new ones [64].
Analysis of policy to control light pollution at night
Therefore, it is time to consider the scope of possible measures to prevent or reduce the environmental impact of light pollution at night, current knowledge of these measures and likely outcomes, as well as the research results required to support positive outcomes [60].
Government measures can help reduce light glare by promoting covered lights, low-glare lighting, and low wattage. Countries have also passed so-called dark-sky laws, promoting energy savings, aesthetic interests, and astronomical research capacities [47].
Waste of energy and excessive lighting can have serious consequences for human health and the environment. Light pollution and wastage cause unnecessary energy costs and carbon dioxide emissions. Many communities are looking into ways to regulate artificial lighting and apply smart lighting strategies to address concerns and the desire for better views of the night sky [65].
Thousands of towns worldwide have implemented laws and methods to help residents manage light pollution, such as glare, incidence, and skyglow. Reduced light pollution has several advantages, including a reduction in the number of stars visible at night, a reduction in the influence of light on the environment, and a reduction in energy use. However, according to scientific studies, light pollution is an inappropriate and excessive use of artificial light that harms the environment and human health, interferes with military operations at night, and wastes energy and money [66].
Artificial light is an indispensable technology for modern society and its operations at night. On the other hand, artificial light has some negative side effects that have only recently been discovered. The increasing and widespread use of ALAN affects our view of the universe and our environment, our security, our energy use, and our health [67].
Most installed LEDs are brighter than the previous luminaires they replace, causing light pollution. However, they are promoted as energy-efficient and clear in colour. LEDs are a significant technique for minimising light pollution because of their capacity to be programmed and regulated, but they can also make things worse [60,67].
Blue light effects reduce melatonin levels in humans. In addition, some people may find that less bright light makes it easier to see in unlit areas, as our eyes adapt to the darkness. There are also some concerns that darker, dimmer lighting could lead to an increase in crime or reduce security at night, but this is not supported by data from Chicago’s West Garfield Park, where dimly lit lanes have led to an increase in reported crime [49].
Most state laws restrict outdoor lighting to those installed on the grounds of state buildings or on public roads. The most common legislation requires the installation of shielded luminaires that do not emit light [47].
To address growing public complaints about light pollution, the National Park Service established the Night Sky Team in 1999. The team created portable field devices to quantify natural and artificial sky lighting and map the entire sky at high resolution and sensors and methodologies to monitor light pollution. They also analysed present conditions in national parks’ night skies to ensure that visibility is clear and a consistent baseline of light pollution can be established [65].
This problem is worsening as China, India, Brazil, and many other countries become wealthier and more urbanised [60].
Policy making and implementation of light pollution
In the definition of an anthropogenic light, the Sierra Club includes wasteful, misdirected, negative environmental impacts as a form of aggression, harmful to health, safety, and other human rights, interferes with our view of the natural night sky and separates us from our cosmic environment—including the Milky Way—where we live. The Sierra Club recognizes that while artificial light can provide desirable benefits to society, such as extending social spaces by night, its excess and inappropriate control and use can cause significant harm [24].
Natural, economic, biological, political, psychological, and cultural factors all contribute to light pollution. Reducing light pollution has several advantages, including increasing the number of stars visible at night, lowering the impact of light on the environment, and lowering energy use [24].
The Dark Sky Society, a Long Island, New York-based advocacy group, has released standards that show which types of luminaires provide the best light protection while also being energy efficient. According to Susan, many localities on Long Island have attached this advice to construction permits, a founder member of the society, and local planning agencies are contacting the group for suggestions for excellent outdoor lighting when planning or developing new areas. When using outdoor lighting, individuals should ensure that it is covered from direct sunlight and that windows, blinds, and curtains are closed at night to keep the light out [65].
The US Department of Housing and Urban Development, for example, advocates the use of electric lighting to reduce energy consumption and light pollution as part of its building research establishment environmental assessment design and sustainability initiatives [65]. Longcore and colleagues presented statistics on the impact of ALAN on energy, humans, and the environment at IDA-sponsored briefings in the US Senate and House of Representatives in the summer of 2008 [65]. Some common legislation requires the installation of a protective shield around luminaires that emit light. In addition, some laws require outdoor lighting to be shielded, apart from emergency, construction, navigation, and airport lighting [47].
Christopher Kyba, a science student studying global light pollution, points to Van Gogh at night as his picture of an ideal night scene. Electric lights are beautiful things that guide us at sunset, keep us safe, and make our homes cosy and bright. Babak Tafreshi, the founder of the World Night TWAN Program, who has documented the night sky over the continent for two decades, shares the value of dark skies and the importance of a natural night environment.
Well thought-out and robust public policies are crucial to fulfilling IDA’s mission to protect the night environment and our dark-sky heritage. Accordingly, IDAs are involved in a variety of efforts to influence the decisions of various legislative and regulatory bodies to formulate, adopt, implement, and assess changes in public policy regarding outdoor lighting. This article examines adverse effects in several categories, examines mitigation strategies, and advocates engagement in planning, science, and practice in the United States [68,69].
Defining “light pollution” and weighing up the competing values of limiting it as a political act challenges a lack of public awareness of the primacy of energy efficiency as a decision-making factor and the link between more light and greater security, among others [68].
The goal is not to condemn or approve the use of light pollution from an ethical standpoint nor to provide conclusive answers to the ambiguities that come with it. Rather, one should begin to accept them as the dominant notion for characterizing emerging environmental challenges, as well as consider their ethical implications and limitations [70].
CONCLUSION
Black-tailed godwits have indications that the nesting site depends on the amount of surrounding light and prefer laying eggs away from street lighting. Moreover, there is evidence that the presence of light affects the habitat choice of mollusks. This is in line with an earlier study by Badman (1966), who discovered that high-intensity light attracts some freshwater snail species (Physa pomillia). Furthermore, artificial night illumination is the cause of changes in bat biodiversity, with many species becoming rarer and others declining in abundance. Light pollution is a severe hazard to nocturnal species, as it has a negative impact on the physiology of plants and animals. It confuses animal navigation, alters competitor interactions, alters the relationship between predators and prey, and causes physiological damage [71].
In the same sense, light pollution in lakes is thought to inhibit zooplankton like Daphnia from eating surface algae, resulting in algae blooms that harm marine plants and damage water quality. Exterior and interior illumination of buildings, advertising, outdoor lighting of car parks, offices, and factories, and street lamps illuminating sports grounds are all sources of light pollution. It also competes with starlight in the night sky for city inhabitants, upsets astronomical observatories, and affects ecosystems, all of which have negative health impacts like other forms of pollution.
According to the qualitative approach, the astronomer’s perspective, light pollution refers to artificial light that impairs the quality of the night sky by obscuring light from stars and other celestial bodies and restricting their investigation. In line with the quantitative approach, the International Astronomical Union points out that light pollution occurs within a well-defined geographical area when artificial light reaches the night sky at more than 10% of its natural luminosity. From an ecological point of view, it refers to artificial lights, which affect the cycle of natural light, the day-night cycle and the seasons by altering the nocturnal components of the environment.
The number of migratory insects and other bugs that fall victim to the illusion of light on our canopies has an increasing impact on our ecosystem. Further, light pollution is exacerbated when the lighting is of poor technical quality, lighting equipment is switched off during unnecessary nights or is poorly maintained or not maintained at all. Light pollution may not be a major problem compared to other problems such as global warming, but it causes serious problems for humanity and our entire environmental system. Although there are no reliable statistics on the number of insects killed, we have seen a minimal reduction in the population of local insects due to unnatural lighting and a reduced ability for bats to feed.
When people are urged to use outdoor lighting, ensure it is shielded from direct sunlight from the sky and close windows, blinds, and curtains at night to keep the light out. If you live in a city, you can go outside at dark times of the night and look up and see a yellow, bright sky as above. You can use certified lighting to reduce the glow and glare of the sky, but the light can still emit to a significant degree.
During this time, people stay in daylight throughout the year with the help of fire, gas lamps and light bulbs. Living organisms rely on their internal clock and external cues to inform them when to wake up and sleep, and this is being interrupted by our artificial illumination. There is no path in the dark, and the animals are unsure what is causing their deaths. Some creatures rely on external cues to tell them when to wake up and when to sleep, which is being affected by our artificial lighting. There’s no way to tell what’s killing the animals in the night, and they have no idea why.
There are numerous negative repercussions, but most people are unaware of them; for those who are, do not believe they are significant; we believe it would be a poor idea to modify it, but some argue that it is not.
Notes
Funding Statement
None
The authors have no potential conflicts of interest to disclose.
Availability of Data and Material
Data sharing not applicable to this article as no datasets were generated or analyzed during the study.
Author Contributions
Conceptualization: Md Shahrukh Jamal, Zeeshan Ahmad Khan. Data curation: Md Shahrukh Jamal, Shahkar Falak. Formal analysis: all authors. Investigation: all authors. Methodology: Md Shahrukh Jamal. Project administration: Zeeshan Ahmad Khan. Resources: Md Shahrukh Jamal, Zeeshan Ahmad Khan. Software: all authors. Supervision: Zeeshan Ahmad Khan. Validation: Md Shahrukh Jamal, Shahkar Falak. Visualization: Md Shahrukh Jamal, Shahkar Falak. Writing—Md Shahrukh Jamal, Shahkar Falak. Writing—review & editing: all authors.