Light Pollution's Economic Impact: A Costly Glow

Light pollution is a pressing issue that has been largely overlooked in economics. It refers to the excessive or obtrusive artificial light caused by poor lighting design, which shines outward and upward into the sky. This type of pollution has significant economic implications, including negative impacts on wildlife, human health, astronomy, and wasted energy.

The economic costs of light pollution are substantial, with the International Dark-Sky Association estimating that one-third of all lighting is wasted, resulting in an annual cost of $2.2 billion in the United States alone. This wasted lighting contributes to air pollution, as coal-fuelled power plants release approximately 15 million tons of carbon dioxide into the atmosphere each year to generate the electricity needed for this lighting.

Light pollution also affects human health, disrupting the natural day/night cycle and reducing melatonin production, which has been linked to increased rates of diabetes, obesity, and certain cancers.

Addressing light pollution through better lighting design and efficient fixtures can lead to significant energy cost savings and reduce its adverse effects on the environment and human health.

Energy waste: Light pollution wastes energy, which has economic costs and contributes to climate change

Light pollution wastes energy, which has economic costs and contributes to climate change. In the US, around 2.5% of the total electricity produced is expended on outdoor lighting at night, with about 30% of this wasted as light pollution. This equates to 17.4 billion kilowatt-hours of electricity, costing the country at least a billion dollars a year in unnecessary electricity charges. This wasted electricity also has environmental costs, with the equivalent of 8.2 million tons of coal burned annually in the US to light up the night sky.

The economic and environmental costs of light pollution are not limited to the US. Globally, outdoor lighting makes up about 8% of energy use, with about 60% of this wasted as unneeded, overlit, or poorly aimed lighting. This waste of energy has an economic cost of nearly $7 billion in the US alone, and contributes to global warming. In the US, the unnecessary electricity used for outdoor lighting generates an additional 66 million metric tons of CO2.

Light pollution is caused by excessive and obtrusive artificial light, which is often the result of poor lighting design. This can be remedied with higher-quality, better-designed lighting, and there are now many energy-efficient lighting alternatives that can significantly reduce energy costs.

Health issues: Light pollution affects human health, with links to cancer, obesity, and mental health issues

Light pollution has been linked to various health issues, including cancer, obesity, and mental health problems. Research suggests that artificial light at night can negatively affect human health, increasing the risks of obesity, depression, sleep disorders, diabetes, breast cancer, and more.

Circadian Rhythm and Melatonin

Humans, like most life on Earth, follow a circadian rhythm, or a sleep-wake pattern, governed by the natural day/night cycle. This cycle is largely influenced by photoreceptors in the eye that are more sensitive to blue wavelengths of light. Exposure to artificial light at night can disrupt this cycle.

Nighttime exposure to artificial light also suppresses the production of melatonin, which is needed to maintain good health. Melatonin has antioxidant properties, induces sleep, boosts the immune system, lowers cholesterol, and helps the functioning of the thyroid, pancreas, ovaries, testes, and adrenal glands.

Links to Cancer

Light pollution has been associated with an increased risk of certain types of cancer, particularly breast cancer. A 2001 study found an association between rotating night shift work and an elevated risk of breast cancer among female nurses. Another study published in 2005 implicated melatonin deficiency in increased breast cancer risk among female night shift workers.

Links to Obesity

Light pollution has also been linked to obesity. A 2022 review in the *European Journal of Cancer* concluded that exposure to artificial light at night is a determinant in the pathogenesis of obesity. Ecological and epidemiological studies have highlighted the association between exposure to artificial light at night and obesity.

Mental Health Issues

Light pollution can also contribute to mental health issues, such as depression and insomnia. Disruption of the circadian clock has been linked to these conditions, as well as to cardiovascular disease and cancer. A 2006 study suggested that constant artificial light exposure in neonatal intensive care units could impair the developing circadian rhythm of premature babies, potentially increasing the risk of depression and other mood disorders in humans.

Other Health Issues

In addition to the health issues mentioned above, light pollution has been associated with various other health problems. For example, exposure to artificial light at night has been linked to increased risks of diabetes, insomnia, and cardiovascular disease.

Overall, light pollution has been shown to have significant adverse effects on human health, including links to cancer, obesity, and mental health issues. Further research is needed to fully understand the complex relationships between light pollution and these health outcomes.

Astronomical research: Light pollution interferes with astronomy and stargazing, damaging a unique scenic resource

Light pollution has a significant impact on astronomy and stargazing, affecting both amateur and professional astronomers. The increasing illumination of the night sky due to artificial lighting drowns out the light from faint celestial objects, such as galaxies and nebulae, and makes it difficult to observe even the brighter stars. This interference with stargazing damages a unique scenic resource and can deprive people of the opportunity to connect with the larger universe.

The adverse effects of light pollution on astronomy and stargazing are well recognised. The International Astronomical Union (IAU), for instance, works to protect existing and potential observatory sites from light pollution, including sites in Hawai'i, continental Spain, the Canary Islands, North America, South Africa, Chile, and Australia. The IAU has also passed resolutions encouraging its members to raise awareness about light pollution and work towards mitigating it at various levels.

Light pollution can be caused by poorly designed, inefficient, or misused light fixtures that scatter light above the horizontal plane. This includes light from streetlights, homes, and towns that is directed upwards or reflected off buildings and the ground. As a result, the night sky takes on an orange hue, a phenomenon known as "sky-glow".

The impact of light pollution on stargazing is significant. In the United States, for example, 66% of the population can no longer see the Milky Way at night due to light pollution. Additionally, about 40% of the US population has lost the ability to experience true darkness during the night, as their eyes never fully adjust to the darkness.

To preserve stargazing opportunities, it is essential to reduce light pollution. This can be achieved through simple measures such as turning off unnecessary lights, shielding lights to direct them downward, and supporting dark sky ordinances that regulate lighting in communities. By taking these steps, we can not only reduce light pollution but also lower energy costs and minimise the negative impacts of artificial lighting on the environment and human health.

Wildlife disruption: Artificial light impacts wildlife behaviour, including migration, feeding, and breeding cycles

Light pollution has a significant impact on wildlife behaviour, including migration, feeding, and breeding cycles. The biological activities of fauna are more intense at night than during the day, and artificial light can disrupt these activities.

Firstly, light pollution can disrupt migration patterns. Migratory birds, for example, use the moon and stars for navigation, and artificial lights can attract and disorient them, leading them away from their intended path. This can result in birds dying from exhaustion or colliding with the light source. Artificial lights can also disorient other animals such as turtles, moths, frogs, and amphibians, affecting their ability to move across landscapes.

Secondly, light pollution can impact feeding behaviours. Predators, such as foxes, are attracted to lit areas, possibly for easy prey, while prey species, such as mice, may eat less in lit areas to avoid being seen by predators. This alteration in feeding behaviour can have cascading effects on population dynamics and ecosystem balance.

Thirdly, artificial light can disrupt breeding cycles. Many plants and animals rely on the length of the night to indicate the proper season for mating and other life cycle activities. Artificial light can interfere with species' natural detection systems, altering their reproductive cycles. For example, artificial lights have been found to alter nest-hiding behaviour in frogs and affect their breeding success.

Additionally, light pollution can create barriers and lead to habitat loss for some species. For example, bats and rodents may be repelled from an area due to artificial lighting, reducing their available habitat. At the same time, other species may be attracted to the light, increasing their concentration in one area and making them more susceptible to predators.

Overall, artificial light can have far-reaching consequences on wildlife behaviour, including migration, feeding, and breeding cycles. These disruptions can have negative impacts on individual species and the broader ecological balance.

Safety and crime: Poor lighting design can reduce visibility, impacting safety and crime rates

Poor lighting design can have a significant impact on safety and crime rates, and this is closely linked to economic factors. Firstly, it is important to understand that light pollution, often a result of poor lighting design, comes at a high economic cost. In the United States, it is estimated that around one-third of all lighting is wasted, amounting to nearly $7 billion in wasted energy annually. This waste is largely due to overlit, poorly aimed, or unnecessary lighting.

Now, addressing the impact on safety and crime rates, it is essential to recognize that the relationship between lighting and crime is complex and multifaceted. On the one hand, there is an assumption that increased lighting improves safety and reduces crime. Brighter spaces may indeed enhance visibility and decrease concealment, contributing to a sense of safety. Well-lit areas can also increase the perception of safety, making individuals feel more secure. This perception of safety is significant, as it can influence people's decisions to go out, engage in economic activities, and participate in their communities.

However, it is important to note that the relationship between lighting and crime rates is not as straightforward as more light equals less crime. Several studies have found little to no evidence that increased lighting deters crime. For instance, a 2015 study in England and Wales showed that lighting changes, such as turning off or dimming streetlights, did not impact road traffic collisions or crime rates. Similarly, a 1997 National Institute of Justice study concluded that improved lighting does not necessarily prevent crime.

In fact, poor lighting design can sometimes have the opposite effect, reducing visibility and even increasing crime. Glare from bright, unshielded lights can decrease safety by causing visual discomfort and making it harder to see. This was demonstrated by the Chicago Alley Lighting Project, which found a correlation between brightly lit alleyways and increased crime. Additionally, some crimes, such as vandalism and graffiti, may actually be encouraged by the presence of lighting.

To strike a balance, smart lighting designs that direct light where it is needed can be employed. This approach ensures that lighting enhances safety without contributing to light pollution. For example, in a study conducted in the Netherlands, it was found that pedestrians felt safer in well-lit areas where lighting conditions provided a clear overview of their surroundings. This sense of safety was particularly important in close-proximity situations where potential threats were more likely to occur.

In conclusion, while lighting design can impact safety and crime rates, it is essential to approach lighting interventions thoughtfully and comprehensively. Simply adding more light is not always the solution, and in some cases, it may exacerbate issues. Well-designed lighting that takes into account the specific needs and characteristics of a community can help improve safety without contributing to light pollution and its associated economic and environmental costs.

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