What is light pollution?
According to National Geographic, light pollution is the excessive or poor use of artificial light outdoors. Types of light pollution include glare – excessive brightness that causes visual discomfort; skyglow – brightness over the night sky in populated areas; light trespass – artificial light directed into non-intended or irrelevant spaces; and clutter – the combination of different light sources that are too bright, excessive or cause confusion. Light pollution is a huge but often unrecognised global issue. In 2016, the World Atlas of Night Sky Brightness – which receives thousands of satellite photos – showed continents like Europe, the Middle East, North America and Asia beaming with light, and only a few remote regions like the Sahara in complete darkness.
Light pollution causes wildlife disruption, impacts human and wildlife safety, increases energy consumption and more. The damage done by this seemingly insignificant issue has been claimed “among the most chronic environmental perturbations” and “inappropriate”. The revolutionary lightbulb has concealed the wonders of the natural world from humans for over a century. A case in point, in 1994, the Northridge earthquake in Los Angeles caused a city-wide power outage. Within minutes, those awoken to the vibration called police and observatories in regards to a mysterious grey cloud. That cloud was the milky way, a galactic marvel that for over a century has been obscured from almost everyone worldwide due to artificial light.
What countries have the worst light pollution?
In places like cities, cloudy skies are now hundreds or even thousands of times brighter than the same skies were only 200 years ago. The new Atlas data suggests over 80% of the human population experience light-polluted skies and 99% of Europeans and Americans. Singapore, Kuwait and Qatar, however, have the most light pollution of all countries around the globe. Science.org claims, “Singapore has the world’s most light-polluted skies, followed by Kuwait, Qatar, and the United Arab Emirates [by population]”. Due to light pollution, nowhere in Singapore is the milky way visible at night anymore. Business Insider states, “Light pollution is so bad in Singapore that people’s eyes never fully adapt to the dark when looking at the sky after sunset”.
Only in recent years has Hong Kong been displaced by the likes of Singapore. In 2013, Hong Kong had the worst light pollution globally. CNN claimed that Hong Kong’s light pollution was the worst in the world. Even after being dethroned by Singapore, places like Hong Kong are still emitting 1,000 times more light than “international norms”.
The repercussions on fauna:
Light pollution has many consequences for wildlife. For instance, sleep cycles for nocturnal animals like bats are disrupted and place them at greater risk from predators. A research scientist, Christopher Kyba, claims, “the introduction of artificial light probably represents the most drastic change human beings have made to their environment”. ABC states, “lighting also affects the feeding patterns of some bat species, and makes them more […] likely to crash into buildings”.
As for animals like sea turtles, when new hatchlings arrive, traditionally new bales would follow the sunset and head towards the sea. Today, however, light pollution provides light sources in every direction, and more often than not, raises the question: the sunset or streetlamp? Commonly, hatchlings shuffle towards the artificial light and are run over by cars, squashed by pedestrians or die from preditors, exhaustion or dehydration. Furthermore, light pollution can also discourage mature sea turtles from laying eggs on beaches in the first place.
There is also the impact on insects. ScienceDirect explains, “artificial light at night (ALAN) is another important—but often overlooked—bringer of the insect apocalypse”. The research reviewed 229 studies and found that about half of insect species globally, are nocturnal “meaning artificial light can have a big impact on their nocturnal life cycles”. A UK study found artificial lighting disrupts the behaviour of nocturnal moths, reducing caterpillar numbers by 47%. Additionally, the caterpillars born under artificial light, from birth, have immediate alteration in feeding behaviour.
Even organisms like oysters are extensively affected by light pollution. Despite their appearance, oysters are indispensable to marine ecosystems, helping remove chemicals from oil spills and filter water. Oysters act much like oceanic cleaners, with single oysters able to filter up to 50 gallons of water per day, removing both nitrogen and phosphorus – the two most prominent pollutants in bays. A UK study found organisms like oysters and mussels don’t often inhabit waters near artificial lighting, meaning lights from oil rigs or cities could deter such organisms from cleaning up the polluted surrounding water sources.
The animals and insects mentioned are just a few examples of a much larger issue. Birds, frogs, monarch butterflies, sea birds and Atlantic salmon are also associated with detrimental consequences due to light pollution in regards to mating, navigation, predation and/or disorientation.
Are we affected?
Humans, like flora and fauna, are also subjected to health implications from light pollution. Not surprisingly, light pollution affects vital cycles like sleep and our overall circadian rhythms. The circadian rhythms are 24-hour behavioural, mental and physical cycles that a biological entity goes through, carrying out essential functions to a body. WebMD says hormones, body temperature and eating habits are a few of the important things your circadian rhythm deals with. A change in cycles from exterior factors like light pollution, in short, messes with a human’s physical state, mental health and behaviour.
Moreover, light pollution changes peoples eating habits and has a direct link to obesity. Kelsey Johnson states, “in a recent  study, they found that light pollution contributed to over 70% of the obesity rates in 80 countries”. Light pollution contributes to as much weight gain “as eating junk food”.
What’s more, light pollution also has an increasing association with breast and prostate cancers. The National Library of Medicine explains, “LAN [light at night], increases cancer risk, especially for cancers (such as breast and prostate cancers) that require hormones to grow”. The International Agency for Cancer Research in 2007, “declared shiftwork a probable human carcinogen”. A study conducted by University of Connecticut epidemiologist Richard Stevens and researchers at the University of Haifa found people in areas with significant light pollution versus minimal light pollution had a 30% to 50% increased risk of breast cancer.
Light pollution can also ignite health issues like increased stress, fatigue, headaches and anxiety. If humans are exposed to light when trying to sleep, melatonin production is terminated. This is the reason why prostate or breast cancer can form, as previously mentioned. The Sleep Foundation states, “In response to darkness, the pineal gland in the brain initiates production of melatonin“. Light exposure, conversely, ceases production engendering headaches, stress, anxiety, fatigue, and possibly worse.
The extra emissions:
The International Dark-Sky Association claims that 15 million tonnes of carbon dioxide (Co2) emissions are produced from residential outdoor lighting in the United States annually. That amount of energy utilised for outdoor spaces would be enough to power all of New York City for 2 years. The IDA (International Development Association), says that at least 30% of outdoor lighting is wasted, generating 21 million tonnes of Co2 emissions.
Over 71% comes from residential outdoor lighting. The International Dark-Sky Association states, “[t]o offset all that carbon dioxide, we’d have to plant 875 million trees annually”. According to the European Union, 19% of global electricity consumption is used for lighting, adding up to 1.9 billion tonnes of Co2. The wasted emissions that come from insufficient use of artificial light distribution leads to a greater accumulation of atmospheric greenhouse gases, contributing to a more threatening climate emergency. The light itself, additionally, being radiated from streetlights and housing also directly warms the air, by emitting additional heat into the local climate.
The extra-economic exasperation:
Cambridge University Press asserts that more light pollution has a direct inverse correlation to economic decline. Research Gate claims that light pollution generates significant impacts on wildlife, astronomic study and human health which is estimated to cost the United States economy $9.73 billion AUD ($7 billion USD) annually. Cambridge University Press states, “[the] equivalent to 17.4 billion kilowatt-hours of electricity” is wasted in the United States alone. More than the entire energy consumption of countries “including Chile, Cuba, Hungary, Ireland, Indonesia, Israel, Libya, Peru, Syria, or Vietnam” as of 2016. The amount of wasted light radiating into the skies consumes the same amount of energy as burning 30 million barrels of oil or 8.2 million tonnes of coal. Obviously, neither oil nor coal is sustainable but surely if we were going to cook the planet, at least the resources to do so would be used productively.
In 2008, the European Commission proposed a plan to phase out incandescent light bulbs by 2012. With approval from European Member States experts, the proposal would enforce the transition to energy-saving lightbulbs. Such transition would save 40 terawatt-hours (trillion) of energy, the equivalent of all Romanian energy consumption or “10 power stations of 500 megawatts”. When more countries adopt this approach, hundreds of millions of greenhouse gas emissions will be suppressed. Saving both the economy valuable dollars and the planet’s imperative biodiversity.
How can we prevent light pollution?
Light pollution, whilst a mammoth global issue, can be dimmed. There are many ways homeowners, developers and corporations can reduce the impacts of light pollution:
– Motion-sensor lighting (outdoors) that only activates when people are near;
– turning off any unnecessary outdoor lighting to invite vital pollinators during the evening;
– switching to LED or CFL lights (only warm-colour bulbs) to reduce both energy and animals affected nearby; and
– outdoor light fixtures which help contain the light emitted from seeping into neighbouring areas.
– Design urban landscapes to only use ‘warm white’ lighting;
– ensure flora and fauna hotspots like wetlands are kept at a distance from large infrastructure;
– install miniature streetlights that face the lighting downwards, keeping the footpath bright but not the surroundings; and
– incentivise ‘light-out nights’ throughout the neighbourhood/estate.
– Turn off office building lights in the evening;
– install smart lighting controls;
– introduce darker and non-reflective tables and other equipment into offices to absorb and not mirror light; and
– drop blinds if lights remain on for late-night employees.
What comes to mind when the word pollution is raised? An entangled turtle, a plastic bottle rolling along the city streets, or cars bolting down freeways? Very few, if any, consider or even know of light pollution. Whilst more prominent forms of pollution like air and water must also be tackled, it goes without saying that minimising light pollution has to now be on everyone’s agenda – from developers to businesses and households to individuals. Why? Because it threatens the entire existence of vital insect, bird and turtle communities, deters indispensable oceanic organisms like oysters, costs the global economy billions, contributes to a sector that’s fast-forwarding global warming, and is subjecting hundreds of millions to probable carcinogens. If you can’t sleep at night, or miss the sound of the insect and animal villages working the night way – more likely than not – light pollution is to blame.
On a positive note, at least there’s only one impaired planet in a milky way of billions. If only we could see that milky way.