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How light pollution is impacting our planet

27 Mar 2020

Earth Hour raises awareness of how energy consumption and human activity can impact climate change and Earth’s biodiversity, and is about to take place this Saturday, March 28th from 8:30pm to 9:30pm. While we’ll be going dark to support this environmental movement once again, we also want to take this moment to illuminate the varying effects light pollution has on Hong Kong and our world.

What is light pollution?

As defined by the International Dark Sky Association, light pollution is “the inappropriate or excessive use of artificial light, which can have serious environmental consequences for humans, wildlife, and our climate.” Light pollution comes in the form of a glare (or excessive brightness that causes discomfort), sky glow (which occurs predominantly in urban areas), light trespass (where light spills into areas it isn’t needed), and glare (excessive grouping of bright light sources).


The city lights of Hong Kong

The invention of the light bulb has certainly transformed our daily lives, enabling us to continue our work and leisure past daylight and safely commute through our streets at night. Nevertheless, an overuse of artificial light can lead to excessive brightness that flood the night sky and can bring implications to our planet in numerous ways. This is especially present in densely populated urban areas. Hong Kong’s light pollution ranks as one of the worst in the world, with levels in areas like Tsim Sha Tsui 1,200 brighter than a normal dark sky!


Light emitted from Hong Kong captured from space (courtesy of NASA / Light Pollution Research at the University of Hong Kong)

Let’s take a look at some of the ways light pollution impacts Hong Kong and indeed our planet…

It wastes energy and contributes to climate change

When Earth Hour began in 2007, its mission was to raise awareness around how excessive artificial light affects climate change. The International Dark Sky Association estimates that in the United States, 30 percent of outdoor lighting is wasted and amounts to 21 million tonnes of carbon dioxide per year. Comparatively, in 2016, Hong Kong’s residential and commercial sectors consumed about 4,3120,000 gigajoules and 103,881,000 gigajoules of electricity respectively. That’s over 52 million tonnes of carbon dioxide entering our atmosphere in just one year – an alarming number given that Hong Kong’s population is 2.25 percent of the United States’.

It affects our sleep

Light pollution doesn’t just affect wildlife; research suggests it has adverse effects on our sleep, too. Our body clock follows the human circadian rhythm – an internal process that regulates our wake-and-sleep cycle, as well as responds to external factors in our environment like sunlight. When it’s dark, our bodies start to produce melatonin, a hormone that calms us down, feel less alert and prepare us for a peaceful slumber.

The presence of light suppresses your body from producing melatonin, affecting your circadian rhythm and, in turn, delaying the onset of sleep. A study suggests there is a correlation between light and the quality of sleep, and that those who have had exposure to light in the evening were more likely to feel fatigued, wake up confused during the night, and have impaired functioning during the day.


Exposure to light at night can have an effect on quality of sleep

Although Hong Kong’s neon lights and skyline are certainly what add to the city’s character and charm, many residents who live in the immediate vicinity of these light sources are impacted by their intense glow. Currently, the Hong Kong government receives about 30-40 complaints on intrusive lighting each year, and this number may continue to rise with the increased use of outdoor lighting.

It disrupts ecosystems

Naturally dark skies are crucial in supporting wildlife and ecosystems. Nocturnal animals depend on darkness to perform certain activities, such as escaping the heat and avoiding predators in the day. Light pollution can cause adverse effects on these species – some may perceive this artificial light as moonlight, while others may be disoriented by it.


Sea turtles depend on darkness to nest and navigate their way back into the ocean

Female green sea turtles, for example, swim ashore to find a quiet dark spot to nest and lay their eggs – in Hong Kong, this occurs in Sham Wan on Lamma Island and Tai Long Wan. But as beaches are becoming a popular spot for residents, tourists and businesses, many coasts are now filled with human activity and artificial light and are no longer an ideal spot to nest. As a result, these reptiles resort to depositing their eggs in the ocean, where chances are survival are slim – a critical issue when they are already endangered.

Likewise, hatchlings rely on moonlight to navigate themselves back into the ocean. However, with artificial light spilling from nearby buildings, newborn turtles can become disoriented and wander inland, leading to dehydration and making them susceptible to prey such as birds, crabs and dogs.


Birds are also heavily affected by artificial light during migration

Light pollution also impacts birds, who use the illumination from stars to guide them whilst migrating at night. Urban lighting may attract these feathered creatures to explore areas off of their path, wasting energy that is much-needed for their journey – and potentially causing collisions into illuminated structures.

What can we do about it?

Indeed, light has brought increased safety and convenience alongside a myriad of other benefits to our day-to-day lives. However, there are small but mighty steps we can all take to minimise light pollution and protect our wildlife, ecosystems, and of course, our well-being:

  • Using light when and where it’s needed is the simplest, most efficient way to curb light pollution. Mood lighting and energy efficient bulbs are also excellent solutions to keeping your space illuminated whilst saving energy (and money on your electricity bill!)
  • Keeping your blinds or curtains closed will ensure the light you use is kept within your home, thereby eliminating any possibility of it contributing to light pollution.
  • Using shielded lampshades that direct light downwards can be crucial in outdoor spaces as this can reduce glare and spillovers.

Saving light, giving light

While we face the problem of light pollution seen especially in industrialised areas, we must not forget about the less fortunate communities who live in darkness. Currently, there are over one billion people in the world who live off grid and lack proper access to adequate lighting, and depend on toxic, dangerous kerosene lamps to keep homes illuminated or continue activities at night.


The WakaWaka Foundation provides solar products to communities in need. (courtesy of the WakaWaka Foundation)

We are delighted to see non-profit organisations such as the WakaWaka Foundation help in the fight against energy poverty. The Foundation provides sustainable, self-sufficient solar products to rural communities in need, giving them access to light that is essential for safety, education and economic activity.

We are excited to be supporting the WakaWaka Foundation through our collection of sustainable lighting coming soon… watch this space!

We hope today’s bLOG post helped give you some insight into how light pollution impacts our world, as well as the quick and simple steps we can take to combat it and reduce its effects!

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