the dark topic of light pollution


How much light do we get exposed to after dark, and how does it matter?

People all over the world are living under the nighttime glow of artificial light, and it is causing big problems for humans, wildlife, and the environment.

~ National Geographic

This illuminating 😉 post on the Harvard site seems to throw some light on the topic… some excerpts below:

Sleep-wake cycles, or circadian rhythms, establish our biological clocks, allowing humans to react to the diurnal cycles. Circadian rhythms are universal patterns observed across bird, reptile, and mammal species.

The amount of light entering the eye is key in helping our brain distinguish times for wakefulness and times for sleep.

Circadian rhythm disruptions have also been observed in avian species, and light exposure was found to impact the genes governing internal clock regulation.

Similar outcomes have been discovered in humans as the distinction between day and night becomes more difficult to distinguish. We now have more devices than ever that emit various types of light. Our smartphones and laptops stream out blue light, while our indoor lamps and overhead lights flood our spaces with white light. There is increasing evidence that indoor light exposure, particularly at night, can contribute to circadian rhythm disorders that have long term health impacts.

The disappearance of our night skies has largely gone unnoticed as the increasingly urban-based population has never had the opportunity to view a pristine night sky.

The good news is that light pollution is reversible. City ordinances and active community efforts have made major impacts in reducing outdoor light pollution and preserving night skies.

There has also been increased advocacy to reduce circadian disruption from light infiltration via smartphones, computers, and indoor artificial light. Steps we can take to reduce our light pollution impacts include: switching light bulbs to warm-colored bulbs or LED lights, making active efforts to turn off unnecessary indoor or outdoor lighting, and protecting our eyes from blue light by using blue light glasses and screen protectors.

~ “I Can’t Sleep… Can you turn off the lights?” – a Harvard article by Samantha Tracy
(Calvin & Hobbes)

People living in cities with high levels of sky glow have a hard time seeing more than a handful of stars at night. Astronomers are particularly concerned with sky glow pollution as it reduces their ability to view celestial objects.

Is it Time to Get Up?

Artificial light can wreak havoc on natural body rhythms in both humans and animals. Nocturnal light interrupts sleep and confuses the circadian rhythm—the internal, twenty-four-hour clock that guides day and night activities and affects physiological processes in nearly all living organisms. One of these processes is the production of the hormone melatonin, which is released when it is dark and is inhibited when there is light present. An increased amount of light at night lowers melatonin production, which results in sleep deprivation, fatigue, headaches, stress, anxiety, and other health problems.

~ National Geographic

The stark difference between the lights of an urban locality near a reserved forest.

civilization living on the edge

What can we do about it as part of an individual lifestyle?

  • After 9 pm, avoiding any screens unless its for office work on exceptional basis. Some alternatives are reading a book or writing a journal, playing a board game, listening to music.
  • Sometimes we have candle/lamp light dinners at home, it just feels magical and the kids love it.
  • Indoor Lighting: At home, around 8 pm we tend to switch off the bright lights and retain only a minimal dim light. Use blinds, curtains, or shades to block unwanted light from escaping your windows at night. Use task lighting instead of overhead lights to minimize unnecessary light spread.
  • Engage in Stargazing Activities: Encourage family outings for stargazing in areas with minimal light pollution. Explore nearby parks or observatories that offer dark sky programs, which promote appreciation for the night sky. Eg BASCOOL arranges some events for stargazing/camping.
  • Camping is a great way to escape light pollution and enjoy the natural beauty of the night sky.
  • Turn Off Unnecessary Lights: Develop a habit of turning off lights when leaving a room or when they are not in use. Teach your family members, especially children, the importance of conserving energy and reducing light pollution.
  • Establish a regular sleep schedule. Going to bed and waking up at the same time each day can help to regulate your body’s natural sleep-wake cycle.
  • Create a relaxing bedtime routine. A relaxing bedtime routine can help you to wind down and prepare for sleep.

Any other suggestions welcome.

3 Comments on “the dark topic of light pollution

  1. Few more possibilities…

    Assess and Adjust Outdoor Lighting: Examine your outdoor lighting fixtures, ensuring they are properly shielded and directed downwards. Use full cutoff fixtures or shielded bulbs to minimize light spillage beyond your property.

    Use Motion Sensor Lights: Install motion sensor lights for areas where safety and security lighting is necessary. This way, lights are only activated when needed, reducing unnecessary light pollution during the night.

    Opt for Warm and Low-Intensity Bulbs: Choose energy-efficient light bulbs with a color temperature below 3,000 Kelvin (preferably warmer tones) as they emit less blue light. Also, consider lower-intensity bulbs or use dimmers to decrease overall brightness.

    Use Technology to Identify Light Pollution Sources: Utilize light pollution apps or online maps to identify areas with high light pollution and choose locations for outdoor activities that are less affected by artificial light.

  2. Street lights are a drain on energy & big pollution point.
    I have a sensor based bulb in toilet for my aged mom who forgets to switch it off..
    We can use the same technology, unless movement is around on streets why do we need light?

  3. Stars Could Become Invisible In 20 Years Due To Light Pollution, Warn Scientists

    Researchers also noted that light pollution confuses sea turtles and migrating birds, who are guided by moonlight.

    In an interview with The Guardian, Martin Rees, the British astronomer royal, explained that light pollution conditions have rapidly worsened in the last several years, including since 2016 when astronomers reported that the Milky Way was no longer visible to a third of humanity. He stated that the increasing use of light-emitting diodes (LED) and other forms of lighting are now brightening the night sky at a dramatic rate.

    “The night sky is part of our environment and it would be a major deprivation if the next generation never got to see it, just as it would be if they never saw a bird’s nest,” Mr Rees told The Guardian.

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