Light Pollution effects on the planet

For three billion years, life on Earth existed in rhythm with the light and darkness created solely by the illumination of the Sun, Moon and stars. Today, artificial lights overpower the darkness and our cities glow at night, disrupting the natural day-night pattern and shifting the delicate balance of our environment. The negative effects of the loss of this inspirational natural resource might seem intangible. But a growing body of evidence links the brightening night sky directly to measurable negative impacts including

Harming human health: Not All Artificial Light has the same impact. Exposure to blue light at night is particularly harmful. Unfortunately, most LEDs used for outdoor lighting (as well as computer screens, TVs, and other electronic displays) create abundant blue light. To minimize harm from blue light in your home, choose the right light bulb and download a colour temperature app that adapts your electronic screen to the time of day. Cool light during the day and warm light at night.

Increasing energy consumption. Lighting that emits too much light or shines when and where it is not needed is wasteful. Wasting energy has huge economic and environmental consequences. Installing quality outdoor lighting could cut energy use by 60–70 percent, save billions of dollars and cut CO2 emissions.

Disrupting the ecosystem and wildlife. Plants and animals depend on Earth’s daily cycle of light and dark rhythm to govern life-sustaining behaviours such as reproduction, nourishment, sleep and protection from predators. Scientific evidence suggests that artificial light at night has negative and deadly effects on many creatures including amphibians, birds, mammals, insects and plants.


Threatening stargazing. Tourist today, travel to far and remote places just to be able to observe dark skies. Unfortunately, with so many people living in brightly lit areas, a large majority of the population has never been able to observe the Milky Way properly. Many are unaware that with a truly dark sky the Milky Way can appear bright enough to cast a shadow. Light pollution affects every citizen. Fortunately, concerns about light pollution are on the rise and a growing number of scientists, homeowners, environmental groups and civic leaders are taking action to restore the natural night. Furthermore, each of us can implement practical solutions to combat light pollution locally, nationally and internationally.

HOW TO MEASURE LIGHT POLLUTION

Measuring light pollution is an intricate process because the natural atmosphere is not completely dark due to airglow and scattered light. To obtain an accurate measurement, scientists use satellite images of Earth at night to determine the number and intensity of the light sources, and calculate the total sky brightness.

Amateur and professional astronomers can also use a Sky Quality Meter, a handheld device that measures sky brightness, to document and compare different areas. Mobile apps like Dark Sky Meter and Loss of Night allow anyone to measure sky brightness.

Another way to gauge light pollution is the Bortle Scale, a nine-level rating system that measures sky quality by providing observable standards. John E. Bortle, a retired fire chief and amateur astronomer, devised the rating system in 2001 as a means to help amateur astronomers evaluate the darkness of an observation site and compare sites. The scale ranges from one, an excellent dark-sky site, to nine, an inner-city sky, and specifies observable criteria for each class.

THE DARK-SKY MOVEMENT

The dark-sky movement is a grassroots movement by professional and amateur astronomers to reduce light pollution. The movement raises awareness about the effects of photopollution and advantages of cutting down on energy usage. The following groups and events are at the forefront of the dark-sky movement and light pollution awareness:

• International Dark-Sky Association (IDA) - Founded in 1988, the IDA is a non-profit organization recognized as the authority on light pollution and night-sky conservation. The organization is responsible developing the following campaigns to raise awareness about luminous pollution:
  • Fixture Seal of Approval (FSA) - A program that review and certifies outdoor lighting fixtures based on strict criteria to determine sky friendliness. Dark-sky compliant lights are fully shielded and do not emit illumination above a horizontal plane. These lighting fixtures provide color temperatures  4100K CCT or below. Manufacturers like Minka Lavery offer beautiful dark sky approved outdoor light fixtures.
  • Dark-Sky Places - Parks, reserves, and communities that have exceptional or distinguished quality skies, and are protected for scientific, natural, educational, cultural heritage, and/or public enjoyment. IDA certified dark-sky places adhere to strict lighting codes and regulations, and promote anti-photopollution education. Dark-sky parks and reserves have been established in Hungary, Namibia, New Zealand, Scotland, Slovakia, United Kingdom, and the United States. Flagstaff, AZ, Borrego Springs, CA, Homer Glenn, IL, and the Island of Sark, Channel Islands, UK, have been certified as dark-sky communities.
• Campaign for Dark Skies (CfDS) - Founded by the British Astronomical Association in 1989, the Campaign for Dark Skies is the United Kingdom's largest campaign against light pollution. The group is affiliated with the IDA and works with the House of Commons Science and Technology Committee to adopt legislation that reduces photopollution.
• Globe at Night - Founded by the National Optical Astronomy Observatory, the Globe at Night is an international research project that asks members to choose the star-chart number, 1 through 7, which best represents what they can see toward the constellation on the month.  More specifically, which chart shows the faintest star the individual can see.  Based on which stars can shine through the surrounding light pollution scientists can compile the information to produce free, public maps detailing global light pollution based on a scale. #1 represents the areas with the most light pollution, like New York City.  Chart #7 shows up in areas like national parks where light pollution tends to be very low. The Globe at Night is also a great resource for teachers and parents to gather information to teach children about light pollution.
• Royal Astronomical Society of Canada (RASC) - Established in 1898 in Toronto, Ontario, Canada, the Royal Astronomical Society of Canada boasts 4,000 members and 29 astronomy centers that provide astronomy education and outreach. In 1991, RASC founded Light-Pollution Abatement Program (LPA) to establish responsible lighting practices that reduce light pollution.
• National Dark-Sky Week - A week long annual celebration held during the new moon in April to raise awareness about light pollution. Founded in 2003 by Jennifer Barlow of Midlothian, Virginia, a high school student at the time, the event encourages participants to turn off their lights and observe the night sky without light pollution.
• Earth Hour - First organized by the Worldwide Wide Fund for Nature (WWF) in 2007, Earth Hour is an annual event that encourages people to turn off lights for one hour to raise awareness about climate change. The occasion is observed in nearly 7,000 cities worldwide.