Light Pollution, Impact on the Environment

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Light Pollution above Honolulu

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Light pollution is the adverse effect of artificial light.  Types of light pollution are: light trespass, glare, and sky glow. 

Light trespass - occurs when unwanted light enters one’s property from a source outside of one’s property.  A common light trespass problem occurs when light enters the window of one’s home causing problems such as sleep deprivation or the blocking of an evening view. 

Glare - is caused by over lighting or badly placed lights where the light shines directly into the eye.  This is usually caused by an unshielded light source where one can actually see the filament of the light bulb.  Glare can cause hazardous driving conditions, and reduce contrast between light and dark areas, making it hard to see details in the areas to either side of the glare source.  After experiencing glare, it then takes the eye some time to readapt to normal night vision. 

Sky glow - can be seen over densely populated areas.  It is the combination of all the light escaping up into the sky from all the badly directed light sources in the area.  This sky glow can be seen for many miles away from major cities.  Sky glow is particularly problematic for astronomers whose ability to observe the night sky is inhibited by the decreased contrast between the stars and the normally black sky.  Sky glow can be reduced by selecting lighting fixtures which limit the amount of light that is emitted above the horizontal plane of the light fixture.

Light pollution has been a major concern for astronomers, but now studies are finding that light pollution is having an impact on the environment.  Light pollution disturbs the nocturnal patterns of animals, and is even being linked to breast cancer due to the decreased production of melatonin.

     “In the beginning God created the heaven and the earth.”  “And God said, Let there be lights in the firmament of the heaven to divide the day from the night.”  For millions of years on planet Earth, it has been light during the day and dark at night.  Life on Earth, man included, has evolved under these conditions.  Prior to the invention of Edison’s incandescent light in 1879, the only light we had at night were our camp fires, oil lamps, and the Moon.  For comparison of the day and night given to us by nature, the Sun is 449,000 times brighter than the Full Moon.  Our eyes have two different receptors, cones and rods.  Rods are our night vision receptors.  Cones can only see at night down to a level equivalent to a night with 50% moonlight, but rods are 1,000 times more sensitive and can see under conditions equivalent to an overcast night with no moon. [1]  As I write this, it has been 132 years since Edison began his work on the light bulb, and since then it has exploded onto the world in a way that is almost hard to imagine.  But try to imagine.  How many lights are in your home?  In your office? On your street?  In your town, or city?  In your state?  In your country?  On Earth?  The light bulb has come a long way in just over 100 years.  So what changes has this wrought for life on Earth?

     Here in Hawaii one of the most notable concerns about light pollution has to do with sea birds.  To find out more, I interviewed Sandra Bingham from Sea Life Park.  Sandra works to rehabilitate hundreds of sea birds that are found around the island and in need of care, but why?  “During our peak season for the park is what we call Wedge-tailed Shearwater season.  It usually runs from the end of October to the beginning of January.  It’s where the birds are fledgling; they fledge at night time, trying to get to the ocean, that’s where the light pollution comes in.  They focus on the Moon shining off the water and that’s what guides them to the ocean.  When people have their lights on in their back yards, they have floodlights or they have big lights, they can draw the birds in.”  The birds follow the brightest light source believing it to be the Moon shining on the ocean.  “So they end up flying around and they get really disorientated by seeing different lights and they’ll just keep flying thinking that’s where they’re supposed to go and eventually get exhausted and end up landing in people’s yards.”  That’s when people pick them up and bring them to Sea Life Park.  During a normal season they receive 200 to 500 birds.  “It’s mostly juveniles that are just now leaving the nest.”  “The same thing applies to turtles, they leave the nest at night and they’ll follow the moonlight into the water and it’s the same, where they can get disorientated by the lights.”  These animals have evolved over millions of years to follow the light shimmering off the ocean.  It has only been in the past 100 years where artificial light would pose this problem.  “One thing that we always recommend is, if you live on the beach; turn off your lights at night.  If you don’t need them, turn them off.  If you have a flood light, get rid of it, or if you have lights, point them down to the ground so that they’re not facing the sky.  If they’re not facing the sky, the birds won’t focus on them as much.”  “What we mostly stress is, if you can turn off your lights at night, go ahead and turn them off, that is a huge help.”

     With so many lights visible in Honolulu, I wanted to get some information on how much energy is used on lighting on Oahu so I contacted Hawaiian Electric.  HECO told me that they had no way of estimating the amount of energy that is used specifically for lighting since they don’t know how people use the electricity in their homes or businesses, and instead sent me their brochure which you can find online.  But one look at Honolulu and you can imagine that the amount is huge.  In my search for information online I found a report on Energy use in state buildings in 2004.  Based on the results of this study, there are approximately 2,625 buildings that are identified as being owned and operated by the State of Hawaii. Approximately 80 % of those buildings are located on Oahu.  The total yearly electrical energy consumption for all State facilities on Oahu for 2004 was 557,654,688 kWh. This amounted to a total cost of $71,372,318 for electricity in 2004, at an average rate of $0.128 per kWh.  In the report, air conditioning is the highest electrical energy consuming category at 44%, followed by lighting at 30%.  What would be more interesting is how much energy goes into outside lighting such as street lights.  There are so many street lights in Waikiki and Honolulu that I often see people driving at night not realizing that their headlights are not on.  It’s not hard to imagine the environmental impact that is caused just by the fuel that is used to make enough energy to turn our night into virtual day.

     While the HECO brochure tells how to save energy by replacing incandescent light bulbs with CFLs or LEDs, keep in mind that the electric company makes money by selling you electricity.  In the past energy was consumed mostly during the day.  That’s when people were awake doing their jobs, or home watching TV, or whatever people do when they’re awake.  As people went to bed the electric company’s found themselves with a low demand for power at night, so they invented a demand in form of security lights.  The electric company will install a pole in your front yard and place a street light on it that will shine all night long, and then add the cost to your electric bill.  What they won’t do though, is install a switch so that you can turn it off when you don’t want it.  I know, I’ve tried to do so at my parent’s house.  In this case what I did was ask the electric company to disconnect the light, and I installed flood lights on the front and sides of my parent’s house.  These lights are controlled both by a switch inside the house, and a motion detector.  The security concern at my parent’s house was illegal aliens coming to the yard.  Having one of the only light sources for miles around might actually attract them to it.  Instead, they are scared off the property when surprised by a flood light that comes on by a motion sensor.  Meanwhile, the light is not wasting energy, or causing light pollution while it is not being used.

     For millions of years man has lived as diurnal creatures.  Living in the light of day, and sleeping in the dark of night.  However if you live in or near a city, you probably never really experience darkness at night anymore.  I know in my apartment, even when I lived on the 27th floor, when I turned off my lights and closed my curtains, there was still enough light pouring into my apartment that I could still find my way around.  Not having darkness at night can actually lead to health problems.  “Recent studies have shown that light pollution can actually have serious health effects. Researchers have found that exposure to bright nocturnal light can decrease the human body’s production of melatonin, a hormone secreted at night that regulates our sleep/wake cycles. And decreased melatonin production has in turn been linked to higher rates of breast cancer in women.” [2]  “Melatonin is a naturally occurring compound found in animals, plants, and microbes.  In animals, circulating levels of melatonin vary in a daily cycle, thereby regulating the circadian rhythms of several biological functions.  Many biological effects of melatonin are produced through activation of melatonin receptors, while others are due to its role as a pervasive and powerful antioxidant, with a particular role in the protection of nuclear and mitochondrial DNA.”[3]

     Humans are not the only animals affected by light pollution, but of those humans that are affected; those that are taking the most active stand against light pollution are astronomers.  For astronomy, the increase in light pollution means a decrease in the amount of stars that can be seen.  Faint galaxies and nebulas require a very dark sky to be seen even through a telescope.  These faint fuzzy objects are best seen against a black sky.  Light pollution has turned the night sky from black to gray, or even amber nearer to cities.  These faint objects can not bee seen against such a bright back ground.  Under good dark sky conditions you can see about 4,000 stars at one time.[4]  If you live in or near a city, you’ll be lucky if you can count 80 stars (2%).  That doesn’t leave much to spark the interest of the next Carl Sagan, or Neil Armstrong.

     I interviewed John Gallagher of the Hawaiian Astronomical Society (HAS).  John is a board member of HAS and active in promoting the awareness of light pollution.  “Back in the 30’s, we would look up at the night sky and wonder, is there anything else up there?  People today have no real concept of what a night sky should really look like.”  In preparation for our meeting, John printed out a copy of a recent bill passed by the Hawaii State Legislature:

SB536, Relating To Sarlight Reserve.

Starlight Reserve; Statewide Lighting Law; Light Pollution

Requires department of business, economic development, and tourism, assisted by a temporary advisory committee, to develop a statewide starlight reserve strategy, including an intelligent statewide lighting law, to preserve the quality of the night sky and its associated cultural, scientific, astronomical, natural, and landscape-related values.

John pointed out that there was supposed to be a committee that was supposed to report back to the legislature this session, which ends this May, but as of our interview it had not happened yet.  As per the bill, one of the members of this advisory committee was to be Harry Zisko, one of the board members of the Hawaiian Astronomical Society.  Reading over the bill, there doesn’t seem to be anything in the bill that makes anyone actually do anything to reduce light pollution, there are no specifics defining what constitutes light pollution, what can or can not be done, no restrictions or fines.  It just seems to be a concept of a good idea with nothing behind it.  John points out that the original version of the bill had these things in it, but were taken out at the last minute before the bill was passed.  John says, “What they ought to do is take the original bill, take the part that was removed from the current bill, take that as the starting ground, because that laid out a lot of specifics.”

     A story in the news in August of 2009 that caught my eye was of a project in Hawaii Kai to spend $6.5 million to put in streetlights that the residents were protesting that they don’t even want because the street is already over lit.  “Three times as many lights are being installed from Kalanianaole Highway to Koamano Street (Phase I) at a cost of $1.96 million. Phase II will continue from Koamano Street to Hawaii Kai Drive for another $570,000, and Hawaii Kai Drive is in the planning stages for an estimated $4 million.”  “The new light fixtures are 150-watt high-pressure sodium lamps, "the same as the existing lights," according to the city. Despite advances in lighting technology, the city is installing outdated inefficient fixtures that create light pollution and a safety hazard from excessive glare.”[5]  In a follow-up story in March of 2010, the residents had convinced the city to install 100 watt bulbs instead of the planned 150 watt bulbs, and also convinced them to us a different light fixture with a flat lens that reduces glare and light pollution.

          Recommendations: 

1.  One of the first things that should be done is to assess the problem.  The International Dark-Sky Association has information on how to make a lighting map.  Such a map can be done with a digital camera, or a light pollution meter that has been made specifically for this purpose.  The map would show the light intensity around the island of Oahu.  This map would show places where the light needs to be controlled and also serve as a baseline that can show change over time.

2.  The state legislature should amend SB536 with the policies that were taken out of the original bill.  These policies were similar to policies that have been adopted by other cities such as Tucson, AZ or Oceanside, CA where light pollution has been greatly reduced.

3.  There should be some kind of office to monitor light pollution.  This office would have a kind of Lighting Marshall that would enforce the policies on light pollution.  This office would also receive complaints about light pollution.  A phone number can be made where people can notify the office of known light pollution problems, whether it is a light that needs to be shielded or replaced, or a case of light trespass from a neighboring property.

[1] “The Eye and Night Vision”, American Optometric Association, 2010, <http://www.aoa.org/x5352.xml>

[2] Larry West, “Light Pollution Raises Risks of Breast Cancer”, About.com, 2010, <http://environment.about.com/od/pollution/a/light_pollution.htm>

[3] “Melatonin”, Wikipedia, 2010, <http://en.wikipedia.org/wiki/Melatonin>

[4] “Magnitude”, Astrometry.org, 2005, <http://www.astrometry.org/magnitude.php>

[5] “Hawaii Kai Residents Protesting 'Offensive and Wasteful' Street Lighting Project”, Hawaii Reporter, 2009, <http://www.hawaiireporter.com/story.aspx?25fb7615-6d5a-442b-8d5a-39bca6157bd3>