Light Pollution

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Light Pollution

• Rachel McCarthy
• Tim Sheaffer
• Elizabeth Stiles
• Kevin Van Develde
• Hannah Zibert

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What is Light Pollution?

• According to the Utah Skies Association, it is
  Misused or misdirected light.
• According to the International Dark Sky
  Association, it is Any adverse effect of
  artificial light including sky glow, glare, light
  trespass, light clutter, decreased visibility at
  night, and energy waste.

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Effect of Light Pollution on Migratory Birds

• Light acts as a magnet for many species, not just
  birds.
• Birds have been seen circling offshore oil rig
  flares until they drop from exhaustion.
• Without the stars, many bird species cannot
  navigate properly.
• Unnatural light also affects the eating patterns
  of birds.
• Faster weight gain leads to early migration
• The weather is not yet suitable for them to
  arrive, which leads to starvation and population
  decline.

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Effect of Light Pollution on Bats

• Insects cluster around streetlights
• Many bat species now rely on feeding at these
  insect clusters.
• In Sweden, the European lesser horseshoe bat
  began to decline after streetlights were
  installed, due to the invasion of Pipistrelle
  bats (which have learned to light-feed).
• Other nocturnal mammals are affected in their
  foraging patterns too.
• including desert rodents, fruit bats, opossums,
  and badgers.

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Light Pollution and the Ocean

• Manta Rays and Sea Turtles

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Manta Rays or Birds of the Ocean

• Costal light pollution
• Hotels, Fishing Boats, Cruise Ships, and Offshore
  Oil Platforms
• Dangerous living conditions
• Attract tourism to frequent warm water haunts
  more lights more light
  pollution
• Ruins their natural ability to find phytoplankton
  on their own

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Sea Turtles and Their Journey with Alternate
Endings
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In Area Where There Is A Good Deal of Development
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Main Point

• Sea Turtle and Manta Ray populations are
  dropping.
• Why do we care?
• Turtle Soup
• Manta Ray Food
• But mostly. Tourism.
• We also do not know what will happen when they
  are gone.
• Lesson we learned before?

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Astronomy

• Two ways light pollution interferes
• Unshielded lights send their light in all
  directions, including straight up, setting the
  sky aglow like the sun does.
• The glow of lights obstructs the light spectrums
  from galaxies that would normally be able to be
  perceived.

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Palomar Observatory
Spectrogram of a galaxy in the constellation
Hercules, taken by the 200 inch telescope at
Palomar
The dimmest direction to point telescopes at
Palomar
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Aesthetics

• "I remember camping as a kid when we could see so
  many stars you couldn't tell one constellation
  from the next, and the Milky Way was a river of
  light". 
• Extraneous lighting is used for advertising and
  personal display
• People vacation in the country for a reason to
  escape the business and brightness of the city
• There is no hard science as to why people
  should see a clear night sky, only the reports of
  enjoyment

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New Hampshire at Night
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New York at Night
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Economic Cost of Light Pollution
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The Waste of Energy

• The biggest cost of light pollution is wasted
  energy.
• Accordingly, poor lighting design contributes to
  increased carbon dioxide emissions and global
  warming. In the United States, roughly 6 of the
  4.054 million megawatt hours (mwh) of electricity
  produced are used for outdoor lighting and an
  estimated 30 of this is wasted as light
  pollution
• (California Energy Commission 2005).
• This translates into 72.9 million mwh of
  electricity needlessly being generated at a cost
  of 6.9 billion a year.
• (Terrel Gallaway , Reed N. Olsen and David M.
  Mitchell)

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The Waste of Energy

• To put it in perspective, fixing the problem of
  wasted energy would eliminate CO2 output that
  would be equivalent to taking 9.5 million cars of
  the road.
• (Terrel Gallaway , Reed N. Olsenand David M.
  Mitchell)
• Waste of energy is not the only cost associated
  with light pollution.

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Health Cost of Light Pollution

• Recent research has begun to connect
  over-exposure to nighttime artificial light to
  increased cases of cancer, especially breast
  cancer
• (Rebecca Berg, Ph.D.)
• Nighttime Light pollution disrupts levels of
  melatonin, a chemical that is released which in
  turn helps regulate the release of hormones such
  as estrogen and testosterone. So one hypothesis
  is that melatonin may have a protective effect
  against cancer by inhibiting tumors that are
  sensitive to those hormones. When nocturnal
  melatonin levels are low, the protective effect
  may be diminished. It has also been suggested
  that melatonin may act directly to inhibit
  replication of cancer cells by increasing the
  expression of a tumor suppression gene.
• (Dana Mirick and Scott Davis)

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Need for Modeling

• The lack of research on light pollution,
  especially in the quantitative sense, keeps the
  solution from being put in motion.
• One article the Economics of Light Pollution
  concludes itself by arguing for the need of
  better and more research. his question, and many
  others, remained unanswered in no small part
  because of the absence of uniform data
• (Terrel Gallaway , Reed N. Olsen and David M.
  Mitchell)

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Solutions Shielding

• Changing to shielded, efficient lights pays for
  itself in 2-5 years.
• Allows for lower wattage bulbs and more efficient
  light direction and lenses, saving 50-80 in
  energy and maintenance costs.
• Prevents glare.
• Greatly reduces light trespass, saving night
  vision and area aesthetics.

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Case Studies

• The Italian Lombardy region, where only full
  cutoff design is allowed has the lowest per
  capita energy consumption for public lighting in
  Italy. (From 2007)
• From 2002-2005, the City of Calgary (Canada)
  replaced their streetlights with efficient lights
  - saving the city at least 2 million a year (the
  money saved will have increased significantly in
  the last few years, as energy costs also
  increase). These changes will have paid for
  themselves by 2011.

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Not shielded
Glare

• Fully shielded

Partially shielded
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Motion Sensors

• Cost 15-75 for indoor lights
• Can cut energy costs in residential and
  commercial structures by up to 75
• Unobtrusive and useful

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Design For Less

• Use only as much light is required.
• Allow the human eye to adjust to darker areas.
• Too much/too bright light can cause difficulty in
  adjusting to unlit areas.
• Use natural light sources to reduce daytime
  usage.

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Turn It Off!

• Most direct way to save energy and reduce
  pollution.

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Conclusion

• Although light pollution uses a comparatively
  small amount of energy, this amount is still
  substantial, and it can quickly and effectively
  be reduced.
• Using simple methods, we could cut light
  pollution to a quarter of its current level while
  saving energy and making money.

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Bibliography

• http//www.environmentalleader.com/2009/07/17/ligh
  ting-retrofits-help-hotels-and-data-centers-cut-en
  ergy-costs/
• http//www.assa.org.au/lightpollution/solution.asp
  
• http//www.socalgas.com/construction/builders/Buil
  ders20Resource20Guide/Full20Cut.htm
• http//aslc-nm.org/Pollution2.
• http//content.calgary.ca/CCA/CityHall/BusinessU
  nits/Roads/Streetlights/EnviroSmartStreetlightRe
  trofit/EnviroSmartStreetlightRetrofit.htm
• http//articles.adsabs.harvard.edu/full/1991ASPC..
  .17...89H
• http//www.missouristate.edu/assets/econ/World_Lig
  ht_Pollution.pdf
• http//cosmicmatters.keckobservatory.org/2006/dec/
  06dec_2.htm
• http//research.myfwc.com/features/view_article.as
  p?id2156
• http//www.astro.caltech.edu/palomar/lp.html http
  //www.physics.emich.edu/sherzer/lightpol.htm