Download presentation
Presentation is loading. Please wait.
Published byEmily Floyd Modified over 8 years ago
1
LIGHT POLLUTION Why proper outdoor lighting is important for communities and ecosystems. Steve Pauley MD Ketchum, Idaho
3
http://www.darksky.org
4
2/3 of the US population and 1/5 of the world can no longer see the Milky way.
5
99% of the population in the lower 48 and the EU live in areas where the night sky is above threshold set for polluted status.
8
The Cost of Throwing Away Electricity The Cost of Throwing Away Electricity The USA spends over $1.5 billion per year in energy costs from wasted light. = 6 million tons of coal or = 23 million barrels of oil per year
9
Light pollution is the easiest kind of pollution to fix. Reduce it, shield It, & shine it down. Light the subject & hide the source. Follow IESNA rec. levels. Use IESNA minimums when can.
10
Light Pollution Outdoor lighting currently stands as one of the most inefficient uses of energy today. 30 to 50% of all light pollution is produced by roadway lighting that shines wasted light upwards and outwards.
11
Light Pollution We wouldn’t allow 30 to 50% of water from a hose to escape onto the pavement un-used. We wouldn’t run our electric heaters in winter with the windows wide open.
12
Light Pollution Then why do we allow 30 to 50% of light photons from outdoor lighting escape into space? We throw away electricity.
13
Three Million Years of Dark Adaptation The same eyes we have today allowed our ancestors to hunt at night by the light of the moon and stars. Let’s be allowed to use our eyes at night.
14
Human Eye At Night 250 million years ago: Evolution of the human eye’s binocular vision began with the appearance of mammals Smaller noses and less sense of smell; Better eyes with acute vision and depth of field
15
Human Eye At Night Two million years ago: Early man huddled around the light of fires on the African savanna 790.000 years ago: Homo erectus used fire to cook food (Middle East digs- 2004)
16
Human Eye At Night 150,000 years ago: Homo sapiens used fire for cooking and warmth. They used the same eyes we have today to navigate, hunt, cook, eat, and give birth under the light of the moon and stars 20,000 years ago: Homo sapiens used shallow stone candles fueled with animal fat and with wicks of plant matter. Stone candles enabled stick figure art work on cave walls (France)
17
We have the same eyes now that they had then.
18
Evolution of Light Pollution 3000 BC: first candles Greeks, Romans through the middle ages: oil lamps 1784: hollow wicks used for brighter light Early colonists: fish & whale oil lamps
19
Evolution Of Light Pollution 1800’s: kerosene lamps 1801: first electric lamp -carbon arc lamp. Sir Humphrey Davy 1879: incandescent lamp. Thomas Edison & Sir Joseph swan
20
Evolution Of Light Pollution 1930’s: Mercury vapor (terrible beginnings) 1939: Fluorescent 1940: PAR lamps 1950’s: Tungsten Halogen ------------- The End of Night --------------------------------------- 1960’s: Metal Halide and HPS 1980’s Compact fluorescents (good – energy savers) 1990’s Electrodless (Induction) lamps 2000’s: Lighting designers run amok - laser shows; bridge lighting; tower lighting; beacons on buildings
21
Thomas Edison Edison’s electric light in 1879 resulted, over time, in forming an industry dedicated to selling the public the idea that the more outdoor light, the better.
22
Today’s Lighting Industry Harsh lighting is sold in the name of “security,” but more often it is used for advertising, and to sell bigger and brighter lighting fixtures. It has proven to be a visual insult to the human eye, and has gradually stolen the night away.
23
Space Needle Seattle, WA Lighting designers run amok
24
Steve’s Fundamental Laws of Light Pollution First law: Without local lighting ordinances, bad lighting gets progressively worse Second law: A. Light pollution is directly proportional to improvements in lighting technology, and B. Inversely proportional to an awareness of the issues at the local level – city planners can reverse the trend
25
Steve’s Fundamental Laws of Light Pollution Examples: Progressive eye insults beginning with incandescent bulbs, then HID lamps, then schemes to light up cities and bridges
26
Evolution of light pollution In Los Angeles 1908-1998 1908
27
1998 What will we look like in 2098?
28
Big Blackout of 2003 Before After
29
New York City Skyline 2003 Blackout
30
Toronto 2003 During blackoutAfter Blackout
33
TYPES OF LIGHT POLLUTION Glare Light Trespass Sky Glow Air pollution Energy waste Confusion and clutter
35
The Enemy of Dark Skies Is Horizontal Light The battleground for light pollution centers on the fixtures that shine light just a little above the horizon. This light is scattered the most.
36
Types of Light Pollution Glare Light that beams directly into your eye from an annoying light fixture Blinding glare: gas stations, theater effect Disability glare : scattering of light – esp. elderly with cataracts Discomfort glare: annoyance, fatigue – car headlights
37
Light Trespass When light crosses property lines The spillover of light where it’s unwanted and unneeded Light trespass: a neighbor’s or a businesse’s unwelcome light can reduce the value of one’s property.
38
Light Trespass
39
Skyglow lights up birds and planes
40
Skyglow from upward lighting
41
Types of Light Pollution (cont’d) Light confusion and clutter: too many kinds of different fixtures and colors of light Air pollution: greenhouse gasses from fossil fuel power plants
42
Good on left, bad on right Gas Stations Who is “safe” here? Glare is never good GLARE
43
Can you find the “bad guy?” Glare lighting does not allow the eye to see into the shadows This tree is “safe”
44
Original globes had soft, incandescent lights Today’s globes and Acorns have glare producing HID lamps (hps, mh)
45
Globes and acorns light the trees better than the ground
46
No lighting awards here Turning night into day while insulting the eye with glare
47
Good: Flag lit from the top-down. Better: Take down the flag at night
49
Nature’s Own Light Pollution Sun Pillars
50
What Is Good Lighting? It lights for the human eye using only the amount of light needed (follow the IESNA guidelines).
51
Good Lighting Good Lighting It lights the subject and hides the light source (lamp). It provides adequate light for the intended task, but never over lights.
52
Good Lighting It uses fully shielded light fixtures. It minimizes adverse impacts (light trespass) on adjacent property. It uses high efficiency lamps while considering the color and quality as essential design criteria.
53
Luminance : The perceived brightness measured in candelas/sq meter. Illuminance: The visual effect that luminance produces. Measured in Footcandles = lumens/sq foot Or Lux = lumens/sq meter
54
Illuminance Foot-candles (fc)= lumens / sq foot. We use fc in the USA Lux = lumens/sq meter - metric A local gas station’s lights peak at 270 fc = over 10,000 times the light from a full moon. The IESNA minimum safe light levels for an urban gas station = 10 fc; rural = 5 fc Lighting ordinances should specify limits in lumens not watts
55
Lumens And Watts A watt = one joule per sec., Or a current of one amp. Under an electrical pressure of one volt. Idaho Power residential now about 6.5 cents/kwh USA’s avg. rate = 8 cents/kWh. A lumen = a unit of luminous flux or a measure of the intrinsic brightness of a lamp. (An isotropic point source of luminous intensity of 1 candela emits one lumen into a unit solid angle of one steradian (sr), or 4 pi lumens on the spherical surface surrounding the point source).
56
. A Light’s Efficiency Is Measured in Lumens Per Watt 70 watt incandescent bulb = 1,200 Lumens 70 watt high pressure sodium lamp = 6,300 Lumens 60 watt incandescent bulb = 900 Lumens 15 watt compact fluorescent Bulb = 900 Lumens Lighting level limits are best expressed in lumens, not w atts. All commonly used outdoor lamps today (HPS, MH, LPS, MV) are over 1800 lumens.
57
Light Sources, Watts, and Lumens SourceWattsLumensLifeLu/W Incandescent1001,690750 hrs 17 Tung-Halogen3006,0002,000 20 Comp. Fluorescent 261,80010,000 70 Merc. Vapor1757,90024,000 45 Metal Halide1008,07510,000 81 Metal Halide40036,00020,000 90 HPS 706,30024,000 90 HPS25026,00024,000 90 LPS18033,00024,000 150 Street lights are on 4100 hrs/year. HPS & LPS lamps may last 5.8 yrs
58
Pole Heights and Lumen Limits Pole HeightLumens 6ft 400-1000 (Incandescent, PAR, 8ft600-1600 fluorescent, halogen) 10ft1000-2000 12ft1600-2400 16ft2400-6000 (begin HID lamps) 20ft4000-8000 24ft6000-9000 28ft8000-12000 32ft9000-24000 36ft12000-28000 40ft16000-32000
60
Useful Reference Levels for Foot-candle Values 1. Full moon.02 fc 2. Living room10 fc 3. Sitting at my computer 12 fc 4. Schools 7.5 - 30 fc 5. AAA league baseball park 85 fc 6. Today’s gas stations 50 - 270 fc 7. Jewelers counter 400-800 fc 8. Operating table light 490 fc 9. Sunlight 10,000 fc
61
Native steelhead (“Hog”) -- Steve Smith Salmon River near Stanley April 2000
62
IESNA = The Illuminating Engineering Society of North America. Sets Minimum Foot-candle Levels Needed to Provide for Safety and Security for Specific Situations, I.E. Parking Lots, Walkways, Roadways, Gas Stations, Etc.
63
IESNA Recommended Practices (RP) Publications
64
Full Cutoff Shielding Essential remedy for glare and skyglow No light rays from the fixture go above the horizontal At least 90 percent of light is blocked in the near-sideways range from 0 to 20 degrees below the horizontal
66
Typical 175 w mv unshielded yard – barn light $35 Sky Cap shield placed to cut glare, trespass, & skyglow
67
Recessed canopy lights Yes. Big Oil can do these canopies
69
Aluminum shielding over canopy lights
70
Security Issues
71
More than meets the eye i.e. not just the use of glare lighting. More light does not = better security. Security = effective, non- glare lighting. SECURITY
72
Lighting and Safety n More light does not equate to better, safer light. You can have less but more efficient lighting and not compromise safety at all.
73
Glare from poor lighting allows criminals to hide in dark shadows. Shielded, non glare lighting allows one to see in the shadows. We’re not saying let’s turn out all the lights. Lighting for security means effective, shielded, non glare lighting that meets the IESNA minimum light levels.
74
Lighting and Crime A complex issue No controlled study proves that more light decreases crime More light does give people the feeling of more security
75
Lighting and Crime Most crimes take place during the day Two congressional crime task forces (1979 & 1997) found no relationship between lighting and crime. The studies that say there is a relationship are not controlled studies “There are simply no good scientific studies that convincingly show the relationship between lighting and crime.” - (Ref - IDA information sheet 42; 4/98)
76
Crime Deterrents at Night: Best: dog (pit bull?) Next best: shielded, infrared motion detector flood lights combined with a video camera. Some schools have gone dark, used this system, and vandalism has decreased
77
Total solar eclipse Zimbabwe June 21, 2001
78
LIGHTNG ORDINANCES There is a better way
79
Why an Ordinance? Enhances the quality of life for all. Sets a uniform code for all outdoor lighting. Architects don’t need to guess what what you want – saves them time and the client’s $$$. Enhances safety and security by reducing glare Reduces light pollution.
80
Allows redress for citizens exposed to a neighbor’s bad light It can lead to cost savings
81
Without lighting ordinances, the bad practices of the last 100 years will simply escalate in the name of economic progress and “safety.”
82
12 Points For A Good Lighting Ordinance 1. Promote good lighting without compromising safety or security. 2. Convert street lights to level full cut-off fixtures. That can result in reduced lumen levels, lower wattage lamps, and a savings in electric bills. Can reflectors on posts be used instead of street lights? 3. Address glare from unshielded flood lights.
83
4. Address light trespass. Use Kennebunkport formula, not light police. H = 3 + D/3 5. Require that only the minimum IESNA lighting levels be reached for a given situation – follow the IESNA RP guidelines 6. Prohibit upward lighting of all types
84
7. Require signs to lit from the top down. 8. Educate all parties on what good lighting should be. 9. Promote the use of motion detector lighting and timing devices. Suggest all non essential lighting be turned off by 11 PM.
85
10. Allow local P & Z’s to require lighting for the human eye and safety using IESNA minimums, rather than up lighting for trees, rocks, and buildings. Down light flag poles. 11. Never allow for more lighting than what is really needed. Make lighting controlled, efficient, and effective. 12. Enforce all lighting ordinances with fines.
86
Cost of Retrofitting Often recovered in three years. Depends on formula your utility company uses to bill for light pole maintenance. San Diego is saving $3 million a year in power bills by retrofitting its street light fixtures to LPS.
87
Other Benefits Looks pleasant. Smooth, uniform illumination. Reduced glare is safer for motorists. You can see pedestrians and objects more easily. The elderly with cataracts are less affected by glare and will be safer drivers.
88
Light at Night and Human Health Researchers have shown a definite link between exposure to light at night and lower melatonin levels – in all living things.
89
Light at Night and Human Health Exposure to light at night = decreased melatonin levels. Mlt. Production is a circadian (light-dark cycle) driven event. Nightly melatonin production by the pineal gland is needed for good health. Natural peak of mlt. = 2- 4 AM.
90
Retrospective Studies - Humans Totally blind women with no light perception to interfere with mlt. production have a roughly 30% less incidence of breast cancer. Shift workers have higher incidences of breast and colon cancers ranging from 36% to 63%. Animal Studies Human breast cancer cells and rat hepatoma cancer cells implanted in rats grow faster when the rats are exposed to light at night. Melatonin levels are reduced by exposure to light at night.
91
Breast cancer rates are highest in industrialized nations where night lighting levels are also the highest. Blask has now shown mlt. To be an anti-cancer hormone in humans. (Blask D; Gordon Conf. ’04) Nurses exposed to light at night had low mlt. Their blood was Infused into the rat – human breast cancer model and cancer cells increased their growth rates. Opposite effect for nurses kept in darkness at night (high mlt.) Nightly melatonin production in humans is beneficial to our health. Light exposure interferes with that.
92
Proposed Mechanism 80% of breast tissue has melatonin receptor sites. High mlt. levels at night from exposure to LAN may allow mlt. to land on those receptor sites and block the uptake of linoleic acid (LA), a fatty acid that Blask measured in his rat experiments. Linoleic acid nourishes cancer cell growth. Low mlt. (light) = more uptake of LA. = cancer growth High mlt (darkness) = less uptake of LA = cancer growth rate drops 70%
94
“Light is a drug and that by abusing it, we risk imperiling our health.” Dr. Russell J. Reiter University of Texas Health Science Center, San Antonio, TX
95
Everybody Wins With Good Lighting Enhances the quality of life for all No compromise to safety or security Can save money Less pollution
96
Everybody Wins With Good Lighting Less glare, light trespass & sky glow Restores dark skies for stargazing Prevents the pervasive spread of light pollution Preserves the night skies for our children
97
Everybody Wins With Good Lighting Important to human health to sleep in darkness. Important to health of ecosystems to minimize exposure of plants and animals to light at night.
98
Ketchum Dark Sky Ordinance- 1999 Incandescent(w) Up to 260 lumens (20w) May be unshielded 260 – 1000 lumens (20-60w) No bulb showing; opaque top 1000 – 1800 lumens (60-120w) = *Floods 0ver 1800 lumens Must be full cutoff fixtures with no (all HID lamps) light above the horizontal ---------------------------------------------------------------------------- *Floods: Lights from 1000 - 1800 lumens: Must have shielding and opening may not tilt upwards more than 25 degrees from horizontal. Timers and motion sensors are encouraged. Motion sensors must go off in 5 minutes.
99
The acorn trap They look their best in daylight.
100
Glare from acorn light
101
Ketchum Lights
102
In Sept. 2001, Idaho Power completed the retrofit of all drop lens street lights to these fco lights. This has reduced glare, sky glow and light trespass without compromising safety. Old drop lens light
103
Guardco Lights
104
Ketchum FCO Parking Lot - Metal Halide Guardco Lights
105
Good FCO Lighting In All Places
106
There are exceptions
107
Overkill – too much full cutoff lighting
108
Total Overkill. These should be compact fluorescents And only 3 per side of the bldg. This bldg. has 15 50 watt hps at 4000 lumens each, 21 ft apart and 9 ft high. Ridiculous lighting.
109
1550watt hps lamps 10 ft high, 4000 lumens each, 21 ft apart. 60,000 lumens of light surrounding the bldg. Overkill
110
Unfortunately this is legal under the Ketchum Ordinance since these are all fco lamps.
111
Overkill
112
Perfect Lighting
116
Bad Wall Pack
117
Better Wall Light
119
Ketchum Post Office
121
Back lit sign with too much white. Neighbors complained.
123
For most business sign lighting, a down-shielded light under 1800 lumens is all that’s needed.
124
These quartz-halogen floods are not shielded, are over 1800 lumens, and therefore illegal
125
Good FCO Lights
126
Opaque cover diffuses light better
127
FCO lights at entry
128
An elementary school parking lot with no lights. No problems.
130
Steve’s Modification of the Iroquois’ 7 Generations Principle 7 Generations Principle We should not pass through this life just to make our own lives We should not pass through this life just to make our own lives easier at the expense of our natural world and future generations of humans. generations of humans. We are OF this planet, not unique to it. We are charged with We are OF this planet, not unique to it. We are charged with acting as stewards of our natural world. acting as stewards of our natural world. We must take actions today that better the lives of those who, We must take actions today that better the lives of those who, in 110 years, replace today’s entire population on earth. Each of us can do just one small thing to better the lives of Each of us can do just one small thing to better the lives of those who will be here 110 years from now –i.e. preserve the those who will be here 110 years from now –i.e. preserve the night sky. night sky.
131
Dark is Good
132
29 inch brown Silver Creek Dry Fly 6-21-92 JAWS
135
Typical 175 w mv unshielded yard light $35 Sky Cap shield placed to cut glare, trespass,& skyglow
138
29 inch brown Silver Creek Dry Fly 6-21-92
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.