Clouds amplify ecological light pollution
The brightness of the nightly sky glow over major cities has been shown to depend strongly on cloud cover. In natural environments, clouds make the night sky darker by blocking the light of the stars but around urban centers, this effect is completely reversed, according to a new study by a group of physicists and ecologists at the Free University of Berlin (FU) and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB).
“We found that overcast skies were almost three times brighter than clear at our rural location, and ten times as bright within the city itself,” says the lead author of the study, Dr. Christopher Kyba, physicist at the Institute for Space Sciences at the FU. Their research was reported on March 2nd, 2011, in the open access journal PLoS ONE.
“The astronomers who founded the study of light pollution were concerned with how sky glow obscured the stars on perfectly clear nights,” says Kyba, “and researchers studying the potential influences of sky glow on human or ecosystem health often cite the results from satellite measurements taken on clear nights. What our study shows is that when considering biological impact on humans and the environment, the amplification of light pollution by clouds is large, and should be taken into account.”
The study compares measurements of clear and cloudy sky brightness data taken using “Sky Quality Meters” during five months in the spring and summer of 2010. Two monitoring stations took data at locations 10 and 32 km from the center of Berlin. “Recognition of the negative environmental influences of light pollution has come only recently,” says Dr. Franz Hölker, ecologist, study author, and project leader of Verlust der Nacht (VdN – Loss of the Night).
“Now that we have developed a software technique to quantify the amplification factor of clouds, the next step is to expand our detection network. The Sky Quality Meter is an inexpensive and easy to operate device, so we hope to recruit other researchers and citizen-scientists from around the world to build a global database of nighttime sky brightness measurements.” The authors encourage those interested in participating in such a measurement to contact them at sqm@wew.fu-berlin.de.
The research was funded by two interdisciplinary projects, MILIEU (http://www.milieu.fu-berlin.de/en/index.html) and VdN (http://www.verlustdernacht.de/index.html). An interdisciplinary project of the FU, MILIEU – center for urban earth system studies, was initiated as a focus area at the FU, funded by the German excellence initiative, in order to investigate the bottom-up and top-down interactions between urban agglomerations and the climate and environment. The VdN project, funded by the German Ministry of Education and Research, is specifically devoted to quantifying light pollution and investigating its impact on humans and the environment.
Citation: Kyba CCM, Ruhtz T, Fischer J, Ho¨ lker F (2011) Cloud Coverage Acts as an Amplifier for Ecological Light Pollution in Urban Ecosystems. PLoS ONE 6(3):e17307.doi:10.1371/journal.pone.0017307
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/journal.pone.0017307
Competing Interests: The authors have declared that no competing interests exist.
Funding Statement: This work was supported by the project Verlust der Nacht (funded by the Federal Ministry of Education and Research, Germany, BMBF-033L038A) and by MILIEU (FU Berlin). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Contact information:
Dr. Christopher Kyba
Freie Universitat Berlin / IGB
+49 30 838 71140
Available weekdays 1pm-4pm (CET), evenings possible by email arrangement
christopher.kyba@wew.fu-berlin.de
http://userpage.fu-berlin.de/~kyba/
Disclaimer:
This press release refers to upcoming articles in PLoS ONE. The releases have been provided by the article authors and/or journal staff. Any opinions expressed in these are the personal views of the contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the release and article and your use of such information.
Who funded these idiots for such a non-study. OK. Let’s talk about the amplification factor of the clouds. Do we start out with X lumens, and wind up with 2X lumens? Is there a multiplier effect in there somewhere? This is garbage.
Studying influences of sky glow on human or ecosystem health is really reaching. Academics are really getting desperate for something to study.
Why don’t they go out and study ant hill pollution, and come up with an answer for the unwanted migration of fire ants or African killer bees?
What we are getting from academia is rubbish.
Get your night time street light cool guy sun shades here at the NASA fund the gobal warming grants center.
FBI style , DEA style, cool Jet Jockey style. $19.98 or two for $19.98 plus shiping.
From Wordweb –
verb: amplify
1. Increase in size, volume or significance
2. To enlarge beyond bounds or the truth
3. Exaggerate or make bigger
4. Increase the volume of, “amplify sound”
synonyms
blow up, exaggerate, expand, hyperbolise, inflate, magnify, overdraw, overstate
Even Sears Family Photos R Us know about this and they get paid minimum wage to know it.
Mohib says:
March 3, 2011 at 6:02 pm
”
The night sky is as much a part of the natural environment as any other and deserves protection. Today millions upon millions growing up in the cities have never even seen the Milky Way or a truly dark sky and people are as awed by a spectacular star studded dark night sky as they are when they see other natural wonders.”
Oh, come on. Put your problem into perspective. Millions of youth sacrifice their virginity every day. This has to be shocking to you.
Less than dark skies are a problem? Get serious. There are real problems in the world, and moaning about a non-problem like less-than-dark night skies only trivializes all of us.
Get real.
North Korea has this aced, you guys should just move there.
In WW2 the blackouts were dreaded as a sign of impending bombs. People yearned for the time when city lights would return as a sign of peace:
Now we’re going to get blackouts again under the marauding enemy army called EPA. Only this time we won’t be allowed to sing about the return of light, because the marauding enemy army is a permanent occupation force.
I don’t think they will find much of a market for their brightness meters. One man’s light pollution is probably 100 mens’ life saving light. Who wants to turn off the lights or get rid of the clouds? If you want to see the sky clearly, get away from the light source and above the clouds and haze layer.
The problem is overprescription of outdoor lighting in the name of safety gone berzerk.
There is also a “keeping up with the Jones” glare problem, where one place has more lights installed, then adjacent areas are hit by the glare and have to upgrade thier light output in order to see again.
It all costs $$, and a lot of outdoor lighting is pure overkill.
10% of all electricity produced goes to nightime lighting, and at least half of it is pure waste.
You have no say in it, as the 1910’s saw street lighting ordinaces which have never been challeneged, but you subsidize it.
Enjoy paying for lighting you cannot switch off.
Have a look at the Earth from Space at night.
http://eoimages.gsfc.nasa.gov/ve/1438/earth_lights_lrg.jpg
Astronomers, professional and amatuer, have known about this problem for decades.
I’m happy to see WUWT tackle this issue.
Let’s get GE right onto that problem. A little of your tax money thrown their way every year and they might eventually come up with a solution.
Brian H says:
March 3, 2011 at 3:32 pm
Every time there’s a recession or energy shortage, Towns in New England talk about shutting off some streetlights, and several have. (And some just fail but don’t get fixed.)
“What our study shows is that when considering biological impact on humans”
What biological impact on humans? I’m asleep at night. who cares if it is light enough to see your hand in front of your face. Let’s try adaption if it is a real problem. Pull the curtains.
Skeptic says:
March 3, 2011 at 4:05 pm
> So What?
Inasmuch as this is a science blog, I for one appreciate the several comets, meteor showers, and an occasional aurora I could watch from home. During Comet Hyakutake’s apparition I lived in a house with windows on three walls of the bedroom, so we could see most of it from bed.
One feature about our property on Mount Cardigan – we can’t see a street light from the yurt.
When I was in college in Pittsburgh in the early 1970s, I figured it was a good night when I could see five stars.
You’re welcome to have no interest in that stuff, but I don’t see how someone can be disinterested in natural wonders yet be interested in a science blog.
Geez…”light pollution” makes my blood boil. I live in northern NM, away from the city and in an area without any street lamps. On a moonless night it’s darker than the inside of your hat. I received a notice from a law firm that alerted me that I was to immediately remove the flood lamps mounted on my garage. I called the local covenant compliance officer and explained that I have lived in this house for 16 years and the installed lights were there when I bought the home and were most likely there when the house was built in 1977. No matter. The local covenant board had issued new rules regarding outside lights. I explained that I only use these lights about once a week for about 5 minutes when I take my trash to the street and that none of my neighbors had ever complained. No matter. The covenant compliance officer had cruised the neighborhoods and was citing everyone with exposed flood lamps. It seems a couple of avid skywatchers sit on the community board and they don’t want THEIR night skies trashed by home owners making use of their own property. So I went out and unscrewed the flood lamps and thereby averted legal action. This is personal to me because a few months later I was taking my recycling out to the street in the pitch dark, tripped, fell and broke a rib. I remember laying on my back that cold November night thinking “Gee…the night sky sure is beautiful!”.
Because of these elitist amateur astronomers I’m denied adequate lighting just to illuminate the area from by backyard to the street (maybe 150 ft) for a few minutes once a week. I am denied safety lighting of MY OWN property because these damn hippies “treasure their night skies”. Hey, I like the vivid, dark night skies, too. But this is MY property and it’s not like a WalMart parking lot. Out of 2,700 homes in this area I would estimate there are probably about 50 or 60 amateur astronomers out here…but a few of them are on the board and set the rules.
I already have a generator. I’m going to buy a couple sets of those portable construction spotlights. These are “portable” and therefore not covered by the covenant. Come summer I will grant my girlfriend her wish of being able to garden after work at night! They picked the wrong the fight.
Light is NOT pollution.
Makes me think, are the effects of the moon and stars heating the earth at all at night? Anyone know the watts/m^2 of starlight and moonlight?
@Jeremy
What most of the posters are deriding is the fact that someone got grant money (read taxpayer money) to prove the obvious. But it is a fact that some businesses do overkill. Tri-Met the Regional transit agency has a bus “barn” a couple of miles from where I live and at night, even when it is clear, their lights are so bright that residents within a couple of blocks can read a newspaper on their back porch. In Chehalis Washington there is a Car Dealership alongside I-5 who’s security lights are so bright that they nearly blind southbound drivers.
Next we’ll have electricity when they want, no lights at night so criminal can truly roam free, water once month etc… but all subscription to public utilities will be going up significantly and no opting out. That’s progress… I mean climate progress type… LOL
Mining the earth’s crust damages it and it must be put back the way it was.
Drawing from and contributing to the earth’s atmospheric gases like any other life form is pollution.
Using water causes shortage and is only to be done at need, to be determined by authorities.
Utilizing electricity, though it is the prime force found throughout the universe and is efficiently and cleanly provided by natural resources, is to be eliminated.
Now, lights…at night. At least the Puritans only frowned at extramarital sex and working on Sundays. I don’t know what to say about these eco-puritans except heaven help you if you let them direct policy.
Where I live, in South Australia, we have to suffer a regular, 28-day cycle of night-time total darkness, moving through extremely bright nights then back to darkness again. I request a large amount of money be granted to me to study this light pollution.
I blame NASA as one of their moon landers must have left the lights on.
The night sky on a moonless night out in the Pacific Ocean (from the rear of a darkened destroyer) is mind-blowing.
Ric Werme,
I have to think that Sceptic’s “SO WHAT” was referring to the study, not the fact that light pollution inhibits star gazing. I am with you. There is absolutely nothing like looking at the stars on a moonless night in the mountains. It makes one really understand why the ancients had such a fascination with them. But, why do we need scientists to tell us that it is brighter in the city when there are clouds?
This should be worthy of an IG-Nobel price, if they where no so serious.
Now if we turn of the lights but equip everyone with night vision goggles, would we save energy in the proces?
Hey, this problem is real. The nearest dark sky location is now some 250 miles from my house, and my grandkids have yet to see a star filled sky, immediate action needed.
So here’s marching orders for the AGW camp:
Ditch the meaningless 0.0005 CO2 fraction campaign and shift all manpower and activists to this very real global problem. Lead by example this time, not with your mouths. Even my house has but one 24 watt bulb outdoors, so a great way to kick this off is to start at Al Gore’s flood lit white mansion. Just keep imagining all of that super-hot nighttime UHI air rising from those sodium-hologen lamps!
If you can’t even get your own Leader Gore to flip a frickn’ light switch, you might as well fold and go home.
( a win-win and at worse a return of some long lost stars )
Ray says: March 3, 2011 at 4:31 pm
. . .That should be a good place to put a change a light bulb joke…
Q. How many climate scientists does it take to change a burnt light bulb?
A. None. The computer model says the light is not burned.
Okay, can’t resist.
Q. How many psychologists does it take to change a light bulb?
A. Only one, but it takes a long time, and the light bulb has to want to change.
But seriously,
This is much akin to our greenhouse effect, only with visible light so we get a feel for how much is happening. Light radiates upward, is absorbed, reflected, refracted around, and some goes on up to space and a small fraction is returned downward to repeat the process. Overall, things are a little brighter, as with greenhouse gasses making earth a little warmer.
A GISS computer model of this might show that if we increase the cloudiness at a given rate, we would find a tipping point where we get runaway light pollution and life on earth ends.
The glow in the Chicago image is like what Dr Spencer’s satellite sees in one of its IR bands. When flying at altitude at night above a low overcast (undercast for pilots), you can see the cities and highways connecting them. With higher clouds, the hot spots are more diffuse and harder to recognize.
I remember when I was in San Antonio going to law school, around 1977-78. We had a major power blackout for about one or two hours across large parts of the city, and it was a very clear night when it happened. In the complete darkness, I was amazed – I had never seen so many stars in the sky before! It was the most awesome sight for me. All those years I was deprived by the city lights of this pleasant sight. And all the subsequent years since.
I wish we’d just turn off all the lights sometime, whether it’s cloudy or clear. Just to see all of the stars again.