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Environment Article - Light pollution in USA and Europe: The good, the bad and the ugly

JNA, thank you for providing this very useful source. Additional scientific research has been completed and written up in the U.K.'s Plymouth University:
August 18, 2020
"Study shows light pollution reaches the sea floor, harming marine life"

  • Artificial light from coastal cities is affecting up to three-quarters of marine life on their neighboring sea floors.
  • 76% of artificial green light wavelengths reach the sea floor.
  • 70% of artificial blue light wavelengths reach the sea floor.
  • LED lights that are used to light up coastal city/area streets emit wavelengths on the green & blue part of the color spectrum.
  • Red light has minimal impact (@ 1%) on sea life & sea floor.
Very important:
This type of light pollution cause what's called an 'artificial skyglow,' disrupting the natural biological cycles of the marine life living on sea floors which relies on the light of the moon to regulate itself for behaviors such as reproduction, sleep, food and protection from predators.
Meh. I can't see it without a subscription.
It requires that, or other special access--but a good portion of it is built upon a previous scientific research article written a few years earlier--which is publicly accessible:
Jan 10, 2016
The new world atlas of artificial night sky brightness
(The accompanying images published next the article's text are both beautiful and highly educational.)
This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies.


Dear Leader
Staff member
Meh. I can't see it without a subscription.

It's all that light pollution in DFW. :D

We have a fairly basic dark skies law which covers direction of light (must be fully shielded and directed to the ground, nothing above vertical) and the amount of light from the luminare (in watts, which is not a unit of light). It doesn't have any standards for lighting levels on the ground, or light temperature. (The regs are about 15 years old, and a lot has changed since then.) Enforcement is reactive.

I wrote some more detailed specs into the TND FBC I've been working on.

Street lighting:


Site lighting:


I recommend lux instead of footcandles. There's a slight difference - lux is an SI unit of luminosity on a level plane of 1 square meter, while footcandles is a traditional unit of measurement for luminosity in 1 cubic foot of space. Lux is more common in the lighting industry, even in the US, and it's something scientists and astronomers -- who are especially concerned about dark skies legislation -- better understand. Don't use watts -- it's a unit of production of consumption of power, not light. Light output per watt varies depending on luminare efficiency. A 60 watt LED is much brighter than a "standard" 60 watt incandescent bulb, which is brighter than a 60 watt rough service bulb.

For what it's worth, I live in the community where I work, about 4 miles (6 km) from downtown (a different municipality, which has no dark skies legislation). On a clear night, the skies are very starry compared to other places where I've lived. I can see the faint glow of the Milky Way, although it's not really that distinct. Skies overhead are mostly black, with almost no skyglow unless there's snow cover.

I replaced the security lights and front entry lights of our house a while ago. All fully shielded and dark skies compliant. Color temperature is 3000K.

And now I'll stop monologuing.