I have scarcely written about light pollution since my first edition of this list two years ago. That’s in part because the original theses covered everything I wish to say on the topic, for now. This update is very minor in form, with just a few small changes throughout.
Light pollution unfortunately continues unabated, with the threat of ever newer and bizarrer ways concocted to ruin our common view of Space.
There is no obvious or quick solution. I hope this list helps to frame the matter for you, and perhaps will assist you in discussing the topic with others.
(I) Light Pollution is pollution.
(II) Light Pollution is possibly the least-understood and least-recognized form of pollution.
(III) Most people do not know what Light Pollution is.
(IV) Light Pollution distorts the Earth’s natural night sky.
(V) Light Pollution’s distortion on the Earth’s night sky, by extension, distorts the Earth’s natural environments.
(VI) Science continues to accumulate evidence of the environmental impacts of Light Pollution.
(VII) The scientific evidence to-date is insufficient to awaken the general population to the existence of Light Pollution and its impact on Earth’s environments.
(VIII) Light Pollution is a recent phenomenon in human history.
(IX) Light Pollution is artificial.
(X) Moonlight is not Light Pollution, but part of the Earth’s natural environment that evolved over billions of years.
(XI) Humans and most non-nocturnal animals have difficulty sleeping under artificial light, preferring the dark of night.
(XII) Light Pollution directly inhibits terrestrial stargazing and other astronomical pursuits.
(XIII) Light Pollution lessens children’s curiosity about the night sky, stunting their desire to learn and imagine.
(XIV) Light Pollution severs our visual conduit of the cosmos from Earth.
(XV) The intended direction of nearly all artificial night lighting is down.
(XVI) Most artificial light illuminates in all directions (down, up, sides).
(XVII) Artificial light that illuminates outside of its intended range wastes energy.
(XVIII) Artificial light that illuminates outside of its intended range may be an encroachment onto surrounding lands and properties.
(XIX) Light Pollution is caused by artificial illumination of the night sky.
(XX) Light Pollution will never be eliminated completely from civilized locations, but it can be greatly mitigated.
(XXI) Light Pollution can be reduced with no impact to quality of life and security.
(XXII) Light Pollution can be significantly reduced by shielding all outdoor lighting to focus illumination on the intended ground target.
(XXIII) Shielded lights make nighttime visibility easier by reducing harsh bulb glare.
(XXIV) Light Pollution can be significantly reduced through the use of timers and motion sensors.
(XXV) All commercial and home decorative lighting should point downward with bulbs or diodes shielded on their sides.
(XXVI) Most Light Pollution comes from street lights.
(XXVII) Newer LED lights contribute far more to Light Pollution than the older, traditional sodium streetlamps. This is because newer LED diodes blast light across almost the entire visible light spectrum, whereas the older sodium lamps emitted light at a very narrow yellow band within the visible spectrum.
(XXVIII) Newer LED lights are OK for outdoors but should be low-intensity, shielded, and ideally triggered by motion sensors.
(XXIX) Blue light is the worst light for outdoors because the Earth’s atmosphere absorbs blue spectrum light the easiest. Think of the daytime blue sky!
(XXX) Images from space of the Earth’s ground illuminated at night were once evidence of progress, but now should be viewed as evidence of our collective ignorance about Light Pollution and not understanding how to lessen its impacts on the Earth’s environments.