Europe will not restore its nights through isolated projects—cooperation is part of the solution.

The European Light Pollution Coalition connects groups working to reduce light pollution across Europe, enabling them to share knowledge, coordinate projects and build joint initiatives for natural nights and healthier nocturnal environments.

🔗 website: lightpollutioncoalition.eu

#lightpollution #darksky #Europe #biodiversity #nocturnalenvironment #sustainablelighting #collaboration

Artificial light does not stop at the shoreline—it can reshape life beneath the water’s surface.

A new systematic review finds that artificial light at night affects fish behaviour, physiology and life history, while its consequences for populations, communities and ecosystem functioning remain largely unknown. Freshwaters, coasts and even offshore waters are exposed through nearby infrastructure, vessels and skyglow.

🔗 research article: https://lnkd.in/ez6PXfZQ

#lightpollution #artificiallightatnight #fish #aquaticecology #biodiversity #darksky #freshwater

👏 Congratulations to @mube!
The picture speaks for itself and clearly demonstrates the benefits of the GRANUM greening solution by GHM x Mube.
#UrbanGreening #SustainableCities #LandscapeArchitecture #GHMxMube

🌃 How far does city light actually travel at night?

Further than you might think — and further than most conservation zones currently assume.

Our new paper, just published in Urban Climate, looks at how artificial light from cities propagates through the atmosphere across different wavelengths and city sizes. The short answer? Light from a major city can reach natural darkness levels hundreds of kilometres away — well beyond standard dark sky protection buffers.

🔦 Different colours of light behave very differently out there in the night sky — and the findings have real implications for how we design lighting, protect biodiversity, and plan our cities.

🌍 This work provides a physically grounded, quantitative basis for setting protection zones around dark sky areas and biodiversity hotspots — and it highlights just how fragile nocturnal habitats can be. Natural protected areas not only in the vicinity of cities, but potentially hundreds of kilometres away, may still be affected by urban light.

📖 Open access — Link: https://lnkd.in/dZAGTFZm, free to read!

Big thanks to my co-author Miroslav Kocifaj for making the computational heavy lifting possible! 🙏

If you work in conservation, urban planning, lighting design, or simply care about the night sky — I'd love to hear your thoughts. Does this change how you think about the areas we consider "protected"? 🌌

#LightPollution #DarkSky #Biodiversity #UrbanClimate #Sustainability #NocturnalWildlife #Conservation #OpenAccess

Join us for an interactive panel on turning your passion for dark skies into stories that capture public and media attention.

Hear from a communications strategist and seasoned DarkSky Advocates who have successfully brought their work to the public eye. From literary publishing to active media campaigns, our panelists will share practical strategies to help you:

✔️ Find and connect with the right journalists
✔️ Pitch compelling local stories
✔️ Stay on-message during interviews
✔️ Create social content that can take your local impact to a global audience

🗓 Date: September 17th, 2026
🕕 Time: 8:30 a.m. PDT

⚠️ You must be registered as a DarkSky Advocate to attend this event. Not an Advocate yet? Register to become one and join us: https://bit.ly/3WhIpam

📷 Photo by Julio Castro Pardo

Moths are quiet nighttime pollinators, helping native plants reproduce after dark.

Artificial light can disrupt their routines and impact the ecosystems that depend on them.

Protecting dark skies helps protect nighttime pollinators.

#DarkSkyTexas #ProtectTheNight #Moths #LightPollution

Vernon, BC Passes Light Pollution Policy

https://lnkd.in/g6J4r4_t

New rules will limit brightness and spill from municipally owned and managed sources, without any new penalties or approval procedures for private lighting.

Canada is home to some of the best dark-sky locations, where low levels of artificial light allow the night sky to be observed with clarity. These protected areas provide ideal conditions for viewing stars, planets, the Milky Way, and other celestial phenomena that are often difficult to see from urban environments. 🌌🔭

The global dark sky community is coming together once again. 🌎✨

Join DarkSky for 24 hours of connection, learning, and inspiration with people around the world working to protect the night.

As light pollution grows and challenges like satellite proliferation continue to reshape our nighttime environment, coming together to share knowledge, strengthen our advocacy, and imagine what’s possible is more important than ever.

✔️ Practical workshops to build your advocacy skills
✔️ Stories and perspectives from across the globe
✔️ Opportunities to connect with fellow DarkSky Chapters and Advocates
✔️ Ideas and inspiration to help create a future where the night can thrive

Early bird tickets are available now for $25 USD.

Get your ticket and join us Under One Sky: https://bit.ly/4qmiBHw

📷 Photo by Samuel Mensák

It was a privilege to take part in this conference with Dark Sky Ireland colleagues Kerem Ali Asfuroglu and Brian Espey. A growing number of County Councils across Ireland are taking light pollution seriously and it is so encouraging to have these events where practice and solutions are explored together. We have a long way to go to get lighting right but the wheels are turning.

Congratulations to all involved at Kildare County Council and the Biodiversity Officers of Leinster for putting this together. Heritage Council

#darkskyireland
#endlightpollution

https://lnkd.in/eG9sqrXr

Did Artificial Light Make Us Forget the Moon? #8/32

For millions of years, the Moon was one of the most predictable biological signals on Earth. Before electric lighting, the difference between new moon and full moon represented an enormous change in the nighttime environment. Around new moon, illumination can fall to thousandths of a lux or less, while full moonlight can reach tenths of a lux. Daylight reaches tens of thousands of lux. Today these nighttime numbers may seem irrelevant because our homes, streets and cities routinely produce much higher illuminances. But evolution had millions of years to respond to these subtle changes. And the bright full moon itself is only a brief part of each lunar cycle.

Many organisms use lunar cycles to coordinate behavior and reproduction. Perhaps the most spectacular example is coral spawning, where huge numbers of organisms synchronize reproduction with the lunar cycle. Artificial light at night has been shown to alter its timing. And humans may not be completely different. The female menstrual cycle occupies a similar timescale to the 29,5 day lunar cycle. This alone proves nothing. However, long-term menstrual records show that human cycles can temporarily synchronize with lunar cycles, and large datasets have detected a small but significant lunar rhythmicity. The lunar cycle is not only a light cycle; gravitational cues have also been proposed as a possible contributor.

This raises a fascinating question: what did female reproductive rhythms look like before electric light? We cannot examine menstrual calendars from 1500, 200 BC or 100000 years ago. Almost all modern data come from people already living in an environment fundamentally different from that in which our biological timing systems evolved. For most of human history, nighttime illumination varied between almost complete darkness and moonlight measured in fractions of a lux. Within only about 150 years, electric lighting has largely erased that contrast.

This does not prove that artificial light causes infertility, nor that human ovulation was universally synchronized with the full moon. But research connecting circadian disruption, light at night, reproductive hormones and menstrual physiology makes an ancient lunar influence worth investigating.

The question extends far beyond humans. Insects, birds, turtles, fish, corals and countless other organisms evolved under the same alternation of sunlight, darkness and moonlight. Unlike humans, they cannot close the curtains. We defend nighttime lighting for a sense of safety, mobility, architecture and comfort. These needs matter. But the biological environment matters too.

Before illuminating every remaining darkness, perhaps we should ask: How deeply are we interfering with biological rhythms that evolved for millions of years under nights illuminated only by the Moon and stars?

#ArtificialLightAtNight #LightPollution #CircadianRhythm #Moonlight #MenstrualCycle #CoralReefs

When cities dim and warm their lights, urban plants may begin to recover their natural seasonal clock.

A new PNAS Nexus study compared New York and Washington, DC with nearby cities lacking equivalent lighting policies. Satellite data found lower nighttime emissions—especially blue light—and vegetation shifts consistent with less artificial disruption, while the authors stress the evidence is exploratory rather than causal.

🔗 News article: https://lnkd.in/exc7-8S3
🔬 Research paper: https://lnkd.in/ex55nF9Q

#lightpollution #darksky #urbanecology #biodiversity #sustainablelighting #plantscience #nightscape

🌙 Earth Night 2026 - NATURAL NIGHT: RETHINKING LIGHT

Friday, 11 September 2026, worldwide.
Every year on the Friday around the September new moon, when no moonlight brightens the sky. Initiated in 2020 by the German non-profit Paten der Nacht. Unlike Earth Hour, this is not one hour in March. It is a whole night: lights off from dusk, 10 pm local time at the latest.

When did you last experience a truly dark night?
A night where the stars come back. Where darkness is not felt as a lack but as something entirely natural.

🌙 Night is part of life.

Once a year, Earth Night invites us to experience the night deliberately: reduce or switch off outdoor lighting and discover what happens when we give darkness room.

Maybe change begins with wonder, and wonder begins with the starry sky.

Because anyone who marvels again at the stars, the quiet of the night and the life that unfolds in the dark may also start asking:
- Do we really need light everywhere?
- Do we really need it all night?
- And does it really have to be this bright?

For Wilfried L. Bott, a dear LinkedIn connection who wrote the original German post and gets all the credit, that is the way into RETHINKING LIGHT.
Not against light.
Not for total darkness. Under a natural night sky there is no such thing anyway. Total darkness lives in a well-stuffed wardrobe.

This is where the economy of effect comes in:
Not producing as much light as possible, but achieving the desired effect with the least effort and the fewest unwanted side effects.

Good light is not maximum light.
Good light is light that works.

🌎 Earth Night 2026
🌙 NATURAL NIGHT
💡 RETHINKING LIGHT

Who's in?
👉 https://lnkd.in/eP7QCiqB

If we want to reclaim a piece of the night, one thing comes first: reduce #LightPollution.

#transformation #regeneration

Photo: NASA - National Aeronautics and Space Administration - "Black Marble"

https://lnkd.in/eWAMNZKj

#nuit #éclairage #environnement

Comment gérer l'éclairage public ?

La #pollution lumineuse, devenue un enjeu majeur de santé publique, environnemental et économique, cristallise les tensions entre extinctions nocturnes contestées et innovations techniques.

Par ses études scientifiques, le Cerema éclaire les décideurs d’éléments factuels et opérationnels.

« Éclairage public : un équilibre fragile », un article de Marie Laure Papaix-Couderc, Paul VERNY, Stéphanie Bordel et Florian Greffier à lire ici :
👉 https://lnkd.in/egAgCWWn

Continuing my discussion on light pollution...
I asked students in my class if they have seen milkyway 🌌. No one had. I feel sad that kids do not get to see such wonders. I remember tracking satellites in the night sky as a kid.

But...

Did you know 💡that India has Two
Official Dark Sky Designations?

Hanle Dark Sky Reserve: Located in Ladakh inside the Changthang Wildlife Sanctuary, this is India's first official dark sky reserve (established in 2022) covering a cluster of villages around the Indian Astronomical Observatory with strict local shielding and lighting restrictions.

Pench Tiger Reserve: Spanning Maharashtra and Madhya Pradesh, it was designated India's first Dark Sky Park in 2024 to safeguard nocturnal animal habitats from artificial light interference.

#lightpollution #environment #OneHealth #DarkZones #Biodiversity

What If Night Time LED Lighting Started With the Human Retina? #6
Look at these images. They show real cone mosaics from people with normal colour vision. Hofer and colleagues found enormous differences in the ratio of L to M cones from 1.1:1 to 16.5:1 while S cones remained a small and remarkably stable minority, around 6%. Despite these dramatically different retinas, the colour normal subjects had normal colour vision.

How is that possible? Because the retina is not a camera sensor producing a finished image. Cones provide signals, retinal circuits begin processing them, and the visual system continues interpreting and comparing this information in the brain. The percept we call colour emerges from this neural processing. We can agree that a surface is “red” because we learned to use the same word for that percept. But whether the subjective red created in my brain is identical to the red created in yours is a much harder question. A spectrometer cannot tell us.

Now consider the light humans experienced after sunset before the LED era. Fire, incandescent and halogen lamps are physically very different sources, but compared with today’s blue pump white LEDs their spectra contain proportionally much less short wavelength energy and are weighted more strongly towards longer wavelengths. Within only a few decades, we introduced a pronounced blue peak into our homes, streets and vehicle headlights at night.

The small number of S cones does not mean blue light is unnecessary. Receptor count alone cannot define an optimal spectrum. But short wavelengths also strongly influence the pupillary light reflex through melanopsin containing ipRGCs. CIE TN 003:2015 shows that the spectral sensitivity of the pupillary light reflex shifts towards shorter wavelengths with increasing stimulus duration, with sustained responses strongly involving melanopsin containing ipRGCs. Spectrum therefore affects not only what we see, but also pupil diameter and consequently how much light reaches the retina.

So perhaps we should ask a simple question: when white LEDs replaced incandescent and halogen sources, what night-time visual benefit justified the large increase in short wavelength energy? Did we determine the spectrum that gives people the visual information they need with minimum glare and unnecessary biological stimulation or did available LED technology and photopic efficiency determine the spectrum first?

LED technology gives us something previous technologies never offered: extraordinary freedom to engineer light and spectrum. Perhaps we should finally use it. The next generation of night time lighting at home, on our streets and in vehicle headlights should begin not with what an LED can produce, but with the human retina, the pupil and the biological night.

#Lighting #VisionScience #LED #HumanVision #Retina #StreetLighting #AutomotiveLighting #LightingScience

Figure: Hofer H. et al., Organization of the Human Trichromatic Cone Mosaic, J Neurosci 2005

Sun Valley Resort recognized by DarkSky

https://lnkd.in/gwX3Ammg

Idaho resort the first US recognized by DarkSky International's Lodging program.