No more starry nights? Light pollution is changing our skies

Light pollution is affecting our view of the stars
Number of stars visible is rapidly reducing
12 year study
Matching star charts with a patch of sky
Model that related visible stars to the brightness of the sky
10% increase in sky brightness every year
Star visibility reducing significantly
The future might be starless
Population growth and new technologies have increased light pollution
Many cities have changed their lightning to modern LED
The lighting paradox
Ironically, the LED revolution has led to a light pollution increase
The cheaper the lighting, the higher the addiction
Light pollution affects human health
Light pollution also affects animals
There is still room for improvement
Keep the blinds closed at night
Use Night Shift settings on all devices
When outside, point your light towards the ground
Let your eyes adjust to less light
Other things we can do to reduce light pollution
Light pollution is affecting our view of the stars
Do you remember starry nights as a distant memory from your younger years? Your mind isn’t playing tricks on you. Light pollution has affected our view of the stars dramatically over the last decade.
Number of stars visible is rapidly reducing

A study, published in the journal Science, revealed light pollution is rapidly reducing the number of stars visible to the naked eye.

 

 
12 year study
The study is the conclusion of 12 years of astronomers and citizen scientists going out at night to count the stars, as part of a project called Globe at Night.
Photo: Greg Razoky/Unsplash
Matching star charts with a patch of sky

Participants were asked to use a website to view a selection of star charts for their location, each showing an incrementally greater number of the stars that exist in that patch of sky and pick the chart that best matched what they could see.

Model that related visible stars to the brightness of the sky

The researchers then created a model that related the number of visible stars to the brightness of the night sky.

Photo: Rad Pozniakov/Unsplash

10% increase in sky brightness every year

The change in stars' visibility that people reported by submitting their star counts was equivalent to an almost 10% annual increase in sky brightness every year.

Star visibility reducing significantly

That means, the scientists say, that a child born in an area where 250 stars were visible, would probably see fewer than 100 stars in the same location 18 years later.

The future might be starless

“If these trends continue, eventually it will be very difficult to see anything at all in the sky, even the brightest constellations,” said Dr Christopher Kyba, author of the study.

Photo: Jack B/Unsplash

Population growth and new technologies have increased light pollution

The study’s authors said that the glow produced by artificial lighting grew exponentially over the 20th century with population growth, new technologies, and expansion of towns and cities.

Photo: Jacek Dylag/Unsplash

Many cities have changed their lightning to modern LED
Although in recent years, many urban centres have changed their older lighting to modern LEDs that are more energy-efficient, light pollution is still increasing.
The lighting paradox

According to a 2022 study by the European Space Agency, the relatively low cost of LED lighting is also contributing to the problem. They described this as a "lighting paradox".

Photo: Du Wei/Unsplash

Ironically, the LED revolution has led to a light pollution increase
“While the LED lighting revolution promised to reduce energy consumption and improve human vision at night, overall light pollution has increased,” said the agency.
Photo: Griffin Wooldridge/Unsplash
The cheaper the lighting, the higher the addiction
“Paradoxically, the cheaper and better the lighting, the higher society's addiction to light," they added.
Photo: Dennis K./Unsplash
Light pollution affects human health
Furthermore, light pollution has been shown to affect human health and disrupt sleep patterns.
Photo: Campbell/Unsplash
Light pollution also affects animals

It also affects the behaviour of some nocturnal animals, with one recent study linking light pollution with local insect decline.

Photo: Erik Karits/Unsplash

 
There is still room for improvement

However, the study’s authors said that there is room for improvement and we can all contribute as individuals to reduce light pollution. Here’s how:

 

Keep the blinds closed at night

After the sun sets, try to get in the habit of using window shades to keep room lights from escaping your house, as it contributes to the light pollution outdoors.

 
Use Night Shift settings on all devices

After dark, the bright lights of our screens are not needed, so switch to a dimmer night setting. It’s also good for our eyes.

 

When outside, point your light towards the ground

When using flashlights or headlights outside to illuminate your way, always try to point them down to the ground. Believe it or not, pointing that tiny ray of light upwards does contribute to light pollution.

Let your eyes adjust to less light

Many of us are used to absentmindedly turning on the lights full blast after the sun sets, but that’s not at all necessary, as our eyes can adjust rather nicely to low-light settings.

Other things we can do to reduce light pollution

Using candles instead of lamps, not driving at night, turning off lights when not absolutely necessary and unplugging from our tech devices after the sun sets, are all ways in which we can contribute to reduce light pollution.

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