The Milky Way has become hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Scientists have known since 2023 that the night sky is getting 10% lighter every year, but until regulations are put in place around artificial light installations in every city, the conversation around light pollution will still be necessary.
I remember a time in my childhood when I could see the stars through my bedroom window, dozens of tiny lights glittering in the night sky. I loved it, it made leaving the blinds open worth the trouble of being woken up early by the always intrusive sun. It’s a nostalgic image for many Gen Zers and an image that Gen Alpha may never again see.
So what is light pollution?
Light pollution is one of the many environmental pollutions affecting our lives: it refers to human-made alterations to outdoor light levels, mostly noticeable when looking at the night sky.
It comes in many forms, like sky glow, light trespass, glare, and over illumination. Sky glow is the bright halo that appears over urban areas at night thanks to light being scattered by water droplets or air particles. Light trespass happens when unwanted artificial light from adjacent property’s street lights reach an area that would otherwise be dark. Glare is created by light that shines horizontally instead of vertically, and overillumination is perhaps the most important term, meaning keeping artificial lights on beyond their normal reasonable use.
You can find a map showing global light pollution here.
Why should you care?
There’s multiple reasons why this is a big deal for Gen Z and Gen Alpha. The effects of light pollution go beyond a minor annoyance to people who enjoy stargazing, it’s a legitimate modern issue.
The big one: the environmental impact
Gen Zers consistently show admirable care towards the environment, from boycotting big brands with unethical sustainability practices, to volunteer beach cleaning campaigns and calling for regulations on AI. But somehow despite its horrible environmental impact, light pollution has stopped being a part of the sustainability discussion over the years. Many don’t recognize the extent of light pollution’s impact, with third-year University of Bristol student, Freya, saying she considered the issue “minor” and wasn’t aware of “any actual dangers” caused by light pollution.
Fabio Falchi, professor of Physics at Istituto Superiore E. Fermi Mantova, and Salvador Bará, former professor at Universidade de Santiago de Compostela, are some of the researchers who have published most extensively on the impacts of light pollution. Most importantly, they’ve reported that certain species of prey animals are expected to face the danger of local and global extinction as a result of the increase in artificial light. Most sea turtle species lay eggs on beaches, with females choosing to nest in the same beach they were born in for decades after. Thanks to artificial lights being set up at these beaches, sea turtles end up disoriented, often wandering onto nearby roadways, which risks their own lives and stops them from nesting. This disorientation is likely to contribute to dehydration and exhaustion in hatchlings as well.
Other researchers have found that light pollution is affecting the interactions between plants and pollinators, changing the time of year trees bloom, and is detrimental to insects’ developments which in turn damages various ecological processes.
Still in progress research: human health
There’s much less conclusive reports made about the effects of light pollution on humans, it’s a developing area of research which receives lower funding than it deserves. Having said that, there are enough studies to justify further research and plenty to justify regulating artificial lighting.
Most animal species (including humans) are facing a decline in their melatonin production, a fundamental hormone that controls the internal circadian clock, leading to sleep disturbances as well as mood and cognitive issues. These sleep disturbances and reduction in melatonin are suspected to be the core cause of various other health concerns particularly in women.
For example, a study from 2008 that used satellite photos to gauge the level of nighttime artificial light overlaid with a map detailing the distribution of breast cancer, found that “women living in neighborhoods where it was bright enough to read a book outside at midnight had a 73% higher risk of developing breast cancer than those residing in areas with the least outdoor artificial lighting.”
What can you do?
Perhaps the most effective method would be for city or state laws to tackle light pollution, it’s not unheard of. For example in 2001, Flagstaff became the first recognized Dark Sky City with their rules regulating the location as well as how much and what type of light could be used.
But expecting these regulations globally may be unreasonable and in the meantime here are some steps you can take to reduce light pollution, ranked from the easiest to the most demanding.
- Reduce the number of external lights you have at home.
- Reduce the intensity of lights you use inside and outside of your home.
- Use warm lighting that is proven to be less damaging than white light.
- Replace your lights with more optimally designed lamps to avoid excessive lighting.
- Get involved with DarkSky through local chapters, advocacy, community improvement and donations.Â
Every little step counts. Let’s build a future where we can see the stars.
