International Dark Sky Week 2025 – Light Pollution

During the week of 21st April, the World has been celebrating International Dark Sky Week. But did you know that Light Pollution is rapidly on the rise. Disturbing nocturnal habitats, diminishing our stars and changing our relationship to the night.

International Dark Sky Week is a worldwide celebration of the night.

From the darkness needed for a restful night’s sleep to the activities we enjoy beneath the stars, the night plays a vital role in safeguarding healthy ecosystems and wildlife biodiversity, enhancing science and exploration, preserving cultural knowledge, and so much more. Unfortunately, artificial light at night is increasing. Due to this, dark skies worldwide are quickly fading, disrupting nocturnal habitats, diminishing our view of the stars, and changing our relationship to the night.

As a result, we encourage you to join us in celebrating International Dark Sky Week. Together, we can discover the night sky and learn more about the harmful effects of light pollution. Taking actions to embrace the dark and save nocturnal biodiversity.

Why celebrate International Dark Sky Week?

Light pollution is increasing at an alarming rate, nearly 10% annually. The time to act is now. By participating in International Dark Sky Week, you are helping to raise awareness and grow the dark sky movement. For many, the dark night is often misunderstood, unfamiliar, and frightening. However, the night is filled with wonder and awe. Like this goofy Badger who is having a good tummy scratch (see video below). Also, it’s critical to the health and well-being of our planet.

Join us as we discover the night together and learn about the harmful effects of light pollution and actions we can take to embrace the dark and save the night.

Video credit: North East Scotland Mammal Network

What is Light Pollution?

Light pollution is the human-made alteration of outdoor light levels from those that occur naturally. As lighting options become more inexpensive and brighter, we are illuminating the night more and more. Every eight years, light pollution around the world doubles! Today, 80% of the world’s population lives beneath light-polluted skies. 8 out of 10 children will grow up never seeing the Milky Way.

Components of light pollution include:

Glare — excessive brightness that causes visual discomfort
Sky glow — brightening of the night sky over populated areas
Light trespass — light falling where it is not intended or needed
Clutter — bright, confusing, and excessive groupings of light sources are the human-made alteration of outdoor light levels from those occurring naturally.

2024 Light Pollution Map for North East Scotland – Click to see World Light Pollution Atlas

Effects of light pollution

A growing body of evidence links the brightening night sky directly to measurable negative impacts on:

Photo Credit: North East Scotland Mammal Network

Isn’t it safer to have lights on at night?

Outdoor lighting at night doesn’t do what you think it does to reduce crime and increase safety. There is no clear scientific evidence that increased outdoor lighting deters crimes. It may make us feel safer, but it has not been shown to make us safer.

Poorly designed outdoor lighting can backfire on safety. Bright and misdirected lights create shadows for criminals to hide, and some crimes, like vandalism, thrive in well-lit areas. Floodlights, for example, may highlight potential targets. Research has also shown that street lighting may enable rather than hinder street crime.

Below is a video by The Dark Ranger explaining this a little better than we can. Trigger Warning: There is a slight jump scare at 0:16.

What can I do to reduce my light pollution?

Light pollution affects everyone. Fortunately, concern about light pollution is rising dramatically. A growing number of scientists, homeowners, environmental groups, and civic leaders are taking action to restore the natural night.

The good news is that light pollution, unlike many other forms of pollution, is reversible, and each one of us can make a difference! Just being aware that light pollution is a problem is not enough — we need to take action.

You don’t need to go completely dark to reduce your lighting (although we would prefer it if you did!). A 2019 study showed there is no difference in pollination success between part-night lighting and full darkness, highlighting the ecological benefit of switching off our street lights even for short periods in the night.

Here are some useful resources to learn how you can reverse your light pollution and start being smart with your lighting:

The Five Lighting Principles for Responsible Outdoor Lighting

How can I help nocturnal wildlife?

We can’t end this post without some resources and information on how you can help nocturnal biodiversity. The species that are affect the most by light pollution are moths and bats. But there are a few things you can do to help other species too. Well other than changing your relationship with your lights!