Light pollution happens when too much artificial light brightens the night in the wrong places. It blocks our view of the stars, harms wildlife, affects our health, and wastes energy. Unlike the natural light of the Moon and stars, artificial light spills into the sky, into homes, and across the land where it isn’t needed.
It’s not just annoying.
Light pollution is stealing our night.
Across the UK, the glow of artificial light is spreading faster than ever. More than 80% of people now live under skies too bright to see the Milky Way. The chance to look up and see a sky full of stars – something our ancestors knew every night – is being stolen from us.
Our stars are disappearing: Children grow up never seeing the galaxy we live in, and the night sky that once inspired wonder, guided our ancestors, and connected us to the universe is slipping away. This loss isn’t just for astronomers – it’s ours, happening right here in our towns and cities. It’s more than just losing our stars.
Explore the hidden cost of losing our night sky.
Our wildlife: Countless species, from bats to birds to insects, depend on darkness to survive. Artificial light disrupts their feeding, migration, and breeding patterns, putting ecosystems at risk.
See what’s at stake for wildlife and the ecosystems that rely on the night.
Our health: Excessive light at night disrupts sleep, hormones, and mental wellbeing. Darkness is not a luxury, it’s a biological need.
Discover what lost nights are doing to our sleep, health, and wellbeing.
Our safety: oor lighting doesn’t always make places safer. It’s often found in deprived areas, while better-designed lighting is more common in gentrified ones. This creates inequality, leaving some communities with glare, shadows, and reduced visibility, conditions that can make people feel less safe, not more.
See how bad lighting can make us less safe, not more.
Our planet: Wasted light is wasted energy. Every beam shining where it isn’t needed adds to carbon emissions and climate change.
Uncover how wasted light is costing our planet and our future.
Sources of light pollution include building exteriors and interiors, advertising, commercial sites, offices, factories, streetlights, and illuminated sports venues. Sadly, much artificial light at night (ALAN) is inefficient, overly bright, poorly directed, or unshielded, and often unnecessary. Instead of lighting only what needs to be seen, it spills into the sky, wasting both energy and money while erasing our view of the stars.
How Bad is Light Pollution?
With much of the Earth’s population living under light-polluted skies, overlighting is an international concern. If you live in an urban or suburban area all you have to do to see this type of pollution is go outside at night and look up at the sky.
According to the 2016 groundbreaking “World Atlas of Artificial Night Sky Brightness,” 80 percent of the world’s population lives under skyglow. In the United States and Europe, 99 percent of the public can’t experience a natural night!
NASA Blue Marble Navigator
A growing crisis… but a shared solution and an easy win
It may feel overwhelming, but the good news is this: light pollution is the easiest kind of pollution to fix, because it’s instantly reversible.
When we switch off unnecessary lights, shield bulbs, or choose smarter lighting, we see the difference straight away. Together, we can restore the night, but only if we act now.
This isn’t just about policies or big decisions, it’s about us, in our homes, making choices that add up to real change.
Take action tonight – 5 simple steps to start right now
Light pollution can feel like a big problem, but change begins at home. Here’s how you can make an immediate difference:
- Use light only when and where it’s needed and always point it downwards.
- For safety, use motion sensors or timers instead of leaving lights on all night.
- Shield your outdoor lights (or angle them down) to keep light from spilling into the sky.
- Close blinds and curtains after dark to stop light escaping from inside.
- Become a citizen scientist – this helps measure light pollution and contribute to real change.
Learn more about outdoor lighting basics.
Want to do more?