Protect our Night Sky

We don’t need to turn off all the lights. We just need to use light more efficiently.

Read more about light pollution, its effects, and how we can reduce it.

What is Light Pollution

The inappropriate or excessive use of artificial light at night (ALAN) is known as light pollution and can have serious consequences for humans, wildlife, and our climate.  The sources of light pollution come from exterior and interior building lighting, advertising signs, streetlights, and illuminated sporting grounds.

Components of light pollution include:

• Glare – excessive brightness that causes visual discomfort
• Skyglow – brightening of the night sky over inhabited areas
• Light trespass – light falling where it is not intended or needed
• Clutter – bright, confusing and excessive groupings of light sources.

A lot of outdoor lighting used at night is overly bright, poorly targeted and improperly shielded. This light, and the electricity used to create it, is being wasted by spilling it into the sky, rather than focusing it on to the actual objects and areas that people need to illuminate. Check out this quick one page infrographic for a good visual of poor lighting compared with responsible lighting.

The best news is that unlike air, land or water pollution, light pollution can be instantly corrected with a few careful adjustments.  Find out how you can help in a few easy steps

John Hernshaw talking about light pollution:

Effects of Light Pollution

On our night sky, our ecosystem & our health

For three billion years, life on Earth existed in a rhythm of light and dark that was created solely by the illumination of the Sun, Moon and Stars. Artificial lights have enabled us to change the natural day-night pattern and shifted the delicate balance of our environment. The negative effects of the loss of this inspirational natural resource might seem intangible but a growing body of evidence links the brightening night sky directly to measurable negative impacts including:

1. Disrupting the ecosystem and wildlife
2. Harming our health
3. Increasing energy consumption
4. Affecting crime and safety

1. Disrupting the ecosystem and wildlife

Like humans, plants and animals possess a body clock that regulates rhythms of activity throughout the day and across different seasons. Specific problems with artificial light at night affects ecology and wildlife, by disrupting the following: 

• Successful pollination of trees and plants  
• Predator-Prey relationships  
• Insects mating, pollination and survival affecting crop success , bird survival and insectivores food supply  
• Bird migration and flight patterns 
• Land and Marine Mammals – feeding, prey distribution and territoriality 
• Plants and Trees – pollination patterns 
• Wetland habitat – amphibians, such and frogs and toads 
• All nocturnal behavioural patterns including mating, reproduction and population survival.  

Hutton’s Shearwater (tītī)

The only place in the world that the endangered and endemic Hutton’s shearwater (tītī) breed is high in the Seaward Kaikōura Ranges at elevations between 1200 to 1800 m. These unique birds are very susceptible to artificial light at night and are prone to crash landing in and around Kaikōura, especially during the breeding season (September to April) when birds fly from their mountain colonies to the sea.

These flights take place at night and birds can become disorientated by the artificial light spill of the Kaikōura settlement which lies within their flight path. Often compounded by poor visibility weather conditions, birds mistake the lights for navigational cues and end up colliding with lamp or power poles and lines or just land prematurely within or around the township instead of the sea, predominantly along Kaikōura’s coastal roads. Once on the ground, birds are unable to take off again. As such, they also won’t budge for approaching cars and can end up as roadkill. They also can’t get away from cats or dogs and fall victim to predation. They need help to get some water under their feet and some wind under their wings to get going again. Most birds (except for those dying upon impact) have a good chance to survive if they get rescued, kept safe and released the following day onto water. We are very grateful to the dedicated work of the Huttons Shearwater Trust and the Kaikōura Wildlife Centre

2. Harming our health  

All artificial light at night should be used with care, respect and restraint. Light acts like a pharmaceutical drug on the body and it impacts every system. We’re putting our health at risk by something known as Circadian disruption and are only just beginning to understand the consequences. When we’re exposed to artificial sources of blue light outside normal daylight hours it can disrupt our body clock. This can make it hard to sleep and function well. It can also cause negative flow-on effects to our health.

Specific problems with blue light are not widely recognised yet but include the following well documented examples in humans:. Prolonged exposure to blue/white lighting may show increased: 

• Disrupted circadian (day/night) rhythms  
• Disrupted sleep and subsequent health deterioration  
• Permanent damage to the retinal ganglion (computer screens & mobile phones)  
• Stress affecting mental health (nightshift workers)
• Adrenal stress.

Fortunately there are very easy actions you can take to help:

1. Be exposed to daylight in the morning and darkness at night for better circadian health and wellbeing.
2. Limit blue light exposure from digital screens including smartphones, televisions and computers at night by reducing screen brightness, using night-time apps that lower blue light output or turning devices off. (Visit our useful apps section).
3. Replace cooler/brighter blueish-white lightbulbs with warmer coloured yellowish-white lightbulbs.

3. Increasing energy consumption

Lighting that emits too much light or shines when and where it’s not needed is wasting energy and therefore your money. Quality lighting design reduces energy use and therefore energy dependence. It also reduces carbon emissions, saves money and allows us to enjoy the night sky better. 

4. Affecting crime and safety

Outdoor lighting is intended to enhance safety and security at night, but ironically too much bright lighting can actually have the opposite effect. Visibility should always be the goal. Glare from bright, unshielded lights actually decreases safety because it shines into our eyes and constricts our pupils. This can not only be blinding, it also makes it more difficult for our eyes to adjust to low-light conditions.

There is no clear scientific evidence that increased outdoor lighting deters crimes. It may make us feel safer but has not been shown to make us safer. A dark sky does not necessarily mean a dark ground. Carefully considered lighting that directs light where it is needed creates a balance between safety and starlight.

View our responsible lighting guidelines for lighting suggestions.

How you can help

5 simple steps to reduce light pollution

Each of us can easily implement practical solutions to reduce light pollution by following the International Dark Sky Association 5 Principles for Community Outdoor Lighting:

1. Useful – Install lighting only when and where it’s needed.
2. Low Light Levels – Light should be no brighter than necessary.
3. Targeted – Shield your lights so they shine down on the ground, which reduces harmful glare and decreases skyglow.
4. Controlled – Use controls such as timers, dimmers, and motion sensors on outdoor lights.
5. The Appropriate Colour – Use warm colour lights where  possible. Limit the use of harmful  blue wavelength lighting.

Short animated video showing the effect of night light on nocturnal animals and easy solutions