What is light pollution?

This page has been reviewed and updated on 21.09.2021 by Michael Nolle.

Light Pollution is caused by badly designed, wrongly installed, or simply too bright lighting fixtures. This is a waste of money and energy and is also harmful to the environment and human health.

It is a danger to vehicle drivers and can be an eyesore. On the other hand, good lighting saves money and energy because the light which is emitted serves its purpose well. It illuminates well and gives life to our streets. So, what are the effects of light pollution? There exist various negative aspects of light pollution. Amongst these, one can mention:

Glare – This is something that we should always avoid. Around Malta and Gozo, one can see many bulbs (especially floodlights) that create a lot of glare and are a continuous hazard to vehicle drivers. Architectural lighting, which is too bright, gives an ugly impression of a building which is being lit up. Additionally, it impedes one from appreciating its architectural beauty.

Waste of energy – It is important to understand that a wastage of light means wastage of energy and money which we used to generate the very same energy we needed in the first place. This means that we will be unnecessarily increasing atmospheric pollution as well desecrating our resources.

Light trespass – Very often we encounter lighting (especially floodlighting) which does not only light up where illumination is wanted but all the areas around! A typical case is the lighting from a football ground. Misfortunate are those whose residence is besides a ground with wrong floodlighting! But also lighting from residential building can give rise to light trespass and nuisance if not installed and used with consideration.

Skyglow – Light, which is either directly or indirectly emitted in the sky gets scattered by particles, droplets and molecules in the atmosphere. This produces that unsightly glow in the night skies, which strongly reduces the visibility of stars and other faint objects. Look at the sky from your village or town. Take a look again from a dark locality and note what a huge difference there is! Some countries like Chile and Portugal use their skies to draw tourists from other countries where light pollution has developed in such a serious problem that it hinders them from appreciating the beauty of our Universe. And certainly, our country has an immense potential in this area of eco-tourism.

Fortunately. in order to reduce and/or eliminating completely light pollution is not a difficult problem. The best way is to plan the lighting requirements carefully. Everyone needs light during the night and we’re not saying that we have to switch off or remove essential lighting. The right proceedings are to be take care of essential light and choosing lighting fixtures that make sense. It would be appropriate then to ask these questions before installing any type of lighting outdoors:

Is this lighting required? Can we make do without it? In the case of roads and streets the use of cat’s eyes and reflectors should be considered. These cost much less to purchase and nothing at all to run them!

Why do we need this lighting? Is it appropriate to leave the lights on all night long? Timers should be used so that unwanted light is turned off after midnight.

Lighting becomes a problem only if it is in excess or incorrectly installed. Do not use too much light.


One often finds floodlights that illuminate a large area with the sole excuse of security. Recent comprehensive and independent studies have shown that permanent lighting has little effect on security and crime rate. For domestic use, LED bulbs of 15W to 20W rating (which emits about the same amount of light like an 100W incandescent bulb) are absolutely enough. Any bulbs and lighting fixtures more powerful than this use up much more energy, produce much glare and reduce security rather than increasing it!

If “security” lighting is really needed, then one should make use of passive infra red sensors (PIR), which light up only when someone gets near. These offer much greater security because they shock trespassers. Turn off the light when you see that there’s no need for it.

Make sure that any type of light that you install, especially the one that is installed outdoors, is of the type called full cut-off. This type of lighting is purposefully made to reduce light pollution. Full cut-off lighting illuminates the ground where light is really needed and does not waste it by illuminating the skies. However, it is important to install these horizontally.

In the case of floodlighting, these should be of the type asymmetric or double-asymmetric, which helps to direct the light to the area needed without the need of tilting the floodlight. This also reduces greatly the amount of light pollution.

Globe Lighting in public gardens

Instead of usual globe lighting, make use of full cut-off lighting in order to reduce light pollution. Did you know that more than half of the light of globe lighting is wasted because it is discarded in the skies. This means that half of our money which we pay to light up the globes is being wasted because their light is not being used. Besides, globe lighting now gives a really old impression to a place because they are now out fashioned!

Reduce glare as much as you can from any type of lighting by limiting the angle of the light beam as much as possible. You can use higher poles to maintain smaller beam angles and reaching wider areas. When you light up billboards and other display boards, every type of lighting should be installed such that it lights up the billboard from above not the other way round. This is something which even the laws of our country emphasize upon. More knowledge can be obtained from the Planning Authority. The same applies when lighting churches and other buildings: make sure that the light shines from above.

Lighting in roads and streets is also a very important aspect. Lately, there are being used many traditional fittings. These look nice during the day, but during the night they don’t illuminate the area where light is needed. Often, we find that they throw more light in the homes of people than on the pavements and street themselves! It is for this reason that the Light Pollution Awareness Group recommends the use of full cut-off street-lighting everywhere, especially in residential areas. This reduces light from going inside houses from windows by illuminating the street instead where there is truly the need for illumination. In this way we have better illuminated streets.

Where to find more information

A excellent site with great information on light pollution is the International Dark Sky Association. You can find them at this link: https://www.darksky.org/

In addition, we recommend watching this 50-minute documentary called The Dark Side of Light by Christine Reiss-Suckow (Germany). Here is the link (opens in a new tab): https://www.cultureunplugged.com/documentary/watch-online/play/12429/The-Dark-Side-of-Light