Preventing Light Pollution: Strategies For A Brighter Tomorrow

Light pollution is the human-made alteration of outdoor light levels from those occurring naturally. It has harmful effects on wildlife, ecosystems, energy use, climate change, and human health. It can also interfere with astronomy and our appreciation of the night sky. The good news is that there are many simple ways to prevent light pollution. For example, individuals can turn off unnecessary lights, use dimmers, motion sensors, and timers, and keep blinds and drapes closed at night. Institutions and governments can adopt measures to govern development around biodiversity and protected areas, and promote dark-sky areas.

Turn off lights when not in use

Turning off lights when they are not in use is one of the simplest and most effective ways to prevent light pollution. This is a habit that many of us were encouraged to adopt from a young age, and it's a great way to reduce overall light pollution as well as energy costs at home.

The negative impacts of light pollution are far-reaching. It severely disrupts nocturnal ecosystems, interferes with the natural rhythms of plants and animals, mars the wilderness experience and landscape beauty, carries risks to human health and safety, and wastes energy.

By turning off lights when they are not in use, we can help mitigate these negative impacts. This is especially important in areas with a lot of light pollution, such as urban areas, where the artificial sky glow from excessive lighting can spill over into neighbouring areas.

It's important to remember that indoor lighting can also contribute to light pollution. Unnecessary indoor lighting, such as in empty office buildings at night, should be turned off to prevent light leakage into the night sky. This simple action can make a significant difference in reducing light pollution and its harmful effects on the environment and human health.

In addition to turning off lights when not in use, there are other complementary practices that can further reduce light pollution. These include using fewer lights when inside, keeping blinds and drapes closed at night to contain indoor lighting, and using downward-facing lights to minimise the amount of light escaping upwards into the night sky.

Minimise blue light emissions

Blue light emissions have a significantly larger geographic reach than lighting consisting of less blue light. Blue-rich white light sources are known to increase glare and compromise human vision, especially as the eye ages.

To minimise blue light emissions, use warmer-coloured lights, such as low-pressure sodium (LPS), high-pressure sodium (HPS), or low-CCT LEDs. These lights have a colour temperature of 3000 Kelvin or below. The higher the colour temperature, the more blue light is emitted.

You can also use blue-blocking glasses when using electronic devices with screens. Apps such as F.lux, Lux, Twilight, and Night Shift (iOS) filter out blue light from the screen at night.

When using outdoor lighting, ensure that it is fully shielded. Full cutoff or fully shielded light fixtures control the direction of the light, aiming it at the ground and preventing any light from going directly towards the sky. This prevents sky glow, light trespass, and glare.

Use shielded light fixtures outdoors

Using shielded light fixtures outdoors is an effective way to prevent light pollution. Light shields, also known as light shrouds or glare shields, are accessories that can be attached to the top and/or sides of light fixtures. They help to focus the light downwards or inwards, preventing light from spreading in unwanted directions.

The benefits of using light shields include reducing glare and improving night vision for drivers and pedestrians. They also help to prevent light trespass, which is when light spills over into neighbouring properties. This can be particularly useful in densely populated areas, where light pollution is more likely to affect others.

There are different types of light shields available for various fixtures. For example, standard wall pack light shields are attached to the top of the fixture to direct light downwards, while shoebox or parking lot light shields can have back shields installed to prevent light from being distributed backward, keeping it focused on the parking lot or intended area. Stadium or sports field light shields can also be used to limit upward light pollution and sideways glare, ensuring that players and spectators can see clearly without the lights affecting gameplay.

In addition to using light shields, it is also important to consider the type of lighting being used. LED lights , for instance, are more directional than other types of lights, such as fluorescent or metal halide, and have a more focused light beam. This makes them useful for preventing light spillover. However, they often contain large amounts of blue light, which can worsen sky glow and negatively impact wildlife. Therefore, when using LED lights, it is recommended to use warm-coloured bulbs with a colour temperature of 3000 Kelvin or lower, as these have the least effect on the night sky.

Use dim red lights

Using dim red lights is an effective way to prevent light pollution. Red light is the weakest in the light spectrum, while blue light is the strongest. Blue light is the biggest contributor to light pollution, as it easily brightens the night sky and has a significantly larger geographic reach than other lights. It also has a negative impact on human health, causing sleep dysfunction and eye strain.

To reduce light pollution, opt for red lights with a colour temperature of 3000 Kelvin or below. These warmer lights have the least effect on the night sky. Warmer light sources include low-pressure sodium (LPS) and high-pressure sodium (HPS) lighting. When purchasing new lights, check the packaging for the colour temperature and look for the International Dark Sky Association (IDA) seal of approval. This ensures that the bulb is environmentally friendly and won't contribute to light pollution.

In addition to using dim red lights, you can also prevent light pollution by using covered bulbs that face downwards, minimising the use of lights, and using motion sensors and timers. These simple measures will help reduce sky glow and protect human health, wildlife, and the environment from the negative impacts of light pollution.

Minimise light use in general

Minimising light use in general is a simple and effective way to prevent light pollution. Light pollution is caused by the human-made alteration of outdoor light levels from those occurring naturally, and it has a range of negative impacts on wildlife, the environment, and humans.

To minimise light use, it is important to only use the lights you need. For example, instead of lighting up an entire room, focus on the specific area you need illuminated. This can be achieved by using shades or covers that force the light downward, reducing glare and improving night vision. LED lights are a good option for this, as they are more directional than other types of lights.

In addition to using fewer lights, consider reducing the duration of their use. For example, outdoor lights do not need to be on all night unless there are security concerns. Using lighting controls can help with this. Dimmers can reduce the intensity of the light, motion sensors can ensure lights only turn on when someone is in the area, and timers can control when lights turn on and off.

Another way to minimise light use is to avoid driving at night. Headlights contribute to the degradation of the night sky, and it is also safer to avoid driving if you have a lack of depth perception.

By following these simple steps, you can help reduce light pollution and its negative impacts.

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