Companies and households worldwide update their lighting systems to save energy, make streets attractive after dark, and improve urban living. Most people are doing so because of light pollution, too. According to UN reports, it is estimated that around 68% of us will live in towns and cities by 2050, which means giving rise to additional 460,000 square miles of forest encroachment for our planet to be urbanized. Sharing this space with wildlife, birds, and insects puts their life in danger as harsh, bright lighting disturbs the circadian rhythms of animals and people alike. So, the most efficient option is to look out for lighting solutions that ensure safety for the residents, wildlife, and the environment.
A similar initiative was taken in one of the best universities of Germany, where a bike path was built with infra-red sensors linked to LED luminaires to dim the light when cyclists were not using the path, ensuring a dark night-time environment for the surrounding wildlife. Such dimmers and sensors are installed to closely control the level of artificial light so that the disruption to wildlife is minimal or negligible.
Along with these monitoring controls, having the correct fixture and light is also important because the large amounts of blue light present in both LEDs and metal halide lights have been reported to be harmful to wildlife and human health. Therefore, the IDA has recommended using lighting that has a color temperature of 3,000 Kelvins or lesser. Thus, it’s essential to limit the amount of blue light emitted and avoid maximum brightening of the night sky so that animals feel at ease.
Lighting options typically include low-pressure sodium (LPS), metal halide, light-emitting diodes (LEDs), and high-pressure sodium (HPS). Out of all these, LPS lights are the most efficient as they emit only a narrow spectrum of soft yellow, amber, or pumpkin-colored light. It is dimmer than the blue-rich and bright white bulbs, which can be three times more disruptive to wildlife than soft amber light. Thus, these are adopted more in environmentally sensitive areas. HPS lights, on the other hand, are commonly used for street lighting in many cities and towns.
LED lights were expected to increase their sales by 69% by the last year 2020. This demand for LED lights is because they have many uses, conserve energy and last longer than other lamps. But the real question is if LED lights are saving energy at the cost of wildlife?
A research scientist concluded that “Predators use light for hunting, and prey species use darkness as cover.”
Sea turtle hatchlings leave beach nests at night and follow artificial light instead of skittering to the ocean. Similarly, such lights also attract migrating fishes, exposing them to predators. Increasing endangerment of insect species has also been linked to increasing light pollution. This also affects the migratory course of birds as they can wander off at night if they are unable to differentiate moonlight from artificial streetlights.
But still, it is argued by researchers and scientists that as long as streetlights are not pointing downward into a sensitive habitat, the directionality of LED streetlights can be an improvement in terms of wildlife impacts.
Perhaps, it’s always better to opt for safer and greener methods for streetlight generation. One of the most effective is solar energy run streetlights like Intelizon’s Zonstreet+, an advanced version of street lighting with an in-built lithium-ion battery, smart charge controller, and motion sensor. This helps to control the variation in light intensity and optimize the power consumption to give a higher battery backup.