A team of international researchers have found that the increasing use of energy efficient lighting systems, such as LED bulbs has rapidly increased the light pollution in the planet. Since, with LED, lighting has become cheaper, more people are using the lights with increased frequency, even when not needed.
The study was published in the journal Science Advances using data from the Visible Infrared Imager Radiometer Suite or the VIIRS, which is located in the Suomi-NPP satellite. Data from 2012 to 2016 was taken to do the research.
What is Light Pollution?
If you have not heard of light pollution before, light pollution generally refers to the presence of too much artificial light in the environment. Light pollution has been linked to health issues, problems and in the ecosystem, and also has harmed the aesthetics of urban environments.
Light pollution can be clearly seen during nights. Even on a clear night, stars are barely visible because too much light from vehicles, street lighting or even homes are scattered in the atmosphere.
Looking Down on Light Pollution
The research on light pollution, this time, was different since the researchers directly used satellite data and looked down at earth instead of looking up at the night sky. The brightness of the night sky is also a way to measure the light pollution of the area, but this time, the researchers decided to look down instead of looking up.
The VIIRS does not sense blue light – something a lot of LED lights give out. However, from the data, lead researcher Christopher Kyba, who is originally from Alberta and is now a physicist at the GFZ German Research Centre for Geosciences, said
“What I had expected to see was that in wealthy places countries — the United States, countries with a lot of lighting, Italy — cities were going to be changing to LED and that would make them look darker,” Kyba said. “But it turns out the United States stayed flat, and other countries like Germany became brighter. That means that the increase is actually even larger than what we report here.
“Somewhere else, there’s new light.”
Over the last four years, the artificially lit surface of the Earth has increased by 2 percent annually, making it about 9.1 percent in total. This is not a problem with the urbanized regions in the West, but also elsewhere in the world.
New street light installed in south-end Halifax ended up being so bright that residents complained that it was like living in a Walmart parking lot. On the other hand, the city of Montreal had to change thousands of street lights since the former colour of the LED bulbs were closer to the colour of the daylight. Hence, they had to get bulbs with warmer colours so that it does not disrupt the natural processes of the eco-system.
When something is mass produced, we often end up using it way more than it is needed. Energy efficient lighting systems are just one such example. A study also found that increasing GDP of a country directly affects the light pollution. Therefore, developing countries such as India are reporting the highest increase in Light pollution.
Consequences of Light Pollution
Light pollution has far-reaching consequences, even though not apparent. It has been linked to potential risk factors for various health issues, including cancer.
Martin Aubé, from Quebec’s University of Sherbrooke, said
“I am concerned about the fact that we now have scientific evidence that the light at night and especially the white light [that contains blue by definition], is linked with many health issues like breast and prostate cancers and sleep disorders,”
Aubé studies light pollution and were not involved in the research paper that was published. Light pollution also has major effects on wildlife. This includes migratory birds flowing off course and crashing into buildings. They have also disrupted the nesting habits and the sea-finding habits of the turtles.
The problem is not the efficiency of LED light bulbs, but their overuse. Cities and municipalities overuse the lighting because the LED lighting is cheap. Even though LEDs cost more than incandescent bulbs, they are way more efficient, making them a cheaper option in the long run.
However, using too much light is a major problem. In 2016, Kyba was also involved in a research forming a new world atlas that illustrated the night sky brightness. That study, published in the same journal, showed that the Milky Way is hidden from more than one-third of the humanity.
Those who are studying light pollution are also trying to optimize lighting systems by making more diffused lighting, including full cut off lighting and reducing blue-light emission. New LED lighting products are coming with better diffusers that enable light to spread more evenly.
At homes, using warmer and low wattage lights at night can improve sleep. Since luminance of LEDs does not reduce over time as much as fluorescent lamps, lower wattage LEDs can provide consistent luminance over a longer time.
Source: CBC Canada