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Expected to help the environment, the immensely popular, energy-saving, light emitting diodes (LEDs) have worsened light pollution. Because of reduced energy consumption, almost everyone on the planet transitioned to LED lighting. The savings in energy cost prompted people to put up more lights thinking that there will be no increase in their energy bill. The result is the proliferation of more LED lights that has made the planet brighter.

Light pollution is not something we often hear about, but scientists say it’s a problem that badly needs attention

A “brighter world” sounds like something that people need, but what’s wrong with it? Why are some sceintists getting concerned about all these LED-lighting?

Light pollution may sound strange especially that people are used to only hearing about noise, water, air and other kinds of pollution. How does light even pollute the earth? Studies show that excessive use of light has negative effects on the earth. Light pollution has several components to it that include illuminating inhabited aread called skyglow; visual discomfort caused by excessive brightness called glare; confusing light sources called clutter; and unintended light or what is known as light trespass.

Solid State, Low Energy

The use of the low-energy consuming solid-state lights shifted people’s concern from the light’s cost to the environment.

A team of scientists, led by Chris Kyba, a physicist from the German Research Center for Geoscience, conducted a study using satellite data to determine how brighter the nights on Earth have become. While the result of the study does not directly blame LEDs, they found out that there was a big problem: the widespread use of LEDs has created a rebound effect that made the planet too bright. 

The rebound effect shows that when people realized savings in their energy bills, they simply pour back the money into the product by buying more LED lights. This is the same rebound effect where people intuitively think they save money by using a fuel-efficient car, so they drive more miles. In effect, it increase rather than decrease their overall fuel consumption.

The cheap energy cost of LED lighting has prompted many jurisdictions all over the world to increase outdoor lighting. The dark sections of a park and the bicycle paths off the highways are now brightly illuminated. There is a widespread attempt to light every dark corner of the planet. The overall result is that the planet has seen a widespread loss of the night. Half of the European continent and a quarter of North America are now experiencing significantly modified light-dark cycles. Outdoor illumination is increased at a rate of three to six percent per year over the second half of the 20th century.

Illuminating the Study

The study used the Visible/Infrared Imager Radiometer Suite (VIIRS) onboard the Suomi NPP satellite of the National Oceanic and Atmospheric Administration.

Researchers limited the data collection to October to avoid the added illumination during the holiday season. The researchers analyzed the growth of light pollution from 2012 to 2016. They also observed an average increase in area illumination by an average of 2.2 percent each year. Areas that were continuously lit also became brighter by 2.2 percent each year.

Growth in illumination occurred mostly throughout Asia, Africa, and South America, with illumination declining in the war zones of Syria and Yemen.

The research finding looks serious but the reality could be worse. The satellite data did not directly detect the bluer wavelengths that many LEDs emit. This means that while the satellite data did not detect any increase in illumination in some countries, there is definitely an increase in brightness in terms of how the lights human eyes perceive light, which the satellite did not see.

The estimate is that by 2020, LED lights will account for about 61% of lighting in the global market