More lights are lit every year around the world. A new study found that the number and brightness of artificial light sources at night are increasing at an alarming rate, affecting all over the world.

An analysis of satellite data for four years from 2012 to 2016 found that the global outdoor artificial lighting brightness increased by 2.2% per year, and the area illuminated by lights also increased by 2.2% per year. The research report was published in the journal "Science Advances". The main author of the report, Christopher Kyba, a member of the International Night Sky Association, expressed his shock at the result.

Kyba’s team analyzed data from 2012 to 2016 and found that the increase in brightness and the expansion of bright areas were mainly in Asia, Africa and South America, but there were a few exceptions in regions such as Yemen and Syria. Due to the escalation of conflict and war, the area There is a decline. Countries such as the United States, Italy and the Netherlands remained stable.

The International Night Sky Association is committed to combating light pollution. Light pollution not only makes astronomers complain, but city residents are also annoyed by the light coming into their homes through windows. Naturalists discovered that light pollution affects animals. The researchers added that light pollution affects the migration and reproduction patterns of birds, fish, amphibians, insects, and bats, and most shockingly human health.

One of the authors of this study, Frank Holker of the Leibniz Institute of Freshwater Ecology and Inland Fisheries in Berlin, said that this situation has reached a tipping point.

"Many people use light sources at night without really considering the cost." He said, "(not just the economic cost), but also the price you have to pay from the ecological and environmental point of view."

Researchers believe that, from a global perspective, LED has become a more energy-efficient and cost-effective light source. Kyba and his colleagues claim that LED lights save electricity, but they also encourage people to light more lights. Reasons for using LED lights include cost savings and reduced energy consumption, but this has led to an increase in demand and more use of LED lighting outdoors. This phenomenon is called the rebound effect.He said, “We will light up places that were not lighted up before, like bicycle lanes in parks, or road sections leading to the outside of the town, which have never been lighted up before.” “So, use all those After the new lights, to a certain extent, offset the energy you saved."

Kyba said that the problem of light pollution is not just related to LED lights. Kipa said the problem is that people are installing more and more LED lights. The team recommends avoiding the use of dazzling light bulbs as much as possible, choosing amber on the so-called white LED, and using a more effective way to illuminate places such as parking lots or city streets.

The American Medical Association (AMA) adopted an official statement on LED street lights last year, recommending to reduce the color temperature and brightness of this new street light.

The instrument on the U.S. meteorological satellite Suomi launched in 2011 provided the observation data for this study. NASA and the National Oceanic and Atmospheric Administration recently launched a second such instrument on a new satellite-the Visible Infrared Imaging Radiometer Suite (VIIRS). This latest VIIRS will facilitate continuous night lighting research.

Data obtained from Suomi Nuclear Power Plant Satellite