Light pollution, or light smog, is a phenomenon in which light from artificial light sources is scattered in the lower layers of the atmosphere. This process adversely affects human health and the state of nature: for example, disrupting the daily cycle of sleep of people and animals. Light pollution increases every year. An international group of scientists came to the conclusion that one of the reasons is attempts to reduce electricity consumption with the help of LED lamps.

Such lamps are considered to be one of the safest sources of light for the environment. They consume less energy than other sources. They do not use mercury in their production, so they are easier to dispose of without harm to the environment than fluorescent lamps. Also they last longer than other types of lamps.

Scientists analyzed the data of observations of the Suomi NPP satellite and traced the dynamics of the illumination of the Earth's surface. According to them, despite the widespread use of LED lamps and energy savings, the level of illumination is growing. In the period from 2012 to 2016, the number of illuminated areas grew by 2. 2% per year. Researchers called this phenomenon "rebound effect" (rebound effect): the more administration of the settlement saves, for example, on street lamps, the more money can be spent on lighting new areas.

Part of the radiation of traditional incandescent lamps lies in the infrared range, this part is recorded by satellite instruments.

Therefore, the territories illuminated mainly by LED lamps, on satellite images should appear "darker". Scientists expected that this will happen in pictures areas of developed countries, who have already switched to LED lights, but figures remain the same, but at some point rose. In the period from 2012 to 2016, the level of illumination in 59 countries increased by 110-150%, in 20 countries - by more than 150%. The indicator has decreased noticeably only in 16 countries. Most actively illumination grew in South America, Africa and Asia, notes naked-science.