Published: Пн, Ноября 27, 2017
Research | By Jennifer Evans

'Light Pollution': Earth's Night Skies Are Greatly Enveloped With Artificial Lighting

'Light Pollution': Earth's Night Skies Are Greatly Enveloped With Artificial Lighting

The findings, described in the journal Science Advances, track what researchers called a worrisome trend that has implications for the environment as well as human health.

"I think we can provide for all the legitimate human needs for light at night.in a way that doesn't result in all this excess light leaving in the form of pollution", Barentine said.

Thanks to electric lights, outdoor lighting grew at a rate of 3 percent to 6 percent annually in the second half of the 20th century.

This graph illustrates the changes in the artificially lit surface of Earth at night.

"In the longer term, perhaps the demand for dark skies and unlit bedrooms will begin to outweigh the demand for light in wealthy countries", the team of authors wrote.

Australia's lit area decreased due to wildfires.

Also on the rise is the spread of light into the hinterlands and overall increased use. It can affect plants and even microbes and could already be harming vital interactions between species, such as the pollination of plants and spreading of seeds by key nocturnal creatures.

The Arizona-based International Dark-Sky Association's executive director J. Scott Feierabend said the study "validates the message IDA has communicated for years" about the hazards of artificial night lights.

The latest findings which appeared in the journal "Science Advances" suggests that a surging light pollution is threating nocturnal life across the globe as the distinction between day and night will disappear in the most heavily populated countries anytime soon.

Researchers only analysed night-time lights during the months of October, to avoid any increase from holiday lights. They found that over that time, Earth's artificially lit outdoor surface grew by 2.2 percent each year, and the total radiance grew by 1.8 percent per year.

An analysis of satellite images has shown light pollution has increased by 2% a year from 2012 to 2016.

"With few exceptions, growth in lighting occurred throughout South America, Africa, and Asia", said the report. This satellite has an instrument that gives scientists a more reliable way to measure nighttime light than they've had in the past. However, the problem isn't with the lights themselves - but the fact that the world is getting brighter because LEDs are illuminating places we didn't bother to light before. The white LED light is associated with disrupting the sleep patterns and its glare could affect eyesight. The combination of losing the infrared signal and not being able to see the blue wavelengths means that VIIRS registers this areas as dimmer, even though they may be brighter than they were before.

"The areas that are getting brighter rapidly are developing countries", says Christopher Kyba, a researcher at the German Research Centre for Geosciences in Potsdam. But Kyba says lots of places in this country are switching to LEDs for light, and this satellite can not detect all the kinds of light that LEDs put out.

However, not all satellites can detect blue light generated by some LEDs, which makes the scientists believe light pollution is far worse than thought.

People also need to raise a question that their hypothesis, for instance, that night lights make the world safer.

Around the world, more lights keep being switched on. There also are ways to position and manage existing light sources - say, the lamps in a parking lot - so that they are not as bright but still are effective.

On a global or national scale, all this wasted light is expensive, he says: "It costs a lot of money to radiate that light into space and it's not doing anybody any good".

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