Satellite data reveal alarming light pollution rise
Satellite images showed that the artificially lit surface of our planet grew by 2.2 percent per year in both size and brightness from 2012 to 2016, according to the study in the U.S. journal Science Advances.
The findings, released this week, were based on data from the first-ever calibrated satellite radiometer designed especially for nightlights, known as Visible Infrared Imaging Radiometer (VIIRS), which is mounted on a U.S. satellite that has been circling our planet since October 2011.
Globally, the increase in light emission closely corresponds to the increase of the Gross Domestic Product (GDP), with the fastest growth occurring in developing countries.
Still, researchers noted they may underestimate the problem of light pollution, because the VIIRS instrument used in this study can not "see" light at wavelengths below 500 nanometers, something called "blue" light, which humans can see.
"Earth's night is getting brighter. And I actually didn't expect it to be so uniformly true that so many countries would be getting brighter," Christopher Kyba from the GFZ German Research Centre for Geoscience, who led the study, told reporters at a news teleconference.
The study found that lighting changes varied greatly by country, far exceeding the global rate in some cases, and with decreases in radiance in only a few, such as war-torn Yemen and Syria, said the study.
In some of the world's brightest nations, like the United States and Spain, radiance remained stable, while for most nations in South America, Africa and Asia, it grew, it said. ■