Bochum.
A Bochum researcher warns that light pollution from street lighting or illuminated facades is increasing drastically. stars fade.
The light pollution at night sky is increasing much more than previously expected and is causing star visibility to drop drastically. This is the result of an analysis published in the journal “Science”, for which scientists use the observations of 51,351 people – especially in Europe and North America – between 2011 and 2022.
The researchers around Christopher Kyba, expert at the GFZ German Research Center for Geosciences in Potsdam and the Ruhr University Bochum, were surprised and concerned. “The speed at which stars are becoming invisible to people in urban environments is dramatic,” Kyba pointed out.
Bochum researchers Kyba: 9.6 percent more brightness every year
Light pollution refers to the artificial brightening of the night sky by light sources such as street lighting, illuminated facades, buildings, parks or illuminated digital advertising spaces. Stars are hardly or not at all recognizable in the brightened sky. The researchers have now found that the sky brightness increases by 9.6 percent per year on average worldwide. For Europe resulted 6.5 percent more brightness per yearfor North America an increase of 10.4 percent.
If we stay with the global average of 9.6 percent more brightness in the sky every year, this means that a child who is born in a place where 250 stars are visible at birth will be there on its 18th birthday only 100 stars left can see, according to Kyba. “I hope that the trend doesn’t continue, that there are more countermeasures. It’s up to us.”
Light bell over conurbations like the Ruhr area
The scientists warn of serious consequences for the environment. Lots behaviors and physiological processes of living beings are determined by daily and seasonal rhythms – and thus influenced by light, explained the US co-author Constance Walker. “The skyglow affects both diurnal and nocturnal animals and also destroys an important part of our cultural heritage.”
The association of star friends – members are amateur astronomers, public observatories and also planetariums – pointed out that even today in densely populated regions the View of the starry sky almost impossible with the naked eye. In conurbations such as the Ruhr area and in metropolitan areas, “unfortunately, you can only see disappointingly little,” said Andreas Hänel. The light bell of Berlin is so far-reaching that it can be seen up to 80 kilometers away. There are more and more local projects and measures to artificial light to reduce, but they were not sufficient.
Artificial light disrupts production of the hormone melatonin
The association demanded that environmental protection must also include the sky. The legislature has light immissions identified as a problem and included in the Federal Immission Control Act, reported Hänel. However, binding limit values are needed. The environmental organization BUND also warned of negative effects on the ecosystem, on flora and fauna. In humans, a disturbed day-night rhythm as a result of increasing nocturnal lighting can suppress the production of the “sleep hormone” melatonin and cause sleep disorders.
According to Hänel, the regions with a dark sky and still a good view of the stars include the Eifel, Rügen or the Mecklenburg Lake District. However, he believes that there is a need for even greater awareness, significantly more light savings and uniform regulations for public lighting. (dpa)
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