Cities are constantly expanding and with them, the use of artificial light at night that prevents us from enjoying the stars.
There are more and more traffic lights for safety reasons and bright signs with advertisements. All this intensity of light generates a type of pollution and affects both human health and the environment.
Although we know that it is necessary to light up city streets and that terraces and balconies are not the right place to contemplate all the splendor that the night sky offers us with its stars and constellations, soon, we will not be able to see anything at all.
Scientists warn that the increased use of light-emitting diodes (LEDs) is causing a decrease in the visibility of the Milky Way and other bodies in the night sky. This situation is making them less and less appreciable and in about 20 years, the stars will be completely invisible to us at night in big cities.
Already in 2016 a study warned of the impossibility of contemplating the Milky Way with the naked eye for one in three people in the world. Currently, the situation is worse.
Fewer stars to see
According to a survey by the German Center for Geosciences, from 2011 to 2022, the night sky of cities artificially increased by 9.6% each year.
This increase in brightness worries astronomers because it poses a threat that could outshine most stars within 20 years. In other words, the next generation will be able to see less than half as many stars as the current one. Being more explicit, they warn that “a child born in a place where you can see 250 stars at night, at the age of 18, will only be able to see about 100”
“A few generations ago, people would have been regularly confronted with a brilliant view of the cosmos, but what was once universal is now extremely rare. Only the richest people in the world, and some of the poorest, experience it. For everyone else, it’s more or less gone.” said Christopher Kyba from the German Center for Geosciences.
However, the scientist assured that there are a number of things that can be done to reduce the growing negative impact of light pollution, especially on animal communities that inhabit cities and, of course, on people. One of those things is to make sure your outdoor lights have well-placed shades and point downwards, limit their intensity and make sure they emit an orange-red spectrum of light.
Human health is also affected by light pollution
In turn, Robert Fosbury, professor at the Institute of Ophthalmology at University College London, pointed out that bluish LED lights can affect our health because they do not have the spectrum of red and infrared light. This type of light affects our body, stimulating the breakdown of blood sugar and the production of melatonin, the hormone responsible for sleep.
“Since the introduction of fluorescent lighting and later LEDs, this part of the spectrum has been removed from artificial light and I believe it is contributing to the waves of obesity and the rise in diabetes that we see today.a,” explained Fosbury.
Artificial lighting also has negative effects on wildlife such as sea turtles, night-migrating birds and other creatures, experts have warned.
Another important fact is that a large number of insects, the main source of food for other animals, are attracted to artificial lights and, when they come into contact with them, they die immediately. This can pose a threat to the balance of the ecosystem.