How much light is too much?
In 2017, the gene that controls the circadian rhythm was isolated in all species, from bacteria to humans.
Our internal clock.
Yes, the one about food and sleep; In fact, all our cells are organized based on these natural cycles.
Night and day, light and darkness.
Our planet shines 24 hours a day. The Earth is a bright ball of artificial light. Between 2011 and 2022, light pollution on Earth increased by 9.6% annually. The entire planet is in permanent jet lag.
And what are the consequences?
The excess of artificial light in which we live has increased insomnia, depression and even obesity: the hormone that controls appetite, leptin, works together with melatonin, the light-sensitive hormone that induces sleep.
We sleep less.
Yes, and that alters our circadian rhythms, affects our hormonal cycles and the immune system. Melatonin is activated by darkness, our heart rate slows down and our body temperature drops, from there many other processes necessary for our body are launched.
Ours and that of all living beings.
Yes, the same goes for the rest of the animals and plants. Furthermore, those that have nocturnal habits are displaced from the dark conditions in which they have evolved and in which they socialize, feed and reproduce.
We have driven out the inhabitants of the night with our light.
In Switzerland they have investigated moths and meadows at night. Because of the lighting, moths cannot do their work and pollination has fallen by 60%, and this affects all ecosystems and the entire planet.
In China, humans pollinate trees.
Yes, I saw those images: in Sichuan province several thousand workers climbed trees to pollinate flowers, doing the work that bees would have done.
But they no longer have bees.
An efficient worker is capable of pollinating ten trees a day. A small colony of bees pollinates a hundred times that amount. Light pollution is one of the main causes of the insect apocalypse we are experiencing. In some places, their populations have fallen by 70% in three decades.
Half of insect species are nocturnal.
They are guided by the stars and the moon, the brightest source of natural light in the night sky, until they encounter artificial light.
They swirl and die exhausted.
Even those that survive have not gotten their nectar and carried plant pollen, have not found a mate, and have not laid eggs.
It’s a sad ending.
Newly hatched sea turtles head toward land instead of toward the moonlit sea. Fooled by outdoor lighting, urban trees stay green longer than their rural counterparts.
Better in half light.
If we restore circadian rhythms in all animals, we will have healthier ecosystems. On the streets we can put motion sensors and timers so that the lights turn off if they are not needed.
That is being a city that thinks.
Less harmful light sources, such as red or yellow light, can also be used. There are many things that can be done without having to turn off the lights completely.
That would change even us.
Yes, we could see some stars, something unusual in cities. We believe that light makes a place safer, but studies show that crime has nothing to do with a bright or dark city.
And no one turns down the light?
In some places measures are already being taken. France adopted a national policy imposing curfews on outdoor lighting.
And dark sky tourism triumphs.
Countries around the world that have regions less polluted by city lights offer trips to stargaze or see the northern lights. There is something about the feeling of being small under the night sky that fascinates us all.
And how do we give the animals back their night?
We need to have some places with total darkness and use dark corridors and nature reserves for the well-being of animals and plants.
