Earth Hour - a signal for climate action

Source: NASA 2016

The international Earth Hour always takes place on the last Saturday in March. Then it's "lights out" again for one hour. This is a global signal for climate action and against light pollution.

Too much light has a negative impact on the environment - here are some examples:

Artificial light sources influence nocturnal life at night. For millions of years, life has been determined by light cycles, including the daily change between day and night. The increasing artificial illumination of the night has serious consequences for the life of humans, animals and even plants.

Insects: However, our cities and streets are getting brighter and brighter. Especially nocturnal animals like insects suffer from this. Insects, whose original orientation is based on moonlight, can no longer find their way around. They are attracted to light sources and die from injuries, exhaustion or as easy prey for spiders and bats.

Researchers have found that on a summer night in Frankfurt alone, up to 150 insects can die at a streetlight. With about 7 million street lamps in Germany, that's over a billion insects every night. This does not include dead insects on illuminated advertising spaces, car headlights, industrial lighting etc. This large quantity of insects is missing as a food source for other animals.

Migratory birds: They also use the starry sky to determine their course. However, too much artificial light over cities makes it difficult for them to find their way. They often fly detours that put an additional strain on their energy reserves. Likewise, the risk of dying at illuminated window panes increases noticeably.

Sea turtles: After hatching, the small turtles head straight for the sea. They normally orient themselves to the brightest part of their surroundings, i.e. the bright horizon above the sea. On illuminated beaches they lose their orientation, get lost on dunes or are run over on roads.

In our Grzimek House you have the opportunity to learn more about the impact of the phenomenon "light pollution".