Now when spring is approaching, or already here, with increasing light, it feels strange to mourn the diminishing of darkness. It is not the changes in light through the natural cycles of the seasons that is dimin fishing, but our ability to witness it fully due to manmade artificial illumination. In the Darkness Manifesto – Why the world needs the night, first published in Swedish as Mörkermanifestet (2020), Johan Eklöf describes the many ways that the diminishing darkness is detrimental to plants and animals and whole ecosystems. His main topic is bats, which of course are night creatures, but many insects, too, and the plants they pollinate are dependent on darkness. Especially the disappearance of the stars and the night sky in many places, for human eyes, stayed in my mind. And the need for some time of darkness or semidarkness for human eyes to get accustomed to seeing in the dark, which takes place with different receptors than the ones distinguishing colours in bright light. One can actually see quite a lot at night outdoors, in areas without streetlights, provided one does not use a torch, which blinds those other receptors. One has to get quite a distance outside the city, to get rid of all human lights that are reflected in the clouds. I remember walking on Örö Island in the dark and experiencing the feeling of total darkness around the bright light of a torch, in contrast to walking in twilight, letting the eyes adjust to the darkness slowly.
The book consists of short chapters and is written, and translated, in a reader-friendly way. The only chapter I have marked is called False summer, and deals with the problems plants face when illuminated, like illuminated trees in cities, which do not shed their leaves in autumn. Eklöf tells about the poet Robert Hunt (1807-87), with one foot in art and the other in science, who studied photography and “discovered that different parts of the light spectrum affected plants in different ways. The shorter wavelengths of sunlight, the blue and violet light, are usually the ones signalling to seeds to germinate, while redder light with longer wavelengths normally initiates the flowering phase.” (p 83) The ‘phytochrome’ pigments or proteins that control this process were discovered only in the twentieth century. (ibid). The context affects how they react, of course, and “plants react to both intensity and colour”. (ibid) LED lights are usually white or bluish, resembling morning sun, while older streetlights are more yellow like afternoon light. When specific plants do not bloom at their usual time because of the lights, they do not attract the usual insects, which do not provide food for the birds that usually feed on them and so on in a detrimental chain reaction. The book is full of concrete examples from various parts of the world, including the sea, but the main point is clearly to wake us up to protect darkness and to be careful with the light we so easily spread around also when unnecessary. Like pollution and smog can dim the sun, light pollution hides the starry sky and deprives us of the experience of the immensity of the universe.
 
Johan Eklöf: The Darkness Manifesto – Why the road needs the night Vintage. Penguin Random House 2023