As someone who always has to be mindful of not disturbing neighbours with excessively loud music, it often puzzles me how we have become so accustomed to minimising our noise levels and yet rarely lose a single thought to light pollution.
At night, the rays of artificial light can be as irritating as the noise of a construction site. Office buildings, shopping malls, advertising signs. They all light up the night sky wherever one goes. The brightness of cities in particular often reaches so far that no distance seems great enough to finally encounter a place of veritable darkness.
This problem is of course not limited to the Grand Duchy and affects our entire globe. Aside from oceans, deserts, and mountains, it seems impossible to escape the constant exposure to artificial night light. Even though the sun only manages to shine on half of the Earth at once, we still have accomplished to create a planet that never sleeps.
In light of the unfolding energy crisis and the war in Ukraine, undoubtedly the most concerning topics since Covid-19, it seems particularly questionable to have countless office buildings and shopping malls still light up our skies. But the thing that makes this problem stand out for me is that, for once, responsibility cannot possibly be put on private citizens, as only government institutions have the power to regulate or limit something as abstract as the use of artificial light at night.
But why is the presence and absence of light even that important?
Natural light as energy and information
First a look at the role of natural light in the lives of plants and animals. "Light is important to organisms as both an energy resource and an information source" (Gaston et al. 1258). For one, sunlight provides energy to plants practising photosynthesis. Even though this may not be a revolutionary insight, it should be mentioned that there are also animals relying on this technique, including salamanders, sea slugs, and even clams.
For another, sunlight, and also the absence of it, are crucial information sources for plants and animals alike. Sunflowers turn their heads along the movement of the sun (hence the name), nocturnal animals use star- and moonlight for orientation, and the circadian rhythms that all living organisms are subjected to rely on the regular change of light and darkness to maintain a healthy cycle.
In this case, what is true for the animal kingdom is also mostly true for human society. We may have a slight advantage in terms of our awareness of artificial light sources and ways to blend them out, but that does not mean that we are completely exempt from any consequences whatsoever. We also have to follow our circadian rhythms to strike a balance between sleeping and being awake, otherwise we may risk physiological degradation.
And yet, our modern societies constantly disturb these natural states. Nocturnal animals can hardly relate on stars when the night sky is so bright that the little dots are nowhere to be seen. This is also known as Skyglow, “the increased night sky brightness that is produced by upwardly emitted and reflected electric light being scattered by water, dust and gas molecules in the atmosphere” (Gaston et al. 1257). Even if one were not to care about starlight as an information source for animals, it is still a pity that on the planet that never sleeps, the humbling sight of stars has become a rare luxury for most of us.
Safety and practicality
Despite all the frustrations over artificial light at night, I think it is important to differentiate between what can be considered unnecessary light, thereby representing a case of light pollution, and justified situations where people have to rely on a source of light for safety or practicality reasons.
A dark alley is not a fun place to be in, and that probably applies to those located in big cities in particular. Light can certainly take on the role of a safety net, as it generally reduces the likelihood of an assault. This in return provides confidence to vulnerable individuals, who otherwise may not dare to move around as much on their own. Even if light is no safety guarantee, it still has notable advantages that justify the use of it in certain places at night.
In terms of practicality, light is necessary for people who work at night, which means that office buildings and shopping malls cannot be pitch-black all the time. Some limited use of light remains necessary to complete basic tasks, after all, we humans do not classify as nocturnal animals and also do not have the sharpest sight in general.
Finding the middle ground
Societies are already working towards eliminating some sources of light pollution. Part of the energy transition is equipping old office buildings with motion sensors to limit the use of light to areas and times of need. Still, it often seems as though these steps do little to combat the overall exposure of light, to which we have become so accustomed.
To return to my earlier point, I think that governments need to start addressing light pollution as the problem that it really represents. Private households contribute little to states such as Skyglow, which is why regulation on the use of artificial night light has to be revised if we want to expect any real change in our reduction of light pollution. If not for the benefit of plants, animals, or our own health, then at least for the benefit of our wallets.