As artificial light has spread across, cities roads and through industry, unadulterated night skies have become something of a rarity. That’s a particular bugbear for astronomers — artificial light obscures their view of the faintest objects. It can also have a negative influence on mental health and changes the ways animals forage for food and even reproduce.
That raises the obvious question of how to tackle light pollution effectively. The answer is with more targeted lights that switch on and off when needed, that point down rather than up or horizontally and with spectra that can be more easily filtered.
But before the process of change can start, policy makers need to understand how their regions compare with other similar ones. The general view is that areas of high population density pollute more than areas of low density. But actual light emissions vary in a more fine-grained and subtle way.
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