Embracing the Night I: Basics of natural darkness and light pollution

The Unintended Consequences of Artificial Lighting

In many cultures and religions, lighting and illumination are closely associated with ideas of progress, modernity and development. The Enlightenment, for example, used light as a symbol goodness and godliness, and darkness as related to ugliness, chaos and evil - something to be feared and eradicated (Lyytimäki et al. 2012). In recent years, accessibility to “cheaper, more efficient” lighting technologies such as light emitting diodes (LEDs) has unintentionally enabled rapid transformation from useful artificial lighting to unnecessary and excessive artificial lighting at night – light pollution.

Natural darkness is becoming a rapidly diminishing natural resource even in sparsely populated countries, cities, and towns. More than 80% of the world’s population, and almost 90% of residents of Europe no longer experience natural darkness where they live (Falchi et. al 2016). Although artificial light has undoubtedly played a major role in cultural and societal development, the unnecessary or excessive use of artificial light at night (ALAN) is increasing globally at an estimated rate of 10% per year (Kyba et al. 2023), making it the greatest threat to natural darkness. The energy costs are also significant; according to Eklöf (2023), one tenth of the world's total energy consumption is used for artificial lighting, even though only one-tenth of produced light is useful or needed, with most escaping unhindered from unnecessary or excessive lighting. The fear of crime has also been used as a reason for increasing the illumination in cities, even though statistics prove that the nighttime crime takes place in the areas with adequate lightning (Science for Environment Policy 2023).

Despite growing scientific evidence of the wide-ranging impacts of light pollution, it continues to receive insufficient attention as an environmental issue—and in some cases, is deliberately overlooked (Lyytimäki et al 2012).

Watch this video on light pollution, its effects and ways to reduce it:

Balancing Light and Darkness

While some artificial light at night is necessary for safety and functioning, darkness is crucial for the wellbeing of humans, animals, and plants. Darkness regulates vital biological functions, including circadian rhythms and overall wellbeing. It also supports plant cycles, wildlife safety from predators, pollination actions, food security, and biodiversity health. Responsible artificial lighting at night allows us to enjoy the night safely while preserving the night sky and its related traditions and narratives. It also protects terrestrial and aquatic ecosystems.

Light pollution is most often created by lights that are too bright, poorly directed, or left on at the wrong time, and can cause various impacts and effects. Glare light dazzles the eyes and trespass light can penetrate through windows of accommodation facilities and residential buildings. Upward-facing luminaires or excessive lighting reflecting upward create sky glow that lightens the sky, obscuring stars and other celestial phenomena even tens of kilometres from the source of pollution. Bright lights directed towards the sky and lit after dark have even confused migratory birds into losing their way.

Bortle scale (ESO/P. Horálek, M. Wallner 2022)

The Bortle scale is a good first step to figuring out how much light pollution may be affecting you and your region. The light pollution map can further illustrate the extent to which combined sources of artificial light are impacting darkness, and how this may threaten tourism-related values and benefits.