Quantifying the economic value of nights with near-natural light conditions

Dark nights have become rare in Europe, especially in urbanised areas. Although artificial illumination provides numerous advantages, research shows that these come at significant costs. As the consequences of widely illuminated nights for both the environment and humans are becoming clearer, dark areas are gaining significant interest from multiple perspectives. Increasing designations of dark sky areas, in which dark nights are actively protected, illustrate this development. Against this background, Working Group 3 aims to better understand the value and potentials of areas in which nights are still fairly dark; how lighting approaches impact these values and potentials; and which conflicts arise when the protection of darkness collides with wishes for illumination.

Research perspectives:


For centuries, the view of the starry sky has inspired poets, artists, philosophers and anyone reflecting about their position in the universe. Today, modern observatories produce impressive pictures of interstellar gaseous nebulae or distant galaxies and research results that fascinate many people. At the same time, we are losing our view of the night sky full of thousands of stars, the faint band of the Milky Way, the faintly glowing pyramid of the zodiacal light created by dust in our solar system, or the faint airglow in the high atmosphere. Artificial light even from far away cities is scattered in the air and, like a veil, reduces the number of visible stars to several hundred or even only some dozen. While professional observatories have reacted by withdrawing to remote places free of light pollution, the general public is quickly losing easy access to another natural wonder.


Compromised sleep – both in duration and quality – is costly to the individual and society. Good quality sleep is interconnected tightly with wellbeing and health and tied to the amount and quality of light we expose ourselves to during day and night. Through widespread and uncontrolled use of artificial light, we create un-natural light scenarios that interfere with the entrainment of our biological clock leading to chronic sleep deprivation, circadian misalignment and adverse lifestyle habits with severe longer-term health risks. Notably, the worrisome consequences concern us all – either directly, for example, when we work at night, or indirectly, when we rely on night workers to be fit while on duty.


Historically, in modern western culture, darkness has been negatively conceived as the realm of ignorance, danger, devilry and deviance. However, there have always been alternative conceptions and practices that have valued gloom more positively. In an era of over-illumination, new practices and understandings about darkness are emerging. At tourist attractions, artistic events and installations, and dark landscapes, people are reconnecting with the qualities of gloom. It is important to identify these alternative conceptions and uses of darkness in contemporary times in order to challenge the hegemony of the imperialism of illumination.

Dark Sky Tourism

As areas with truly or even nearly natural light conditions become increasingly rare, the experiences that are tied to these conditions are also harder to come by – whether it is observing a star-filled night sky or encountering true darkness on an overcast moonless night. Organisations such as the International Dark-Sky Association (IDA) seek to safeguard the opportunity for such experiences by combining the protection of the nocturnal environment with the promotion of eco- and astro-tourism in their concepts for dark sky designation. Therefore, the question arises how dark sky tourism with its potential benefits for the (local) economy can be sustainably combined with environmental protection, including that of the night.


In 1987, it was first brought into discussion that artificial light at night (ALAN) might be a possible contributor to the development of cancer. Since then, the relation between ALAN and cancer has been investigated in different species and for different types of the disease. For humans, the focus has especially been on breast and prostate cancer. However, while knowledge about the impact of indoor artificial light at night is fairly advanced and shift work was declared a carcinogen by the WHO in 2007, insights into the health-effects of outdoor artificial light in the sense of light pollution (e.g. from street lamps shining in through bedroom windows) is still insufficient.

Lighting Conflicts

If natural darkness and the nocturnal environment are to be protected, the adoption and enforcement of lighting policies is essential. Areas that seek certification as dark sky areas by organisations such as IDA must demonstrate substantial efforts to this end: policies that affect future options for lighting must be adopted, changes to existing lighting made and political and public support demonstrated. This makes lighting a political matter – particularly when towns are located in or near areas striving for designation, as is often the case in Europe with its dense settlement patterns. Tensions can occur where the wish for lighting and the aim to protect darkness meet in one place. For the protection of nights with near-natural light conditions to be successful, these potential conflicts must be identified and negotiated.

Nature Conservation

The rapid increase of artificial light has fundamentally transformed nightscapes worldwide, yet the impacts of artificial lighting on the biosphere are rarely considered. This poses an emerging challenge for nature conservation, as all living organisms, irrespective if diurnal or nocturnal, have evolved endogenous circadian clocks for their function and survival, which are controlled by natural day–night cycles. By distorting the natural day–night cycle in natural habitats, the loss of darkness becomes a potential threat to biodiversity, as it can lead to dramatic changes in the balanced function of complex ecosystems. A main strategy for biodiversity conservation focuses on preservation of the integrity of ecosystems through the creation of protected areas. The preservation of natural light regimes in protected areas requires the application of effective management plans such as the designation of dark sky areas and appropriate lighting policy and regulations.

Selected activities and publications of WG 3 members:

  • Proposals for the protection of conservation areas as dark sky areas:
  • Naturpark Westhavelland, Germany – IDA Dark Sky Reserve (designated 2014, A. Hänel)
  • Biosphärenreservat Rhön, Germany – IDA Dark Sky Reserve (designated 2014, A. Hänel)
  • Ramon Crater Nature Reserve, Israel – IDA Dark Sky Park (in preparation, N. Leader)
  • Drafting a statement for managers of conservation areas concerning the protection of the nocturnal environment (in preparation, A. Hänel, J. Meier, N. Leader)
  • Creating guidelines, regulating and implementing dark-sky friendly illumination planning for major infrastructure projects throughout Israel (N. Leader)
  • “Designating Dark Sky Areas – Actors and Interests” – book chapter by J. Meier in the volume “Urban Lighting, Light Pollution and Society” edited by J. Meier, U. Hasenöhrl, K. Krause, M. Pottharst (Routledge 2015)
  • Analysis of current lighting- and health-related designations (ongoing, K. Gabriel, J. Meier)
  • Analysis of lighting conflicts and lighting practices (esp. changes to lighting in the course of the night) as a means of understanding forms of lighting governance (ongoing, D. Henckel, J. Meier)
  • Research on circadian entrainment, sleep and ambient lighting (ongoing, T. Kantermann)


Early stage researcher (ESR) theses and projects:

  • Identification of  factors of success for tourism in dark sky areas (Thesis by S. Kossack, Hochschule Eberswalde,  2013)
  • Darkness as an Opportunity – Sustainable Tourism in the Nature Park Westhavelland (student research project led by J. Meier, TU Berlin, 2014)
  • Dark sky areas as World Heritage sites? – An evaluation of development perspectives (Thesis by N. Kramer, TU Berlin, 2014)
  • Sustainable options for lighting retrofits in Milow, a town in the dark sky area Westhavelland (Thesis by S. Höhne, TU Berlin, ongoing)


This working group is led by:

Prof. Dietrich Henckel, Technische Universität Berlin, Germany
Dr. Thomas Kantermann, University of Groningen, Netherlands

Further members of WG 3:

  • Samuel Challéat – RENOIR research group, Toulouse, France
  • Tim Edensor – Manchester Metropolitan University, Manchester, UK
  • Katharina Gabriel – Universität Bremen, Bremen, Germany
  • Andreas Hänel – Dark Sky Germany, Osnabrück, Germany
  • Noam Leader – Israel Nature and Parks Authority (INPA), Israel
  • Josiane Meier – Technische Universität Berlin, Germany