--- title: Ecology and Society: The dark side of light - A transdisciplinary research agenda for light pollution policy date: 2015-11-10T13:52:23Z source: http://www.ecologyandsociety.org/vol15/iss4/art13/ tags: science --- description: | Hölker, F., T. Moss, B. Griefahn, W. Kloas, C. C. Voigt, D. Henckel, A. Hänel, P. M. Kappeler, S. Völker, A. Schwope, S. Franke, D. Uhrlandt, J. Fischer, R. Klenke, C. Wolter, and K. Tockner. 2010. The dark side of light: a transdisciplinary research agenda for light pollution policy. Ecology and Society 15(4): 13. keywords: | artificial light; energy efficiency; lighting concept; light pollution; nightscape; policy; sustainability; transdisciplinary title: | Ecology and Society: The Dark Side of Light: A Transdisciplinary Research Agenda for Light Pollution Policy ... +--------------------------------------------------------------------------+ | ------------------------------------------------------ | | ![Ecology and Society](/images/custom/ojs_title.jpg) | | ------------------------------------------------------ | +--------------------------------------------------------------------------+ | [Home](/index.php) | [Archives](/issues/) | [About](/about/) | | | [Login](/login.php) | [Submissions](/about/submissions.php) | | | [Subscribe](/register/) | [Contact](/about/contact.php) | | | [Search](/issues/search.php) | +--------------------------------------------------------------------------+ | +----------------------------------------------------------------------- | | ---+ | | | ----------------------------------------------------------------- | | | | | |  **[E&S Home](/) \> [Vol. 15, No. 4](/vol15/iss4/) \> Art. 13** | | | | | | ----------------------------------------------------------------- | | | | | +----------------------------------------------------------------------- | | ---+ | | | | \ | | Copyright © 2010 by the author(s). | | Published here under license by The Resilience Alliance.\ | | Go to the [pdf](ES-2010-3685.pdf) version of this article | | | | The following is the established format for | | referencing this article:\ | | Hölker, F., T. Moss, B. Griefahn, W. Kloas, C. C. Voigt, D. Henckel, A. | | Hänel, P. M. Kappeler, S. Völker, A. Schwope, S. Franke, D. Uhrlandt, J. | | Fischer, R. Klenke, C. Wolter, and K. Tockner. 2010. The dark side of | | light: a transdisciplinary research agenda for light pollution policy. | | *Ecology and Society* **15**(4): 13. [online] URL: | | http://www.ecologyandsociety.org/vol15/iss4/art13/\ | | | | ------------------------------------------------------------------------ | | | | Perspective | | | | The Dark Side of Light: A Transdisciplinary | | Research Agenda for Light Pollution Policy | | | | [Franz Hölker](#AUTHOR) ^1^, [Timothy | | Moss](mailto:MossT@irs-net.de) ^2^, Barbara Griefahn ^3^, Werner Kloas | | ^1^, Christian C. Voigt ^4^, Dietrich Henckel ^5^, Andreas Hänel ^6^, | | Peter M. Kappeler ^7^, Stephan Völker ^8^, Axel Schwope ^9^, Steffen | | Franke ^10^, Dirk Uhrlandt ^10^, Jürgen Fischer ^11^, Reinhard Klenke | | ^12^, [Christian Wolter](mailto:wolter@igb-berlin.de) ^1^ and Klement | | Tockner ^1,13^ | | | | ------------------------------------------------------------------------ | | | | ^1^Leibniz Institute of Freshwater | | Ecology and Inland Fisheries, Berlin, ^2^Leibniz Institute for Regional | | Development and Structural Planning, Erkner, ^3^Leibniz Research Centre | | for Working Environment and Human Factors, Dortmund, ^4^Leibniz | | Institute for Zoo and Wildlife Research, Berlin, ^5^Technische | | Universität Berlin, Department of Urban and Regional Planning, ^6^Dark | | Sky Germany, Museum am Schölerberg, Osnabrück, ^7^Leibniz Institute for | | Primate Research, Göttingen, ^8^Technische Universität Berlin, | | Department of Energy and Automation Technology, Berlin, | | ^9^Astrophysikalisches Institut Potsdam, ^10^Leibniz Institute for | | Plasma Science and Technology, Greifswald, ^11^Freie Universität Berlin, | | Institute for Space Sciences, ^12^Helmholtz Centre for Environmental | | Research, UFZ, Leipzig, ^13^Freie Universität Berlin, Institute for | | Biology | | | | ------------------------------------------------------------------------ | | | | \ | | - [Abstract](#ABSTRACT) | | - [Introduction](#INTRODUCTION5) | | - [The Current Focus on Energy | | Efficiency](#THECURRENTFOCUSONENERGYEFFICIENCY8) | | - [Beyond Energy Efficiency](#BEYONDENERGYEFFICIENCY11) | | - [Responses to this Article](#RESPONSESTOTHISARTICLE14) | | - [Acknowledgments](#ACKNOWLEDGMENTS) | | - [Literature Cited](#LITERATURECITED20) | | | | ------------------------------------------------------------------------ | | | | \ | | ABSTRACT | | | | \ | | Although the invention and widespread use of artificial light is | | clearly one of the most important human technological advances, the | | transformation of nightscapes is increasingly recognized as having | | adverse effects. Night lighting may have serious physiological | | consequences for humans, ecological and evolutionary implications for | | animal and plant populations, and may reshape entire ecosystems. | | However, knowledge on the adverse effects of light pollution is vague. | | In response to climate change and energy shortages, many countries, | | regions, and communities are developing new lighting programs and | | concepts with a strong focus on energy efficiency and greenhouse gas | | emissions. Given the dramatic increase in artificial light at night (0 - | | 20% per year, depending on geographic region), we see an urgent need for | | light pollution policies that go beyond energy efficiency to include | | human well-being, the structure and functioning of ecosystems, and | | inter-related socioeconomic consequences. Such a policy shift will | | require a sound transdisciplinary understanding of the significance of | | the night, and its loss, for humans and the natural systems upon which | | we depend. Knowledge is also urgently needed on suitable lighting | | technologies and concepts which are ecologically, socially, and | | economically sustainable. Unless managing darkness becomes an integral | | part of future conservation and lighting policies, modern society may | | run into a global self-experiment with unpredictable outcomes. | | | | \ | | Key words: artificial light; energy | | efficiency; lighting concept; light pollution; nightscape; policy; | | sustainability; transdisciplinary | | | | ------------------------------------------------------------------------ | | | | \ | | INTRODUCTION | | \ | | \ | | In 2009, the UN’s Year of Astronomy drew worldwide attention to an area | | affected by a long neglected environmental stressor: the increasing | | illumination of our nightscapes. The Year of Astronomy coincided with | | the 400th anniversary of Galileo’s first observations with a telescope | | in Padua. However, to look at today’s firmament Galileo would have to | | escape to remote areas for his research. This is because the Earth has | | become brighter at night. The rapid proliferation of electric lights has | | drastically reordered nightscapes across the globe, in terms of both | | light intensity and light spectrum (Cinzano et al. 2001, Elvidge et al. | | 2007). Although artificial lighting has clearly enhanced the quality of | | human life (Jakle 2001, Doll et al. 2006), the benefits are accompanied | | by hidden costs. Astronomers were the first to recognize that sky glow | | hampers the detection of faint celestial objects, obliging them to | | conduct their observations from darker areas or from orbit (Riegel 1973, | | Smith 2009). It is only very recently that the multiple negative effects | | of artificial lighting on ecology, human health, and social well-being | | have gained broader recognition (Jakle 2001, Rich and Longcore 2006, | | Navara and Nelson 2007).\ | | \ | | Light pollution is now a widely accepted term for adverse effects of | | artificial light on nature and humans (Longcore and Rich 2004, Navara | | and Nelson 2007). Nearly all living organisms, including human beings, | | have evolved under a natural rhythm of day and night. Interestingly, | | around 30% of all vertebrates and more than 60% of all invertebrates | | world-wide are nocturnal (Hölker et al. 2010). As lighting becomes | | brighter and extends farther into rural areas and offshore in marine | | systems (see Appendix 1), the distinction between day and night becomes | | blurred. Our understanding of the adverse effects of light pollution is | | vague and based mostly on purely observational case studies. | | Nonetheless, there is clear evidence that artificial lighting can alter | | physiology, including hormonal balance, as well as behavior, | | orientation, organism fitness, food web interactions, and biotope | | connectivity (Rich and Longcore 2006, Navara and Nelson 2007). The | | artificial disturbance of the natural day/night cycle may, as a result, | | have serious psycho-physiological and even medical consequences for | | humans, along with ecological and evolutionary implications for animals, | | plants, and even entire terrestrial, freshwater, and marine ecosystems | | (Rich and Longcore 2006, Navara and Nelson 2007). Light pollution is | | most probably an important but underestimated driver behind the erosion | | of provisioning, e.g., loss of light-sensitive species and genotypes; | | regulating, e.g., decline of nocturnal pollinators such as moths and | | bats; and cultural ecosystem services, e.g., loss of aesthetic values | | such as the visibility of the Milky Way (Rich and Longcore 2006, | | Carpenter et al. 2009, Smith 2009). The principal effects become most | | apparent at the interfaces between the physiological, ecological, and | | socioeconomic realms (Fig. 1). The problem is escalating worldwide as | | artificial lighting is rapidly increasing by around 6% per year (range: | | 0-20%; Table 1).\ | | \ | | | | ------------------------------------------------------------------------ | | | | \ | | THE CURRENT FOCUS ON ENERGY EFFICIENCY | | \ | | \ | | Artificial lighting consumes 19% of total global electricity, | | accounting for greenhouse gas emissions of 1900 Mt of CO~2~ per year | | (OECD/IEA 2006). It is no surprise that current artificial lighting | | policies focus primarily on energy efficiency and greenhouse gas | | emissions (e.g., OECD/IEA 2010), although safety, astronomical, and | | other considerations appear sporadically (see Appendix 2). The | | International Energy Agency has calculated that the systematic use of | | ‘least life-cycle cost’ lighting solutions (see Appendix 3) from 2008 | | onward would reduce the electricity consumption attributable to lighting | | until 2020 by 1311 TWh and 763 Mt of CO~2~ emissions per year compared | | to projections on the basis of current policies (OECD/IEA 2006).\ | | \ | | Recently, the European Ecodesign Directive established a framework to | | phase out the incandescent lamp and other particularly energy-intensive | | lighting products, e.g., high-pressure mercury lamps (The European | | Parliament and the Council of the European Union 2009). This step could | | reduce CO~2~ emissions in the EU by approximately 42 Mt per year, | | corresponding roughly to a 10% reduction of the greenhouse gas emissions | | the EU promised to achieve under Kyoto (Denneman 2009, Managenergy | | 2010). In the United States, President Obama has proposed a scheme for | | more energy-efficient lamps and lighting equipment as part of his | | climate change policy. This would result in savings of approximately 20 | | Mt CO~2~ annually (The White House 2009). Similar activities are | | reported inter alia for China, Australia, and New Zealand (OECD/IEA | | 2006, 2010).\ | | \ | | Within such policy frameworks, many countries, regions, and communities | | are developing new lighting programs and concepts. For example, the EU | | has launched a number of programs, e.g., GreenLight | | [www.eu-greenlight.org](http://www.eu-greenlight.org/), E-Street | | [www.e-streetlight.com](http://www.e-streetlight.com), to adopt | | efficient lighting systems and to initiate a permanent market | | transition. Although most of these programs and concepts are driven by | | energy efficiency motives alone, there remain causes for concern. For | | example, technological innovations that help improve the efficiency of | | energy appliances and systems often lead to greater energy use because | | of direct ‘rebound’ effects (Herring and Roy 2007, Charles 2009). New | | technologies and reduced costs could generate steep increases in the | | overall use of lighting and may stimulate innovative additional uses for | | lighting (Herring and Roy 2007, Fouquet and Pearson 2006). Lighting | | efficiency has doubled over the past 50 years in the UK; however, per | | capita electricity consumption for lighting increased fourfold over the | | same period (Fouquet and Pearson 2006). Due to the development and use | | of new lighting technologies, e.g., compact fluorescent lamp (CFL), | | light-emitting diode (LED), organic light-emitting diode (OLED), we can | | expect a dramatic drop in the cost of lighting services, a desirable end | | in itself, but with possibly higher energy consumption and wider loss of | | dark nightscapes as a consequence. Technological innovations should, | | therefore, not only save consumers money, but also consider human | | health, ecological, and socioeconomic aspects.\ | | \ | | | | ------------------------------------------------------------------------ | | | | \ | | BEYOND ENERGY EFFICIENCY | | \ | | \ | | Whereas air, noise, or water pollution have been high priority policy | | issues for decades, light pollution remains scientifically, culturally, | | and institutionally in the dark. Given the dramatic increase in | | artificial light in recent years, we see an urgent need for research on | | the physiological, human health, ecological, and socioeconomic | | significance of the loss of the night that addresses how illumination | | can be improved both technically and institutionally yet having fewer | | adverse effects. Managing darkness has to be an integral part of future | | conservation planning and illumination concepts. If not, our modern | | society may run into a global self-experiment with unpredictable | | outcomes (Fig.1).\ | | \ | | Any attempts to reduce light pollution run up against positive | | connotations of lighting which are deeply ingrained in modern societies. | | Culturally, light is a symbol of enlightenment, modernity, urbanity, and | | security (Jakle 2001). Policy initiatives against light pollution | | therefore need to take into consideration the many advantages of | | artificial lighting, real and perceived, for economic production, social | | lifestyles, and security while at the same time addressing its negative | | side effects. For this, a sound understanding of the historical, | | socioeconomic, and cultural reasons for the emergence and dissemination | | of lighting systems is needed. We then need to ask how far recent | | changes in attitudes, in particular relating to the environment and | | human health, are creating openings for a shift in policy and practice. | | Part of this process involves identifying and building up a coalition of | | interest around the light pollution issue, incorporating such diverse | | stakeholder groups as ecologists, astronomers, and health professionals, | | but also electricity utilities, lamp manufacturers, property owners, | | local businesses, city planners, or those concerned about nighttime | | security.\ | | \ | | Thus, the research needed is transdisciplinary, i.e. it should cut | | across boundaries between scientific disciplines and between science, | | policy, and practice and should address facts, practices, and values | | (Wiesmann et al. 2008). The following natural, social, and engineering | | science questions are central to this research agenda:\ | | - What characteristics of light disrupt human health and ecological | | communities? | | - How does light pollution interact with other stressors such as air, | | water, and noise pollution, or climate change? | | - What technologies can address the environmental, health, and | | economic disadvantages of current lighting practices in different | | areas or settlement types? | | - What alternative lighting strategies and policies are politically, | | culturally, and economically viable? | | - To what extent are users willing to minimize light pollution and | | adopt alternatives? | | | | \ | | Such research should validate indicators and guidelines, set priorities | | for human health and environmental protection, identify technical and | | economic possibilities for improvements in lighting, and develop | | sustainable lighting concepts and techniques for future nightscapes.\ | | \ | | With our present understanding, there is little choice but to develop | | guidelines in accordance with energy efficiency criteria and the few | | available case studies on the ecological and health impacts of lighting. | | The Commission Internationale de l’Éclairage (CIE), the International | | Dark-Sky Association (IDA; [www.darksky.org](http://www.darksky.org/)), | | and the Illuminating Engineering Society of North America (IESNA 2000) | | provide preliminary recommendations, illustrating how local lighting | | ordinances and innovative designs may promote low impact, | | energy-efficient and aesthetically pleasing lighting systems (e.g., CIE | | 1997, 2000, 2003). Promising options are, for example, lamps that direct | | their light more accurately toward where it is needed, lamps that emit | | light with a spectral distribution causing minimal harm, timers and | | sensors to turn lights on only when needed, and the consideration for | | light-sensitive areas, especially the periphery of residential areas, | | forests, parks, and shores of water bodies. The comprehensive and | | transdisciplinary research advocated here will result in more advanced | | regulations and guidelines at, in particular, the national level and the | | development of intelligent, i.e., adaptive and context-dependent, | | lighting concepts for local communities. These will help countries, | | regions, and cities to maximize the social and economic benefits of | | artificial light at night, while minimizing its negative and unintended | | ecological and health impacts. On this basis, future generations will be | | able to experience nightscapes comparable to those which Galileo knew | | without having to travel to the Australian Outback or the Chilean | | Andes.\ | | \ | | \ | | | | ------------------------------------------------------------------------ | | | | \ | | RESPONSES TO THIS ARTICLE | | \ | | \ | | Responses to this article are invited. If accepted for publication, your | | response will be hyperlinked to the article. To submit a response, | | follow [this link](/responses.php?articleid=3685&mode=add). To read | | responses already accepted, follow [this | | link](/responses.php?articleid=3685).\ | | | | \ | | | | ------------------------------------------------------------------------ | | | | \ | | ACKNOWLEDGMENTS | | | | *We are grateful to Steve Carpenter, Jens Krause, Elisabeth K. Perkin, | | and Michael Monaghan for helpful comments. This work was supported by | | Milieu (FU Berlin), the Leibniz Association, the Senatsverwaltung für | | Bildung, Wissenschaft und Forschung, Berlin, and the Federal Ministry of | | Education and Research, Germany.* | | | | ------------------------------------------------------------------------ | | | | \ | | LITERATURE CITED | | \ | | \ | | **Agence de l'Environnement et de la Maîtrise de l'Energie (ADEME).** | | 2007. *Energie et Patrimoine Communal, Enquête 2005.* [online] URL: | | | | .\ | | \ | | **Campaign to Protect Rural England (CPRE).** 2003. *Night blight!* | | Campaign to Protect Rural England, London, UK.\ | | \ | | **Carpenter, S. R., R. DeFries, T. Dietz, H. A. Mooney, S. Polasky, W. | | V. Reid, R. J. Scholes.** 2009. Science for managing ecosystem services: | | beyond the Millennium Ecosystem Assessment. *Proceedings of the National | | Academy of Sciences USA* **106**:1305-1312.\ | | \ | | **Carrasco, B. E., A. Carramiñana, F. J. Sanchez-Sesma, and F. J. | | Lermo.** 1998. Protection of the observatorio astrofisico "Guillermo | | Haro". *Astronomical Society of the Pacific Conference Series* | | **139**:141-149.\ | | \ | | **Charles, D.** 2009. Leaping the efficiency gap. *Science* | | **325**:804-811.\ | | \ | | **Commission Internationale de l’Éclairage (CIE).** 1997. Guidelines | | for minimizing sky glow. CIE Technical Report 126-1997, Vienna, | | Austria.\ | | \ | | **Commission Internationale de l’Éclairage (CIE).** 2000. Guide to the | | lighting of urban areas. CIE Technical Report 136-2000, Vienna, | | Austria.\ | | \ | | **Commission Internationale de l’Éclairage (CIE).** 2003. Guide on the | | limitation of the effects of obtrusive light from outdoor lighting | | installations. CIE Technical Report 150-2003, Vienna, Austria.\ | | \ | | **Cinzano, P.** 2000. The growth of light pollution in North-Eastern | | Italy from 1960 to 1995. *Memorie della Società Astronomica Italiana* | | **71**:159-165.\ | | \ | | **Cinzano, P., F. Falchi, and C. D. Elvidge.** 2001. The first world | | atlas of the artificial night sky brightness. *Monthly Notices of the | | Royal Astronomical Society* **328**:689-707.\ | | \ | | **Denneman, J.** 2009. Light relief. *Parliament Magazine* **281**:42.\ | | \ | | **Doll, C. N. H., J.-P. Muller, and J. G. Morley.** 2006. Mapping | | regional economic activity from night-time light satellite imagery. | | *Ecological Economics* **57**:75-92.\ | | \ | | **Elvidge, C. D., P. Cinzano, D. R. Pettie, J. Arvesen, P. Sutton, R. | | Nemani, T. Longcore, C. Rich, J. Safran, J. R. Weeks, and S. Ebener.** | | 2007. The nightsat mission concept. *International Journal of Remote | | Sensing* **28**:2645-2670.\ | | \ | | **Fouquet, R., and P. Pearson.** 2006. Seven centuries of energy | | services: the price and use of light in the United Kingdom (1300-2000). | | *The Energy Journal* **27**:139-177.\ | | \ | | **Garstang, R. H.** 1989. The status and prospects for ground-based | | observatory sites. *Annual Review of Astronomy and Astrophysics* | | **27**:19-40.\ | | \ | | **Garstang, R. H.** 2004. Mount Wilson observatory: the sad story of | | light pollution. *The Observatory* **124**:14-21.\ | | \ | | **Hänel, A.** 2001. The situation of light pollution in Germany. | | *Preserving the Astronimical Sky IAU Symposium* **196**:142-146.\ | | \ | | **Herring, H., and R. Roy.** 2007. Technological innovation, energy | | efficient design and the rebound effect. *Technovation* **27**:194-203.\ | | \ | | **Hölker, F., C. Wolter, E. K. Perkin, and K. Tockner.** 2010. Light | | pollution as a biodiversity threat. *Trends in Ecology and Evolution* | | **25**:681-682.\ | | \ | | **Illuminating Engineering Society of North America (IESNA)** 2000. | | *Technical memorandum on light trespass: research, results and | | recommendations.* TM-11-00, IESNA, New York, New York, USA.\ | | \ | | **Isobe, S., and H. Kosai.**1998. Star watching observations to measure | | night sky brightness. *Astronomical Society of the Pacific Conference | | Series* **139**:175-184\ | | \ | | **Jakle, J. A.** 2001. *City lights. Illuminating the American night*. | | John Hopkins University Press, Baltimore, Maryland, USA.\ | | \ | | **Krisciunas, K.** 1997. Optical night-sky brightness at Mauna Kea over | | the course of a complete sunspot cycle. *Publications of the | | Astronomical Society of the Pacific* **109**:1181-1188.\ | | \ | | **Krisciunas, K., D. R. Semler, J. Richards, H. E. Schwarz, N. B. | | Suntze, S. Vera, and P. Sanhueza.** 2007. Optical sky brightness at | | Cerro Tololo Inter-American Observatory from 1992 to 2006. *Publications | | of the Astronomical Society of the Pacific* **119**:687-696.\ | | \ | | **Lockwood, G. W., D. T. Thompson, and R. D. Floyd.** 1990. Sky glow | | and outdoor lighting trends since 1976 at the Lowell Observatory. | | *Publications of the Astronomical Society of the Pacific* | | **102**:481-491.\ | | \ | | **Longcore, T., and C. Rich.** 2004. Ecological light pollution. | | *Frontiers in Ecology and the Environment* **2**:191-198.\ | | \ | | **Managenergy**. 2010. *Key information related to energy efficiency.* | | European Commission on Energy. [online] URL: | | .\ | | \ | | **Massey, P. and C. B. Foltz.** 2000. The spectrum of the night sky | | over Mount Hopkins and Kitt Peak: changes after a decade. *Publications | | of the Astronomical Society of the Pacific* **112**:566-573.\ | | \ | | **McNeill, G.** 1999. Street lighting: a development and economic | | history since 1924. *Lighting Journal* **64**:37.\ | | \ | | **Narisada, K., and D. Schreuder.** 2004. *Light pollution handbook.* | | Springer, Dordrecht, The Netherlands.\ | | \ | | **Navara, K. J., and R. J. Nelson.** 2007. The dark side of light at | | night: physiological, epidemiological, and ecological consequences. | | *Journal of Pineal Research* **43**:215-224.\ | | \ | | **Organisation for Economic Co-operation and Development | | (OECD)/International Energy Agency (IEA).** 2006. *Light’s labour’s | | lost - policies for energy-efficient lighting*. OECD/IEA, Paris, | | France.\ | | \ | | **Organisation for Economic Co-operation and Development | | (OECD)/International Energy Agency (IEA).** 2010. *Energy efficiency | | policies and measures database.* [online] URL: | | .\ | | \ | | **Pedani, M.** 2009. Sky surface brightness at Mount Graham: UBVRI | | science observations with the large binocular telescope. *Publications | | of the Astronomical Society of the Pacific* **121**:778-786.\ | | \ | | **Rich, C., and T. Longcore, editors.** 2006. *Ecological consequences | | of artificial night lighting.* Island Press, Washington, D.C., USA.\ | | \ | | **Riegel, K. W.** 1973. Light pollution. *Science* **179**:1285-1291.\ | | \ | | **Smith, M.** 2009. Time to turn off the lights. *Nature* **457**:27.\ | | \ | | **Stalin C. S., M. Hegde, D. K. Sahu, P. S. Parihar, G. C. Anupama, B. | | C. Bhatt, and T. P. Prabhu.** 2008. Night sky at the Indian astronomical | | observatory during 2000-2008. *Bulletin of the Astronomical Society of | | India* **36**:111-127.\ | | \ | | **Teare, S. W.** 2000. Night sky brightness at Mt. Wilson observatory. | | *The Observatory* **120**:313-317.\ | | \ | | **The European Parliament and the Council of the European Union.** | | 2009. Directive 2009/125/EC of the European Parliament and of the | | Council of 21 October 2009 establishing a framework for the setting of | | ecodesign requirements for energy-related products. *Official Journal of | | the European Union L* **285**:10-35.\ | | \ | | **The White House, Office of the Press Secretary.** 2009. *Obama | | Administration launches new energy efficiency efforts.* Press Release, | | The White House, Washington, D.C., USA. [online] URL: | | \ | | \ | | **Walker, M. F.** 1973. Light pollution in California and Arizona. | | *Publications of the Astronomical Society of the Pacific* | | **85**:508-519.\ | | \ | | **Wiesmann, U., G. Hirsch Hadorn, H. Hoffmann-Riem, S.Biber-Klemm, W. | | Grossenbacher, D. Joye, C. Pohl, and E. Zemp.** 2008. Enhancing | | transdisciplinary research: a synthesis in fifteen propositions. Pages | | 433-441 *in* G. Hirsch Hadorn, H. Hoffmann-Riem, S. Biber-Klemm, W. | | Grossenbacher-Mansuy, D. Joye, C. Pohl, U. Wiesmann, and E. Zemp, | | editors. *Handbook of transdisciplinary research.* Springer. Dordrecht, | | The Netherlands.\ | | \ | | \ | | | | ------------------------------------------------------------------------ | | | | ------------------------------------ --------------------------------- | | --- | | Address | | of Correspondent:\ | | Franz Hölker\ | | Leibniz Institute of Freshwater | | Ecology and Inland Fisheries\ | | 12587 Berlin\ | | Germany\ | | \ | | | | ------------------------------------ --------------------------------- | | --- | | | | [![Up](/images/uparrow.gif)](#top) | +--------------------------------------------------------------------------+ | [Home](/index.php) | [Archives](/issues/) | [About](/about/) | | | [Login](/login.php) | [Submissions](/about/submissions.php) | | | [Subscribe](/register/) | [Contact](/about/contact.php) | | | [Search](/issues/search.php) | +--------------------------------------------------------------------------+ +--------------------------------------------------------------------------+