This dissertation contributes to an emerging, interdisciplinary body of research that aims to better understand how and why artificial outdoor lighting is used, and what impact the individual and cumulative unintended effects of artificial lighting, generally subsumed under the term light pollution, have. By providing classifications and developing methods of comparative inquiry, it contributes to the further generation of foundational knowledge that is urgently needed to inform the ongoing search for ways of balancing the manifold costs and benefits of artificial lighting in policy-making and planning. With its geographic focus on the brightly lit countries of the global North, this dissertation embraces the complexity of lighting and light pollution and addresses voids in the landscape of interdisciplinary research with systematic inquiries into three largely uncharted territories. Firstly, it explores everyday lighting practices, taking into view the composition and temporality of urban lightscapes, for which it develops a method of documentation and analysis. Secondly, it inspects the novel policy approach of protecting darkness via designation in largely unlit areas, and the range of actors and interests involved in such dark-sky designations. Thirdly, it takes into view contemporary conflicts about concrete artificial outdoor lighting situations, and develops a tool for their analysis to allow for comparative studies and systematizations of lighting conflicts. By generating knowledge on (1) the diversity of lighting practices, (2) the diversity of stakeholder interests in the protection of darkness, and (3) the diversity of conflicts revolving around lighting, this dissertation complements the evolving mosaic of knowledge emerging from interdisciplinary lighting studies. The range of case studies and issues addressed reflect the spectrum of lighting situations: the first section focuses on areas that are amongst the most brightly lit, the second on areas in which artificial lighting is at a minimum, and the third adopts a transversal approach by studying a cross-section of conflicts about lighting in a variety of contexts. This dissertation demonstrates, and exemplifies, the necessity to look far beyond the technical realm to achieve sustainable lighting policies, and makes the case that such policies need to address both public and private forms of lighting, as well as the unequal balance of power between producers and receivers of light. Through developing reproducible methods able to capture and analyze the multidimensionality of artificial outdoor lighting and its effects, it makes a contribution to the systematization of knowledge on lighting and light pollution. Such knowledge is much needed, as it provides essential points of orientation for the development of more sustainable planning and policy approaches for artificial outdoor lighting.