Environmental psychology is the study of transactions between individuals and their physical settings (Gifford, 2007a). In these transactions, individuals change their environments, and their behavior and experiences are changed by their environments. It includes theory, research, and practice aimed at making the built environment more humane and improving human relations with the natural environment. Considering the enormous investment society makes in the physical environment (including buildings, parks, streets, the atmosphere, and water) and the huge cost of misusing nature and natural resources, environmental psychology is a key component of both human and environmental welfare.Environmental psychologists work at three levels of analysis: (a) fundamental psychological processes like perception of the environment, spatial cognition, and personality as they filter and structure human experience and behavior, (b) the management of social space: personal space, territoriality, crowding, and privacy, and the physical setting aspects of complex everyday behaviors, such as working, learning, living in a residence and community, and (c) human interactions with nature and the role of psychology in climate change (e.g., Gifford, 2008a).The history of environmental psychology has been reviewed elsewhere (see Bechtel & Churchman, 2002, Bell, Greene, Fisher, & Baum, 2001, and Gifford, 2007a. But, for perspective, we note that early 20th century psychologists studied the effect of noise (United States) and heat (England) on work performance, while scholars in Germany and Japan explored concepts and moral philosophy related to environmental psychology. By mid-century, environmental psychology was a clearly established discipline with work on topics such as sensory isolation, personal space, and building design. Journals devoted to the field were established; the most prominent of these are the Journal of Environmental Psychology and Environment and Behavior.