Mass media is typically defined as a form of technology (including radio, film, and television, but also encompassing newspapers, magazines, and book publishing, as well as advertising, marketing, and public relations) or institutional organization (Time-Warner, RCA, BBC, AOL, Al-Jazeera, and so on). Beyond these narrow definitions, mass media also encompasses shifting cultural forms shaping human perception and possibilities for social change. Mass media therefore simultaneously includes technical, institutional, and cultural dimensions. This broad conception is required to understand how media shape contemporary human/environment conditions, including representations of nature, popular perceptions of environmental issues, and public opinion on phenomena ranging from swimming with dolphins to global warming.