The New Environmental Paradigm (NEP) Scale, published in "The Journal of Environmental Education" by R. E. Dunlap and K. D. Van Liere (1978), has become the most widely used measure of environmental concern in the world and been employed in hundreds of studies in dozens of nations. This article tells the story of the NEP Scale, beginning with how the author developed the notion of an environmental paradigm and then decided to measure it. The author describes the original NEP Scale and its 3 revisions, 1 of which is rapidly replacing the 1978 version in most studies. The author then reviews current uses of the various NEP Scales and examines major criticisms of them. Last, the author discusses the failure of an ecological worldview to become institutionalized in the United States, stemming from intense opposition to it since the 1990s, and the need to understand the sources of this opposition and monitor the situation.