This dissertation tests an original hybrid methodology to explore the rapid spread of the idea of human-made climate change that began in the 1950s after the idea had lain dormant for half a century. It describes the 1950s rhetorical events that triggered the idea’s diffusion, then traces how its rhetorical uses gradually gave root to the end-of-thecentury political impasse over how to respond to the societal implications of the idea. The research methodology rests on the simple logic that an idea can only spread by being used in human discourses. It combines traditions of rhetorical historiography with a philosophical view of intellectual history as the cumulative effect of a “natural selection” of ideas and their spread by human individuals over time and geography. It calls for sampling and analyzing rhetorical artifacts in light of the rhetorical situations in which they originate, focusing on how the idea of human-made climate change is used rhetorically in scientific and other discourses. The analyses form the basis of a narrative giving emphasis both to rhetorical continuities and to conversation-changing rhetorical events. They also show how these rhetorical dynamics involve interactions of human communities using or attacking the idea for their communal purposes. The results challenge science-focused understandings of the history of the idea itself and also suggest that the methodology may be more broadly useful. As to the history, the analyses highlight how changes in the rhetorical uses of the idea made possible its 1950s breakout in climate science, then led to uses that spread it into other sciences and into environmentalism in the 1960s, attached it to apocalyptic environmentalism in the 1970s, injected it into partisan politics in 1980s and shaped the political impasse during the 1990s. The data show that the methodology reveals elements of the discourses missed in histories emphasizing the “power of ideas,” suggesting that a focus on the usefulness of ideas may be more fruitful. A focus on rhetorical uses of ideas grounds the causation of intellectual change in human motivation and agency, expressed in material acts that multiply and disperse naturally through communities and populations. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection