THREE REVOLUTIONS IN PALEOCLIMATOLOGY AND THE COMING NEW REVOLUTION

Changes in the study of paleoclimate are demarcated by three revolutions. Plate tectonics was a major (“Kuhnian”) revolution. Two “smaller revolutions” (as defined by Kuhn) that were nevertheless significant were the ocean-drilling revolution and the climate-model revolution. The history of paleoclimate studies shows, in general, an evolution from geographically and/or temporally focused studies in the pre-plate tectonics era, to development of paleoclimate proxies and studies of global climate patterns, to predominately global studies in connection with paleoclimate modeling. These three revolutions have been responsible for some of the shifts in focus in paleoclimate studies, and together constitute a cycle that is beginning to be repeated. This repetition has come about because, in the most recent decade, new questions posed by global studies and paleoclimate models have driven a reexamination of, and new attention to, geographically and/or temporally focused research. This research is informed not just by previous results, but also by recent advances in geochronology, coupled with current new energy in developing paleoclimate proxies. This new cycle holds the promise of creating a fourth, possibly Kuhnian, revolution: the human-impacts revolution. In this revolution, Earth-system models that take full advantage of all that is known about the climatic and environmental evolution of the Earth for the last half-billion years will be coupled with economic and social models, with the potential of creating a new paradigm in humanity’s understanding of its place on Earth.