Norris ALM Thesis Final 02-27-2017
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Discovering the Causes of the Ice Ages and Human-Caused Climate Change: a History of the Late Nineteenth and Early Twentieth Century The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Norris, Thomas. 2017. Discovering the Causes of the Ice Ages and Human-Caused Climate Change: a History of the Late Nineteenth and Early Twentieth Century. Master's thesis, Harvard Extension School. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:33825890 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Discovering the Causes of the Ice Ages and Human-Caused Climate Change: A History of the Late Nineteenth and Early Twentieth Century Thomas L. Norris A Thesis in in the Field of History of Science, Technology and Medicine for the Degree of Master of Liberal Arts in Extension Studies Harvard University May 2017 Abstract Human-caused climate change is a contentious issue today among some non- scientific communities who argue that scientists support climate change because of their political beliefs. In contrast, some historians today argue that the carbon dioxide hypothesis, which says that increased carbon dioxide in the air increases global temperatures and that much of the increase in carbon dioxide is due to human causes, was not taken seriously during the early twentieth century. These contradictory views led to my investigation of the history of human-caused climate change, which originally evolved out of the search in the late nineteenth and early twentieth century to find a cause(s) of the ice ages. This thesis investigates early research into the origin of the ice ages, which generated fourteen hypotheses, including the carbon dioxide hypothesis. Historically, climate change research included contributions from many scientific disciplines: astronomy, chemistry, geology, meteorology, and others. The main challenge to finding the cause(s) of the ice age was the diversity and limitations of the evidence and the inadequate scientific instrumentation and theories in the early twentieth century, which explains why the plausibility of hypotheses by this problem-centered scientific community changed during this period, including the changing views on human-caused climate change. Still, progress was made and, 1950, only five hypotheses were still under consideration. Contrary to what some historians say today, the carbon dioxide hypothesis was treated like any other hypothesis, and there is no evidence that the scientific communities were biased against it. In addition, the criticisms that the carbon dioxide hypothesis received in the early twentieth century demonstrate that it was not always unquestioned by the scientific community, contrary to assertions made by some non-scientists today. However, there was less controversy surrounding the origin of the ice ages during this period. Acknowledgments I thank Professor Peter Galison, Harvard University, Department of the History of Science, for his insightful suggestions and encouragement. His suggestions have made this a much better thesis. I thank Dr. James Morris, Harvard University, Division of Continuing Education, for guiding me through the process of completing the thesis. I thank Susan Matheson for her editing skills, which helped to make the thesis more readable. Of course, any errors or omissions in the thesis are my responsibility. v Table of Contents Acknowledgments ............................................................................................................. v! List of Tables ................................................................................................................. viii! List of Figures .................................................................................................................. ix! Chapter I. Introduction ...................................................................................................... 1! Scope and Study Questions of Thesis ........................................................................... 4! Methodology .................................................................................................................. 8! A Final Aspiration for this Thesis ............................................................................... 12! Chapter II. Setting the Stage—Discovery of the Ice Ages ............................................. 15! Chapter III. Climate Change Hypotheses—Their Histories ........................................... 27! Astronomical Hypothesis ............................................................................................ 31! Carbon Dioxide Hypothesis ........................................................................................ 41! Changes in Atmospheric Circulation Hypothesis ........................................................ 54! Geographical Hypothesis ............................................................................................. 60! Cosmic Dust Hypothesis ............................................................................................. 70! Chapter IV. Solving the Cause of Climate Change—What Were the Challenges? ........ 77! Scientific Communities—Who Was Interested in this Problem? ............................... 77! How They Did Science: An Example and Comments on Others’ Methods ............ 82! Challenges When There Are Many Scientific Communities—Network Analysis .. 86! Scientists and Their Views ....................................................................................... 95! Response to the Views of Others, Evidence from Obituaries ................................ 100! Summary Scientific Communities ......................................................................... 101! Generating the Core Data Set .................................................................................... 102! vi Local versus Global Ice Ages? ............................................................................... 104! Synchronicity ......................................................................................................... 107! Patterns in the Timing of the Ice Ages ................................................................... 109! Changes in the Understanding of the Core Data Set .............................................. 112! Making Progress ........................................................................................................ 117! Infrared Spectroscopy ............................................................................................ 117! Geochronology ....................................................................................................... 122! Progress Was Made, Nonetheless .............................................................................. 129! Chapter V. Concluding Remarks—No Simple History ................................................ 131! Thesis Questions and Summary of Results ............................................................... 133! Philosophical Models of Scientific Change .............................................................. 141! Kuhn’s Theory and Climate Change ...................................................................... 142! Lakatos’ Model and Climate Change ..................................................................... 147! Philosophy of Science Concluding Remarks ......................................................... 150! Final Remarks from the Research ............................................................................. 151! References ..................................................................................................................... 155! vii List of Tables Table 1. Categories of the Hypotheses on the Origin(s) of the Ice Ages. ....................... 30! Table 2. Core Data Set. ................................................................................................. 113! Table 3. Summary of Preferred (P) and Challenged (C) Hypotheses from Papers by Climate Scientists. .................................................................................................. 114 viii List of Figures Figure 1. Typical Erratic Block, from Mont Blanc Range. ............................................ 21! Figure 2. Striated Rock. .................................................................................................. 22! Figure 3. Lyell’s Proposed Distribution of the Continents During the Ice Ages and Warm Interglacial Periods. ....................................................................................... 63! Figure 4. Major Scientists in Discovery of the Ice Ages. ............................................... 87! Figure 5. Models of Scientific Change Applied to Development of Plate Tectonics Theory. ..................................................................................................................... 88! Figure 6. Full Network of Papers and Citations. ............................................................ 90! Figure 7. Simplified Network. ........................................................................................ 93! Figure 8. First Cluster – Focused Primarily on the Carbon Dioxide Hypothesis. .......... 94! Figure 9. Second Cluster – Related to work by Simpson and Brooks ...........................