Norris ALM Thesis Final 02-27-2017

173 Pages·2017·3.95 MB·English

by  Tom Norris

Discovering the Causes of the Ice Ages and Human-
Caused Climate Change: a History of the Late
Nineteenth and Early Twentieth Century
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.
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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

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.

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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
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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

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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

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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 ............................ 95
Figure 10. Number of Times Preferred Hypotheses Mentioned by Decade. ................ 116
Figure 11. Number of Times Hypotheses Critiqued by Decade. .................................. 116
Figure 12. Plot of the Milankovitch cycles. .................................................................. 126

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