Downloaded from http://sp.lyellcollection.org/ by guest on October 1, 2021 Charles Lyell and climatic change: speculation and certainty JAMES RODGER FLEMING Science, Technology and Society Program, Colby College, Waterville, ME, 04901, USA Abstract: In the first edition of the Principles of Geology, Charles Lyell announced his theory of the geographical determination of climate and speculated on possible climatic changes during the geological and historical past. In light of the subsequent discovery of ice ages, the proliferation of theories of climatic change, and the great climate debates of his time. Lyell's theory remained remarkably stable. This paper examines Lyell's appropriation, modification and rejection of the views of his contemporaries. It provides perspectives on elite and popular ideas of climate and climatic change from the late eighteenth century to 1875. examines Lyell's position on climatic change in geological and historical times, and explores in some detail the mutual influences of Lyell and James Croll, the proponent of an astronomical theory of ice ages. I have often told (and been told) humorous stories positions created and defined? The answers are about climate and human affairs. This one, from varied and worthy of extended reflection. In the 1865, comes from a letter to Lyell from John absence of means to observe the climate system in Carrick Moore, FRS, field geologist and long-time its entirety, (as an astronomer might view a star or member of the Geological Society. Moore writes: planet) or to experiment on it directly (as a chemist might view a reaction), how did scientific under- I fear you have not time to read the Reader, I standing of it emerge? must call your attention to the last number, in One approach, popular in the eighteenth century, which there is a true story of a Physician who was through appeals to authority-references to warned a Unitarian preacher that he would make historical literature, first impressions of explorers no proselytes in Northern Virginia because the or the memory of the elderly. This was the people all had fair complexions and therefore rhetorical strategy of Enlightenment writers who were Calvinists. If he wished to preach against wanted to support a particular theory of cultural the eternity of punishment, he should go to the development or decline. I will say more about this Hill Country. A map of the world is evidently shortly. much wanted to show the influence of Climate Another way of approaching the issue was to on Creeds, with contour lines-[Buddhism] collect massive amounts of meteorological data below the 50 foot level, Calvinists near the Snow over large areas and extended time periods in the line, and Papists principally on the Volcanic hope of deducing climatic patterns and changes. tufts... (J. C. Moore to C. Lyell, 5 March 1865 in Individual observers in particular locales dutifully Lyell papers) tended to their journals, and networks of cooper- So you see, climate is not only a complicated ative observers gradually extended the frontiers of issue, it is also a cultural one; even more so for meteorology. Although many of the basic meteoro- climatic change. logical instruments were invented in the seven- teenth century, they were not standardized or widely distributed until well into the mid-nine- Apprehending climatic change teenth century. In pursuing historical research on climate change, I During Lyell's lifetime, meteorology emerged as have had to ask several crucial questions. How do an organized, if not yet fully disciplined, obser- people (scientists included) gain awareness and vational science. Observations were tabulated, understanding of phenomena that cover the entire charted, mapped and analysed to provide represent- globe, and that are constantly changing on time- ative climatic inscriptions. This process profoundly scales ranging from geological eras to centuries, changed climate discourse and established the decades, years and seasons? How was this foundations of the science of climatology (Fleming accomplished by individuals immersed in and sur- 1990). National weather services were established rounded by the phenomena? How were privileged in Europe, Russia and the United States in the third FLEMING, J. R. 1998. Charles Lyell and climatic change: speculation and certainty, hz: BLUNDELL, 161 D. J. & SCOTT, A. C. (eds) Lyell: the Past is the Key to the Present. Geological Society, London, Special Publications, 143, 161-169. Downloaded from http://sp.lyellcollection.org/ by guest on October 1, 2021 162 J.R. FLEMING quarter of the century, and by 1872, within Lyell's Montesquieu's ideas on climate and governance, lifetime, regular meetings were being held of the David Hume's ideas on recent climate change in the directors of national weather services (Fleming Americas, and of course, generations of colonial 1997). settlers and revolutionary patriots (Fleming 1998). A third approach to privileged knowledge was to As late as 1779 - in other words in the prime of establish from first principles what the climate Hutton's life- the EncyclopdFdie of Diderot and ought to be and how it ought to change. Joseph D'Alembert still defined 'climat" in the ancient Fourier, John Tyndall and James Croll, to name but way, geographically, as a 'portion or zone of the a few, engaged in such speculative and theoretical surface of the Earth, enclosed within two circles practices. These approaches-based on mathe- parallel to the equator', within which the longest matical, physical and astronomical principles- day of the year on the northern and southern tended to be most satisfying to those scientists boundaries differs by some quantity of time, for working within a particular disciplinary per- example one half hour. The Encyclopd(die spective; most only grudgingly admitted other provided a medical definition of climate as well, possible secondary causes of climate change. Lyell, understood primarily through the effects of climate of course, had his own favourite causal mechanism on the health and well-being of the inhabitants of which was solidly grounded in geological field various climes. It also mentioned Montesquieu's evidence. position on the influence of climate on people's In the twentieth century, climatic phenomena mores, character and forms of governance (Diderot have been rendered three dimensional by the & D'Alembert 1751-1765). development of upper-air observations, extended With no established science of climatology, into the indefinite past by palaeoclimatic authors such as Du Bos, Montesquieu and Hume techniques and, finally, globalized in the era of appealed directly to cultural sensibilities and satellite remote sensing. Many climate scientists prejudices, the authority of their positions residing today are working on links between remote sensing in their considerable literary skills and the lack of and more sophisticated computer models. They are other evidence to prove them wrong. Collectively, hoping, through advances in technology, to provide they generated a powerful vision of the climates of new privileged positions. For most scientists the Europe and America, shaping the course of empire goal is better understanding of climate: for some it and the arts: the concerted efforts of innumerable is also prediction and, ultimately, control. I might individuals in turn shaping the climate itself. By the add that an additional strategy for claiming end of the century, physiocrats had come to the privileged knowledge is the consensus method, for following general conclusions on climate change, example as currently practised by the culture and cultivation: Intergovernmental Panel on Climate Change (IPCC I. Cultures are determined or at least strongly 1995). shaped by climate. 2. The climate of Europe had moderated since ancient times. Perceptions of climatic change in the 3. These changes were caused by the gradual eighteenth century clearing of the forests and by cultivation. 4. The American climate was undergoing rapid and Climate-from the Greek term klima, meaning dramatic changes caused by settlement. slope or inclination-was originally thought to 5. The amelioration of the American climate depend only on the height of the Sun above the would make it more fit for European-type horizon, a function of the latitude. A second civilization and less suitable for the primitive tradition, traceable to Aristotle, linked the quality native cultures. of the air (and thus the climate) to the vapours and exhalations of a country. The Hippocratic tradition This was the dominant popular understanding of further linked climate to health and national climate at the dawn of the nineteenth century character. Enlightenment ideas linking climate (Fleming 1998). change and culture were grounded in the work of the diplomat, historian and critic Abb6 Jean- LyeU's position Baptiste Du Bos, perpetual secretary of the French Academy, who argued that the rise and fall of In the first edition of his Principles of Geology creative genius was not due primarily to 'les causes (1830-1832), Charles Lyell announced his theory morales' (education, cultivation, governance), but of the geographical determination of climate: a was largely attributable to changes in 'les causes theory that influenced generations to follow, physiques' (the nature of the air, land, soil and including G. E Wright (1889), M. Ramsay (1909- especially, climate). These ideas influenced 1910), and C. E. R Brooks (1926). He syste- Downloaded from http://sp.lyellcollection.org/ by guest on October