Changing Notions of Environmental Change in the 19th Century (Invited Presentation)

Long before the professionalization of meteorology, climatology, or ecology, awareness of environmental change was frequently accompanied by concerns about vulnerability to exposure. Early migrants experienced sea changes in their airs, waters, foods, and places, which they perceived as existential challenges to their health and vitality. Would food and fuel stocks last through the winter? Would the new climate of their new homes be beneficial or deleterious? People at the mercy of the elements echoed the Baron Montesquieu’s enlightenment era epigraph, that “the empire of climate is the first of all empires.” In the early decades of the 19^th century, Thomas Jefferson and his colleagues called for systematic measurements of the American climate to document its rapid changes and coordinate their program of climate improvement. In the 1840s, the identification of a worldwide “ice age” prompted scientists to speculate on its causes and the possible return of the deadly glaciers. In the 1860s, James Croll articulated an astronomical theory of recurring ice ages that convinced Charles Darwin that climate change and evolution were inextricably linked, and John Tyndall’s experimental work on atmospheric radiation convinced him that changes in the amount of any of the radiatively active constituents of the atmosphere, including notably, carbon dioxide, could have produced “all the mutations of climate which the researches of geologists reveal.” By the close of the century, networks of meteorological measurements spanned much of the inhabited globe, and Svante Arrhenius suggested that a modest reduction or augmentation of the concentration of atmospheric carbon dioxide, might account for the glacial advances and retreats. Nils Ekholm foresaw this leading to a possible future ice age, but also pointed to the “remarkable” human influence on climate through increased coal burning. He speculated that humans might someday “control” climate by artificially increasing or decreasing the supply of carbonic acid. Yet, scientific weather prediction and climate analysis were only just beginning, and notions of environmental determinism remained dominant. While perceptions of environmental change had changed dramatically over the course of the century, so too had ideas of how to cope.