The First Global Warming Debate

Joshua Kendall, the author of The Forgotten Founder: Noah Webster’s Obsession and the Creation of an American Culture, has written a short essay in Smithsonian Magazine arguing that Thomas Jefferson was the first American to be concerned about global warming and Noah Webster was the first American to challenge the theory.  Here is a taste:

In his 1787 book, Notes on the State of Virginia, Jefferson launched into a discussion of the climate of both his home state and America as a whole. Near the end of a brief chapter addressing wind currents, rain and temperature, he presented a series of tentative conclusions: “A change in our climate…is taking place very sensibly. Both heats and colds are become much more moderate within the memory of the middle-aged. Snows are less frequent and less deep….The elderly inform me the earth used to be covered with snow about three months in every year. The rivers, which then seldom failed to freeze over in the course of the winter, scarcely ever do so now.” Concerned about the destructive effects of this warming trend, Jefferson noted how “an unfortunate fluctuation between heat and cold” in the spring has been “very fatal to fruits.”

Jefferson was affirming the long-standing conventional wisdom of the day. For more than two millennia, people had lamented that deforestation had resulted in rising temperatures. A slew of prominent writers, from the great ancient naturalists Theophrastus and Pliny the Elder to such Enlightenment heavyweights as the Comte de Buffon and David Hume, had alluded to Europe’s warming trend.

A contemporary authority, Samuel Williams, the author of a 1794 magnum opus, The Natural and Civil History of Vermont, had studied temperature readings at several points in the 18th century from his home state and half a dozen other locales throughout North America, including South Carolina, Maryland and Quebec. Citing this empirical data, Williams claimed that the leveling of trees and the clearing of lands had caused the earth to become warmer and drier. “[Climate] change…instead of being so slow and gradual, as to be a matter of doubt,” he argued, “is so rapid and constant, that it is the subject of common observation and experience. It has been observed in every part of the United States; but is most of all sensible and apparent in a new country, which is suddenly changing from a state of vast uncultivated wilderness, to that of numerous settlements.”

This opinion had been uttered for so long that it was widely accepted as a given—until Webster.