- Historic Sites
Part Iii What Can We Do About It?
For more than two hundred years, Americans have tried to change the weather by starting fires, setting off explosions, cutting trees, even planning to divert the Gulf Stream. The question now is not how to do it, but whether to do it at all.
June/July 1986 | Volume 37, Issue 4
Such was the atmosphere in which James Pollard Espy of Pennsylvania carried on his lonely crusade in the 183Os and 184Os for human control of the weather. Espy was no crank (though John Quincy Adams found him “methodically monomaniac”), but a distinguished meteorologist. Rain showers, he had shown, occurred when air that had been warmed at ground level rose and the vapor in it condensed. It followed, then, that rain could be made artificially by building a fire on the ground. A small grass or forest fire would most likely suffice, Espy thought, and he drew upon a large store of anecdote and tradition to prove that such fires, set for other reasons, often triggered showers.
The idea itself, then, was not a new one. What was novel was the length to which Espy took it. Once a week, he proposed, let a string of small timber lots, stretching from the Great Lakes to the Gulf along the Western frontier, be set ablaze. On that chosen day, each week, a long line of rain showers would be formed and would make its way eastward across the states, until it broke over the Atlantic. The passage of this curtain would wring the moisture from the air, and the rest of the week would be clear. The plan, said Espy, would banish all the inconveniences of the fickle weather: drought, floods, “oppressive heats” and “injurious colds,” hail, tornadoes, and “violent wind.” It could be done at a cost of half a cent per citizen per year.
Espy implored a deaf Congress to listen, and never saw his plan tried. He had been born too early. For the halfcentury between 1865 and 1915 would prove to be, if not the Golden Age, at least (to use Mark Twain’s useful tag) the Gilded Age of American weather modification.
In 1864 George Perkins Marsh published a book entitled Man and Nature . He drew upon a lifetime’s store of reading and travel to create a classic of environmental literature—a picture of the havoc that human carelessness and ignorance had wrought on the natural world. Like many classics, the book had its ambiguities. While deploring the harm done to the earth by man’s actions, Marsh took a practical, not a romantic, view of nature and considered its subjugation for the benefit of humans to be the great goal of science. His very stress on the power of civilization to unwittingly damage the natural world suggested that man was more powerful in the face of the elements than had previously been thought. Until very recent times the main argument against weather modification was not that its results would be harmful, but rather that it lay beyond human ability to bring about. Man and Nature spoke to both concerns, but it was the réévaluation of man’s power that had the most influence in the nineteenth century.
Marsh found deforestation an especially disturbing problem. Trees, he argued, protected the soil from erosion, while forests regulated the flow of streams. Some of the quotations in the book argued for a still larger role for trees. Their presence, many believed, increased precipitation, and their removal would reduce it. Marsh made clear his doubts about this view, but when Ferdinand V. Hayden read Man and Nature , it was the pro-tree quotations, and not Marsh’s disavowals, that sparked his enthusiasm. Though still young, Hayden was already a distinguished geologist in the 186Os. In the following decade he would lead one of the great surveys of the western lands.
If the noise of battle touched off rainstorms, then rain could be made artificially by loud noises.
In a government report in 1867, Hayden urged that trees be planted on the Great Plains in order to increase the yearly rainfall. His advocacy, wrote the historian Henry Nash Smith, made the idea respectable: “Hayden had rationalized and had given pseudo-scientific status to what had originally been but a vague poetic expression of the massive optimism of the westward movement.” A hostile critic summed up the view, fairly enough: “the humidity and rainfall,” wrote the geologist John Wesley Powell, “is attributed to the lakes and forests, and the aridity is attributed to the plains and deserts,” rather than the other way around. The opinion of climate had come full circle from the Revolutionary days. Trees, once the villains, had become the heroes.
The nation was ready to take Hayden at his word. Settlement expanded rapidly over the area once known as the Great American Desert. The idea of tree planting, though, gradually receded. Hayden’s successors, in the 187Os, breezily waved aside this irksome duty. Cultivation alone, they said, would bring enough rain to water the crops. Charles Dana Wilber, a land promoter, coined the motto of this school of thought. “Rain,” he declared, “follows the plow.” Others argued that it followed the railroad, or the telegraph. As the movement grew, it left reality farther and farther behind and became basically a matter of faith.