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Conservation in the Progressive Era
Man and the Earth

Nathaniel Shaler was a Harvard geologist who wrote books and essays in support of resource conservation in the early 1900s. In his book Man and the Earth, Shaler contends that resources are finite and that humankind is well on the way to depleting the earth's natural resources. Excerpts from his book follow. How do "lower" animals and "primitive" humans differ in their treatment of the environment from "civilized" humans? According to Professor Shaler, how has the "civilization" of mankind impacted minerals, water, and the soil? If humankind does not change its environmental behavior, Shaler predicted dire results. What predictions did he make?

View the entire document from which this excerpt was taken, from Evolution of the Conservation Movement, 1850-1920. Use your browser's Back Button to return to this point.


To see our position with reference to the resources of the earth it is well to begin by noting the fact that the lower animals, and primitive men as well, make no drain on its stores. They do not lessen the amount of soil or take from the minerals of the under-earth: in a small way they enrich it by their simple lives, for their forms are contributed to that store of chemically organized matter which serves the needs of those that come after them. With the first step upward, however, and ever in increasing measure as he mounts toward civilization, man becomes a spoiler.

So long as men remained in the estate of the hunter the damage they could do was limited to the destruction of the larger beasts and the birds, such as the moa, that could not fly. Prolific species, even of considerable size, such as the bisons, if they were nimble and combative, seem to have been able to hold the field against the attacks of primitive hunters. While in this station the tribes of men are never very numerous, for their wars, famines, and sorceries prevent their increase, which, under the most favorable conditions, is never rapid among savages. As soon, however, as stone implements begin to be replaced by those of metal, man begins to draw upon the limited stores of the under-earth, and with each advance in his arts the demand becomes the greater. In the first centuries of the iron age the requisition was much less than a pound each year for each person. Four centuries ago it probably did not exceed, even in the most civilized countries, ten pounds per capita each year. It appears to have been at something like that rate when the English colonies were founded in North America. At the present time, in the United States, it is at the average rate of about five hundred pounds per annum for every man, woman, and child in the land, and the demand is increasing with startling rapidity. It seems eminently probable that before the end of the present century, unless checked by a great advancement of cost, it will require a ton of iron each year to meet the progressive desires of this insatiable man. . . .

The advance in needs of dynamic power, in modern times, has been even greater than in ponderable things. Even two centuries ago, the energy available for man's work was mainly limited to that obtained from domesticated animals. The wind served in a small measure through the sails of ships and of windmills, and there were water-wheels, but the average amount of energy at his service was certainly less than one horse-power per capita. At the present time it may safely be reckoned that in the United States and in European countries on a similar economic basis, the average amount is at least ten times as great, and the present rate of increase quite as high as in the case of mineral resources. It is true, that, so far as water is concerned, this increase in the demand for energy in the arts does not come as a tax on the store of the under-earth, as it is obtained through solar energy which would otherwise be dissipated in space. But the use of falling water as a source of power, though rapidly increasing, does not keep pace with that of coal, which is obtained from a store which is in process of rapid exhaustion, one that cannot be relied on for more than a few hundred years to come:-if the world keeps the rate of consumption with which it enters the twentieth century it will be exhausted before the twenty-third. . . .

As soon as agriculture begins, the ancient order of the soils is subverted. In order to give his domesticated plants a chance to grow, the soil-tiller has to break up the ancient protective mantle of plants, which through ages of natural selection became adjusted to their task, and to expose the ground to the destructive action of the rain. How great this is may be judged by inspecting any newly ploughed field after a heavy rain. If the surface has been smoothed by the roller, we may note that where a potsherd or a flat pebble has protected the soil it rests on top of a little column of earth, the surrounding material having been washed away to the streams where it flows onward to the sea. A single heavy rainstorm may lower the surface of a tilled field to the amount of an inch, a greater waste than would, on the average, be brought about in natural conditions in four or five centuries. The result is that in any valley in which the soils are subjected to an ordinary destructive tillage the deportation of the material goes on far more rapidly than their restoration by the decay of the underlying rocks. Except for the alluvial plains whereupon the flood waters lay down the waste of fields of the upper country, nearly all parts of the arable lands which have been long subjected to the plough are thinned so that they retain only a part of their original food-yielding capacity. Moreover, the process of cropping takes away the soluble minerals more rapidly than they are prepared, so that there is a double waste in body and in the chemical materials needed by the food-giving plants.
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View the entire document from which this excerpt was taken, from Evolution of the Conservation Movement, 1850-1920. Use your browser's Back Button to return to this point.