Civilization and climate / by Ellsworth Huntington.

  • Ellsworth Huntington
Date:
1924
Catalogue details

Licence: In copyright

Credit: Civilization and climate / by Ellsworth Huntington. Source: Wellcome Collection.

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    irregularly in great waves. Even in early historic times certain centuries were apparently drier than today, while others not long ago were moist. In 1909, this view was confirmed during the Yale Expedition to Palestine, the results of which are set forth in Palestine and Its Transformation. Then a series of journeys in the drier parts of the United States and in Mexico and Central America, in cooperation with D. T. MacDougal of the Desert Botanical Laboratory of the Carnegie Institution, showed that the main features of previous conclusions apparently apply to the New World as well as the Old. The most important feature of this work in America was the measurement of the thickness of the annual rings of growth of some four hundred and fifty of the Big Trees of California— the Sequoia Washingtoniana, which grows high in the Sierras. These measurements made it possible to form a fairly reliable climatic curve for 2000 years and an approximate curve for another thousand. The final data as to the Big Trees were pub¬ lished in The Climatic Factor, which appeared in 1915, at the same time as Civilization and Climate. The agreement of the California curve with the climatic curve of western Asia as pre¬ viously worked out, and the constantly growing evidence as to the reliability of tree growth as a measure of climate have done far more than anything else to cause the hypothesis of climatic pulsations to be widely accepted. Here is the way the matter is summed up by the British meteorologist, C. E. P. Brooks, in his book on The Evolution of Climate (1922) : “The question of climatic changes during the historic period has been the subject of much discussion, and several great meteorologists and geog¬ raphers have endeavoured to prove that at least since about 500 b.c. there has been no appreciable variation. It is admitted that there have been shiftings of the centers of population and civi¬ lization, first from Egypt and Mesopotamia to the Mediterra¬ nean regions, and later to northern and western Europe, but these have been attributed chiefly to political causes and es-
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