Trewartha, Glenn (1896–1984)

Born in southwestern Wisconsin in 1896, Glenn Trewartha was an influential 20th-century American geographer. Trewartha's academic career was impressive in both its length and scope. His publication career covers seven decades, from his first publication in 1923 to his last in 1982 (just 2 yrs. [years] before his death in 1984). Most impressively, Trewartha was a recognized leader in three distinct areas of geography: (1) weather and climate, (2) the geography of Japan, and (3) population geography.

Trewartha was hired as an instructor at the University of Wisconsin, Madison, in 1922, and received his PhD there in 1925. After receiving his doctorate, Trewartha was promoted to assistant professor at Wisconsin in 1926 (and later to associate professor and professor). He spent the next 40 yrs. at Madison before retiring in 1965 as the Finch Research Chair in Geography.

First and foremost, Trewartha was a leading expert on weather and climate. He published the very influential textbook An Introduction to Weather and Climate in 1937. The book went through five editions over the next 40 yrs., the [Page 2883]last edition being published in 1980. Trewartha is best known for his introduction of and modifications to the Koppen climate classification system. Also, Trewartha is credited with coining the term greenhouse effect in 1937.

In addition to his work on climate, Trewartha was also a leading American scholar on Japan. One of the first American geographers to specialize in the regional geography of Japan, Trewartha published his first book on the country in 1934, with subsequent editions published in 1945 and 1965. As a leading American scholar on Japan during World War II, Trewartha served as a consultant to the U.S. government during the war and afterward during the Allied occupation government's reconstruction efforts.

Trewartha is also remembered as the founder of the subdiscipline of population geography. As president of the Association of American Geographers, Trewartha used his 1953 presidential address to advocate for population geography as a distinct and prominent subdiscipline. He believed that population geography had long been ignored by geographers and argued that the study of population should be central to the discipline. He proposed that geography had three main elements: (1) the “physical earth,” (2) the “cultural earth,” and (3) population. Trewartha saw the study of population as a central organizing principle of geography and as the key linkage between the human and physical sides of the discipline.