Glenn Thomas Trewartha (1896 – 1984)[1] was an American geographer of Cornish American descent.[2]
He graduated from the University of Wisconsin–Madison, with a Ph.D. in 1924. He taught at the University of Wisconsin.[3]
He gave an address to the Association of American Geographers, "A Case for Population Geography", in which he argued that "fundamentally geography is anthropocentric, and if such is the case, that numbers, densities and qualities of the population provide the essential background for all geography. Population provide the essential background for all geography. Population is the point of reference from which all other elements are observed, and from which they all singly and collectively derive significance and meaning".[4] He also wrote about climate, explaining that the atmosphere was like "a pane of glass in a greenhouse... thus maintaining surface temperatures considerably higher than they otherwise would be."[5][6]