This text is a slightly edited version of a lecture given when the author was installed as professor of environmental history at Umeå University on October 9, 1993. The author sketches tendencies in historical research--the Annales-school and the historiography of the West in the United States--leading up to the formation of environmental history as an independent field of research during the last quarter century. He comments on some recent examples of excellent scholarship--works by Alfred Crosby, Carolyn Merchant, Donald Worster--before turning to an older tradition of environmental description in 19th century geography, geology and the life sciences. He then puts environmental investigations into the framework of a general history of science starting with John Evelyn's study of the quality of the London air, published in 1661, but also mentioning major naturalists and thinkers such as Pascal, Linnaeus, Haeckel, and Humboldt. The author finally takes up the theme of biodiversity, indicating that a history of the environment and of the environmental sciences also has implications for how nature is treated today and how it will be treated in the future.