This book tells the story of a fertile European country that, as a result of over-population and military armament, over-exploited its fields and forests in a non-sustainable fashion. By the eighteenth century Denmark, along with other European countries, found itself in an ecological crisis: clear felling of forests, sand drift, floods, inadequate soil fertilization and cattle disease. This crisis was overcome by a green biotechnological revolution that changed the whole pattern of agriculture, and by the abandonment of wood as a raw material and source of energy in favor of coal and iron. This book outlines the background of the present-day ecological crisis, both in the industrial world and in developing countries, and is the first attempt to understand early modern Europe from a consistently ecological viewpoint.