ABSTRACT
Imagine observing the earth from space at night 100,000 years ago. Would it be diffi cult to see any clues of human presence on the surface of the earth? It is believed that homo sapiens have always used fi re and that the use of fi re likely goes back one million years to homo erectus (James, 1989). Nonetheless, the dark side of the earth has probably been too dark to detect human presence from space for most of human history. It is likely that only during the past 200 years have we used nocturnal high elevation perspectives to assess human activity at night. During the U.S. Civil War, balloons were used to count enemy campfi res, and in the past 50 years we have had satellites making nocturnal observations of the earth (Croft, 1978). In recent years, night-time satellite imagery produced by the Defence Meteorological Satellite Program’s Operational Linescan System (DMSP OLS) ( Figure 15.1 ) has been used to model numerous human phenomena including population, population density, economic activity, energy consumption, CO 2 emissions, pavement and the human ecological footprint (Doll, Muller & Elvidge, 2000).
