Archaeology of Overshoot and Collapse

The literature on sustainability and the human future emphasizes the belief that population and/or mass consumption caused resource degradation and collapse in earlier societies. Archaeological literature proposing overshoot and collapse appears in current debates over resource conservation versus continued economic growth. The prominence of this debate, with its national and international dimensions, makes it important to assess whether there is evidence in the archaeological literature for overshoot and collapse brought on by Malthusian overpopulation and/or mass consumption. 59 A nn u. R ev . A nt hr op ol . 2 00 6. 35 :5 974 . D ow nl oa de d fr om a rj ou rn al s. an nu al re vi ew s. or g by A R IZ O N A S T A T E U N IV . o n 09 /2 5/ 06 . F or p er so na l u se o nl y. ANRV287-AN35-04 ARI 13 August 2006 6:41 Overshoot: the outcome when a trajectory is unsustainable for environmental, technical, or social reasons Collapse: rapid loss of an established level of social, political, and/or economic complexity INTRODUCTION Overshoot is a term and concept in the wild. Like a computer virus in the wild, it proliferates in the public arena. It mutates like a biological virus, assuming altered forms and new meanings. Overshoot is part of contemporary politics, ideology, and public discourse. Many believe that humanity has overshot the carrying capacity of some resource or other (e.g., Rees 2004). Conversely, neoclassical economists and the politicians they influence argue that resources, and the concept of overshoot, can be left out of economic calculations. As a resource becomes scarce, they believe market prices will signal that there are rewards to innovation: A new resource or technology will emerge. This debate tinges public life and international relations. It also means that academic discourse, including archaeological and historical research, about overshoot has political connotations. The concept of overshoot is often traced to Malthus’ (1798) Essay on the Principle of Population. Malthus believed that whereas agricultural production increases linearly, population tends to grow geometrically. Population will overshoot food supply. Malthus was influenced by Wallace (1761), who argued that progress would undermine itself by filling the world with people. Stimulated by Malthus, Jevons (1866 [1865]) wrote The Coal Question, in which he proposed that Britain’s industrial development would outrun the coal supply. Ehrlich (1968) brought Malthusian overshoot to public attention in The Population Bomb. The concept was systematized by Catton (1980) in Overshoot: The Revolutionary Basis of Ecological Change. Catton defines overshoot as follows: (v.) to increase in number so much that the habitat’s carrying capacity is exceeded by the ecological load, which must in time decrease accordingly; (n.) the condition of having exceeded for the time being the permanent carrying capacity of the habitat (p. 278). The concept of overshoot clearly depends on that of carrying capacity, which Catton (1980) defines as follows: the maximum population of a given species which a particular habitat can support indefinitely (under specified technology and organization, in the case of the human species)