Climate and society: lessons from the past 10,000 years.

This paper distinguishes three major "revolutions" in the socio-environmental interactions that reflect growth in the extent to which human beings invest in and modify their environments. As people settled in villages during the Neolithic, interactions between more people became an important element in survival strategies, shifting the emphasis in survival strategies from mobility to sociality. The emergence of cities changed human societies by: i) creating dependencies between more and more distant regions, ii) increasing the degree of aggregation of human populations, iii) narrowing the range of subsistence resources on which people depended, and iv) increasing further their investment in the natural environment and in material culture. Altogether, urbanization drove human social systems further and further away from flexibility and rapid adaptation to environmental change, while increasing the demands on the social system, including major increases in energy and matter to support urban populations. This was achieved by linking together larger and larger hinterlands for these cities, in effect creating Empires. The fundamental change is one from humans responding to environmental change and disruption by migration to humans investing in the environment, and therefore responding to environmental change by problem solving. One therefore needs to look at the combined socio-environmental systems over the longer term that reflect the buildup and culmination of the shifts in the social and environmental risk spectra due to the human-environmental interactions in periods before the "crisis" occurs, which are a fact of life in any society's interaction with its environment, and should be seen as "social" challenges rather than "environmental" ones. These are generally due to the fact that the society in question has invested so much in a particular way of life that it cannot innovate itself out of difficulty before time runs out. This implies that we have to shift our thinking about socio-environmental issues, from "population thinking" to "organization thinking." In this perspective, a crisis does not imply the disappearance of the people involved, but a transformation of the organization that links them.