Historical analyses also reveal wide- spread disasters, social disruption and disease outbreaks in response to the more acute, inter-annual, quasi-periodic ENSO (El Niño Southern Oscillation) cycle (1). The depletion of soil fertility and freshwater supplies, and the mismanage- ment of water catchment basins via excessive deforestation, also have con- tributed to the decline of various regional populations over the millennia (2). Today, climate scientists predict that humankind’s increasing emission of greenhouse gases will induce a long-term change in the world’s climate. These gases comprise, principally, carbon dioxide (mostly from fossil fuel combustion and forest burning), plus various other heat-trapping gases such as methane (from irrigated agriculture, animal husbandry and.
