Climate is by no means the only ecosystem variable affecting human fortunes. Some
of the greatest losses of human life have resulted from epidemic diseases; new forms
of these may appear through evolution, altered communications and other shifts. Human
societies have repeatedly been affected by earthquakes; the migration or decline of fish
stocks; volcanic eruptions (the Toba explosive eruption in Sumatra c. 74,000 BP may
have come close to exterminating Homo sapiens – Oppenheimer, 2003: 72–78); and
tsunamis. Environmental management should consider the threat of infrequent but severe
events, and whenever possible steer development to reduce human vulnerability and
conserve biodiversity and cultural riches.