Environmental catastrophe in the Pacific Islands around A.D. 1300

Abstract

Paleosea-level data for the Pacific Islands suggest that sea level in the region fell, possibly in two stages, between 680 and 475 cal yr B.P. (A.D. 1270–1475). This was associated with a ∼1.5°C fall in temperature (determined from oxygen-isotope analysis) and an observed increase in El Nino frequency. For a long time, it has been clear that these changes—characterized as the “A.D. 1300 event”—brought about environmental and cultural changes on Pacific Islands. These are documented here systematically for the first time. Temperature fall, sea-level fall, and possibly short-lived precipitation increase are the principal effects of the A.D. 1300 event. Temperature fall stressed ecosystems, but its effects are difficult to separate from those of the others. Sea-level fall saw dramatic falls of nearshore coral-reef productivity and the formation of (habitable) reef islands (motu). Precipitation rise increased upland erosion and lowland sedimentation. The human outcomes of these environmental changes are organized in three groups: conflict, settlement-pattern changes, and the end of long-distance voyaging. Conflict increased during/after the A.D. 1300 event because of an abrupt fall in the food resource base. This also caused large coastal settlements on many islands to be abandoned in favor of caves and/or smaller fortified hilltop settlements. Successful long-distance voyages ceased during/after the A.D. 1300 event, as did interisland exchange within many archipelagoes. The regional (rather than local) extent of the A.D. 1300 event is demonstrated. Questions remain as to its synchronicity and duration. © 2000 John Wiley & Sons, Inc.