Paleoclimates and the emergence of fortifications in the tropical Pacific islands

Paleoclimatic data from the tropical Pacific islands are compared to archaeological evidence for fortification construction in the Holocene. The results suggest that in some regions, people constructed more fortifications during periods that match the chronology for the Little Ice Age (AD 1450–1850) in the Northern Hemisphere. Periods of storminess and drought associated with the El Niño Southern Oscillation have less temporal correlation with the emergence of fortifications in the Pacific, but significant spatial correlation with the most severe conditions associated with this cycle. These temporal and spatial correlations require additional study to investigate possible causal relationships.