The Tree-Ring Record of Drought and Disaster Over North America

Severe drought over North America has a long history and prehistory of serious socioeconomic impacts.  Tree-ring reconstructions of the soil moisture balance across North America provide an exactly dated, spatially detailed record of decadal droughts during the past millennium.  Tree-ring reconstructed droughts with known or inferred social impacts included the Dust Bowl migrations of the 1930’s, the mid-19^th century drought and Native American crisis on the Great Plains, the late-18^th century drought of “El Año de Hambre” over Mexico, the 17^th century Pueblo drought and famine in the Southwest, the 16^th century megadrought linked with early colonial famine and disease, the late-13^th century “Great Pueblo Drought” associated with Anasazi abandonment, and the megadroughts contemporaneous with Classic Period decline in Mesoamerica.