Solar Variability, Climate, and Human Response: A View from the Southwest

David A. Gregory [dagpt@cybertrails.com] and Fred L. Nials [fnials@earthlink.net],Center for Desert Archaeology, Pinetop, Arizona.

            Variation in middle and late Holocene14C serves as a proxy for variation in solar activity. The influence of solar output on climate events and trends is explored, as are the effects of those events and trends on prehistoric cultural developments in the American Southwest. These analyses strongly suggest that particular rates and directions of change in atmospheric 14C (and thus solar activity) co-occur with variations in a number of natural and cultural phenomena. These include the frequency of El Niño events, the occurrence of drought and “wetter” periods, flood frequency and magnitude, as well as documented changes in demography, subsistence activities and material culture, and possibly even linguistic differentiation in the prehistoric Southwest.