Reference
Lamy, F., Arz, H.W., Bond, G.C., Bahr, A. and Patzold, J. 2006. Multicentennial-scale hydrological changes in the Black Sea and northern Red Sea during the Holocene and the Arctic/North Atlantic Oscillation. Paleoceanography 21: 10.1029/2005PA001184l.
What was done
In the words of the authors, "paleoenvironmental proxy data for ocean properties, eolian sediment input, and continental rainfall based on high-resolution analyses of sediment cores from the southwestern Black Sea and the northernmost Gulf of Aqaba were used to infer hydroclimatic changes in northern Anatolia and the northern Red Sea region during the last ~7500 years," after which the cyclical periodicities evident in their reconstructed hydroclimatic history were compared with Δ14C periodicities evident in the tree-ring data of Stuiver et al. (1998).
What was learned
Lamy et al. report that the "pronounced and coherent" multi-centennial variations they observed in their data "strongly resemble modern temperature and rainfall anomalies related to the Arctic Oscillation/North Atlantic Oscillation (AO/NAO)." In addition, they say that "the multicentennial variability appears to be similar to changes observed in proxy records for solar output changes," although "the exact physical mechanism that transfers small solar irradiance changes either to symmetric responses in the North Atlantic circulation or to atmospheric circulation changes involving an AO/NAO-like pattern, remains unclear."
What it means
This study is but another in a long line of studies that indicate that cyclical solar activity induces similar cyclical climatic activity on earth (for many more examples, see Solar Effects (Decadal-Scale Cycles, Centennial-Scale Cycles and Millennial-Scale Cycles) in our Subject Index); and it indicates, in Lamy et al.'s words, that "the impact of (natural) centennial-scale climate variability on future climate projections could be more substantial than previously thought." In fact, the current manifestation of that natural climatic impact could well be what climate alarmists are presently mistaking for global warming induced by rising greenhouse gas concentrations.
Reference
Stuiver, M., Reimer, P.J., Bard, E., Beck, J.W., Burr, G.S., Hughen, K.A., Kromer, B., McCormac, G., Van Der Plicht, J. and Spurk, M. 1998. INTCAL98 radiocarbon age calibration, 24,000-0 cal PB. Radiocarbon 40: 1041-1083.