NOAA/WDS Paleoclimatology - Smith et al. 2006 500-year Northern Hemisphere Speleothem Temperature Reconstruction

The magnitude of recent warming, and the variability of climate on centennial-millennial time scales are compromised by questions concerning the ability of tree rings to capture low-frequency climate fluctuations. Annually laminated stalagmite records can potentially provide a low-frequency climate archive through variations in annual growth rate. Presented here is an initial attempt to demonstrate the applicability of annually laminated stalagmite series to a large-scale climate reconstruction, by producing a 500-year Northern Hemisphere temperature reconstruction. The reconstruction shows an overall warming trend with a magnitude of 0.65 K and several other low-frequency characteristics consistent with other independent Northern Hemisphere archives. The result is sufficiently encouraging to warrant significant future effort in characterising annual growth rate records from laminated speleothems.