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Late Holocene Climate in South Africa
Reference
Lee-Thorp, J.A., Holmgren, K., Lauritzen, S.-E., Linge, H., Moberg, A., Partridge, T.C., Stevenson, C. and Tyson, P.D. 2001. Rapid climate shifts in the southern African interior throughout the mid to late Holocene. Geophysical Research Letters 28: 4507-4510.

What was done
The authors developed a 6500-year record of climate from proxy data (18O for temperature) derived from an aragonitic stalagmite taken from Cold Air Cave in the Makapansgat Valley in Northeastern South Africa.

What was learned
Following an approximate 4000-year period of little to no long-term trend in temperature, the authors find a decreasing trend that, in their words, "reflects an in-phase cooling trend observed in both Antarctic and Greenland ice cores from 1400 years ago." This decrease in temperature culminates at AD 1750, at the center of the coldest period of the entire 6500-year record, which latter period they identify as the Little Ice Age. "Recovery from this episode," they further say, "is likely still in progress."

What it means
These observations contradict several climate alarmist claims. First, they substantiate the occurrence of the Little Ice Age in a part of the planet far removed from the lands surrounding the North Atlantic Ocean. Second, the data indicate this climatic interval was the coldest anomaly of the last 6500 years, both in Greenland and Antarctica, as well as South Africa, which suggests that a lot of warming was needed thereafter just to get back to the average temperature of the 4000-year period preceding the climatic deterioration that began about 1400 years ago. Third, the data - as well as the authors' interpretation of the data - suggest that the warming of the past century or so is likely nothing more, as they put it, than a "recovery from this episode."


Reviewed 9 January 2002