The Medieval Warm Period (and Little Ice Age) in Coastal Syria
Kaniewski, D., Van Campo, E., Paulissen, E., Weiss, H., Bakker, J., Rossignol, I. and Van Lerberghe, K. 2011. The medieval climate anomaly and the little Ice Age in coastal Syria inferred from pollen-derived palaeoclimatic patterns. Global and Planetary Change 78: 178-187.
Based on an analysis of pollen types and quantities found in a 315-cm sediment core retrieved from alluvial deposits within the floodplain of a spring-fed valley located at 35°22'13.16"N, 35°56'11.36"E in the coastal Syrian lowland, Kaniewski et al. converted the pollen data into Plant Functional Types (PFTs) that allowed them to construct pollen-derived Biomes (PdBs) similar to the regional studies of Tarasov et al. (1998), after which they were able to relate "the ratio of PdB warm steppe (WAST) divided by PdB cool steppe (COST) to local temperature, as also was done by Tarasov et al.
The seven scientists say their WAST/COST record "indicates that temperature changes in coastal Syria are coherent with the widely documented warming during the MCA and cooling during the LIA," the first of which epochs they assign to the period of approximately AD 1000 to 1230, while the latter they assign to approximately AD 1580 to 1850; and with respect to the Current Warm Period, they say that "modern warming appears exceptional in the context of the past 1250 years, since only three warm peaks of similar amplitude are registered during the High Middle Ages." However, they clearly state -- in the very last sentence of their paper -- that the "three peaks centered on ca. 1115, 1130 and 1170 cal yr AD suggest similar or warmer temperatures compared to AD 2000." And when one consults the actual plot of their WAST/COST record, it can be seen that the warmth of the first and last of these peaks was essentially identical to that centered on the end of the last century (AD 2000), while the central peak at AD 1130 was the warmest of them all.
The 880-1870 cal yr AD warm-cool ratio WAST/COST temperatuer reconstruction of Kaniewski et al. (2011). Adapted from their Figure 5.
Although they do not directly say it in their paper, the findings of Kaniewski et al. do indeed reveal whether or not "recent climate trends are atypical or not over the last millennium." And the answer is: They are not ... at least not in the region of Syria they studied, and not in many of the other parts of the world for which we have evidence of the MWP, as demonstrated by the materials we have assembled in our Topical Archive of the subject. And this result clearly suggests that Earth's current level of warmth need not be attributed to the current high level of the air's CO2 content; for the peak warmth of the MWP was even greater than it has been over the past couple of decades, and at a time when the atmosphere's CO2 concentration was approximately 100 ppm less than it is today, which suggests that whatever phenomenon was responsible for the warmth of the Medieval Warm Period could also be responsible for the warmth of the Current Warm Period; and that something would have to be something other than CO2.
Alpert, P., Krichak, S.O., Shafir, H., Haim, D. and Osetinsky, I. 2008. Climatic trends to extremes employing regional modeling and statistical interpretation over the E. Mediterranean. Global and Planetary Change 63: 163-170.
Tarasov, P.E., Cheddadi, R., Guiot, J., Bottema, S., Peyron, O., Belmonte, J., Ruiz-Sanchez, V., Saadi, F. and Brewer, S. 1998. A method to determine warm and cool steppe biomes from pollen data; application to the Mediterranean and Kazakhstan regions. Journal of Quaternary Science 13: 335-344.