Hier beweeg je je op glad ijs hoor. Voor zover ik weet is daar nog veel discussie over onder wetenschappers zonder dat er een duidelijke consensus is.
Wouter
Dit wijst waarschijnlijk ook al op afwezigheid van het verschijnsel.
The IPCC TAR says of the MWP that the posited Medieval Warm Period appears to have been less distinct, more moderate in amplitude, and somewhat different in timing at the hemispheric scale than is typically inferred for the conventionally-defined European epoch. The Northern Hemisphere mean temperature estimates of Jones et al. (1998), Mann et al. (1999), and Crowley and Lowery (2000) show temperatures from the 11th to 14th centuries to be about 0.2°C warmer than those from the 15th to 19th centuries, but rather below mid-20th century temperatures [2].
The TAR discusses Was there a "Little Ice Age" and a "Medieval Warm Period"? and says Thus current evidence does not support globally synchronous periods of anomalous cold or warmth over this timeframe, and the conventional terms of "Little Ice Age" and "Medieval Warm Period" appear to have limited utility in describing trends in hemispheric or global mean temperature changes in past centuries.http://www.grida.no/climate/ipcc_tar/wg1/070.htm
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