The Medieval Warm Period in the Alpine Regions of Europe
Kress, A., Hangartner, S., Bugmann, H., Buntgen, U., Frank, D.C., Leuenberger, M., Siegwolf, R.T.W. and Saurer, M. 2014. Swiss tree rings reveal warm and wet summers during medieval times. Geophysical Research Letters 41: 1732-1737.
The eight researchers - representing Switzerland, Germany and the Czech Republic - report they found that after an initial high occurrence of drought events in the ninth century, there was "a pronounced period (A.D. 900-1200) with few dry extremes." And they say that "this absence of droughts, in combination with a slightly enhanced number of wet extremes, suggests a relatively wet/warm period, roughly coinciding with the MCA," which they note "is broadly consistent with Marcott et al. (2013), who concluded that greater warmth was often associated with greater wetness during the Holocene in the extra-tropical Northern Hemisphere (>30°N)." With respect to the implications of their work, in concluding the abstract of their paper, Kress et al. state their findings point to "beneficial conditions for agriculture and human well-being during the MCA in this region."
Marcott, S.A., Shakun, J.D., Clark, P.U. and Mix, A.C. 2013. A reconstruction of regional and global temperature for the past 11,300 years. Science 339: 1198-1201.
Seager, R., Graham, N. and Herweijer, C. Gordon, A.L., Kushnir, Y. and Cook, E. 2007. Blueprints for medieval hydroclimate. Quaternary Science Reviews 26: 2322-2336.
Trouet, V., Esper, J., Graham, N.E., Baker, A., Scourse, J.D. and Frank, D.C. 2009. Persistent positive North Atlantic Oscillation mode dominated the Medieval Climate Anomaly. Science 324: 78-80.