The Work of Umberto Monterin (1937) on the MWP & LIA in Italy
Crescenti, U. and Mariani, L. 2010. Carbon dioxide and global temperatures: A causal and historical perspective. Italian Journal of Engineering Geology and Environment 2: 51-62.
Monterin - who they describe as "an eminent glaciologist and geomorphologist, then Director of the Monte Rosa Royal Observatories of Meteorology and Geophysics - reported a large mass of data highlighting the alternation of hot and cold phases in the past millennium, with particular emphasis on the Medieval Warm Period and subsequent Little Ice Age." His published work (Monterin, 1937) was focused, for the most part, on the Aosta Valley and adjacent valleys; and his findings were derived from the following sets of observational or documentary data: (1) variations of the timberline, (2) past altitude limits of crops, (3) the presence of networks of irrigation canals at high altitude, (4) evidence of transit across now inaccessible mountain passes, and (5) the current and former extent of glaciers.
Based on these "still observable geomorphological and historical data, not biased by subjective interpretations or mathematical modeling," as Crescenti and Marianai describe them, Monterin's findings suggest that the MWP had temperatures they describe as being "at least 1-3°C warmer than present ones." Yet they report that "no negative phenomena, e.g. extensive flooding of coastal areas by the sea, extreme meteorological events and so on, occurred." In fact, they note that these types of events "were instead typical of the period of decline of the MWP (Lamb, 1977) and the LIA that Europe experienced from the 16th to the 19th century (Giraudi, 2009)."
And so it was that the two Italian researchers concluded that the work of Monterin, like that of many others, "validates the thesis that climate change is mainly driven by natural determinants," and not by anthropogenic CO2 emissions.
Giraudi, C. 2009. Late Holocene glacial and periglacial evolution in the upper Orco Valley, northwestern Italian Alps. Quaternary Research 71: 1-8.
Lamb, H.H. 1977. Climate, Present, Past and Future. Volume 2. Climatic History and the Future. Methuen & Co. Ltd., London, UK.
Monterin, U. 1937. Il clima sulle Alpi ha mutato in epoca storica? CNR, Comitato Nazionale di Geografia, 54pp.