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The Roman, Medieval and Current Warm Periods in the Northwestern Italian Alps
Giraudi, C. 2009. Late Holocene glacial and periglacial evolution in the upper Orco Valley, northwestern Italian Alps. Quaternary Research 71: 1-8.

What was done
The author examined "long-term relations among glacial activity, periglacial activity, soil development in northwestern Italy's alpine River Orco headwaters, and downvalley floods on the River Po," based on "studies carried out by means of geological and geomorphologic surveys on the glacial and periglacial features," including a sampling of soils involved in periglacial processes that "provided a basis for development of a chronological framework of late Holocene environmental change" and an analysis of "a stratigraphic sequence exposed in a peat bog along the Rio del Nel" about 1 km from the front edge of the Eastern Nel Glacier.

What was learned
Among a number of other interesting findings, Giraudi determined that between about 200 BC and AD 100 -- i.e., during the Roman Warm Period -- "soils developed in areas at present devoid of vegetation and with permafrost," indicative of the likelihood that temperatures at that time "probably reached higher values than those of the present [our italics]." He also concluded that "analogous conditions likely occurred during the period of [the] 11th-12th centuries AD, when a soil developed on a slope presently characterized by periglacial debris," while noting that "in the 11th-12th centuries AD, frost weathering processes were not active and, due to the higher temperatures than at present [our italics] or the longer duration of a period with high temperatures [our italics], vegetation succeeded in colonizing the slope." He also determined that "the phase of greatest glacial expansion (Little Ice Age) coincides with a period characterized by a large number of floods in the River Po basin," and that "phases of glacial retreat [such as occurred during the Roman and Medieval Warm Periods] correlate with periods with relatively few floods in the River Po basin."

What it means
This study provides a double refutation of the climate-alarmist claim that late 20th-century temperatures were the warmest of the past two millennia. And it demonstrates that in this part of Europe, cooler periods have generally experienced less flooding than have warmer periods.

Reviewed 8 April 2009