Alpine glacial advance in relation to a proxy summer temperature index based mainly on wine harvest dates, A.D. 1453–1973

Abstract

A highly significant correlation was calculated between French wine harvest dates and central England summer temperature from 1659 to 1879 which harvest dates might be used to approximate western European summer temperatures for the pre‐instrumental period. A proxy summer temperature index was thereby constructed which combined French and German wine harvest and central England temperature data. This index was significantly correlated with a tree‐ring density prealpine Swiss summer temperature index from 1484 to 1973 and also with Northern Hemisphere annual temperatures from 1579 to 1973. Comparison of the proxy index with Alpine glaciation summaries showed highly significant relationships between glacial advance and intervals of below‐ median proxy temperature for all glacial studies combined and for the two most complete individual studies allowing a, even‐year lag between temperature decline and glacial advance. The initial Little Ice Age glacial expansion around A.D. 1600 occurred towards the close of the longest below‐median proxy temperature sequence which lasted from A.D. 1569 to 1604. Subsequent to this, glacial readvances were related to summer temperature declines of lesser duration or magnitude.

Climate Change and its Effect on Social Phenomena

“…3. Northern European grape harvest dates (see data set #18) coupled with observations of temperature in England later in the period [15]. 4.…”