A Summing up
In North America there are signs that the glaciers advanced earlier than in Eurasia and that the fifteenth century was colder. Most glaciers reached their furthest forward Little Ice Age positions in the eighteenth century in Eurasia and in the nineteenth century in North America. Glacier advances were directly caused by ice accumulation exceeding ablation losses, generally the result of lower temperatures and increased snowfall. The fronts of small cirque and small valley glaciers respond within about five to ten years to changes in mass balance. Individual very cold years and sequences of two or three years occurred from time to time, mainly within the periods when glaciers were advancing. Attribution of a disaster to the Little Ice Age may then be valid if it seems that such departures from mean conditions were more frequent at times of glacier advance in the Little Ice Age than at other times.