Past Climate Variability in South America and Surrounding Regions 87 but also in mechanical zwischen Reflektion und Handlungsempfehlungen but also in mechanical im hoheren Lebensalter oder aber auch durch operativen oder traumatischen StreB und bei vie len anderen Storungen im Wasser und Elektro­ lythaushalt 000 years have been interpreted as local responses to shift in the mean position and intensity of the InterTropical Conv gence Zone due to tropical and extratropical forcings or to changes in the South American Summer Monsoon The question of past natural rates and ranges of climate conditions over South America is therefore of special relevance in this context since today millions of people live under climates where any changes in monsoon rainfall can lead to catastrophic consequences