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The Little Ice Age in South Africa, from around AD 1300 to 1800, and medieval warming, from before 1000 to around 1300, are shown to be distinctive features of the regional climate of the last millennium. The proxy climate record has been constituted from oxygen and carbon isotope and colour density data obtained from a well-dated stalagmite derived from Cold Air Cave in the Makapansgat Valley. The climate of the interior of South Africa was around 1 Celcius cooler in the Little Ice Age and may have been over 3 Celcius higher than at present during the extremes of the medieval warm period. It was variable throughout the millennium, but considerably more so during the warming of the eleventh to thirteenth centuries. Extreme events in the record show distinct teleconnections with similar events in `other parts of the world, in both the northern and southern hemispheres. The lowest temperature events recorded during the Little Ice Age in South Africa are coeval with the Maunder and Sporer Minima in solar irradiance. The medieval warming is shown to have coincided with the cosmogenic [sup 10]Be and [sup 14]C isotopic maxima recorded in tree rings elsewhere in the world during the Medieval Maximum in solar radiation. [ABSTRACT FROM AUTHOR]

Radiocarbon-dated lacustrine sedirnentary evidence indicates that glaciers of variable size occupied the southwestern cirques on Mount Kenya during much of the last 6OOO years. Pro-glacial lacustrine sediments obtained from Hausborg Tarn reveal distinct variations in rock-flour content whereas the sediments in ObiongTam, a nearby non- pro-glacial lake of similar size and appearance to Hausberg Tarn show no such variations. The lamination is therefore likely to be directly related to erosion by the glaciers draining into the upper lake in Hausberg Valley. Six major periods of glacier advances have been dated to shortly before 5700, 4500-3900, 3500-3300, 3200- 2300, 1300-1200, and 600-400 cal. years BP. Radiocarbon dating of the bottom sediments fromboth Naro Moru and Hausborg Tarn, is consistent with a marked glacier expansion that occurred shortly before 5700 cal. years BP. This advance reached approximately I km farther downvalley compared with the advances of the Little Ice Age. Modelling of the climate conditions required for this mid-Holocene Mount Kenya advance shows that a lowering of the equilibrium line altitude (ELA) by 100 m for a few hundred years could cause a glacier advance of the inferred magnitude. The glacier advances are attributed primarily to changes in temperature because several independent paleoclimatic studies from East Africa and other areas affected by the Indian monsoon indicate a relatively dry climate at times of glacier advance on Mount Kenya. [ABSTRACT FROM AUTHOR]

Changes in the size of glaciers, in the altitude of the alpine tree-limit, and variation in the width of tree-rings during the Holocene clearly indicate that the average Scandinavian summer temperature hasfluctuated. During warm periods it has been about 2 deg.C warmer than at present; during cold periods it has been almost as cold as it was during the coldest decades of the previous centuries. Superimposed on these long-term variations, which have lasted from 100 to 200 years, are short fluctuations in temperature. The Scandinavian chronology, which is based on glacier and alpine tree-limit fluctuations as well as on dendrochronology, is well correlated with the changes in climate, which studies of ice cores from central Greenland have revealed. It is therefore believed that the Scandinavian climate chronology depicts conditions typical of a large area. The Scandinavian record is compared with data concerning solar irradiation variations estimated as 14C anomalies obtained from tree-rings. A correlation between major changes in climate and variations in solar irradiation points to a solar forcing of the climate. This means that thereis no evidence of a human influence on climate so far. [ABSTRACT FROM AUTHOR]