to the 19th centuries. Despite variances throughout the continent, a general trend of declining temperatures in Africa led to an average cooling of 1 °C. In Ethiopia and North Africa, permanent snow was reported on mountain peaks at levels at which it does not occur today. Timbuktu, an important city on the trans-Saharan caravan route, was flooded at least 13 times by the Niger River, but there are no records of similar flooding before or since that time. Several paleoclimatic studies of Southern Africa have suggested significant changes in relative changes in climate and environmental conditions. In Southern Africa, sediment cores retrieved from Lake Malawi show colder conditions between 1570 and 1820, which "further support, and extend, the global expanse of the Little Ice Age." A novel 3,000-year temperature reconstruction method, based on the rate of stalagmite growth in a cold cave in South Africa, further suggests a cold period from 1500 to 1800 "characterizing the South African Little Ice age." The δ18O stalagmite record temperature reconstruction over a 350-year period (1690–1740) suggests that South Africa may have been the coldest region in Africa and have cooled by as much as 1.4 °C in summer. Also, the solar magnetic and Niño-Southern Oscillation cycles may have been key drivers of climate variability in the subtropical region. Periglacial features in the eastern Lesotho Highlands might have been reactivated by the Little Ice Age. Another archaeological reconstruction of South Africa reveals the rise of the Great Zimbabwe people because of ecological advantages from the increased rainfall over other competitor societies, such as the Mupungubwe people. Pollen records derived from rock hyrax middens in the Cederberg Mountains of southwestern South Africa indicate an increase in humidity in the region at the start of the Little Ice Age. Other than temperature variability, data from equatorial East Africa suggest impacts to the hydrologic cycle in the late 1700s. Historical data reconstructions from ten major African lakes indicate that an episode of “drought and desiccation” occurred throughout East Africa. The period showed drastic reductions in the depths of lakes, which were transformed into desiccated puddles. It is very likely that locals could cross Lake Chad, among others, and that bouts of “intense droughts were ubiquitous.” That indicates local societies were probably launched into long migrations and warfare with neighboring tribes, since agriculture was made virtually useless by the dry soil. Antarctica Kreutz et al. (1997) compared results