EcoAlert: Mega-Drought! A Prelude to Future Climate Change?


A new analysis of deep lake sediment suggests that the breakup and melting of massive icebergs in the North Atlantic may have triggered one of the most widespread and intense droughts in the past 50,000 years known as Heinrich Stadial 1.  The megadrought, which struck between 15,000 to 18,000 years ago, dried up large expanses of the monsoon regions of Africa and Asia, including Lake Victoria, the world's largest tropical lake with severe consequences for Paleolithic cultures.

Curt Stager of Paul Smith's College in New York, together with an international team of researchers, concluded that Henrich 1 corresponded with larger climatic changes near the equator. Sea surface cooling may have weakened rain bands in the Afro-Asian tropics and pushed them farther south. Microscopic crystals from grass in Lake Victoria, suggest these conditions favored the spread of grassland over forest. While the exact cause of this extreme drought is still unclear, these clues from the deep could teach climatologists about the possible repercussions of climate change to come.

The Daily Galaxy via Science, DOI: 10.1126/science.1198322

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