Past Andean Drought and Glacial Retreat Tied to Abrupt Warming in the Arctic

Nature Communications, October 12
 

Past abrupt warming periods in the Arctic were related to near-complete disappearance of glaciers in the tropical Andes up to around 4,700 meters.  Arctic warming caused changes in ocean currents that then altered inter-hemispheric heat distribution: weakening the South American summer monsoons, as reflected in sediment records of Andean lakes dating back 50,000 years.  These rapid climate fluctuations also significantly reduced the water level in Lake Junín, one of Peru’s largest lakes. Continued rapid warming in the Arctic could therefore reduce precipitation rates in the northern Andes, even more rapidly reducing glaciers and snowpack; further jeopardizing household water supplies, hydropower, and irrigation for agriculture by tens of millions in the region.

https://www.nature.com/articles/s41467-020-19000-8

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