[Paper] End of Green Sahara amplified mid- to late Holocene megadroughts in mainland Southeast Asia

via Nature Communications, 21 August 2020: A new paper from Laos show a major decrease in monsoon rainfall in Mainland Southeast Asia between four and five thousand years ago – in effect a prolonged drought.

Between 5 and 4 thousand years ago, crippling megadroughts led to the disruption of ancient civilizations across parts of Africa and Asia, yet the extent of these climate extremes in mainland Southeast Asia (MSEA) has never been defined. This is despite archeological evidence showing a shift in human settlement patterns across the region during this period. We report evidence from stalagmite climate records indicating a major decrease of monsoon rainfall in MSEA during the mid- to late Holocene, coincident with African monsoon failure during the end of the Green Sahara. Through a set of modeling experiments, we show that reduced vegetation and increased dust loads during the Green Sahara termination shifted the Walker circulation eastward and cooled the Indian Ocean, causing a reduction in monsoon rainfall in MSEA. Our results indicate that vegetation-dust climate feedbacks from Sahara drying may have been the catalyst for societal shifts in MSEA via ocean-atmospheric teleconnections.

Source: End of Green Sahara amplified mid- to late Holocene megadroughts in mainland Southeast Asia | Nature Communications

See also:

• Southeast Asian megadrought dating back 5,000 years discovered in Laos cave | Penn Today, 21 August 2020
• UCI and international institutions link Southeast Asia megadrought to drying in Africa | UCI News, 21 August 2020