Sahara Event

[uniface]

Research points to abrupt and widespread climate shift in the Sahara 5,000 years ago.

http://phys.org/news/2013-04-abrupt-wid ... ahara.html

Cause ?

[kbs2244]

I was somewhat surprised to learn that in Brazil they routinely get dust, or muddy rains, that are Sahara dust.
It sometimes sparkles. Like super fine sand.

[E.P. Grondine]

You migh want to look at the work on the melting of the glaciers of Mt Kilamenjaro at that time:

http://abob.libs.uga.edu/bobk/ccc/cc111003.html

It appears there were impacts around 3011 BCE, but whether this climate shift is related or not is not currently known, to my knowledge. I certainly currently have no ideas on any relationship.

[Minimalist]

I saw a documentary on this a few years ago.

http://www.nature.com/scitable/knowledg ... y-82884405

The African Humid Period exemplifies the dramatic climate transitions that our planet experiences as a result of subtle changes in the Earth's orbit. The "greening" of the Sahara not only represents a remarkable transformation of the hydrologic cycle, but evidence that gradual climate forcing can result in rapid climate responses. The wealth of North African paleoclimate and archeological data highlights the fundamental importance of water availability on sustainability and human populations, and the central role of climate in shaping major events in cultural development leading to the rise of complex, urban cultures (deMenocal, 2001; Kuper and Kröpelin, 2006).