WASHINGTON, Aug. 16 (UPI) -- Sediments in the Nile Delta record ancient droughts and fires, including a drought 4,200 years ago linked with the end of Egypt's Old Kingdom, scientists say.
Ancient pollen and charcoal preserved deep in the sediment reveal the impact of droughts and fires during what is known as the pyramid-building time.
"Humans have a long history of having to deal with climate change," said Christopher Bernhardt, a researcher with the U.S. Geological Survey. "Along with other research, this study geologically reveals that the evolution of societies is sometimes tied to climate variability at all scales -- whether decadal or millennial."
One of those climate events was an abrupt and global mega-drought around 4,200 years ago, a drought that had serious societal repercussions, including famines, and which probably played a role in the end of Egypt's Old Kingdom, a USGS release said Thursday.
"Even the mighty builders of the ancient pyramids more than 4,000 years ago fell victim when they were unable to respond to a changing climate," USGS Director Marcia McNutt said. "This study illustrates that water availability was the climate-change Achilles Heel then for Egypt, as it may well be now for a planet topping 7 billion thirsty people."