From the USGS:
Using Fossil Pollen to Augment Historical Records
Ancient pollen and charcoal preserved in deeply buried sediments in Egypt’s Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt’s Old Kingdom, the era 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.”
Bernhardt conducted this research as part of his Ph.D. at the University of Pennsylvania, along with Benjamin Horton, an associate professor in Penn’s Department of Earth and Environmental Science. Jean-Daniel Stanley at the Smithsonian Institution also participated in the study, published in July’s edition of Geology.
“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,” said USGS Director Marcia McNutt. “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 seven billion thirsty people.”
The researchers used pollen and charcoal preserved in a Nile Delta sediment core dating from 7,000 years ago to the present to help resolve the physical mechanisms underlying critical events in ancient Egyptian history.
They wanted to see if changes in pollen assemblages would reflect ancient Egyptian and Middle East droughts recorded in archaeological and historical records. The researchers also examined the presence and amount of charcoal because fire frequency often increases during times of drought, and fires are recorded as charcoal in the geological record. The scientists suspected that the proportion of wetland pollen would decline during times of drought and the amount of charcoal would increase.
And their suspicions were right.
Large decreases in the proportion of wetland pollen and increases in microscopic charcoal occurred in the core during four different times between 3,000 and 6,000 years ago. One of those events was the abrupt and global mega-drought of 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 and affected other Mediterranean cultures as well.
“Our pollen record appears very sensitive to the decrease in precipitation that occurred in the mega-drought of 4,200 years ago,” Bernhardt said. “The vegetation response lasted much longer compared with other geologic proxy records of this drought, possibly indicating a sustained effect on delta and Nile basin vegetation.”
Similarly, pollen and charcoal evidence recorded two other large droughts: one that occurred some 5,000 to 5,500 years ago and another that occurred around 3,000 years ago.
These events are also recorded in human history – the first one started some 5,000 years ago when the unification of Upper and Lower Egypt occurred and the Uruk Kingdom in modern Iraq collapsed. The second event, some 3,000 years ago, took place in the eastern Mediterranean and is associated with the fall of the Ugarit Kingdom and famines in the Babylonian and Syrian Kingdoms.
“The study geologically demonstrates that when deciphering past climates, pollen and other micro-organisms, such as charcoal, can augment or verify written or archaeological records – or they can serve as the record itself if other information doesn’t exist or is not continuous,” said Horton.
This study, Nile delta response to Holocene climate variability, was published in the July edition of Geology, and was authored by Christopher Bernhardt, USGS; Benjamin Horton, Penn; and Jean-Daniel Stanley, Smithsonian Institution. Support for the work came from the University of Pennsylvania, the U.S. Geological Survey, and the Smithsonian Institution.
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It is understood that rainfall patterens changed over what is now Ethiopia, changing water inflows to the Blue and then White Nile rivers, drying out Geza around about this sort of time. Must have been all those SUVs.
[;) ~ac]
I wonder how high those CO2 levels were before the big drys hit?
“Ancient pollen and charcoal preserved in deeply buried sediments in Egypt’s Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt’s Old Kingdom, the era known as the pyramid-building time.”
——
I find it hard to believe they built these mega pyramids around that time. These people may have simply inherited these buildings. Like Mann, Hansen, etc have their own narrative of how global warming occurs, the mainstream academic also have their own narrative of how/when the pyramids were built.
Dr. Robert Schoch, a geologist who thinks Pyramids may have been a lot older. http://www.robertschoch.com/sphinxcontent.html based on geological evidences (weathering).
Also, when you take a closer look at the design of the mega pyramids, etc, the mainstream narrative of pyramids building makes even less sense. http://www.gizapower.com/Articles.htm Ask granite sculpture artists what they’d need to produce large Ramses granite statues, granite objects with perfect 90* inside corners, etc found inside mega pyramids and outside.
I’m going with the narrative what these people 4,000 years ago may have simply inherited these places. Great Sphinx, mega pyramids, granite statutes, etc are probably closer to 10,000 years old. Maybe 12,000-15,000 years old. It’s not the only place that is old. There are some places all over the world that are that old. Remember, the end of ice age 12,000-13,000 years ago that probably caused a big change in weather patterns when the sea level rose 400 feet.
If we could determine what triggered the droughts…
Hope we aren’t “due” for another, although folks might think we’re already in one, in this neck of the woods.
It’s worth noting that the Sahara Desert was once a lush savannah with plentiful rainfall about 10,500 years ago. This, of course, had nothing to do with CO2. It was because the axial tilt of the earth at that time created air pressure and temperature imbalances (the sea absorbs more heat from the sun, making it cooler than land), which brought monsoon rains to the Sahara. Rock paintings found in the Sahara at that time even show people swimming! In a nutshell: our planet’s climate and weather is cyclical due to its orbit around the sun and axial tilt.
The Egypt area is particularly susceptible to expansion, contraction and latitudinal shifting of the Sahara in response to the changing sizes, positions and intensities of the permanent climate zones.
Such changes appear to be a global air circulation response to changes in the vertical temperature profile of the atmosphere caused by a top down solar effect primarily due to spectral changes affecting ozone quantities at different levels.
Pyramids… They didn’t build that. Their government did.
@Nerd – you have some of your timelines crossed. Pyramid building happened from ~2700BCE to ~2200BCE. It ceased when the mega-drought hit. The Indus Valley (Harrapan?) civillization collapsed then, too. The weathering that indicates the older age you refer to is on the Sphinx, not the pyramids. The sphinx is carved out of a natural rock, and may have been the site of rituals going back thousands of years before the Egyptians carved a face on it.
There was a very interesting programme on English TV (BBC 4) a few months ago about this very subject. It was about 1 hour long and about half was devoted to natural climate change with no AGW mantra. I seem to recall that some Expert in Greenland ice/Arctic ice/Gulf stream patterns was talking about a natural 1500 year cycle.
I cannot recall what the programme was called and doubt that it is still on BBC iplayer. At the time, I posted a comment about the programme on the Bishophill cite. If the programme can be tracked down, it is well worth a view.
Humans would not be inhabiting Earth but for past climate change. Humans have always been able to adapt and if climate change is truly happening, Humans will easily adapt.
Climate zones changed dramatically just 1000 years ago when the Anazazi peoples of Chaco canyon in New Mexico and Mesa Verde in Colorado migrated from those areas to the Rio Grande basin. At approximately the same time, the Vikings left Greenland. At Chaco, not only was there sufficient water to store in reservoirs and to use for irrigation, but there was also forest. The ancient roots of those trees can be found just beneath the sand. Chaco went from semi-arid to a bleak desert in a very short time.
@ur momisugly richard verney
I think you’re referring to BBC’s Orbit: Earth’s Extraordinary Journey? I also enjoyed this three-part documentary about natural climate cycles, especially because there was no AGW crap involved. It can still be viewed online at the following links, highly recommend everyone to give it a go, well worth the time:
Episode 1: http://bit.ly/PiAyBs
Episode 2: http://bit.ly/Nsw7kn
Episode 3: http://bit.ly/MCa5yx
Note: The two female presenters are pretty hot too! 😀 Hot girls + interesting science = must watch.
Don wrote:
“It’s worth noting that the Sahara Desert was once a lush savannah with plentiful rainfall about 10,500 years ago. This, of course, had nothing to do with CO2. It was because the axial tilt of the earth at that time created air pressure and temperature imbalances….”
The obliquity of the Earth’s axis reached a maximum of 24 deg 14′ about the year 7530 BC.
Presently, the tilt is 23 deg 26′. Can a difference of only 48′ result in a sensible effect on the climate of a region? Just asking.
The way the Egyptians dealt with floods, droughts, etc., was to sacrifice virgins until the Gods relented and made things right again.
Some things never change.
richard verney says (August 17, 2012 at 5:13 am)
—
That was a brilliant documentary – I cited it here at the time for the amazing work done discovering the 1500 year cycle by checking how far Icelandic ash trapped within icebergs got before the ice melted and the ash settled to the bottom of the Atlantic. It’s at about 30 minutes in:
Kudos to the BBC, for once.
Yaggh! Wrong link for some reason. Here’s the real one:
I recently had the pleasure of visiting Turkey and the Greek island of Simi. In many places you can see evidence of ancient agriculture in places which are today not viable. On Simi for example, I photographed many examples of very old stone terraces high up on the mountains, while today the island is dry as toast, supporting only goats and olive trees. Roman warm period? Medieval warm period? Who knows, but clearly the past was much wetter than it is today.
The same thing can be seen in the Uubamba Valley in Peru, where the Inca civilization developed between about 1000AD and 1300. They built fantastic terracing and irrigation systems right up to the mountain tops, which presumably supported a rapidly growing population and empire. The Spanish arrived more or less at the end of the warm period and optimistically built their capitol
at Cusco, which promptly dried out and is today a high almost-dessert.
Trouble is, even though evidence of natural variability is obvious to anyone with eyes, today every climate change, hotter, colder, wetter, drier, is taken as de facto evidence do AGW. No matter what happens in the future, it will have been “our fault.”
Article on BBC site entitled “The Fall of the Egyptian Old Kingdom” by Professor Fekri Hassan:
http://www.bbc.co.uk/history/ancient/egyptians/apocalypse_egypt_01.shtml
See section 4: Climactic change.
Timbuctoo was once a large and presumably thriving city. Has anyone else seen the amazing aerial footage which reveals its original extent? Today it is a fraction of its original size.
I have been sneered at and derided for mentioning this as an example of pre industrial ‘climate change’!
Actually, there was more than one reason for the demise of the First Kingdom. Pepi was the last pharaoh of the dynasty, and lived to be over 100. To this day, he is the longest reigning king ever know anywhere/anytime. He became pharaoh at age 6. Out lived all his heirs. An obvious power vacuum. Also, if you go back in the C13 record, you will note that the First Intermediate Period started with a bump in the C13 content. Gee, might the sun have something to do with climate and cosmic rays? Who wudda thunk it? I always thought it was evil coal companies.
The timing appears to have the possibility of tying in with the eruption of Thera (Santorini) which may have cooled the planet causing widespread drought for a very long time.
http://archaeologybriefs.blogspot.com/2009/11/erujption-on-ancient-santorini-sent.html
This study puts even more impetuous on finding out more precisely just how far ‘more violent’ it was.
It’s about the same time as Joseph of the Bible. Interesting.
If you have grassland and you want to turn it into desert just introduce goat herders. Goat herders will always overgraze the land, and afterward you get desert.
The present day Egyptians are destroying their best agricultural land at the moment by a mixture of building, growing cotton on marginal land and increasing erosion down stream of the Aswan dam.
@ur momisugly Alan Watt. The Egyptians did not practice human sacrifice. To suggest that they did is to slander a great ancient civilisation.
Similarly, while there is some contentin over the age of the Sphinx, there is no doubt at all that the major pyramids were built during the Fourth Dynasty. We know this because they contain grafitti and other marks that could only have been placed there during construction and these marks relate the date the stones were laid.
It is highly unlikely that there is a connection with the fall of the Minoan civilisation as the Egyptian Fourth Dynasty ended circa 2200 BC and this is some 800 years before the fall of the Minoans. One could argue that the Old Kingdon fell before the Minoans even rose.
That climate change was a factor in the fall of the Old Kingdom is no real surprise. The society was reliant on the flooding of the Nile and a failure of the flood meant very lean times indeed. Such a failure would also be seen as a sign that Pharoah was no longer in favour with the Gods and lead to the collapse of the government itself.
Ancient Egypt: husbanding a crucial resource requires huge collective action and central planning, which fosters a centralized government, which in turn becomes totalitarian -a “hydraulic empire”. After the sweat and blood of the long-suffering peasants is expended on sensible projects -canals- an absolute monarchy and an elite priesthood sets them to work on senseless ones -pyramids- to avert non-existant catastrophes. Subsequent generations then take the propaganda of their forefathers as religious truth and the process continues for thousands of years.
But nothing lasts forever.
The ancients would make burnt offerings to their gods but the new religion require us to “sequester” our carbon to appease Gaia. Parodying such idiocy has a long history.
Aristophanes presented his latest play The Birds at Dionysia in 414 BC. It describes how the birds of the earth conspire to establish a kingdom in the sky and extract tribute from the humans for allowing their (carbon) offering to pass through their territory to the gods.
Of course, it all goes wrong.
The Birds is not read in our schools anymore, but it did give us the phrase “cloud cuckoo land” : )
Never has humanity been more capable of adapting to climate change than we are today. Yet our ability to control the climate is no greater than it was 4,000 years ago. So why is all the fuss and expense devoted to trying to control the climate instead of adapting to it?
Eventually, all attempts to control climate change will prove fruitless and we will adapt…just not a well as we would if we had wisdom to begin with.