Climate and Human Civilization over the last 18,000 years

Guest essay by Andy May

This document is meant to explain the accompanying poster and expand on the poster’s content. Some references to the images and data shown in the poster are on the poster and others are in the bibliography. I’ve done my best to verify the accuracy of the content by checking multiple sources. When references had different dates for the same event, I chose the most commonly cited date or the date from the most prestigious sources. I considered dates from articles in Nature, Science, the Encyclopedia Britannica, and Steven Mithen’s book2 to be the most reliable.


Click image for a full sized print (3000 pixels wide, suitable for printing) or choose the PDF below

Younger_Dryas_to_Present_Time_Line (PDF)

The heart of the poster (above) is a time line that shows the significant documented events in human civilization over the last 18,000 years and documented climatic changes over the same period. 

The Last Glacial Maximum (LGM) ended around 19,000 years ago1, and the illustrations on the lower left of the poster illustrate what the world was like then. Much of the land area of the world was under ice or desert at the time, especially in the Northern Hemisphere, and the exposed land had less precipitation than we do today2. As we will see, the cooler climatic events, during the history of civilization, are periods with less precipitation than we observe during warmer times. If there were any organized human civilizations at the time, we have not found any evidence of it, other than some pottery in China, dated to 20,000 years ago3. Humanity, 20,000 years ago, lived in small communities of a few families and hunted for animals and edible natural vegetation. Domesticated animals (with the possible exception of dogs) and large scale agriculture would not be invented for another 6,000 to 7,000 years34,21

Dogs were probably domesticated by the Natufians in the Middle East by 14,000 years ago. This seems to be supported by exhumed graves in the ancient villages of Ain Mallah and Hayonium near Lake Tiberias (also called the Sea of Galilee) in Israel. In these graves dogs and humans were deliberately buried together2. That suggests that they lived and worked together in life. The Natufians collected wild grains, fruits and vegetables and probably cultivated small gardens as early as 14,000 years ago. But, this early, large scale organized farming was unlikely.

The upper part of the poster shows three ice core records. The top record is actually a composite reconstruction of six Greenland ice core records4. The middle chart is the most recent portion of the Vostok Antarctic ice core record, the entire Vostok 400,000 year record is show in the upper left of the poster5. The 95,800 year Milankovitch cycles2 are very apparent in the Vostok record. These cycles are composed of an overarching 95,800 year cycle where the Earth’s orbit changes from roughly circular (warm and wet climate in the Northern Hemisphere) to elliptical (cold and dry in the Northern Hemisphere) and back again. The elliptical part of this cycle causes the Northern Hemisphere to have stronger seasons and the Southern Hemisphere to have less seasonality; this is what kicks off glacial periods.

Another cycle is when the inclination of the Earth’s axis changes from 21.39 degrees to 24.36 degrees and back again. This cycle is 41,000 years. As the angle increases the seasons become more intense. The Earth also wobbles on its axis in a periodic way. This is a 21,700 year cycle.

You might just be able to see that the middle graph (Carbon Dioxide concentration) slight lags the temperature by about 800 years on average. This suggests that the changes in temperature might cause the Carbon Dioxide changes rather than the other way around. The airborne dust concentration increases when the world is cooler because in the cool periods it is also dryer.2

Next to the complete Vostok record is a reconstruction of the temperature record for the last 600 million years. Temperatures, today, are lower than they have been for over 250,000,000 years according to this data. The bottom large chart is the actual temperature, calculated from a single central Greenland ice core.6

Bond Events

Just below the Central Greenland ice core record the “Bond” cooling events over this 18,000 year period are noted7. The Bond cooling events average around 1,500 years apart and some are more dramatic than others. The 8.2, 5.9 and 4.2 kiloyear events were major events8,9, with dramatic cooling and they were huge disruptions for civilizations around the world. Others, like the 2.8 kiloyear event in the Iron Age were hardly noticed.

During the last glaciation, the Greenland ice core record documents rapid climatic change events called Dansgaard-Oeschger events or “D-O events.”10 These are very rapid warming events, followed by slower cooling, that occur in a cycle of roughly 1,470 years +- 12%.11,12 These events are probably the glacial period equivalent of the Bond events. In modern times, the cooling period, which is slower to develop, is more noticeable than the warming, because the cooling (and the droughts that accompany the cooling) seem to cause more disruption of civilization. Warming events tend to coincide with man’s better times, since they are associated with more precipitation and more abundant plant life. At the beginning of a D-O event, temperatures increase rapidly, perhaps 8 degrees C over 40 years as they did at the end of the Younger Dryas period. A more normal D-O event warming period is about 5 degrees C over 40 years. The cooling period after a D-O event normally lasts a few hundred years. Although most of the evidence for D-O events is from the Greenland ice cores, some have suggested that they are global events13. These events can also be seen in Antarctic ice cores, but they are more subtle.

The Bond Event/D-O Event cyclicity is probably happening, it is well documented. But, no cause for this cyclicity has been found. Some have suggested that the Little Ice Age was the cold part of a D-O/Bond event.14

Sea Level

Moving just to the right of The Last Glacial Maximum map on the lower left of the poster, you can see an artist’s (Robert Rohde) rendition of the rise in global eustatic sea level after the glaciers started melting. The data used to make the graph is from numerous sources listed in the referenced web site.15 The earliest well documented evidence of human civilization dates to the middle of the most rapid rise in sea level in this period, roughly 12,000 years ago at Gobekli Tepe, Turkey.16,17 From 14,000 years ago until 7,500 years ago sea level rose an astonishing 1.5 cm/year on average. This is almost 5 feet per 100 years. According to the University of Colorado Sea Level Research Group, the current rate of sea level rise is about 6.8 12.6 inches per 100 years or 3.2 mm per year.18

Earliest evidence of civilization

The earliest evidence of large scale construction by man is found in Gobekli Tepe (near Urfa in southern Turkey). This site is roughly 300 meters by 300 meters and contains intricately carved stones. It is 12,000 years old and predates Stonehenge and the earliest Egyptian pyramids by over 7,400 years. Construction at Gobekli Tepe began during the Younger Dryas19 “Big Freeze.” The Younger Dryas was a sudden and short lived (geologically speaking, the Younger Dryas cold period lasted over 1,000 years) return of very cold weather, similar to the cold that existed in the Last Glacial Maximum. The Gobekli Tepe site is composed of multiple circular stone monuments; the tallest pillars in these monuments are 16 feet high and weigh over seven tons. The rings are 65 feet across and probably have religious significance. Construction of the site appears to have occurred during a hiatus in the sea level rise between 11,000 and 12,000 years ago. Then the site was mysteriously and deliberately buried around 10,000 years ago. The reasons for its construction and later burial are not known. But, one can probably safely speculate that it was buried to protect and preserve it. This task was accomplished and it is remarkably well preserved for its age.

Gobekli Tepe is the earliest religious monument known and also the earliest major construction project. It is interesting that the wild wheat that grows in the area is the closest relative, genetically, to modern domestic wheat. One can speculate that the early religious fervor that caused Gobekli Tepe to be built, may have inspired farming2. After all, the construction of the religious monument would have required a number of people to live in one spot for a long time, they could not migrate in search of food, so it may have occurred to them to grow their own food.

The earliest evidence of large scale organized agriculture is seen in the Levant region of the Middle East in present day Syria and Israel21. This occurred about 13,000 years ago in the middle of a very wet climatic time (Late Glacial Interstadial) that went from 13,500 years into the Younger Dryas “Deep Freeze,” which began around 12,800 years ago. Precipitation decreased during the Younger Dryas and increased after its end 11,500 years before present. There are also some preserved pottery fragments from 13,000 years ago in Japan and perhaps even older20. Others have reported that pottery existed in China 20,000 years ago22. The pottery from 20,000 years ago probably did not belong to farmers, but hunter/gatherers. It is possible that rice was farmed in China 13,900 yearsagoand in India 10,000 years ago34.

Between 13,000 and 14,000 years ago a lot seemed to happen at various archaeological sites in the Middle East, buildings improved, villages got larger and were more advanced. But, they were mostly abandoned as temperatures got cooler at the beginning of the Younger Dryas. This cool period lasted over 1,000 years and the climate was very dry. Few advances in human civilization happened in the period, people were just trying to survive2. This is evident as the late Natufians, who lived during the Younger Dryas period, were in much poorer health (fewer teeth, often with caries) than the earlier Natufians from the Late Glacial Interstadial period. Further, the animal bones in their garbage dumps held bones of smaller animals than the earlier period. Both the animal herds and the human population were of smaller size2.

According to many archaeologists, Homo floresiensis, a species of human often called the “Hobbit” man, survived until around 12,500 years ago before dying out in Indonesia23. This was the last species of man to become extinct. Recent archaeological finds may indicate that Homo floresiensis was not a separate species, but just a variant of Homo sapiens.

Larger Cities

The Middle Eastern Neolithic B culture began around 10,800 years ago according to Kathleen Kenyon24. It is a significant period in the history of human civilization because at this time man became more dependent upon domesticated animals and organized large scale farming. Oddly, it has also been found that the earliest Indian agriculture appears to have been in the Indus valley around 11,000 years ago34. Also, in the Levant region, man began building larger settlements, rectangular buildings and organized communities. Plaster and pottery are first seen in Middle East at this time. The period may have begun when people migrated to the Levant from the Black Sea area8. The period ended with the 8,200 year BP event or Bond climatic event 57, this was another sudden cold period that affected civilization worldwide and caused massive migrations of people in search of food and water25,8. During this event, over a period of 20 years, temperatures cooled, roughly, 3.3°C. It was not as severe as the Younger Dryas, but still significant. It only lasted a total of 200 to 400 years.

During the Neolithic B period evidence of relatively large settlements is found. Catalhoyak, a city of 8,000, existed near present day Cumra Konya, Turkey. This is a large, relatively modern “city” that existed 9,700 years ago27,43,44,2.

Jericho is often considered the world’s oldest continually occupied city26. Remains of early settlements, probably not cities, but villages of 500 people or so, in Jericho have been dated to 11,600 years ago2. The first woven cloth known was found in Ofer Bar-Yosef, Israel. It is around 10,000 years old, it was found with bone shuttles that were used to weave the cloth2. The cloth was a type of linen and not cotton, cotton was developed later in India.

8.2 Kiloyear Bond Event and the Great Floods

Just before the 8,200 year cold event, around 8,400 years ago, the Black Sea, which was a fresh water lake at the time, filled from Mediterranean Sea8,2. This event is only the most recent of many catastrophic flooding events due to the melting of the glaciers after the LGM. The Baltic Sea, was a lake until 9,200 years ago, when it was finally connected to the Atlantic Ocean. These flooding events and , perhaps others, due to rising sea level are probably the cause of multiple “Great Flood” stories that populate early writings like the Noah’s Flood story in the Bible and Torah and the older Gilgamesh story28.


Simple writing appears in Jiahu, China around 9,200 years ago30 and in Tartaria, Romania around 7400 years ago29. Whether either is true writing or not is a subject of debate, the symbols on the Tartaria tablets have not been translated and may be a “picture” story. The Chinese writing has some symbols that are similar to modern Chinese writing symbols. Because Chinese writing is not phonetic, it is hard to tell where “picture writing” stops and true modern writing begins.

True writing has been discovered from 5,600 years ago in Syria in the Uruk period33. By this time very large cities existed and the city of Uruk had over 50,000 people in it32. The Uruk period was characterized by large scale urbanization, irrigation, roads and canals. It may have begun as early as 6,200 years ago. The end of the Uruk period of the Sumer civilization coincided with the end of the Holocene Thermal Optimum a period of warm weather with a lot of precipitation and a very green world.

5.9 Kiloyear Bond Event

About 5,900 years ago the Sahara became a desert (The 5.9 kiloyear event or Bond event 4) and this very severe drought also ended the Ubaid empire and caused a huge migration of people from the Sahara region in search of food and water35. The people migrated to river valleys, such as the Nile Valley in Egypt, in order to be close to water. Claussen, et al., 199936 has suggested that this drought was caused by a severe cooling event that occurred at the same time. The Sahara never recovers from this event. But, since the drought forces people into river valleys, larger cities are built and societies become more complex.

Following the end of the 5.9 kiloyear event and the end of the Holocene Thermal Optimum, around 4,500 years ago the earliest Egyptian pyramids are built, Stonehenge is constructed37 in present day England and the first large cities appear in India38. The earliest Mayan cities appear a little over 600 years later around 3,900 years ago39.

4.2 Kiloyear Bond Event

The 4.2 kiloyear event was a very cool period in the Arctic (the Bond Event 37) and it caused a very severe drought in the Middle East. This period caused a sudden collapse of the Egyptian government40, famines and social disorder. Similar disruptions occurred in the Akkadian Empire41, the Indus Valley and in China42.

Around 3,300 years ago, the great Bronze Age civilizations in the Middle East collapsed. These included the Mycenaean’s, the Hittites and the Egyptian New Kingdom43. This sudden collapse was probably caused by another extended and severe drought. The onset of this drought coincides with a sudden and extended cooling period in the Central Greenland ice core data. In general, most large scale droughts in the last 18,000 years appear to be associated with cooling in the Arctic. This marks the end of the Minoan Warm Period.

Iron Age

Starting 3,300 years ago, there seems to be a hiatus in the development of Middle Eastern civilization and not much happens until around 2,400 years ago with the beginning of the Roman Warm Period. This is just after the time of the Shang Dynasty (3,600-3,050 years BP), which is a very well documented period in China.  The last capital of the Dynasty was at Yin and the Yin Dynasty is synonymous with the second half of the Shang dynasty.

The preceding Xia Dynasty was from 4,070-3,600 years before present.  This part of Chinese history is very poorly documented and some historians wonder if it existed at all.  It remains very poorly understood and barely documented44.

Mayan settlements begin to appear about 4,700 years ago in Belize. The first well established Mayan cities (or large settlements) are dated to 3,600 years ago in Soconusco, Mexico46. This is near the beginning of the cold period in the Iron Age. However, evidence of a true Mayan civilization does not appear until 2,900 years ago. The first written Maya history dates to 2,350 years BP. This is also the time of the first large scale cities and significant intellectual and artistic development. This is roughly the time when Rome emerged as a major power in the Mediterranean.

Roman Warm Period

Once we reach the beginning of the Roman Warm Period, roughly 2,400 to 2,200 years ago, robust civilizations have developed in the Americas, around the Mediterranean, China and India. By the time Alexander invaded India (2,339 years ago) they had a very advanced civilization. Very advanced cities were built in India beginning 4,100 years ago, but history is not well established until around 2,400 years ago. This warm period truly marks the beginning of modern civilization, written records document all major events since this time. Writings at this time suggest that the temperatures during the Roman Warm Period were comparable to temperatures today47.

Normally the end of the Roman Warm Period is given as around 450 AD (1,563 years ago) and the Central Greenland temperature cooled by about one degree C in 200 years, it reaches the maximum drop of 1.4°C by 1,206 years ago or around 800 AD, the height of the Dark Ages in Europe.

Medieval Warm Period

The Medieval Warm Period is normally given as 950 AD to 1250 AD or 1063 years BP to 763 years BP. In the beginning of this period, temperatures in Central Greenland rose by 1.5°C in less than 200 years. This has been fairly well documented as a worldwide event48. It is uncertain what the global average temperature was during the period and whether the world as a whole was warmer than now, or not. But, certainly in areas where we have records, such as Greenland, the UK, and in China, temperatures were comparable to temperatures today and in some cases warmer. A considerable amount of recent research attempts to compare temperatures during the Medieval Warm Period to today on a global basis48.

Little Ice Age

The Little Ice Age was not a true ice age, but the cooler period after the end of the Medieval Warm Period. It is generally considered to have started by 1350 AD (663 years BP)49 and it pretty much ended by 1850 AD (163 years BP)50. In Central Greenland, temperatures drop about 1.5°C from 964 years BP to 597 years BP, which is a significant drop. It was not cold over the entire period, but the Little Ice Age saw many periods that were very cold, from the famous year without a summer (1816) to the great famine of 1315, New York Harbor completely froze over in 1780, the Norse colonies in Greenland starved and were abandoned in the 1400’s51.

Modern Warm Period

The Modern Warm Period starts around 1850, which is also the time when people began systematically recording and collecting air temperature data from around the world. These temperatures were spotty in the beginning, but by the middle of the 20th Century a fairly good worldwide temperature database was developing54. Finally, in 1979, satellites were launched that could give us a reasonably accurate and complete temperature record over the entire globe52. In the poster, on the lower right, both datasets are shown. The satellite dataset is from UAH MSU53. This is the best data to use, since it is global and has minimal editing. It shows warming of 0.35°C over the period from 1979 to the present. This is not particularly significant by historical standards.

The period from 1850 to 1979 is not as well documented globally and the records used to construct the global temperature average have had to undergo significant editing, which raises doubts about the accuracy of the record. But, the curves are shown for the Northern Hemisphere, the Southern Hemisphere and the whole globe on the lower right of the poster. These are made from the HADCrut dataset54. They show a warming of about one deg. C in a period of 163 years. This is also not unusual by historical standards. Fluctuations of a degree C, either warmer or cooler, are very common in the historical record. Over this length of time warming of over 13°C was seen at the end of the Younger Dryas period in the Central Greenland ice core. In the same core, the beginning of the Holocene Thermal Optimum period saw a warming of five degrees C.


In general, the best times for man in the last 18,000 years are the warmer periods. The times of the disruption of civilization are the cooler and more arid times. This is quite consistent and since we have not seen unusual warming in the present warm period, relative to other warming events in the last 18,000 years, it seem doubtful that this warming period will be a problem for man to adapt to. Much of the last 18,000 years is characterized with much more rapid sea-level rise than we see today and this has caused a lot of disruption as it will in the future. But, the current rise in sea level is very slow relative to sea level rise during most of man’s civilized period. Our current warming and the current rate of sea level rise are very unspectacular.

In the words of Professor Steven Mithen, 2003 in “After the Ice…2” (page 507)

“The next century of human-made global warming is predicted to be far less extreme than that which occurred at 9600 BC. At the end of the Younger Dryas, mean global temperature had risen by 7°C in fifty years, whereas the predicted rise for the next hundred years is less than 3°C. The end of the last ice age led to a 120 meter increase in sea level, whereas that predicted for the next fifty years is a paltry 32 centimeters at most,…”


Andy May is a Petrophysicist residing in The Woodlands, Texas

Bibliography for “Climate and Human Civilization over the last 18,000 years”

1. Clark, Dyke, Shakun, Carlson, Clark, Wohlfarth, Mitrovica, Hostetler, McCabe, “The Last Glacial Maximum,” Science 7, August 2009, Vol 325, No. 5941, pp. 710-714.

2. Mithen, Steven (2003), “After the ice: a global human history, 20,000 to 5,000 BC., Cambridge Ma., Harvard University Press.

3. Wu, Zhang, Goldberg, Cohen, Pan, Arpin, Bar-Yosef, 2012, Science, Vol. 336, No. 6089, P 1696-1700.

4. Vinther, Buchardt, Clausen, Dahl-Jensen, Johnsen, Fisher, Koerner, Raynaud, Lipenkov, Andersen, Blunier, Rasmussen, Steffensen, Svensson, “Holocene thinning of the Greenland ice sheet,” Nature, Vol 461, September, 2009.

5. Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J., Delaygue G., Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V., Lorius C., Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V., Lorius C., Pépin L., Ritz C., Saltzman E., Stievenard M., 1999, Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica, Nature, 399, pp.429-436.

6. Alley, Richard, “The Younger Dryas cold interval as viewed from Central Greenland, Quaternary” Science Reviews, Vol. 19, Jan. 2000, p 213-226

7. Bond, Showers, Cheseby, Lotti, Almasi, deMenocal, Priore, Cullen, Hajdas, Bonani, 1997,  “A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and Glacial Climates” Science 278 p. 1257–1266)

8. Ryan and Pittman, “Noah’s Flood: The New Scientific Discoveries about the Event That Changed History,” 1998, Simon and Schuster.

9. deMenocal, Peter, 2001, “Cultural Responses to Climate Change During the Late Holocene,” Science 292, p 667-673.


11. Schulz, M. (2002). “On the 1470-year pacing of Dansgaard–Oeschger warm events” Paleoceanography 17

12. Rahmstorf (2003). “Timing of abrupt climate change: A precise clock” (PDF). Geophys. Res. Lett. 30 (10): 1510.

13. Voelker, Antje, 2002, “Global distribution of centennial-scale records for Marine Isotope Stage (MIS) 3: a database” Quaternary Science Reviews 21: 1185-1212

14. Bond, et al., 1999, “The North Atlantic’s 1–2 kyr climate rhythm: relation to Heinrich events, Dansgaard/Oeschger cycles and the little ice age” in Clark, P.U., Webb, R.S., Keigwin, L.D., Mechanisms of Global Change at Millennial Time Scales (PDF). Geophysical Monograph (112). American Geophysical Union

15. Rohde, Robert,







22. Wu, et al., “Early Pottery at 20,000 years ago in Xianredong Cave,” Science, 2012

23. Morwood, Soejono, 2004, “Archaeology and Age of a new hominin from Flores in eastern Indonesia,” Nature, 431, p 1087-1091.





28. George, A. R., The Babylonian Gilgamesh Epic, Oxford University Press.

29. Haarman, H, 1990, “Writing from Old Europe”, The Journal of Indo-European Studies.

30. Rincon, Paul, 2003, “Earliest Writing in China,” BBC News

31. Li, X, Harbottle, Garman, Zhang, Wang, “The Earliest writing? Sign use in the seventh millennium BC at Jiahu, Henan Province, Chinese” Antiquity 77, p. 31-44



34. Gupta, A., 2004, “Origin of agriculture and domestication of animals linked to early Holocene climate amelioration,” Current Science, 87, Indian Academy of Sciences.

35. Parker, Adrian, 2006, “a Record of Holocene climate change from lake geochemical analyses in southeastern Arabia,” Quaternary Research 66, p. 465-476.

36. Claussen, et al., 1999, “Simulation of an Abrupt Change in Saharan Vegetation in the Mid-Holocene,” Geophysical Research Letters 26-14.

37. Morgan, et al., 2008, “Dig Points Stonehenge origins,” BBC

38. Fagan, Brian, 2003, “People of the Earth: An Introduction of world prehistory,” Pearson, 414 p.

39. Hammond, et al., 1976, “Radiocarbon chronology for early Maya occupation at Cuello, Belize,” Nature 260, 579-581.

40. Stanley, 2003, “Nile Flow Failure at the end of the Old Kingdom, Egypt: Strontium isotopic and petrologic evidence,” Geoarchaeology 18 395-402.

41. Kerr, 1998, “Sea Floor Dust Shows Drought Felled Akkadian Empire,” Science, 16 Vol. 279, no. 5349 p325-326.

42. Chun, et al., 2011, “Extraordinary floods related to the climatic event at 4200 BP,” Quaternary Science Reviews 30 460-468.

43. Langer, 1972, An Encyclopedia of World History, Houghton-Mufflin


45. Israel Finklestein

46. Liu and Xiu, “Rethinking Erlitou: legend, history and Chinese archaeology”, Antiquity, 81:314 (2007) p 886-901

47. Pletcher, Kenneth, “The History of India,” in print, Britannica Publishers, 341 pages

48. Clark and Blake, 1994, “The Power of Prestige: Competitive Generosity and the Emergence of Rank Societies in Lowland Mesoamerica,” Cambridge University Press.

49. Bianchi, and McCave, 1999, “Holocene periodicity in North Atlantic climate and deep-ocean flow south of Iceland,” Nature 397, 515-517.


51. Miller, et al., 2011, “Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks,” Geophysical Research Letters

52. IPCC AR4, “Solar Variability and the Total Solar Irradiance,” Chap. 1


54. Rao, Smith and Koffler, “Global Sea-Temperature Distribution Determined Froma an Environmental Satellite,” Monthly Weather Review, Vol 100, No. 1



57. Veizer, J., Ala, D., Azmy, K., Bruckschen, P., Buhl, D., Bruhn, F., Carden, G.A.F., Diener, A., Ebneth, S., Godderis, Y., Jasper, T., Korte, C., Pawellek, F., Podlaha, O. and Strauss, H., 1999. 87Sr/86Sr, d13C and d18O evolution of Phanerozoic seawater. Chemical Geology 161, 59-88.) is that of Harland et al.(1990) A Geological Time Scale 1989, Cambridge University Press


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“It’s worse than we thought!”

Doug Proctor

Awesome compilation!
Mannian analyses: items considered and interpreted by themselves. Taking multiple events together gives you a setting in which to understand or interpret individual items. Reality is messy, very difficult to get your head around (which is why history is easier to explain than the present).
Good stuff. I’ll print for reference.


Paleolithic culture was more “advanced” than often assumed. Before 14 Ka some groups did practice ceramics of some kind, if not always pottery. Some also lived at least part of the year in small settlements at prime locations. They made structures more elaborate than tipis. They practiced division of labor & besides having dogs, also seem to have herded or at least in some way controlled reindeer much as do the Sami today, possibly even horses as well.
The dog-wolf divergence appears to have occurred before Natufian times.
In favored environments even historical hunter-gatherers familiar with agriculture have given it up or not adopted it because nature is so rich in their area. Consider the NW Coast Amerindian maritime cultures, indigenous Californians & the Plains tribes.

In fact there is new research that dogs were domesticated a lot earlier in Europe:
“The mitochondrial genomes of all modern dogs are phylogenetically most closely related to either ancient or modern canids of Europe. Molecular dating suggests an onset of domestication there 18,800 to 32,100 years ago. These findings imply that domestic dogs are the culmination of a process that initiated with European hunter-gatherers and the canids with whom they interacted.”

So how come only one of the 3 temp series has the little uptick?

David in Cal

Author is a petrophysicist, thus associated with oil companies. ‘Nuff said! /obligatory
REPLY: Right, typical closed-mindedness from somebody who chooses stereotypes over data. Pathetic.
Read what areas of study in geology it covers.

Charles Stegiel

I suspect a Northern Hemisphere bias. And the Tamil people talk of a sunken landmass that once was their lost world, So it is feasible that civilization during the ice age was a Southern Hemisphere phenomena and these lands are now submerged.

Lance Wallace

Anthony, I think David in Cal was being ironic. What gives it away is his little “/obligatory” comment, which I take to refer to the predictable reaction of the alarmists.
REPLY: Possibly, /sarc is the usual way to flag such things – Anthony


Charles Stegiel says:
November 17, 2013 at 1:11 pm
Between the Mascarene Plateau & Madagascar lies an abyssal plain, not a sunken continent. During the Cretaceous Period, the Indian Plate passed by this region on its way to collide with the Eurasian Plate, however.
If actual events lie behind the Tamil legend, then it would be the flooding of Indian continental shelf at the last deglaciation. Sri Lanka & India are almost connected by land (Adam’s Bridge islands & islets) now & were completely during the Last Glacial Maximum & much of the time before & after that interval.


It’s quite a marvellous piece of work. Congratulations to the author!


What I find fascinating is that 14,000 years ago, as soon as temperatures get warmer, civilization crops up. The list of references are great… and to think that someone has already used an ad hominem attack instead of attacking the references and substance of the article.
The Egyptian Nile and flooding is also an interesting topic if people want to follow up on that area. It’s quite amazing the ability of people to migrate and take advantage of beneficial climate when it occurs.

Peter C.

What Charles said. You can’t ignore a 120 meter sea level rise…people have always settled by the water’s edge for various reasons,food and transport,etc.Those low lying areas would not have been empty,they would be the most populated land in the area,just like today.
When the lowlands flooded,refugees would appear suddenly with agriculture and all that neat stuff.

Kees van der Pool

Apologies for being off-subject but this is worth a quick look: The graph shows the yield of about 60,000 MW of installed Wind & Solar ‘renewable energy’ capacity in Germany. The grand total (wind+solar) is about 100 MW or 0.16% of capacity at 3pm on 11/17/13.
It does not look a whole lot better for tomorrow ( It does not seem to be a very viable ‘renewable’ energy scheme without 100% conventional backup.


Andy, great write up
Thanks for mentioning a one degree decrease in temps will be devastating….and they are pushing it the other way trying to say a one degree increase will be….while we are on a long slope going down
All we’re in right now is one of those small uptics…while the overall trend is still down


Even if you could, fighting global warming sounds like a horrible, misanthropic idea.


Nice compilation, demonstrating once again four straightforward conclusions:
1. Human civilization has always benefitted from warmer times
2. There is no evidence WHATSOEVER of anything resembling a “tipping point” in paleoclimate
3. Temperature change comes long before CO2 change, both rising and falling
4. Viewed over geologic (even millennial) timescales, human activities are insignificant
So why are so many so intent on pi$$ing away our economic future over a trace gas??

Jericho, in Israeli occupied Palestine
What about settler occupied North America. Or Russ Occupied Northern Europe? Why don’t they get any credit for what they now hold?

You appear to have some of your dates cockeyed. Shang Dynasty was roughly contemporary with the Late Bronze Age (note the Shang bronzes from archaeological contexts in China) in western Asia, 1600-1100BC. Hence, Shang was contemporary with that period and Xia was prior to 1600BC. You have Xiaq 3200-2800 years ago and Shang at 2800-2200 years ago. The Late Bronze in the Near and Middle East, and the Aegean and Iran, ended around 1200BC and the Iron Age is generally dated after that. I suggest you use a more detailed source than Mithen as his is a broad brush approach to a huge period, the last 20,000 years. One source might be the tree ring chap, Mike Baillie – try ‘A Slice Through Time’ as starters.
The Younger Dryas event is generally regarded as the 7th Heinrich event, very cold periods. Funnily enough it pans out at 1300 years which is roughly equal to one Bond or Dansgaard-Oeschger event. The Oldest Dryas period is equal to two times Bond event as it works out at roughly 3000 years in extent (although the actual numbers may be mudded by a massive C14 plateau). The 6200-6000BC cooling event (8.2ky) was easily the most significant event in the Holocene. It also coincided with a massive spike in sea levels. Sunda Land was submerged and what is left is now the islands of Indonesia and the Philippines (see Stephen Oppenheimer, Eden in the East). At the same time a large part of the North Sea basin was drowned as well – and there is plenty of evidence to say it happened very quickly (blamed on a collapse of the Storegga Shelf off Norway). Funnily enough, along the coast of South America the land was raised – equally abruptly. What was a lagoon on the sea shore was elevated to a great height to become Lake Titicaca. Hence, you might like to have a look at the sea level graphs. It is smoothed data. We all know how climate scientists smooth data – but so do other scientists, and sea levels are averaged from what they were 18,000 years ago to what they are now – but even then the smoothing can’t hide the fact there was a steep rise in sea levels at 6200BC. After that the sea level rise slowed down – and has not changed greatly since 3000BC (but even this disguises ups and downs). We may assume the sea level graph from 18,000 to 6,000BC was not a continuous and gradual rise, as produced by the averaging or smoothing of the data, but could well have involved several steep step changes.
The treatment of the Medieval Warm Period and the Little Ice Age might also be looked at more closely. The former included one of the coldest years of the last 2000 -1014AD. The latter included a heat wave in London as recorded by Samuel Pepys. What we have is a difference in average temperatures – and it is a mere 1 degrees celsius either way. The LIA, often presented as a hundred years of chilling was nothing of the sort. Puritans might have gone around in thick trousers and long coats but it was not universally cold. It had an unusual cluster of cooling spikes. These can be attributed to volcanoes spewing lots of gas and dust into the atmosphere. The 17th century also had an unusual number of comets and meteor showers – and some of the latter were exceptional. Theoretically they could also have been responsible for opaque skies on occasion – leaving dust and debris at the top of the atmosphere. As far as I know this has not properly being explored – but has been suggested by various astronomers rather than climate scientists. In other words, low sun spot numbers may have played a role, and cycles of solar activity – but the LIA was primarily caused by short spikes and some of these were very cold. That must mean other years were not so cold – or even warm.
All in all, a good overall look at the post-LGM period – and I’m also a big fan of Steven Mithen. As with all such endeavours the more stones that are upturned the more problems that emerge. Brian Fagan has also written some interesting books on Holocene climate, addressed to a popular market. They are very good.

Thank you! You are correct, the Shang Dynasty was from 3700 BP to 3100 BP. I do think the Yin period is the latter part of it though. I certainly agree with you on the 8.2 kyr event, good summary. The LIA is a mystery to me as well, such a mixture of extreme events that are hard to get your arms around.

Lance Wallace says:
November 17, 2013 at 1:27 pm
Anthony, I think David in Cal was being ironic. What gives it away is his little “/obligatory” comment, which I take to refer to the predictable reaction of the alarmists.
REPLY: Possibly, /sarc is the usual way to flag such things – Anthony

I read it as being “obligatory” sarcasm, just as many “it’s worse than we thought” comments are.

Perhaps we need an “/obsarc” tag?

Peter C., you make a very important point. Ryan and Pittman (ref 8) note that when it turns cold and dry, people will congregate around what fresh water they can find, for example the Black Sea (lake). They will have come long distances and while the cold period lasts they exchange technologies and they have a strong incentive to improve them, because life is so hard. Once the climate warms and the rain comes back they disperse to new areas and thrive with the new knowledge. This is a cycle that seems to have repeated many times, but the 8.2 kyr event was, perhaps, the most significant example. This idea is supported by common key words in many languages for eye, hear, etc.

The effects of global warming or cooling vary depending on location.
For example, as far back as 50,000 year ago tribal groups were slowly making there way from India around the shores of the land mass that today is called Indonesia but was then connected directly to India due to the lower sea levels Some of these groups ended up in Australia after crossing the Timor trench. Although these people were primarily hunter gatherers and fishermen they must have lived and traveled in communities because they had to have been well organised as they were able to built boat or rafts that crossed the Timor trench even though even in those days it was far too wide to have been sure that there was a land mass on the other side.
Also during the Medieval warm period there was a prolonged period of low rainfall in Polynesia. This forced Polynesian people to look for other places where they could grow their food crops. They found New Zealand. It was then warm enough in New Zealand for Maori tribes to settle as far south as Stewart Island. But as the little ice-age progressed the tribes had to vacate Stewart Island and then most of the South Island as food couldn’t be grown there in the cooling climatic conditions. It is still too cold for people to live in Stewart Island during the winter – except for a very hardy souls. This suggests that ocean currents connected to Antarctic waters must be gradually changing to cool the southern part of New Zealand.


The graph looks great but why doesn’t the graph of temps and CO2 derived from Vostok ice cores show a vertical green line on the y axis of CO2 rise in the last 100 years. I know you could argue that the time period is thinner than the line or, perhaps, that they don’t bother analysing cores from 1900 because they know the ppm from other sources. But none of that washes- there’s an omission of the truth that leads the casual observer to think that CO2 has cycled for 420,000 years and never gone above prehistoric levels. That’s especially the case with people who aren’t great at reading graphs or don’t know the current ppm levels- or kids. WUWT readers are the exception in terms of knowing these data and seeing sleights of hand at a glance. The general public isn’t. If you don’t think you can fit a green line going up to 395 ppm then there should be an arrow to the 395 point with a label: “ppm as of 2013”.
I’m surprised the alarmists haven’t arrived yet to harangue you on that one. That’s why I am. You can’t play their game with these sleights of hand.
But on the plus side a) you never see a comment like this getting through on Skeptical Science or other such sites but WUWT has a good history of self-policing. b) I still think this graph is a really good idea and is beautifully laid out and has had a lot of research put into it.


could someone email the graph to U.S. envoy Kim Carnahan at the Warsaw climate talks:
15 Nov: Bloomberg: Alex Morales: U.S., EU, Reject Brazilian Call for Climate Equity Metric
“Temperature is a lagging indicator and does not show up until well after emissions have occurred,” U.S. envoy Kim Carnahan told delegates on Nov. 11…

Jim Herbert

Facts, not model results…priceless…


This really is a great resource! Thanks for the time and effort that went into it.
By the way, Scute, we have absolutely no idea what the Greenland ice core dredged up in 1000 years will record today’s CO2 ppm as. Despite claims of precision, ice cores are at best an approximation, and very low resolution. There’s no reason to believe there haven’t been many spikes and excursions to higher CO2 levels in the past.


Great article, but the dog issue you just missed out on.
Why have you spent so much effort stating the obvious? Most people here know that warmer periods are better. Look at the planet from the equator to the poles. Look at biodiversity from the equator to the poles.
The people of planet Earth have NEVER had it so good. Now that’s stating the obvious. 🙂

The cult of warm is not a science but another failed dialectical philosophy. Mann et al are wilfully ignorant of real factual climate records and openly antihumanist in their deluded zeal to rewrite climate history in effect criminalizing modernity and humans. As the article concludes there is no historically significant warming in our current era.

Peter Miller

A really enjoyable read.
Putting my climate alarmist hat on, I would say: “Heresy, there are no such things as natural climate cycles!”
Putting my citizen of the Earth hat on, I would say: “global warming – man made or natural, I don’t care – it’s global cooling I worry about,”
As a sceptic, I believe man’s actions are almost irrelevant in affecting climate, however there must be some impact, but small and too difficult to measure accurately – and how the heck would you measure it accurately (forget the IPCC guesses).


A very great read indeed and a very good compilation of events. The problem is that climate alarmists don’t put the current levels of Co2 or the temperature in perspective, they just cherry pick what gives the public a distorted view. As I said in another thread earlier today we are Co2 starved and actually rather cool too. We are merely visitors to this planet and we adapt to our surroundings as and when they change. When we enter the next ice age the sea will give up the land again. Until then the sea levels shall continue to rise very slowly and glaciers that are remnants from the last ice age shall continue to diminish.
Our oceans aren’t becoming acidic, they are becoming less alkaline. We have coral reefs because the ph suits it right now. As and when Co2 responds to temperature it is either sequested to the oceans or returned to the atmosphere, affecting the ph. We are not to blame for coral reefs disappearing, climate is.
The list goes on and on of all the possible inconveniences of a warmer world. The fact is that they shall continue with or without us.


Good stuff. Nice to see that some people are actually carrying out serious climate research.


Thanks Anthony for posting this very interesting essay. Real science instead of the persistent AGW mumbo jumbo we get fed elsewhere. I will be printing out the graphs sheet in a large format and hanging it on the wall for family and friends to look at. Thanks to Andy May for compiling this valuable article.(It would not of course have passed muster on Wicker Pedia.)


To Peter Miller – you cannot measure or quantify the effect of our Co2 contribution on our climate. The fact that the IPCC try to with a certainty of 97 percent, when oddly 97 percent of Co2 is natural is absolute madness.
And I agree about global cooling too. Here is a scenario that I have posted on many other sites before. Suppose we did start cooling and the IPCC maintain that Co2 is a warming guess – are the policy makers going to suggest that we start burning coal. I fear not. The threat of man made climate change is convenient to the oil and gas producers – nothing more and nothing less I am afraid.
I still maintain that our explosive population is a very real problem. And what we do about that? We can’t / won’t etc etc. Co2 is a scapegoat for population that allows us to sleep well in the belief that we are doing something to save our future.


To Andrew. The problem is getting the message out to the right places and the public at large. Everyone is guilty of barking at the moon on any site or blog that discusses the merits of man made climate change. It is so entrenched in policy now that it is very difficult to argue against. Sooner or later it will end up being like a religious belief that is not open to scrutiny.

Climate agnostic

pat says:
November 17, 2013 at 3:10 pm
“Temperature is a lagging indicator and does not show up until well after emissions have occurred,” U.S. envoy Kim Carnahan told delegates on Nov. 11…”
And this is what Fred Singer says (regarding antropogenic emissions):
“Finally, note that the temperature ‘blade’ starts around 1910, while CO2 starts its sharp upward climb around 1780AD.”
In other words we are taking about two different fenomena, 1) the natural rise of CO2 due to rising temperatures and 2) the unnatural CO2 rise due to man.

Go Home

Using my calibrated eye, it would appear that CO2 rise leads temperature rise in this chart, contrary to what I have come to understand from this site.

On ( ) he has the two curves overlain and you can see the lag.

David in Cal

I meant my oil company comment to be a joke. Clearly it missed. Sorry.

No problem, I get it.

Go Home

OK I recant, it appears I used my bad eye. I see current year is to the left on the chart and not the right side of chart.

Chad Wozniak

Excellent summary, but a few nits: the Roman Climate Optimum actually ended around 300 AD, not 450, with references to the unusual cold at that time and afterwards (inter alia) in Edward Gibbon’s Decline and Fall of the Roman Empire.

This is great and I will be sharing it.


Just before the 8,200 year cold event, around 8,400 years ago, the Black Sea, which was a fresh water lake at the time, filled from Mediterranean Sea.
I don’t understand this. If the level of the lake was below that of the Mediterranean, the lake couldn’t have had an outlet, and so its water couldn’t have been fresh; but if the lake was higher, then how could it be [“filled”], and where was the catastrophic flooding?


Of course, “fillled” should be “filled”.

Robert of Ottawa

This is a good general overview of the past climate and human history.


Thank you for doing an analysis that should have been done years ago, and for doing it so well.

Robert of Ottawa

Beale, the history of the Black Sea is very controversial. It is assumed that the BS was lower than the Mediterranean and there was a blockage in the gorge at Constantinople, but there appears to be little subsea evidence of a flash flood into the BS. The Sea of Marmara may have been part of an explanation, but the jury is still out.
However, the BS is very strange in that it is very different at depth than at the surface. I hope you do some googling; I am fascinated by this topic but do not have ready links. I think the rise of sea levels throughout the world at the end of the last ice age were rapid and significant (Watts has the chart somewhere) and these level changes may well have been catastrophic in places. Giving rise to the almost universal stories of Great Floods, a la Noah.
Interestingly, Noah landed on Mnt. Ararat, in Turkey! And the earliest agriculture is found in Turkey, as are… Maybe they went there to escape the flooding BS.


[…] the current rate of sea level rise is about 6.8 inches per 100 years or 3.2 mm per year.
Shouldn’t that be about 12.6 inches/century?
Regardless, a fine article.


The contortions that the CAGW faithful go through to justify the CO2 lagging temperatures is about the funniest thing in their whole argument. IIRC, it basically states that the CO2 causes the warming, and then that warming causes more CO2 to be released from the oceans, which causes more warming, etc.

In the case of warming, the lag between temperature and CO2 is explained as follows: as ocean temperatures rise, oceans release CO2 into the atmosphere. In turn, this release amplifies the warming trend, leading to yet more CO2 being released. In other words, increasing CO2 levels become both the cause and effect of further warming. This positive feedback is necessary to trigger the shifts between glacials and interglacials as the effect of orbital changes is too weak to cause such variation. Additional positive feedbacks which play an important role in this process include other greenhouse gases, and changes in ice sheet cover and vegetation patterns.

Note the lack of an actual logical deduction, apart from the throwaway “the effect orbital changes is [too] weak” line. The rest is speculation, and this single item is unproven (as far as I am aware).

What is being talked about here is influence of the seasonal radiative forcing change from the earth’s wobble around the sun (the well established Milankovitch theory of ice ages), combined with the positive feedback of ice sheet albedo (less ice = less reflection of sunlight = warmer temperatures) and greenhouse gas concentrations (higher temperatures lead to more CO2 leads to warmer temperatures). Thus, both CO2 and ice volume should lag temperature somewhat, depending on the characteristic response times of these different components of the climate system. Ice volume should lag temperature by about 10,000 years, due to the relatively long time period required to grow or shrink ice sheets. CO2 might well be expected to lag temperature by about 1000 years, which is the timescale we expect from changes in ocean circulation and the strength of the “carbon pump” (i.e. marine biological photosynthesis) that transfers carbon from the atmosphere to the deep ocean.

Again, ‘expecting’ the result that you already have, as long as it explains your argument, of course.
The problem with the arguments is mostly that if this were valid, temperatures would never stop rising! There is no valid theory (in this scenario) that explains why the rise stops and does not go on for ever, if CO2 is the real driver behind warming. I cannot see how that logical dichotomy can be resolved.
The problem with that is that the whole edifice then becomes completely unstable, and the argument just crumbles into dust. This is why ‘the faithful’ have to defend it so vehemently, and why they end up looking so foolish (among other reasons).

Robert of Ottawa

Most people DO NOT know that warmer is better. They are told day and hour that warm is bad; even though they know cold is not good. It’s called propaganda; a propaganda that George Orwell would be proud of.


“Dogs were probably domesticated by the Natufians in the Middle East by 14,000 years ago. This seems to be supported by exhumed graves in the ancient villages of Ain Mallah and Hayonium near Lake Tiberias (also called the Sea of Galilee) in Israel. In these graves dogs and humans were deliberately buried together2”
Nope, dogs lifetimes are short, way too short in my opinion.
They didn’t die together.
One of them might have been put to death.
Guess which one ??
On that note: let us proceed.

Robert of Ottawa

Brent Walker November 17, 2013 at 3:07 pm
I haven’t heard of the “Timor Trench”. The Torres Straits and Arafura Sea between Papua New Guinea and Australia is very shallow and would have been dry land 50,000 years ago, when the Australian Aboriginals moved there.
Also, they did not have boats and they didn’t have boats when the Europeans found them.