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.
Writing
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.
Conclusions
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,…”
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Andy May is a Petrophysicist residing in The Woodlands, Texas
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15. Rohde, Robert, http://www.globalwarmingart.com/wiki/Image:Post-Glacial_Sea_Level.png
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19. http://www.ncdc.noaa.gov/paleo/abrupt/data4.html
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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.
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44. http://globalheritagefund.org/onthewire/blog/catalhoyuk_world_heritage_list
45. Israel Finklestein http://www.nytimes.com/2013/10/23/world/middleeast/pollen-study-points-to-culprit-in-bronze-era-mystery.html
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.
50. http://www.co2science.org/data/mwp/mwpp.php
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
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54. Rao, Smith and Koffler, “Global Sea-Temperature Distribution Determined Froma an Environmental Satellite,” Monthly Weather Review, Vol 100, No. 1
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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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Yes clearly the people who were already there when the Romans invaded and conquered them are occupying the land whose rightful name was given to it by Hadrian, following the terminology of the Greeks, who was referring to a group of people that did not yet exist, of a culture surrounding a religion originating in a completely different area, which also did not yet exist, who adopted the name much later from the Byzantines.
Clearly.
A most enjoyable big picture chart and article. If I had my editor hat on, I would strike many of the “very”s from the text and if possible reverse the upper left chart so the timeline reads past to present as in the rest of the charts.
Excellent and suggestive. Thank you.
But get some tutoring on comma use. Yours is distracting and incompetent.
I have a feeling that the great invasions are also climate linked. Firstly the Celtic tribes into Europe, then the Goths et al, then the Mongols. All driven by massive population growth in very balmy conditions.
Very useful summary – thank you. A great poster, I will be printing it out
Steven Mithen is well worth reading. I have just finished two of his books, one on the development of the modern brain (Prehistory of the Mind) and development of music (The Singing Neanderthals) They are both very original and well written. I Have just bought After the Ice, – but it is 600 pages long so I am pausing before starting.
Not to be a spoil sport….you might want to check your math on the seal level rise…last line in the section…..3.2mm/year = 320mm/century = ~12.6 inches….not 6.8 inches/century. Nice compilation of information.
Dogs were domesticated in Europe long before your Middle East 14K years ago.
http://www.telegraph.co.uk/science/science-news/10449885/Dog-ancestors-were-Ice-Age-mans-best-friend.html
The chart shows that the Present Warm Period is warmer than the Medieval Warm Period.
Climate agnostic says:
November 17, 2013 at 4:17 pm
pat says:
November 17, 2013 at 3:10 pm
…………………………………….
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.
—————————————————————————————————————
Yes to different “fenomena” but no to the second reason you have given.
http://blogs.telegraph.co.uk/news/jamesdelingpole/100022226/agw-i-refute-it-thus-central-england-temperatures-1659-to-2009/
Integrate the temperature rise and you get the CO2 curve according to one researcher.
re : “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.”
The problem with this conclusion is that it assumes that the current warming is like past warmings. A couple of differences are:
1) The current warming is going up from the near the top of an interglacial. None of the species on the planet evolved with the new climate, and therefore one would expect that many of them will be less well adapted to it.
2) This warming is accompanied by a return to a far greater acidity of the oceans than in the recent past.
3) The current warming is a very fast warming and human land use change is making a barrier to range changes for many species.
So I think that a better estimate of whether the current warming period will be a problem to adapt to would be to look at the actual effects of the warming, and the consequent costs. Such as was done in the Stern Review.
Other than a misunderstanding regarding the eccentricity of the earth’s orbit within the context of the Milankovitch cycles, the article was a very good read.
Thank you, Andy. I generally follow the climate “debate” for entertaining purposes but there are two or three topics that actually interest me. This is one of them. The effort is appreciated.
Robert of Ottawa says:
November 17, 2013 at 6:11 pm
When sea level is lower during glaciations, New Guinea & Australia are indeed connected by dry land. However even at the Last Glacial Maximum the Australia-New Guinea continent was not connected to the Sunda Platform, ie the dry land exposed then around Borneo, Sulawesi & Sumatra. Therefore the ancestors of the Aborigines had to have crossed the narrow stretch of deep water in the Timor Trough on boats or rafts. Their descendents lost this technology because they no longer needed it.
Take a look at bathymetric charts of the region & you’ll see that this is so. At the LGM sea level was at most about 140 m. lower than now.
This is certainly an excellent chart, although I’m a bit disappointed the resolution is not higher. I have difficulty in reading some of the smaller numbers on the smaller graphs, such as the recent sea level data from CSIRO.
I find the climate change issue quite fascinating. I recall recently on an ABC program called The Drum, Dr John Hewson (former Liberal Party leader whilst in opposition), explaining why he believed that CO2 emissions are a threat to be taken seriously.
He claimed that scientists in general are always disputing the validity of theories and the interpretation of data, yet on the issue of anthropogenic climate change, all the scientists working in the various fields of climate science are in agreement, that the current warming is caused by humanity’s CO2 emissions. Therefore they must be right.
That statement immediately struck me as being quite illogical and certainly unscientific. Assuming it is true that there is a large consensus of opinion on the matter of AGW (which fact is uncertain), the fact that there appears to exist such a conformity of views on such a very complex area of research, should be cause for alarm bells to ring.
Is there not likely to be some other reason for the consensus? Perhaps Dr John Hewson thinks that climate science is a relatively simple and straightforward area of research that is easily settled with a bit of government funding.
However, this leads me to speculate on the real reason why there appears to be an unusually large consensus of opinion on the matter, when scientists are usually very ready to express differing views on any complex issue, and even admit quite often that they simply don’t know.
(1) The first reason that springs to mind is the fact that most climate research centres have been set up, and funded by governments, because of a perceived threat from our CO2 emissions. Their purpose is to investigate the nature of that threat. I’m sure that all the scientists employed in such research centres are able to work out that their continued employment is dependent upon the threat being maintained. There is an unavoidable bias in such a situation. Scientists are also human, have families to support, and probably wish to hang on to any job in their field of interest which allows them to get paid for doing what they like doing.
(2) The first reason leads to an issue of ethics. Would any scientist worth his salt, continue in a job after becoming aware that his gathered data was being interpreted in a biased way by his ‘superiors’? That is, apart from his need for a job, how can he rationalise as a scientist such behaviour, turning a blind eye or keeping quiet about his doubts and concerns regarding the validity of some of the interpretations of his data?
(3) It occurred to me that one very powerful motive to continue riding on the bandwagon of climate-change alarmism, would be a concern for a future world that has depleted its relatively cheap fossil fuel reserves without making adequate provision for alternative energy supplies.
Humanity seems to have a short memory for past events and often fails to learn from them, perhaps because its main focus is usually on economic development in the present. We build low-set houses in flood plains, apparently oblivious to the historical evidence that such areas have been flooded several times during the past century or two, and might be due for another major flood at some time in the near future. We could protect our houses by raising them on piers above previous, known flood levels, and/or build flood-mitigation dams, but that would be too expensive, and the imposition of stringent building regulations tends to discourage investment.
Given our head-in-the-sand past record on such issues, is it not likely that unless we are provoked and alarmed we would continue to use fossil fuels till the very end, without setting aside sufficient resources to develop efficient, alternative energy supplies.
The world might then experience a huge crisis as people fight for the last remaining fossil fuel reserves. Simply warning people that such reserves are not infinite, and that we should prepare now for a future in which most of our energy needs are met by renewables, may not be sufficient.
People have a tendency to fail to act on advice simply because it’s sensible and the right thing to do. They often need to be alarmed, or be made to feel very afraid. The priests of religions know this. One can’t expect everyone to love their neighbour and ‘do unto others as you would have them do unto you’, simply because it seems a sensible and reasonable way to behave. People (well, some people) seem to need the fear of a punishment in everlasting hell, in order for them to behave sensibly and reasonably towards their neighbour or the foreigner.
In other words, does it really matter in the long run if this apparent consensus of opinion on the dangers of our CO2 emissions is a fabrication? if in say 30 years’ time when electric-only cars are the norm, and everyone’s house roof is totally covered with a polymer type of solar panel that is painted onto the roof and which charges the spare battery of the electric car during the daytime, does it really matter if it becomes crystal clear to everyone that the climate scientists of today largely got it wrong? Can they not claim credit for at least having motivated society to invest in renewable energy technology?
Don’t forget the Anasazi who flourished as cliff dwellers in southwestern U.S. during the Medieval Warm Period, whose civilization ceased around 1300 for unknown reasons. Could it have been due to a lack of moisture during the Little Ice Age?
A further extremely informative and enjoyable atricle. However, we must be absolutely accurate in our data and unfortunately, the conversion of sea level changes from metric to imperial units is incorrect:
“… According to the University of Colorado Sea Level Research Group, the current rate of sea level rise is about 6.8 inches per 100 years or 3.2 mm per year.”
3.2 mm per year is 320 mm per 100 years which is 12.6 inches and not 6.8 inches.
I apologize for the error in converting the current sea level rise to inches. Good catch guys. I do want to get it right.
People do tend to live by the sea, and when the sea rose hundreds of feet at the end of the ice age it covered a lot of evidence (I imagine) that humanity was “advanced.” The flooding of the Black Sea was later, but it too would cover evidence. While some effort has been made to find signs of drowned ports using submarines, the largest ports would likely be at the mouths of rivers like the Volga, and now be buried by deltas.
The “flood” exists as lore in many societies. Besides Noah we have “Utnapishtim,” and of course Atlantis, and the lore about Avalon and Blessed Isles “to the west,” which Tolkien built upon.
Sometimes, when I look around, I entertain grave doubts that we are the most advanced civilization this earth has ever seen. Other times I think we aren’t so bad. We may not levitate about on flying carpets, but we do have computer models, (both good and bad,) and websites like WUWT, which at times is a sort of flying carpet for the mind.
FrankK says:
November 17, 2013 at 8:53 pm
Well, Central England is hardly showing global temperatures. I trust Fred Singer who is an expert on climate a lot more than James Delingpole who is a journalist and blogger. Both of them are skeptics but the difference between them is enormous, to say the least.
People don’t seem to realise that human emissions since 18th Century haven’t disappeared. They have been added to the Earth’s carbon cycle and are recycled both in the sea, the biospere and the atmosphere. Thus part of the natural CO2 is in fact anthropogenic in origin.
Can I echo the comments of others that this is a very good resource which looks at our climate in the context of millions of years rather than a few decades. A great deal of hard work has gone into this.
The resolution is not good and whilst it may be great as a large poster it is less useful in the size we can output on our printer so perhaps it might be possible to rejig it for home use? If so, thanks.
FrankK quoted Delingpole who used a chart from 1659 to 2009 for Central England temperature.
The one below is much more informative
http://wattsupwiththat.com/2013/05/08/the-curious-case-of-rising-co2-and-falling-temperatures/
The downwards curve is however now even more pronounced with an anomaly of only 0.3C.
tonyb
Seth,
1) So are you suggesting that evolution stopped before or during the last glaciation? If that’s what you’re saying then you’re mistaken, but if what you’re saying is that some rapid and significant evolutionary process is necessary to cope with a small uptick in global average temperatures then that is just idiotic.
2) The oceans are alkaline. How many times do we have bear this lie from AGW advocates?
3) The first part is factually incorrect, the warming is not rapid compared to past changes, and overall warmth is still somewhat less than previous peaks. The point about species range being limited by our ever expanding population and need for land would be valid if there was a problem, which there does not appear to be at the moment. In addition to which I take a rather anthropocentric view of things. For me people are always more important than anything else.
u.k.(us) on November 17, 2013 at 6:01 pm
Interesting comment……YOU invented the words “die together” in order to make it……
Why?
Just a small nit pick old boy but I said (my bold.)
And if you think about it just where do millions of people in the cold parts of the northern hemisphere head off each year? Look at US retirees in Florida. People know deep inside that warmth is better. Roasting maybe not. 🙂
Homo sapiens are tropical animals.
COLD KILLS.
UK excess winter deaths.
https://www.gov.uk/government/publications/excess-winter-mortality-2012-to-2013
http://www.wmpho.org.uk/excesswinterdeathsinEnglandatlas/
“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 constructed in present day England and the first large cities appear in India.”
The 5.9Ky and 4.2Kyr BP both were warmer periods in Greenland. Around 3300-3200 BP was apparently even warmer in Greenland, though it was manifested as an harsh cold period in the Temperate Zone, with the collapse of many civilisations.
https://www.google.co.uk/?gws_rd=cr#q=climate+1200+BC
The thermal optimum in the Temperate Zone of 4750-4400 BP, with major cultural expansions occurring from around 4600 BP, was much cooler in Greenland, and is fairly equivalent to contemporary times:
http://smpro.ca/crunch/GISP2Civil.png
At this scale we see Greenland proxies move mostly in opposition to Central England:
http://www.21stcentech.com/wp-content/uploads/2012/07/Greenland-ice-core-data.png
http://climexp.knmi.nl/data/tcet.dat
I conclude that at least through the Holocene, that Greenland temperatures are an inverse proxy for the Temperate Zone temperatures. That means rethinking the implications of the warm spike in Greenland temperatures around 1000 BP:
http://www.geo.arizona.edu/palynology/geos462/holobib.html
Further evidence of Arctic temperatures moving in opposition to Temperate Zone temperatures:
http://wattsupwiththat.com/2013/08/23/the-medieval-warm-period-in-the-arctic/#comment-1398577
Wonderful! Thank you, Andy. There’s a lot to argue about in almost every period along your timeline, no doubt. But the underlying fact of massive natural variability is quite clear.
Humility, perspective, and a healthy respect for natural change (in all fields, climate change, geology, anthropology, biology, et. al.) should be the order of the day for scientists.
A very well researched (and attributed) article. It’s always nice to have things put within a human context and time-frame. Thank you.