HUMANPAST.NET

Environment                  3,000 BC
Africa
Southwest Asia
Egypt
Indus Valley
China
Europe
South America
Mesoamerica
North America
Other

In General

 In order to date a magnetically orientated substrate a calibration chart showing variations in the direction of the Earth's magnetic field has been created from the available data. The calibration graph generally shows the very smooth wobble which is to be expected from the precession of the magnetic generator. However, in the last 10,000 years there have been two exceptions when the direction of the magnetic field has changed abruptly and in a manner which suggests an outside impulse. There is a clear perturbation at around 3150 BC, which probably means a cometary impact, but there is a significantly larger one around 7000 BC. Knowing that the system is highly damped with a time-constant of over 1,000 years suggests that there must have been a very large current pulse affecting the system between 7000 and 8000 BC. (160)

Africa

 The climatic record is, however, unequivocal: for most of the time between around 14 kya and 5 kya the Sahara experienced a monsoonal climate. The region had considerably greater rainfall than now and much of the land had permanent vegetation. (145)

There is no doubt about the sudden decline in rainfall across the Sahara. Around 5.5 kya deep-sea sediment records off the west coast of North Africa show a sudden increase in the amount of dust being transported in the winds from the east. At the drop of a hat the climate shifted to a drier form and the desert began to take over. (145)

Modern scientific investigations show that the Earth has been hit many times by objects such a comets and meteorites. Large impacts have a considerable effect on the environment and cause long-term changes in both climate and geography. Laboratory work on the effects of impacts shows that tidal waves of more than five kilometres high and travelling at up to 640 kph can be caused. Waves of this size would over run much of the Earth's land area. The debris forced into upper atmosphere by the impact would cause a short-term nuclear winter and a longer term global warming effect. It would also leave traces of nitric acid, magnetic fingerprints, tektite trails and radiocarbon blips which could be used to date the event. This type of evidence shows that there have been two large impacts in the last 10,000 years: a seven-fold impact into all the world's major oceans around 7640 BC, and a single impact into the Mediterranean a bout 3150 BC. ...Professor Liritzis had found evidence that a comet did hit the Mediterranean Sea around 3150 BC. (160)

Southwest Asia

Between about 5500 and 3500 B.C. Mesopotamian climates were comparatively humid, with a change to cooler and drier conditions after about 3500 BC. Subtle changes in climate like this might have had major effects on the settlement history of the area, because the zones in which dry-field rainfall-base grain cultivation was possible may have shifted. (46)

The climatic record is, however, unequivocal: for most of the time between around 14 kya and 5 kya the Sahara experienced a monsoonal climate. The region had considerably greater rainfall than now and much of the land had permanent vegetation. (145)

Recent results obtained from a speleothem in Oman provide a record of the summer monsoon (July to September) between 10.3 and 2.7 kya and between 1.4 and 0.4 kya. This shows a marked long-term decline from high levels between 10 and 8 kya including a notably dry period between 5.5 and 5 kya. (145)

Modern scientific investigations show that the Earth has been hit many times by objects such a comets and meteorites. Large impacts have a considerable effect on the environment and cause long-term changes in both climate and geography. Laboratory work on the effects of impacts shows that tidal waves of more than five kilometres high and travelling at up to 640 kph can be caused. Waves of this size would over run much of the Earth's land area. The debris forced into upper atmosphere by the impact would cause a short-term nuclear winter and a longer term global warming effect. It would also leave traces of nitric acid, magnetic fingerprints, tektite trails and radiocarbon blips which could be used to date the event. This type of evidence shows that there have been two large impacts in the last 10,000 years: a seven-fold impact into all the world's major oceans around 7640 BC, and a single impact into the Mediterranean a bout 3150 BC. ...Professor Liritzis had found evidence that a comet did hit the Mediterranean Sea around 3150 BC. (160)

Egypt

 The political breakdown of Egypt toward the end of the Old Kingdom may have been in part a result of dramatic climatic changes. Rainfall decreased in much of Egypt after about 2900 BC, and Butzer notes that decreasing rainfall would have reduced the resources and numbers of desert nomads as well as eliminated much of the seasonal pastoral movements into the deserts. (47)

Fossil shells of the large land snail, found in stage 3 surface soils in northwestern Sudan, provide evidence of at least twelve inches of annual precipitation during the late stage of this Neolithic Pluvial. Radiocarbon ages determined on the organic fraction of the snail shells range from 4500 BC at the north end of the study area, to later than 1100 BC at the south end, indicative of a retreating forest-savanna during the final stages of the pluvial period in northwestern Sudan. (70)

Aridity may have slightly lessened during the fourth millennium BC, with annual rainfall around six inches, but the climate continued to deteriorate. Plant fossils suggest that the climate through 2000 BC became increasingly more arid, with estimated annual rainfall of less than four inches. (70)

The climatic record is, however, unequivocal: for most of the time between around 14 kya and 5 kya the Sahara experienced a monsoonal climate. The region had considerably greater rainfall than now and much of the land had permanent vegetation. (145)

Modern scientific investigations show that the Earth has been hit many times by objects such a comets and meteorites. Large impacts have a considerable effect on the environment and cause long-term changes in both climate and geography. Laboratory work on the effects of impacts shows that tidal waves of more than five kilometres high and travelling at up to 640 kph can be caused. Waves of this size would over run much of the Earth's land area. The debris forced into upper atmosphere by the impact would cause a short-term nuclear winter and a longer term global warming effect. It would also leave traces of nitric acid, magnetic fingerprints, tektite trails and radiocarbon blips which could be used to date the event. This type of evidence shows that there have been two large impacts in the last 10,000 years: a seven-fold impact into all the world's major oceans around 7640 BC, and a single impact into the Mediterranean a bout 3150 BC. (160)

...Professor Liritzis had found evidence that a comet did hit the Mediterranean Sea around 3150 BC. The biggest clue that something major occurred is the fact that this date is precisely the point at which the first Ancient Egyptian Dynastic period began. In his book Chronicle of the Pharaohs, Egyptologist Peter Clayton gives a starting date of 3150 BC for the Dynasty Zero...(160)

Indus Valley

 

China

 Conditions across much of China at 5 kya seem to have been warmer than present, but perhaps cooler than in the early Holocene. These conditions seem to have remained similar to those at 8 kya, with warm temperate forest extending hundreds of kilometres further north than at present. Over much of China, pollen records indicate temperatures 2-4°C warmer than at present (perhaps as much as 5°C higher in the Tibetan Plateau], cooling after about 4 to 3 kya. In northwestern China increased dust deposition indicates that the climate became much more arid from 6 to 5 kya. This dry, dusty period interrupted the formation of the brown soil developing under a warm­humid subtropical climate during the Holocene Optimum. (145)

In the northeast of China [Manchuria], peat deposition seems to have begun in the mid-Holocene, coincident with a cooling of climate after 5 kya. Lake levels indicate conditions moister than present over most of China up until 3.5 kya. Magnetic susceptibility of loess profiles presents the same picture. Evidence of Neolithic agriculture in northwestern regions of China that are currently too arid for crop­growing is further testimony of the moister climate that prevailed at around 5 kya. Agriculture was already present and expanding throughout the southeast Asian region, but deforestation in southern China and in the monsoon zones of Indo-China does not appear to have been significant until after around 4 kya. (145)

Europe

 In 1931 a trawler working in the southern North Sea dredged up a lump of peat containing an exquisitely crafted spearhead made from a deer's antler. Dated as being nearly 14 kyr old, this artefact was dramatic evidence of how early humans exploited the broad expanses of land that had been exposed during the last ice age, and were only reclaimed by the sea some 7 kya. When this spearhead was buried, dense oak forests had yet to spread into the region, known to archaeologists as 'Doggerland', where now the sea is over 30m deep. This famous find emphasises that the rise in sea level between about 15 and 5 kya covered up large areas of habitable land that had been exploited by humans and made movement around the continental margins easier. (145)

Modern scientific investigations show that the Earth has been hit many times by objects such a comets and meteorites. Large impacts have a considerable effect on the environment and cause long-term changes in both climate and geography. Laboratory work on the effects of impacts shows that tidal waves of more than five kilometres high and travelling at up to 640 kph can be caused. Waves of this size would over run much of the Earth's land area. The debris forced into upper atmosphere by the impact would cause a short-term nuclear winter and a longer term global warming effect. It would also leave traces of nitric acid, magnetic fingerprints, tektite trails and radiocarbon blips which could be used to date the event. This type of evidence shows that there have been two large impacts in the last 10,000 years: a seven-fold impact into all the world's major oceans around 7640 BC, and a single impact into the Mediterranean a bout 3150 BC. ...Professor Liritzis had found evidence that a comet did hit the Mediterranean Sea around 3150 BC. (160)

South America

 By about 2500 BC, many small sedentary communities had appeared along the Andean coast. (52)

...an extremely dry period took place' between 5,000 and 6,000 years ago, "during which Titicaca fell some 250 feet below its present-day level." (69)

When the lake plunged to its lowest level, about 5,000 years ago, Tiahuanaco would have ceased being a port because it would have been more than 20 miles from the shoreline. (69)

Mesoamerica

 

North America

 In some prehistoric periods the Southwest was wetter than it is today, but for most of the last ten thousand years the Southwest has usually been at least as hot and dry as it is today, and there were short periods of extreme drought. (53)

Other