Holocene Periods That Were Warmer Than Today Allowed Early Civilization And Societies To Flourish

A Short History of the Human Race
Part 3. Empires
By Ed Caryl

After the cold snap of 8200 years ago, civilization really began to develop in the Middle East. Villages became towns. Towns developed into cities. Societies adopted formal rulers, religions, and the beginnings of social stratification. The first large temple structures date from much earlier, in eastern Turkey, even before the people building them had domesticated grain or animals, but there are no villages, towns, or cities associated with these structures.

Figure 1 is a diagram of the last 10,000 years. The graph resolution is 100 years. Many significant events are marked on the Greenland GISP2 Ice Core temperature plot. The Greenland and Antarctic ice core temperature records only indicate temperature trends in the surrounding seas, the sources of the snow-water. Global temperatures are represented more accurately by the sea level.

People and animals require fresh water, so the first villages began along the shorelines of the Persian Gulf, and the rivers and streams that ran into it, or at permanent springs. As the cooling at 8200 BP (Before Present) set in, it became dryer, and crops that depended on the monsoon rains began to fail. Irrigation became necessary. The development of irrigation required organization to build and maintain the infrastructure. Organization requires that someone be in charge. As more organization developed, more people could be fed, and more people were necessary to do the work. Villages became towns. Now, the towns were centered around temples. In Mesopotamia, each town had its own deity with its own temple, with dedicated attendants. Towns became cities. Town chiefs became Kings.

The period from 8200 BP to 5900 BP was the last period of the Neolithic, the last period before metal replaced stone for toolmaking. Pottery was in wide use.

In this period, beer was discovered. I say discovered, because beer happens naturally when bread is soaked in water and allowed to ferment. Good beer is just a refinement of that natural process. After a day working in the fields, liquid refreshment is a necessity. Drinking water can be easily contaminated and beer has advantages in that the alcohol kills off bacteria. Beer became a product of the temples. Beer became a civilizing influence.

As the population grew, cities became larger. Eridu was the first large city. Eventually, many cities grew along the Tigris and Euphrates rivers. These are known now as the Sumerian civilization, named for the city of Sumer, but each of these cities had their own king, and there was no central ruler. This situation lasted through the period of the Holocene climate optimum, from 8400 years BP until 5900 years BP, a period of 2500 years. This time span is called the Ubaid period, named after one of the important cities.

The cooling and drying at 5900 years BP put an end to all this. The North African Pluvial ended. The Sahara and Arabian Deserts began to dry out. The drying was so sudden, it is now called the 5.9 KY event (kilo-years BP). In Saudi Arabia, settlements on the Persian Gulf coast died out and population dropped for a thousand years. In Egypt, people migrated from the Sahara into the Nile Valley. In Mesopotamia, this period is known as the Uruk period, again for an iconic city. Just before this period ended, during a warm peak, the first writing appeared as cuneiform pictographs. A bit later Egyptian hieroglyphics appeared. This was also the beginning of the Bronze age in the mid-east and the Mediterranean.

Sea levels had been falling for 500 years before the 5.9 KY event. At the low-stand in sea level, people in western England began populating the Somerset Levels. Islands emerged there that were easily defensible because of the surrounding swamps. These were connected to the mainland by some of the earliest “roads” or plank trackways. These were preserved because as the sea level rose again they were protected in oxygen-poor bogs.

The Uruk period ended with the Piora oscillation, 5200 years BP, another cold period, colder than the 5.9 KY event, but this time cold and wet. The Dead Sea rose 100 meters. There were floods on the Tigris and Euphrates rivers. Cities were wiped out. This may also be the source of the Gilgamesh and Biblical flood stories. Other areas, like the Central Sahara, dried out even further. Climate change in Central Asia prompted a change in the domestic animal choice from cattle and sheep, to the horse, as a horse is better adapted to pawing away snow to get to forage in the winter. Glaciers in the alps advanced.

At this time upper and lower Egypt were two separate kingdoms. During the warm period of 5000 years BP, Egypt was unified by the first pharaoh of the First Dynasty. There is uncertainty about his name. It could have been Menes, or Narmer, or Hor-Aha. Confusing the issue, was the ancient practice of using a “Horus name” instead of a personal or nebty-name on monuments. Menes and Narmer, for instance, were likely the same person. This was the beginning of monument and temple building in Egypt.

In about 4700 BP, a cold period is recorded in the Greenland ice cores, and a seven-year drought and famine is recorded in Egypt in the reign of Djoser. Two hundred and fifty years later, as things warmed and improved, the great pyramids were constructed.

A cooling period and drought 4200 years ago lasted for two hundred years and the resulting series of famines pushed the Akkadian culture into collapse. This is known as the 4.2 KY event and it signaled the end of the Bronze Age in the Mediterranean. The Greek Dark Age followed. It was the end of the Old Kingdom in Egypt, and a period of major unrest throughout the region.

A warm period came after the 4.2 KY event 4000 years ago. Minoan civilization on Crete began to prosper. On Crete, the palace at Knossos was built 3900 years ago. By 3500 years ago, the Minoans were under pressure from the Mycenaean Greeks. Mycenae reached their height of power about 3200 years ago, their expansion was assisted by the destruction caused by the eruption of Thera/Santorini in 1628 BCE. The palace at Knossos was rebuilt after it was destroyed, not by Minoans, but by Mycenaean Greeks

There were four major volcanic events (VEI 7) in the Holocene that caused brief temperature drops that barely appear in the ice core records. I have used a one hundred year centered average on the available data, and the data itself barely resolves these events. The first was the collapse of Mount Mazama (Crater Lake) in what is now Oregon, USA, 7600 to 7900 years ago, just before Erdu was settled, the second was the collapse of Thera. Both events probably depressed global temperature by a degree or so for three to five years, the second causing recorded crop failures in China. The third was Mount Samalas (Lake Segara Anak) in Indonesia in 1257 AD. This collapse may have helped begin the Little Ice Age. The fourth was Tambora, also in Indonesia in 1815, following which we had the “year without a summer.

The generally warm period from 6000 years BP to 4200 years BP fostered the Bronze Age in the Fertile Crescent and the Mediterranean. This period saw the rise of empires in Mesopotamia and Egypt. When the tin required for making bronze ran low, the Iron Age began out of necessity. When this period came to a close, a reordering took place, driven by a cooling and arid climate.

History tells us that rainfall and water availability enables civilization, as well as warm temperatures. Warm temperatures and increased rainfall usually occur together. When it is cold, it is usually dry. Again, when it is warm we thrive, when it is cold we die.

Next: The Iron Age