This is the End

From the BBC (hat tip: Ron Good), a spine-tingling article on civilizational collapse:

While there is no single accepted theory for why collapses happen, historians, anthropologists and others have proposed various explanations, including:

CLIMATIC CHANGE: When climatic stability changes, the results can be disastrous, resulting in crop failure, starvation and desertification. The collapse of the Anasazi, the Tiwanaku civilisation, the Akkadians, the Mayan, the Roman Empire, and many others have all coincided with abrupt climatic changes, usually droughts.

ENVIRONMENTAL DEGRADATION: Collapse can occur when societies overshoot the carrying capacity of their environment. This ecological collapse theory, which has been the subject of bestselling books, points to excessive deforestation, water pollution, soil degradation and the loss of biodiversity as precipitating causes.

INEQUALITY AND OLIGARCHY: Wealth and political inequality can be central drivers of social disintegration, as can oligarchy and centralisation of power among leaders. This not only causes social distress, but handicaps a society’s ability to respond to ecological, social and economic problems.

The field of cliodynamics models how factors such as equality and demography correlate with political violence. Statistical analysis of previous societies suggests that this happens in cycles. As population increases, the supply of labour outstrips demand, workers become cheap and society becomes top-heavy. This inequality undermines collective solidarity and political turbulence follows.

COMPLEXITY: Collapse expert and historian Joseph Tainter has proposed that societies eventually collapse under the weight of their own accumulated complexity and bureaucracy. Societies are problem-solving collectives that grow in complexity in order to overcome new issues. However, the returns from complexity eventually reach a point of diminishing returns. After this point, collapse will eventually ensue.

Another measure of increasing complexity is called Energy Return on Investment (EROI). This refers to the ratio between the amount of energy produced by a resource relative to the energy needed to obtain it. Like complexity, EROI appears to have a point of diminishing returns. In his book The Upside of Down, the political scientist Thomas Homer-Dixon observed that environmental degradation throughout the Roman Empire led to falling EROI from their staple energy source: crops of wheat and alfalfa. The empire fell alongside their EROI. Tainter also blames it as a chief culprit of collapse, including for the Mayan.

EXTERNAL SHOCKS: In other words, the “four horsemen”: war, natural disasters, famine and plagues. The Aztec Empire, for example, was brought to an end by Spanish invaders. Most early agrarian states were fleeting due to deadly epidemics. The concentration of humans and cattle in walled settlements with poor hygiene made disease outbreaks unavoidable and catastrophic. Sometimes disasters combined, as was the case with the Spanish introducing salmonella to the Americas.

RANDOMNESS/BAD LUCK: Statistical analysis on empiressuggests that collapse is random and independent of age. Evolutionary biologist and data scientist Indre Zliobaite and her colleagues have observed a similar pattern in the evolutionary record of species. A common explanation of this apparent randomness is the “Red Queen Effect”: if species are constantly fighting for survival in a changing environment with numerous competitors, extinction is a consistent possibility.

More at the link.

Younger Dryas and Gobekli Tepe

Interesting new theory: a comet killed off the wooly mammoth – and impelled the rise of civilization!

Experts at the University of Edinburgh analysed mysterious symbols carved onto stone pillars at Gobekli Tepe in southern Turkey, to find out if they could be linked to constellations.

The markings suggest that a swarm of comet fragments hit Earth at the exact same time that a mini-ice age struck, changing the entire course of human history.

Scientists have speculated for decades that a comet could be behind the sudden fall in temperature during a period known as the Younger Dryas. But recently the theory appeared to have been debunked by new dating of meteor craters in North America where the comet is thought to have struck.

However, when engineers studied animal carvings made on a pillar – known as the vulture stone – at Gobekli Tepe they discovered that the creatures were actually astronomical symbols which represented constellations and the comet.

Using a computer programme to show where the constellations would have appeared above Turkey thousands of years ago, they were able to pinpoint the comet strike to 10,950 BC, the exact time the Younger Dryas begins according to ice core data from Greenland.

The Younger Dryas is viewed as a crucial period for humanity, as it roughly coincides with the emergence of agriculture and the first Neolithic civilisations.

Before the strike, vast areas of wild wheat and barley had allowed nomadic hunters in the Middle East to establish permanent base camps. But the difficult climate conditions following the impact forced communities to come together and work out new ways of maintaining the crops, through watering and selective breeding. Thus farming began, allowing the rise of the first towns. 

Emphasis added. There’s more at the link. Gobekli Tepe has been noticed earlier on this blog.