In Part 2 of A New Green History of the World: The Environment and the Collapse of Great Civilizations, Clive Ponting tells us that “The best estimate for the total population of the world about 10,000 years ago, just before the adoption of agriculture in a few areas, was not more than about 4 million and in earlier periods it would have been considerably less than that.” “The human population multiplied rapidly and within a few thousand years had spread to the tip of South America. By about 10,000 years ago, nearly all parts of the globe had been settled, adapted to every possible environment in the world.” “Hunting animals made it a lot easier to damage the ecosystem because the number of animals at the top of the food chain is small and take longer to recover from over-hunting.” “The extinction of species in Eurasia was on a relatively small scale; elsewhere it was massive. These developments were of fundamental importance for the rest of human history and the future of the earth.” “The adoption of agriculture was the most fundamental change in human history, producing settled societies and radically changing society itself.” “Food surplus was the foundation for all later social and political change as it could be used to support people in occupations other than farming.” “The crucial period for the development of civilisation was the 1,000 years leading up to 3000 BCE in Mesopotamia, Egypt, The Indus Valley, China and the Americas.” “These societies provide the first examples of societies that so damaged their environment that they brought about their own collapse.” “Recent evidence from central Jordan suggests that as early as 6000BCE, within 1000 years of the emergence of settled communities, villages were being abandoned as soil erosion caused by deforestation resulted in a badly damaged landscape, declining crop yields and eventually inability to grow enough food.”
A NEW GREEN HISTORY OF THE WORLD
THE ENVIRONMENT AND THE COLLAPSE OF GREAT CIVILISATIONS
VINTAGE BOOKS 2007
Chapter 3: Ninety-Nine Per Cent of Human History
- For all but the last few thousand years of their roughly 2 million years of existence, humans have obtained their subsistence by a combination of gathering foodstuffs and hunting animals.
- In nearly every case people lived in small, mobile groups. It was without doubt the most successful and flexible way of life adopted by humans and the one that caused the least damage to natural ecosystems.
- It enabled them to spread across the face of the globe into every terrestrial ecosystem and to survive not just in favourable areas with easily obtained food but also in the rigorous conditions of the Arctic, the tundra of ice-age Europe and the marginal dry lands of Australia and southern Africa.
- It was this basic form of subsistence – gathering and hunting – that was to last as the human way of life until the development of agriculture about 10,000 years ago.
Gathering and hunting
- Most groups survive with very few goods because their wants are few and because they would find extra goods a hindrance to their mobile way of life.
- Within the group there is no concept of food ownership and food is treated as available to all.
- Food is not stored because that would interfere with mobility and because their experience dictates that some food will always be available even if certain items are occasionally in short supply.
- The Bushmen of south-west Africa illustrated how easily gathering and hunting groups could obtain sufficient food. Compared with modern recommended levels of nutrition the diet of the Bushmen was more than adequate.
- Many contemporary groups fail to see the attractions of agriculture with its much greater workload.
- All gathering and hunting groups, both contemporary and historical, seem to have tried to control their numbers so as not to overtax the resources of their ecosystem.
- The best estimate for the total population of the world about 10,000 years ago, just before the adoption of agriculture in a few areas, was not more than about 4 million and in earlier periods it would have been considerably less than that.
Technology and development
- The gradual development of human societies and the spread of settlements across the globe into different environments can be traced to the four basic traits that distinguish humans from other primates: a bigger brain with the power of abstract thought; an ability to stand fully upright on two feet, increasing mobility and freeing hands to use tools; the use of speech and communication opening the way for group co-operation and more elaborate social organisation; the adoption of technological means to overcome difficulties imposed by hostile environments.
- It was not until the last, long, glacial period that began about 80,000 years ago and lasted until about 12,000 years ago that the first permanent occupation of Europe took place. The climate was most severe at the height of the last glaciation period 25,000 – 20,000 years ago.
- In these semi-settled conditions a highly integrated society emerged that produced the great cave paintings.
- The permanent settlement of Europe at a time of extremely severe climatic conditions was a major human achievement and a sign of increasing human control over the environment, made possible by new technologies and sophisticated animal management.
- The human population multiplied rapidly and within a few thousand years had spread to the tip of South America.
- By about 10,000 years ago, nearly all parts of the globe had been settled, adapted to every possible environment in the world.
Gathering, hunting and the environment
- Hunting animals made it a lot easier to damage the ecosystem because the number of animals at the top of the food chain is small and take longer to recover from over-hunting.
- The extinction of species in Eurasia was on a relatively small scale; elsewhere it was massive.
These developments were of fundamental importance for the rest of human history and the future of the earth. Humans had become the only animals to dominate and exploit every terrestrial ecosystem. Yet at this stage the overall impact of the gathering and hunting groups was small because of the low, thinly spread population and their limited technology. Even so they were already making their presence felt as a number of animals were hunted to extinction and the environment was modified in subtle ways. For hundreds of thousands of years it was the only way in which humans were able to extract the necessary subsistence from the environment. The number of people that could survive in any one area was constrained by their position at the top of the food chain. Only in exceptional cases such as the Pacific coast of North America were resources so abundant that settled populations could develop in sizable villages. Then, about 12,000 years ago, the methods humans used to obtain their food began to change in a number of locations across the globe. The pace of change was still slow but far faster than in the past. It brought about the most fundamental alteration in human history – and one which made possible all the subsequent developments in human society.
Chapter 4: The First Great Transition
- The radically different way in which humans obtained their food was based on major alterations to natural ecosystems in order to produce fields to grow crops and pasture animals.
Agriculture: how and why
- Only slowly and unconsciously did a radically new solution to the human problem of finding enough food emerge.
- Several thousand years after domestication, the ‘secondary products revolution’ took place – the provision of milk and dairy products, continuing today with the Green Revolution and genetically modified crops.
- The major drawback with agriculture is the amount of work involved and food shortages in a bad season.
Despite the similarities in the overall structure in the evolution of agriculture across the world the varieties of plants and animals domesticated and the very different timescales involved mean that it is best to study the most fundamental change in human history on a regional basis. Each region of the world – south-west Asia, China, Mesoamerica, the Andes and the Tropics – had its own unique characteristics. Most important of all, in each of these regions agriculture developed in isolation from the rest of the world.
The spread of farming
The Andes and the rest of the world
The impact of farming
- The adoption of agriculture was the most fundamental change in human history, producing settled societies and radically changing society itself.
- Food surplus was the foundation for all later social and political change as it could be used to support people in occupations other than farming.
- Chiefs, clan leaders and religious authorities controlled the food surplus and distribution.
The emergence of civilisation
In a handful of areas some societies, without any external influence, went much further
Some societies created the organisations, institutions and culture which we call civilization.
- The key element was the environmental problems encountered and the level of organization this demanded.
- The crucial period for the development of civilisation was the 1,000 years leading up to 3000 BCE in Mesopotamia, Egypt, The Indus Valley, China and the Americas.
- Hierarchal, militaristic societies ruled by religious and political elites with immense control over their populations were established.
- Societies that were broadly egalitarian were replaced by ones with distinct classes and huge differences in wealth.
- All these changes depended upon the development of farming and the use to which the food surplus was put.
- The ability to support people not engaged in food production was the basis for all subsequent human, cultural and scientific advances.
- The overwhelming mass of the population lived on the margin of subsistence, suffering hunger and the ever-present threat of famine. Only a very small minority could be supported in a more affluent or a more intellectually rewarding style of life.
- These societies provide the first examples of societies that so damaged their environment that they brought about their own collapse.
Chapter 5: Destruction and Survival
- The adoption of agriculture, combined with its two major consequences – settled communities and steadily rising populations – placed an increasing strain on the environment.
- The emergence of villages and towns meant that the demand for resources was now more concentrated, and efforts to increase supply would inevitably impose significantly greater strains on smaller areas.
- Recent evidence from central Jordan suggests that as early as 6000BCE, within 1000 years of the emergence of settled communities, villages were being abandoned as soil erosion caused by deforestation resulted in a badly damaged landscape, declining crop yields and eventually inability to grow enough food.
- In sensitive ecosystems the foundations of society could be so damaged as to cause its collapse.
- These early societies were dependent on the production of a food surplus in order to feed and support the growing numbers of priests, rulers, bureaucrats, soldiers and craftsmen. If food production became more difficult and crop yields fell then the very basis of society was undermined.
The decline and fall of Sumer
- The Sumerians destroyed the world they had created so painstakingly out of the difficult environment of southern Mesopotamia.
- The valley of the twin rivers, the Tigris and Euphrates, posed major problems for any society, especially in the south.
- The rivers were at their lowest between August and October, the time when the newly planted crops needed most water. Water storage and irrigation were essential.
- Summer temperatures of 40°C, increased evaporation, building up the salt in the soil.
- Waterlogging increased because the soil had low permeability, made worse by the silt coming down the rivers, caused by deforestation of the highlands.
- As the land became more waterlogged and the water table rose, more salt was brought to the surface where the evaporation produced a thick layer.
- Modern agricultural knowledge suggests that the only way to avoid the worst of these problems is to leave the land fallow and unwatered for long periods to allow the level of the water table to fall.
- The internal pressures within Sumerian society made this impossible and brought about disaster.
- The limited amount of land that could be irrigated, rising population, the need to feed more bureaucrats and soldiers and the mounting competition between the city states all increased the pressure to intensify the agricultural system.
- Short term demands outweighed any consideration of the need for long-term stability and the maintenance of a sustainable agricultural system.
- About 3000 BCE Sumerian society became the first literate society in the world.
- About 3500 BCE roughly equal amounts of wheat and barley were grown in southern Mesopotamia. But wheat can only tolerate a salt level of ½% whereas barley can still grow in twice this amount.
- The increasing salinisation of the soil can be deduced from the declining amount of wheat cultivated and its replacement by the more salt-tolerant barley.
- By 2500 BCE wheat had fallen to only 15% of the crop; by 2100 Ur had abandoned wheat production and overall it had declined to just 2% of the crops grown in the Sumerian region.
- Rising population, and the demand for a greater food surplus to maintain the army as warfare became more frequent, reinforced the demand for new land.
- But the amount of land that could be cultivated, even with the more extensive and complex irrigation works that were becoming common, was limited.
- Until about 2400 BCE crop yields remained high, possibly higher than in medieval Europe.
- Then, as the limit of cultivatable land was reached and salinisation took an increasing toll, the food surplus began to fall rapidly.
- Crop yields fell by 40% between 2400 and 2100 BCE and by ⅔ by 1700 BCE.
- From 2000 BCE there are contemporaneous reports the ‘the earth turned white’, a clear reference to the drastic impact of salinisation.
- The bureaucracy and army could not be maintained and the state became vulnerable to external conquest.
- The artificial system that was the foundation of Sumerian civilization was very fragile and in the end brought about its downfall.
- Around Baghdad in the 7th and 8th centuries CE, the area was flourishing with high crop yields from irrigated fields supporting a wealthy and sophisticated society.
- But the same pressures seem to have been apparent as in Sumer over 3,000 years earlier. The agricultural collapse brought about through intensive irrigation and the Mongol conquest in the 13th century caused a massive decline in population and brought about the end of the sophisticated society that had survived in the area for centuries.
The Indus valley