1. Demography and Environment
Populations and how they Changed the Earth

2. EARLY CIVILIZATIONS
Early populations (pre-agricultural) increased for two reasons:
1) Modern humans produce more food
2) Migrated away from diseases (jungles)

3. Early Civilizations, cont.
With agriculture came population growth and migration to find new cultivable land
Migration to river valleys c BCE (very approximate)
Austronesian migrations c. 3,500 BCE
Bantu migrations c BCE
Population growth because of high birthrates, not because of better nutrition or lack of diseases
Not a biological evolution, but a cultural adaptation- humans learning to control their environment
Begins a much more rapid period of resource depletion: esp. wood, water—eventually, some urban centers decline because of overuse of resources
Austronesian migrations—S. China peoples moving into Taiwan, eventually pacific islands (i.e. polynesians)
By 1000 CE Austronesians had settled New Zealand, the last uninhabited large place left on earth
URBAN CENTERS IN THE MESOPOTAMIA AND INDUS RIVER ESPECIALLY

4. CLASSICAL PERIOD
Agrarian civilizations mostly dominated non-agricultural peoples
Populations were affected by two major factors during this period:
Technology 2) Diseases
1) Technological advances:
Iron metallurgy allows for movement out of River Valleys
Also, democratized access to metals
Resulted in tremendous depletion of forests
Shovels, hoes, axes, plows
In medieval Europe an iron forge consumed an area of forest with a radius of 4 KM/year; worse in classical times

5. Classical Period, cont. 2) Diseases: Cities were filthy and crowded
Mortality rate exceeded fertility rate, needed inflow of people from rural areas
Armies moved all around, and poverty pushed people out of urban areas—brought diseases with them
Constant exchange of people allowed for diseases to thrive in unexposed populations
Pastoralists were the best match for large civilizations because they generally had significant exposure to diseases
Africa had the most plentiful array of pathogens, and the Americas and Australia had the least
Contact between Rome and China resulted in huge population decreases and civil war in the 2nd and 3rd cent.
Native population in India had resistance to disease far superior to that of the Aryans- resulting not in takeover, but the caste system

6. Classical Period, cont.
Environmental interactions during this period included:
Deforestation in Mesopotamia resulted in more destructive flood patterns
Saline in the Tigris and Euphrates water supply forced gradual relocation north
Large scale depletion of timber resources for ships in the Mediterranean
Significant migrations:
Chinese population migrated north to south during the Han Dynasty (also resulting from deforestation along the Yellow River highlands)
Germans, Huns and Slavs came in to take over disease-ridden, weak governments

7. POST-CLASSICAL PERIOD Nomadic "Barbarians" & Plague
Big events/trends in Europe:
Invasion of Goths at the end of the Roman Empire—led to large scale migrations
Population in Northern Europe actually grew- plague very rare, and less infection because of fewer cities
Led to Viking raids in 9th and 10th centuries
Over this period, increasing biological homogenization across Eurasia

8. Disease Justinian Plague, 542 CE – 1/2 to 1/3 died in Constantinople
China, 610 CE
Large scale migration in the face of disease was much more prevalent in China than in Europe or the Middle East- the Chinese continued to move south
Island civilizations like Japan and Britain suffered terrible losses—populations generally remained low

9. Population Growth in the Post-Classical Period
Egypt and Mesopotamia hit their limit early- little growth during this period, and even decline
Baghdad was the center of the Abbasid dynasty, but saline content of the T & E was problematic
India? No one really knows. But, they didn't seem to be seriously affected by plague, just famine
Africa- populations up because of new iron technology, Bantu migrations, but the Nile River Valley was basically maxed out by 1 CE

10. Recovery of Europe and China
Europe first recovers economically, then politically- focus shifts away from Mediterranean to NW (better, less abused land, lots of forests)
China experiences an opposite pattern of recovery- focus shifts to the South
The introduction of the heavy plow suddenly makes ag. in NW Europe feasible and productive
Success in agriculture came along with developments in trade and the exchange of crops—led to huge population growth in China esp.
Sugar and SE Asian & African crops in Europe; Champa rice in China (alongside wet rice cultivation and terracing)
Heavy wheeled plow 6th and 7th centuries in europe

11. EARLY MODERN PERIOD Eurasia is fairly well integrated by this point
No "push factors" for the common people during this period- most exploration was done by profit-seeking urbanites, and improvements in ship building allowed explorers to venture further away from Europe

12. Colombian Exchange- A biological invasion
"Virgin soil epidemics"- exposure to diseases for which there was no built-up resistance
African slaves appear to have carried the more virulent form of smallpox and malaria to the Americas—many Europeans died from these diseases as well
Disease, violence, slavery, and a sharp decline in fertility all contributed to the decimation of the Native American population
Introduction of European and African diseases completely disrupted this formerly healthy region (i.e. the Caribbean population dropped from over 6M to about 80,000 people in the century after the conquest)
The ecosystems of the Americas also changed completely

13. Africa
Small numbers of African slaves had been brought to work in Europe since the fall of Rome- with the discovery of new Atlantic islands, this trade increased
With the discovery of the "New World," African slavery became very widespread- 10 M brought to the Americas until 1820; only 2M Europeans
Population remained fairly steady- declined due to slave trade, but grew because of American crops like peanuts, sweet potatoes and corn- no immigration until 19th century because of all the diseases there
Smallpox also was transferred to regions in Africa, and seriously affected some populations in the region
Only 57 of 100 slaves reached the coast of Africa, says “one estimate”…

14. China & Europe China: Europe:
Population grew until 17th century, declined (climate change and political upheaval), and then tripled within a century (climate change and new crops—potatoes and corn)
Europe:
Urban populations especially began to grow in the 16th century, putting pressure on governments and cities
They also needed more food, which led to the second agricultural revolution
By 1630, Europeans were experiencing a population decline though, which was followed by a rapid increase due to new crops and increased fertility rates
India, Japan and SE Asia all had very different patterns from China and Europe
Early 17th century decline in China possibly due to climate change (Mongolia also got colder, invaders from the north)—India too, particularly in the 16th century, but then rebounded somewhat (not a lot)
Japan—rapid growth in the 17th century, slow in the 19th and 19th

15. LONG 19th CENTURY
Populations explode as a result of industrialism—a nearly vertical rise in population
Prior population growth also contributes
Much more intense exploitation of the environment and pollution

16. Europe Higher standard of living
Government involvement in the health of its citizenry
Demographic transition- conscious birth control in part, as some (like Malthus) are increasingly freaked out about population growth- also, children were less valuable as laborers
New food crops continued to encourage population growth
Increased urbanization
Cholera (solved by improvements in water sanitation)
Emigration was caused by rising populations

17. Asia Population started out much larger than that of Europe
Hard to get anything accomplished politically or economically with so many people to support
Asian immigrants were alternately recruited and denied entry to work in the Americas
Indentured laborers (many from India) also caused population shift

18. 20th Century- The Contemporary Period
Population growth during the 20th century dwarfed that of the 19th century
World population quadrupled
Why?
Sustained rates of reproduction and more efficient (though often destructive) use of the environment
Population growth is of very serious concern to many nations and international organizations as a result

19. Causes for change
Public health measures undertaken by governments (urban public health systems)
Mortality rates plummet (for example, India from 5% to 1.5%)
Immunization and developments in medical care decrease mortality rate
More dependable food supply

20. Effects Agriculture had to keep up with growing populations
Green Revolution- transferred Western agricultural technology and methods to developing countries, including genetically modified plants
Not enough food some places- internal/external migration
Increased crime in poor, urban areas (Mexico City, Calcutta, Buenos Aires, etc.)

21. Patterns of Movement West Asians to America and Europe
Indians to S. Africa and Caribbean
Asians to SE Asia
Former colonial subjects to former mother countries

22. Overpopulation
Encouragement of UN and some governments to curb population growth
This view drew opposition from traditionalists who saw growth as a sign of strength, stability
China, India and Latin America have all decreased the fertility rate, but in different ways and with differing levels of success
Causes environmental problems- resource over-consumption, overgrowing and epidemic disease