Lecture 6People and peoples in history

and pre-history

Malthusian population theory, Celts and Romans 1200BC to 900AD

Reading, Fagan 2004 Chapter 10

Malthus’ Population Theory

http://www.hort.purdue.edu/newcrop/tropical/lecture_14/lec_14.html

• Thomas Malthus: English scholar 1776-1834• Proposed that “The power of population is indefinitely

greater than the power in the earth to produce subsistence for man". ie. population growth is geometric eg. 2,4,8 etc whereas resources growth is arithmetic eg. 1,2,3 etc

• That the increase of population is necessarily limited by the means of subsistence

• That population does invariably increase when the means of subsistence increase

• Society relies on human misery to limit population growth eg. famine, disease, war, natural disaster

Neo-Malthusian theory

• World population currently in state of rapid increase

• If plot population on log. scale, three distinct phases apparent

Neo-Malthusian Theory

• Two approaches – ’alarmists’ (population explosion, mass starvation) and ‘technocrats’ (science and technology will find a way)

• Malthus did not foresee tremendous growth of food with modern agriculture

• Also the ‘demographic transition’ – accompanying economic development and urbanisation – death rates fall, followed by declining birth rates – developed countries first

Demographic transition

• In 1875 birth rate high 40 per thousand population (4%)

• By 1975 only 1.5-2%

World population growth• Current world popn.

6 billion• Expected 12 billion

by 2100• World food

production has kept up but there is disequilibrium between countries

World Population Growth, 1990–2100 Population (billions) Increase (%) Countries 1990 2025 2100 1990–2100Developing 4.08 7.07 10.20 250Developed 1.21 1.40 1.50 24World Total 5.30 8.47 11.70

• Future- population pressures will vary with location low birth rates in Europe, America, China stabilising, India increasing rapidly, Africa unstable due to Aids, political instability, warfare

• Climate is a wild card

Climate and Human history • Palaeolithic period throughout Pleistocene glacial period,

from 2.5m ya to end of last glacial 10k ya- alternating cold and warm phases

• Prehistoric period of human history• Earliest hominids Autralopithicenes 2.6m ya- used fire and

stone tools

Many great mammals such as woolly mammoth, woolly rhinoceros and cave lions inhabited places like Siberia during Pleistocene

Human ‘ages’• Palaeolithic• Mesolithic• Neolithic

• Stone age 200k BC• Bronze age 3-1000 BC• Iron age 1000 BC

Humans in Pleistocene• Palaeolothic distinguished by development of stone

tools – also used wood,bone, leather and fibres- beginning of human control of environment

• Homo-sapiens evolved from earlier primates 200,000 y ago

• Human society grouped in small bands, gathered plants and hunted wild animals

Palaeoindians hunting a Glyptodon: driven to extinction after humans arrived in S. America

Artist’s impression ofa human house based on evidence found in Nice, and dated to Lower Palaeolithic 400ka BP

Climate and Peoples in Europeduring Neolithic period

Neolithic House from Orkney Islands(N. of Scotland)

Neolithic House from Jura area of N. Italy

Neolithic Climatic trendsNeolithic period (10ky BC) – beginning of

human settlement – due to Farmers adapting to cooling, by growing millet (can stand short growing season and drought, can store well)

• Millet provided grain for bread and porridge, and fermented for beer

• Also grew beans – fast growing in cool climate

• A gradual cooling over Europe since 3500BC- climate increasingly continental

Lima beans

Temperatures of last 11,000 years

Add map on p.195- climatic zones

Last 3,000 years

Neolithic Climatic fluctuations

• Volcanic eruptions throughout Neolithic age from Icelandic volcanoes brought cooling episodes lasting up to 5 years eg.Hekla eruption in 1159BC

• Subsistence farmers only enough grain to get through one band harvest and plant for the next - cold summers brought winter famine as well as the ‘cutting cold and dreaded darkness’

Meet Otzi

• The Ice Man – frozen corpse from 3100BC found high in Alps

• “Harris lines’ on bones resulting from malnutrution at ages 9, 15 and 16

His quiver held 14 arrows

Bronze and Iron ages: Europe divided by climate

• Celts (Gauls) lived N. of Alps often raided settlements to S. eg. 390BC raid on Rome

• Their homeland cold, wet, difficult to farm: subsistence agriculture dependent on summer rain: Greenland high pressure in winter many deaths

• Mediterranean zone mild- wet winter, dry hot summer

• Boundary b/w N and S Europe shifted N and S, past 3000 years (Bronze age though Iron Age)

Bronze age Europe

Culture of the northern Celts• Small round houses in hamlets or villages

with farmland among the wooded landscape

• Society dominated by local chiefs: life revolved around the field, household and village workshop

• Cultivated wheat and barley (wheat intolerant of heavy rain and cold summers), turnips, potatoes

• Use of amber and bronze for currency

Shaugh Moor, Dartmoor, UK

Bronze age field boundaries marked by low stone walls

Bronze age Subsistence farming• Even in good years, threat of winter famine

present• Only ancient ties of kinship, social reciprocity, use

of wild plant food and game ensured survival• In good years agric prod increases, populations

increase, additional woodland cleared and grazing on marginal uplands eg. Shaugh Moor

• Invisible equation b/w popn/good harvests/land carrying capacity

• Almost always ppl farmed close to limit and beyond

• Many hungry winters, and people died• Hunger and malnutrition a fact of bronze age life

Iron age culture 1000BC• Used iron tools and ploughs farmed landscape• Much of what Romans called “Gaul” (France) and

southern Britain came under cultivation• Julius Caesar visiting Britain in 55 BC noted popn. was

‘exceedingly large, the ground thickly studded with homesteads”

• Iron also enabled better weapons – coupled with crowding of the landscape – many local wars

• Life revolved around farming, war and cattle herding• Subsistence agric - In drought years they fall back on

game and edible plants or try to develop more land• By 400BC no more land, if cannot move, wars erupt• Resulted in the great Celtic migrations of 4thCentury BC• Ferocious Celtic warriors went south- conquered Rome

in 390BC• Whenever climate changed to warmer- ecotone b/w

Mediterranean and continental moved north

Tragedy of the Commons

Tragedy of the commons• what can happen in groups when individuals

act in their own best self interests and ignore what’s best for the whole group

• group of herdsmen share a communal pasture, and all want their own cattle to get as much grass as possible

• brings unintentional tragedy -destruction of the common grazing area

• Other examples – world fisheries, waste disposal - NIMBY

Tragedy of Commons: solutions• Provide more information to avoid

uncertainty• Reinforce social identity and sense of

community• Need to trust governing bodies• Incentives for reducing over-use/penalties• People have fundamental need to

understand environmentVan Vugt, M. (2009). Averting the tragedy of the commons: Using social psychological science to protect the environment. Current Directions in Psychological Science, 18(3), 169-173.

http://psychcentral.com/blog/archives/2009/07/29/the-tragedy-of-the-commons/

Please read Lee, H.F. and Zhang, D.D. 2012. “A tale of two population crises in recent Chinese History”, Climatic Change DOI 10.1007/s10584-012-0490-9, before next lecture

Pay particular attention to: social coping mechanismsrelationship between climate and social conflict

A tale of two population crises in recent Chinese History

• Now we skip 4 centuries to 17thC Ming Dynasty• Research on impacts of recent climate change on

population by HKU, using over 100 data sources• Focus on 2 short periods of popn collapse 1626-

46 and 1852-70• Challenged conventional Malthusian theory of

cycles of population catastrophe and overshooting of resources

• Much more data available than previous epochs, so premises for theories more sound

• Provides insight into how Malthusian mechanisms actually work and many parameters involved

Initial hypotheses• In an agricultural economy with low level of technology,

temperature change will affect population growth by reducing agric. prodn.

• In pre-industrial era, technological innovation cannot aleviate popn. pressure (resulting from land carrying capacity vs. popn growth) and in past Chinese popn. already reached demographic saturation repeatedly (ie. state of near-starvation and misery) (but not population collapse due to social buffering mechanisms)

• When there is long-term climate change, popn collapse is caused by shrinkage of land carrying capacity beyond social coping mechanisms famine, epidemics, wars

• Cold periods often accompanied with variability – floods, droughts. Tendency to cultivate marginal lands in periods of popn. pressure increases susceptibility to floods and drought

Initial Hypotheses• Weakened agric production of the state creates

internal conflicts, reducing resistance to external invasion: war and invasion often go together

• Mass migration driven by famine/war facilitiates spread of disease

• Mass migration causes violent conflict b/w nomads and settled farmers over land and food

• Because mortality factors interlinked, popn. collapse occurred, then followed by reduced popn. pressure, and decrease of mortality factors

• Sequence followed by renewed popn. growth- another cycle

Population growth in agrarian China

Arrows mean Change in X means change in Y – positive or negative

Questions to ask

• Starting from the relationship between climate change and population pressure in prehistoric China, do you see any parallels in the modern world?

• Can lessons learnt from the past inform our response to modern day climate change?