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Energy in human-environment interactions WS 2007
1
Hunter-Gatherer societies and traditional agriculture
Maria Lackner 0025209
Tamara Neubauer 0201045
Mirjam Weber 0052101
Energy in human-environment interactions WS 2007
2
Structure of the presentation
1) How to measure energy in human-environment interactions – (general considerations)
2) Energy flows in Hunter-Gatherer and early agricultural societies
3) Energy flows of traditional agriculture in Pura (India)
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
(general considerations)
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
general questions:
• What problems do we encounter when assessing energy in human-environment interactions?
• How do we estimate human energy?
• How do we assess the energetics of human labor?
• How do we measure energy efficiency?
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 1Focus on „commercial“ energy in statistics
Example India:
energy use/capita = U.N. coal equivalent of 150 to 190 kg
but: total energy use from all sources = 490 kg
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 2Estimation of Human Energy
Method
energy per worker (kcal/hour)gross input (expenditure)
Pimentel et al. 580
Makhjani and Poole 870
Passmore and Durnin 250
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 2Estimation of Human Energy Pimentel et al.:
energy utilized in farm labor = total food energy input of a fulltime farm worker (40 hours a week)
Makhijani & Poole:
energy in the food intake of all persons in a farming village = gross energy input for human labor
Passmore & Durnin:metabolic energy used in different work activities (oxygen consumed, carbondioxide exhaled)
580 kcal/hour
870 kcal/ hour
250 kcal/ hour
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 3Estimation of Animal Energy
Method
energy input per bullockkcal/hour/bullock
1a) 12.1 x 10³ kcal/hour of work
1b) 10.9 x 10³ kcal/hour of work
2) 5.3 x 10³ kcal/hour of work
3) 2.3 x 10³ kcal/hour of work
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 3Estimation of Animal Energy
1a) net energy input (feed energy – energy in dung) – energy in milk and other products
1b) consideration of the herd‘s milk production
12.1 x 10³ kcal/h
10.9 x 10³ kcal/h
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 3Estimation of Animal Energy
2) [energy/year consumed by the bullock (feed) – energy in dung] / hours worked = gross energy expenditure per working hour
3) weekly energy expenditure of a bullock is ca. 43% of ist total food energy intake for the week
5.3 x 10³ kcal/h
2.3 x 10³ kcal/h
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 4Energy efficiency – which parameters?
e.g. maximization of economic profit vs. minimization of risk
e.g. maximization of crop yield vs. minimization of ecosystem degradation
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No. 5power generation
total energy requirements = sum of 2 flows of energy
1. flow used directly to generate power
2. flow calculated as the energy spent in the construction and maintenance of the structure delivering power
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No.6power level is often not considered
work = carrying 400 kg of sand upstairs 5 m of height
5 m400 kg
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No.6power level is often not considered
work = carrying 400 kg of sand upstairs 5 m of height
3 possibilities:
a) 5 trips carrying 80 kg
b) 20 trips carrying 20 kg
c) 100 trips carrying 4 kg
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No.7difficulty in quantifying a defined work done
Power system Labor requirement
(h)
Level of power (W)
Power generation
cost (EI/AP)h
Acquirement index
Manpower 400 75 100 1.00
Oxen pair 65 895 25 0.51
6-HP tractor 25 4476 8 0.25
50-HP tractor 4 37300 8 0.20
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Problem No.7difficulty in quantifying a defined work done
Applied power (MJ) Gross energy requirements (MJ)
Manpower 107 10700
Oxen pair 209 5200
6-HP tractor 403 3100
50-HP tractor 537 4100
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
factors related to the level of energy consumption per capita for rural/poor societies based on manpower:
1. body size
2. quality of the diet
3. exosomatic energy flow (energy flows converted to useful work outside the human body)
Energy in human-environment interactions WS 2007
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How to measure energy in human-environment interactions
Literature:
• Roger Revelle – Energy Use in Rural India
• Giampietro & Pimentel – Energy efficiency: assessing the interaction between humans and their environment
• Giampietro & Pimentel – Assessment of the energetics of human labor
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer and early agricultural societies
•Energy flows in gerneral•The Kung! Bushmen – hunter and gatherers•The Tsembaga – early agriculture society
•The energetic benefits of domestication
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer societies (Pimentel 1996)
Wherefore energy? Obtaining food + collecting firewood
Basal metabolism: 1080 kcal + …
Examples for Energy requirements for various activities In kcal/h
Sitting, standing relaxed 20
Walking 130-240
Climbing 400-900
Running very quickly 1240
Walking loaded (10kg) 400
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer societies (Pimentel 1996)
Wherefrom energy? Wild plants and animals (wood for fire ?)
Total annual production of plant biomass in a temperate region averages about 2400kg per ha. Under favourable conditions this quantity might support an animal and microbe biomass of about 200kg per ha.
The proportion of the total animal and microorganisms biomass of 200 kg
42%
25%
20%
2%
1%
10%
Microorganisms
Earthw orms
Arthropods
Mammals
Birds
Other animals
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer societies (Pimentel 1996)
How much land do hunter-gatherers need?
Pimentel: 40 hectare (ideal ecosystem)Modern-day hunter-gatherers need much more (150-250ha)
In the northwestern Canadian region about 14.000 ha per personIn subarctic lands up to 50.000 ha per person !Kung Bushmen about 1000ha.
Comparison: Austria is 84’000 km2 = 8.400.000 ha
200.00040.000
8.400
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer societies - The !Kung Bushmen
• Population density: 1 person per 1040 ha• Most of the daily calorie intake of the !Kung
Bushmen (56%) are mongongo nuts.• A critical decision for the bushmen is where to
locate their camps. Food and water must be near enough. They occupy a camp for a period of weeks and eat their way out of it.
• Energy Output/Input ratio falls with distance(19km: 2 day trip)
Lee, 1969
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer societies - The !Kung Bushmen
hours Kcal
Travel to location of nuts 1,2 270
Collecting nuts 3 675
Return trip (+12,5kg nuts) 1,2 462
Sleep 10,5 473
Other activities 8 800
INPUT 24 2.680
OUTPUT (shelled nuts 1,75kg) 10.500
Output/Input ratio 4:1
Output/Input analysis of !Kung bushmen gathering mongongo nuts at a distance of 4,8 km from their camp
Energy in human-environment interactions WS 2007
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• Population density: 1 person per 4 hectare• Early agricultural society in New Guinea• Tropical mountainous ecosystem, rainy• Swidden-type agricultural system
(Brandrodungsfeldbau)
• Food of plant origin (taro, sweet potatoe, fruit, leaves, bananas, yams) 99%
• Some pigs
Energy flows in early agricultural societies – The Tsembaga
Rappaport, 1968
Early agriculture:no fossil fuels, no animal power
Energy in human-environment interactions WS 2007
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Energy flows in early agricultural societies – The Tsembaga
Hours/ha Kcal/ha
Clearing underbush 175 70.000
Fencing garden 84 42.000
Weeding and burning 78 23.400
Planting and all weeding 742 222.600
Harvesting 277 83.100
Axe, machete - 16860
INPUTS 1.860 739.160
OUTPUT (Crop yield) 11.384.462
OUTPUT/INPUT RATIO 15:1
Output/Input analysis of New Guinea swidden agriculture for 1 ha of mixed crops
Energetical input of wood and vegetation for fire ?
Energy in human-environment interactions WS 2007
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Livestock in early agricultural societies – The Tsembaga
Output/Input ratio of pigs 1:2 Why?
• Stock (Pimentel)• Distribution of surplus wealth (Rappaport)
Kaiko ritual (pigs for the ancestors < carrying capacity)
Energetic benefits of domestication
• „Non convertable“ grasses → usable energy • Animal power → energy source (beast of burden)• Need of protein →Herding more energy efficient as hunting
Energy in human-environment interactions WS 2007
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Energy flows in Hunter-Gatherer societies
Food, Energy and Society, David and Maria Pimentel, 1996.
• Chapter 6: Hunter – Gatherers and early agriculture.
• Chapter 7: Early livestock systems and animal power.
AgricultureAn example from India
Pura 1977
www.export.gov.il
www.faorap-apcar.org
Energy in human-environment interactions WS 2007
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Pura 1977
• South India
• Karnataka State
• - 56 households
• - 357 people
• - 671 meters above sealevel
• - Annual rainfall of 127 centimeters
Energy in human-environment interactions WS 2007
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Overview
Energy consumption patterns of Pura
Ranking of energy sources
Energy- Activity Matrix
Ranking of activities requiring energy
End Uses of Human Energy
Health Hazards for the people of Pura
Energy in human-environment interactions WS 2007
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Energy Consumption Patterns
Energy used for:
- agricultural operations
- domestic activities
- lighting
- Industry
www.news.bbc.co.uk
www.images.wir.orgwww.images.wir.org
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
33
Ranking of energy sources per year:
1) Fuelwood (89%)2) Human energy (7%)3) Kerosene (2%)4) Bullock energy (1%)5) Electricity (1%)
www.rcfa.cfan.org
www.glamro.gov.uk
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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Energy- Source Activity Matrix
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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Ranking of activities requiring energy:
1) Domestic activities (91%)
2) Industry (4%)
3) Agriculture (3%)
4) Lighting (2%)
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
38
Women Children Men
Gathering fuelwood
42% 25% 33%
Fetching water
80% 14% 6%
Grazing
livestock15% 33% 52%
www.rediff.com
Energy in human-environment interactions WS 2007
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The use of low level energy sources in Pura causes:
- high human time input
- high labor effort
- health hazardswww.fao.org
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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Why health hazards?
- Dependence on biomass cooking fuels
= fuelwood, dung cakes, crop wastes,...
= high toxic emissions like carbon monoxide, suspended particulates, hydrocarbon!
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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Health Effects
Production: Skin infections, enteric infections,...
Collection: Trauma, allergic reactions, bites from reptiles,...
Combustion: respiratory irritation, burns, chronic bronchitis,...
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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A Greater Health Impact for women and girls (1)
- daily subsistance chores lead to a higher calorie expenditure/day (not compensated by food intake)
- Domestic tasks more often done by women or girls are perennial and not seasonal
- Depletion by repeated births
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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A Greater Health Impact for women and girls (2)
- especially traditional rice cultivation methods cause complications for pregnant women
- Increase of stillbirths, premature births and neonatal mortality while rice during rice planting months
- Lack of adequate water = increase of genito- urinary and reproductive tract infections which stay untreated für years
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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Facit: low levels of energy services are a serious problem!
- People of Pura depend on human energy and primitive technologies for their daily survival
Agriculture
An Example from India
Energy in human-environment interactions WS 2007
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Literature:
• Srilatha Batliwala - Energy as an obstacle to improved living standards
• Roger Revelle - Energy Use in Rural India
Agriculture
An Example from India
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