Food

1
Food

• The major limiting factor to human population
  growth
• Depends on environment and socio-political
  issues
• Right now distribution is the main problem
• If the human population continues to grow,
  quantity will be the problem

2
Where does our food come from?
Earth as an Apple http//www.farmland.org/Flash/ap
pleEarth.html

• Land crops and livestock!
• Only 14 species of plants
• Cash crops
• Subsistence crops
• Top food crops
• Wheat, rice, maize, potatoes

3
How much food do people need?

• 2600 calories/day
• If they dont get this undernourishment
• If they dont get specific nutrients
  malnourishment
• Marasmus, kwashiorkor, chronic hunger
• On the flip side of the coin obesity

4
Nutrition

• Undernourishment
• too few calories
• (especially developing world)
• Overnutrition
• too many calories
• (especially developed world)
• Malnutrition lack of nutritional requirements
• (causes numerous diseases, esp. in developing
  world)

Figure 9.2
5
Percentage of population affected by
undernutrition by country, according to United
Nations statistics
6
Global food security

• The world still has 800 million hungry people,
  largely due to inadequate distribution.
• Global food security is a goal of scientists and
  policymakers worldwide.

7
HOW TO FEED THE WORLD

• http//www.youtube.com/watch?vQloMOOG-bbE

8
The best ways

• Give a man a fish and you feed him for a day.
  Teach a man to fish and you feed him for a
  lifetime. Lao Tzu
• Create systems where food is grown and
  distributed locally

9
Agriculture
10
2,000
1,500
Grain production (millions of tons)
1,000
500
0
1950
1960
1970
1980
1990
2000
2010
Year
Total World Grain Production
11
400
350
Per capita grain production (kilograms per person)
300
250
200
150
1950
1960
1970
1980
1990
2000
2010
Year
World Grain Production per Capita
12
3,700
Developed countries
3,500
3,300
3,100
Calories per day per person
2,900
World
2,700
Developing countries
2,500
2,300
2,100
1990
1960
1970
1980
2000
2010
2030
Year
13
Figure 14-3Page 276
Natural Capital
Croplands
Croplands
Ecological Services
Economic Services
Ecological Services
Economic Services

• Help maintain water flow and
• soil infiltration
• Provide partial erosion protection
• Can build soil organic matter
• Store atmospheric carbon
• Provide wildlife habitat for some
• species

• Food crops
• Fiber crops
• Crop genetic
• resources
• Jobs

Help maintain water flow and soil
infiltration Provide partial erosion
protection Can build soil organic
matter Store atmospheric carbon Provide
wildlife habitat for some species
Food crops Fiber crops Crop genetic
resources Jobs
14
Biodiversity Loss
Soil
Loss and degradation of habitat from clearing
grasslands and forests and draining wetland Fish
kills from pesticide runoff Killing of wild
predators to protect livestock Loss of genetic
diversity from replacing thousands of wild
crop strains with a few monoculture strains
Erosion Loss of fertility Salinization Waterlog
ging Desertification
15
Air Pollution
Water
Water waste Aquifer depletion Increased runoff
and flooding from land cleared to grow
crops Sediment pollution from erosion Fish
kills from pesticide runoff
Greenhouse gas emissions from fossil Fuel
issue Other air pollutants from fossil fuel
use Pollution from pesticide sprays
Surface and groundwater pollution from
pesticides and fertilizers Overfertilization of
lakes and slow-moving rivers from runoff of
nitrates and phosphates from fertilizers,
livestock wastes, and food processing wastes
16
17 of total commercial energy use
4
2
6
5
Crops
Livestock
Food processing
Food distribution and preparation
Food production
17
Producing and eating meat

• Land use issues
• More land needed
• More land needed for grazing than grain
  production
• Acre of grain for human consumption feeds more
  than an acre used for grazing
• Land needed to grow forage AND raise animals
  Housing, food storage and waste disposal

18
Producing and eating meat

• Energy issues
• Eating at a lower trophic level
• More solar energy available to humans, less lost
  through trophic transfer
• Storage of grain less energetically expensive
  than processing and storing meat
• Transport, slaughter and refrigeration
• Energy costs associated with meat production
• Producing grain for livestock
• Fertilizers, irrigation, pesticides, farm
  machinery
• Animal waste management
• Pumping, treatment, transport, disposal
• Animal care and round up of free range livestock

19
Eating less meat Pro and Con

• Advantages
• Reduced risk of disease
• Cholesterol
• Clogged arteries
• Hypertension
• Heart disease
• Reduced chemical exposure
• Hormones
• Steroids
• Antibiotics
• Pesticides (Biomag!)
• Reduced exposure to disease
• Mad Cow
• Salmonella/ E. coli
• Parasites

• Disadvantages
• Meat an excellent source of protein
• Essential amino acids
• Rice and Beans!
• Difficult to get enough protein without meat
• Nutritional deficiencies
• Kwashikor Protein
• Blindness Vit. A
• Pollegra Vit. B
• Anemia Iron
• Inadequate essential fats balance

20
How do we address world hunger?

• Policy and behavioral changes
• Eat lower on the food chain?
• Modify food distribution
• Improve infrastructure
• Economic policies
• End subsidies

21
To feed the world.

• Conservation of matter
• Available resources limit agricultural production
• Nutrients used by plants
• Nitrates Protein and DNA
• Phosphates DNA, RNA, ATP
• Soil degraded as nutrients removed by harvest
• Conservation of Energy
• Trophic level energy loss
• Vegetarian vs Carnivorous diets
• Green revolution
• Increase yield per acre
• Monoculture
• Intensive tillage soil erosion
• Requires
• Energy Emissions and oil
• Fertilizers and pesticides Toxic pollution, soil
  salinization
• Irrigation Water rights and usage