World population expected to rise to 10 billion
Demand for food and water will rise
Next topics covered in class are about food and water
FoodProduction
PopulationGrowth
Time
Am
ount
Concern that population growth would continue after food production levels off
Changes brought about by modern agriculture and the Green Revolution
• Temporarily closed the gap between food production and need in some countries– food production has increased (& fertility starting to come down)
• Heavy reliance on irrigation and fertilizers• Negative impact on small farmers and culturally specific
crops
Subsistence Farming
• Labor intensive• Use of marginal lands• Clearing of tropical rain forests• Can cause environmental degradation
mechanization: fossil fuels
new lands: best land already in production (~25% in US, ~38% world wide)little new land available in US, land still cleared in developing countries
agro-chemicals: fertilizers & pesticides
increased irrigation: conflicting water uses, irrigated land produces ~40% of worlds food
selected cultivars: loss of diversity
Industrial Agriculture
How have we increased world food production?
Traditional agriculture
•small farms
•animal labor
•low use of chemicals and irrigation
•natural plant varieties
Industrialized agriculture
•large farms
•fossil-fuel driven machinery
•intense use of pesticides, fertilizer and irrigation
•high-yield plant varieties
Green Revolution
Father of green revolution (Norman Borlaug) won Nobel Peace Prize in 1970
Very positive effect on world hunger
Many high yield crops require high water and fertilizer
Favors non-traditional cultivation methods
Many traditional African crops not affected
Bio tech crops & Genetically Modified Organisms
Insert genetic material (DNA) from one organism into another to provide a desired trait
Examples of desired traits
Insect resistance
Herbicide resistance
Drought/heat/salt tollerance
Improved nutritional value
Vaccine delivery
Spread of genes to non-crops: super weeds, harm wild species
Food safety: ex, allergies, big concern in Europe
Access to technology: yearly seed purchase & dependence on foreign technology in developing countries
Problems
Burden of proof
Should regulators need to prove that food is not safe?
Should companies have to prove that food is safe?
[per capita gross national product – 1999-2000]
High income countries: Too much meat, salt, fat. Not enough fiber. Food processing may reduce mineral and vitamin content.
Low income countries: Lack of proteins and vitamins (malnutrition) and lack of calories (undernutrition)
Why do the fries taste so good?
Read excerpt from Fast Food Nation.
Potato farming is example of trends towards industrial farming
The story of one potato baron- and lots of other potato farmers
For each $1.5 spent on fries in restaurant, $0.02 goes to farmers
Fast food companies purchase potatoes for $0.03 per pound and sell fries at $6.00 per pound
Why do the fries taste so good?
“natural and artificial flavoring” is made in NJ
1950’s processed food sales increased dramatically
10,000 processed foods introduced every year in US
“flavorists” (chemists) create compounds that give processed foods taste
Undernourished:People who receive less than 90% of their minimum dietary intake on a longterm basis.
U.N. World Health Organization:
Seriously undernourished:People who receive less than 80% of their minimum dietary intake on a longterm basis.
Overnourished:People who take in excess calories on a routine basis over the longterm.
Malnourished:A nutritional imbalance caused by the lack of specific dietary components or an inability to absorb or utilize essential nutrients.
U.S. Department of Agriculture Food Guide Pyramid; http://www.mypyramid.gov/index.html
North Americans consume on average about 35% of their daily calories as fat.
• Distinguishes between healthy and unhealthy types of fat and carbohydrates.
• Fruits, vegetables, healthy fats and whole grain foods are encouraged.
• Consumption of refined carbohydrates, butter and red meat should be limited.
Source: Scientific American 2002
Essential dietary requirements• Complex carbohydrates
– Usually 80% of daily caloric intake
• Proteins
– About 40 grams/day needed. Essential aminoacids
– Enzymes, cell structures, nervous tissue
• Lipids (fats, oils, etc.)
– Energy storage; cellular membranes
• Minerals (ex. calcium, iodine, iron, etc.)
– Component of cellular structures; regulation of cellular reactions
• Vitamins
– Organic molecules we cannot synthesize and have to get from our diet.
Major Crops
• Wheat, rice, maize– 60 % of the calories and 56 % of the protein that humans consume
directly from plants.– staple of most of the 4 billion people in developing countries
• Potatoes, barley, oats, rye– grow well in cool, humid climates– staple of mountainous and higher latitude regions
• Cassava, sweet potatoes and other root crops– grow well in warm wet climates (South America, Africa, South
Pacific region)
• Meat/milk– Uneven distribution
• Fish– Important source of protein
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