Transcript How have we increased world food production?

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
Concern that population growth would continue
after food production levels off
Food
Production
Population
Growth
Time
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
Fig. 9-3. Yield of several major crops increased greatly
with modern agriculture techniques
Subsistence Farming
•
•
•
•
Labor intensive
Use of marginal lands
Clearing of tropical rain forests
Can cause environmental degradation
Industrial Agriculture
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
Global Population and Grain and Meat
Consumption
Fig. 9-9 here
How have we increased world food production?
Traditional agriculture
Industrialized agriculture
•small farms
•large farms
•animal labor
•fossil-fuel driven
machinery
•low use of chemicals
and irrigation
•intense use of pesticides,
fertilizer and irrigation
•natural plant varieties
•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
Problems
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
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
U.N. World Health Organization:
Undernourished:
People who receive less than 90% of their minimum
dietary intake on a longterm basis.
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
Causes of Famine and Hunger
Hotspots
• Civil Wars
• Drought
• Government
Incompetence
Life boat Ethics
(same author as Tragedy of the Commons)
Some lifeboats crowded & people keep falling out
Some not crowded- could pick up the people in the water
but
Then the uncrowned boats would be crowded and
unsafe and everyone could die
?