Environment vs Food
Myth
• To feed the hungry we
are pushing production
onto marginal land
– destroying rainforests
– causing erosion
– poisoning the environment
with pesticides
• Cannot feed the hungry
and protect the
environment
Environmental Destruction
• 70% of 5.2 billion
hectares of ag land is in
danger of being turned
into desert
• Rain forests will be
destroyed in 40 years
– At current rates
• Global pesticide use 4.7
Amazon Deforestation (purple)
http://whyfiles.org/238earthday/images/brazil_combined.jpg
billion tons/yr.
– 220,000 die each year
from pesticide poisoning
Africa
• Traditional agriculture
preserved semi-arid land
– diverse mix of crops, trees and
livestock
• 19th century colonists view:
– Land is a mine to extract wealth
from
• Monoculture of export crops
without rotation
African cotton
– quickly depleted soil
• Peanuts, cotton
• Best land for Europeans
– worst land for Africans
http://www.hewlett.org/NR/rdonlyres/7C6CC2D1-58A5-4544-B08D9726E5A35423/0/CottonField.gif
Africa
• With independence
(1960s)
– cash crops needed
• Low prices encouraged
more planting
• Livestock displaced to
drier lands
– increased desertification
• Now pastorialism is
equated with poverty
http://children.foreignpolicyblogs.com/files/2007/08/p1.jpg
Agriculture in Africa
http://go-kids.grolier.com/map?id=mtlr001&pid=go
U.S. Soil Destruction
• 30% of farmland abandoned
since 18th century
– Erosion
– Salinization
– water logging
• 1/3 of U.S. topsoil has been lost
• 1/2 of U.S. pastureland
overgrazed
– erodes at high rate
Dustbowl 1930s
http://www.ehponline.org/members/2002/110-2/dustbowl.jpg
• Export boom in 1970s
– increased erosion in Corn Belt 39%
– in three years
Iowa Topsoil Loss
• 150 years ago
– Iowa topsoil was 12-16” deep
• Now is 6-8” deep
• Current rate of loss:
– 10-15 tons/acre/year
http://publications.iowa.gov/1745/1/images/Buffer.jpg
Global Soil Degradation
http://www.utafoundation.org/soil_loss.jpg
Rain Forests
• Rainforests 7% of land
– 50% of plant and
animal species
• Source of
– Beauty
Amazon rainforest
http://www.wwf.org.uk/picturelibrary/jpeg350/ra/rainforest1.jpg
– CO2 sink
– Pharmaceuticals
– Chocolate, cashews,
bananas, brazil nuts,
cortisone, quinine
Rainforests of the World
http://www.d.umn.edu/~pask0020/educ5413/mywebquest/Rainforest%20map.jpg
Rain Forest Destruction
• In 20th century rain forests
depleted 50%
• At current deforestation rates
– rainforests will be totally cleared
in 40 years
• Amazon is being destroyed at
a rate of 20,000 sq miles/year
http://www.unep.org/wed/2007/english/Photo_Gallery/WED_2007/Zoom/PA0176629.jpg
Rondonia, Brazil
• 1980s displaced poor farmers
flooded Amazon region
– slashed and burned to clear land,
plant crops
• Swiden agriculture
– Displaced indigenous peoples
• Most failed after few seasons
when land exhausted
– Cattle ranchers then moved onto
land
• 1990s: Cattle, Soybeans,
Logging destroy forest
http://www.css.cornell.edu/ecf3/Web/new/AF/pics/SlashBurn7.jpg
http://photos.mongabay.com/07/trop_defor_bar-600.jpg
Deforestation in Brazil has Dropped
Slash and burn agriculture
• Rainforest:
– rain leaches nutrients from soil
– except those captured by plants
• Forest burned
– Ashes rich in nutrients
– Serves as mineral fertilizer
• Farming possible
– for a few years
– Then soil exhausted
• Land often used for pasture
Slash and burn maize, Peru
http://www.mongabay.com/images/peru/tambopata/Tambopata_1030_5148.JPG
– Cattle ranching
Deforestation: Bolivia
• 80% clearing carried
out by large land
holders
– for cattle, soybeans
• 20% cleared by small
farmers
• Thus most of clearing
is not to feed hungry
http://www.boliviabella.com/images/bolivia_facts_geography_amazon_deforestation.jpg
Deforestation: Central America
• Most of the tropical
rain forest has been
affected by:
– Logging
– Banana Plantations
– Cattle Ranching
Deforestation: Indonesia
• 1997-8 tropical fires
created huge smoke
cloud
– thousands of square miles
• Fires blamed on poor
– clearing land
• Actually, most from
– Logging
– plantations
http://www.rssgmbh.de/img/projekte/projekte_international/ssffmp3.jpg
Pesticides
• 4.7 billion tons pesticides
used worldwide
• 2 billion pounds in U.S.
– 25% in California
• Fruits and vegetables
– 30% U.S. use for corn,
wheat.
– 25% U.S. use in golf
courses and lawns
• Pesticide poisoning in
U.S.
California lettuce
http://evolution.berkeley.edu/evosite/relevance/images/pestspray.jpg
– 300,000 farmworkers/ yr
Atrazine Use in the U.S.
Pesticides in Developing Countries
• The most harmful pesticides
– are banned in U.S.
• Used, made in developing countries
– Without much protection to workers
• Used for export fruit, vegetables
– About 50% used for appearances
• Not used for staple crops in
developing countries
– Expensive
– Mixed cropping of staple crops less
susceptible
Pesticides in Developing Countries
• Protection for workers low
• Regulations lax
• Toxicity education poor
Mexican girl drinking from
pesticide container
Pesticides
• Despite 10x increase in
toxicity
– crop losses have doubled
from insect pests
• 0.1% pesticides reaches
pests.
– Rest into environment
Pesticide Treadmill
• Central America increased
cotton production
– between 1945-1970
• Boom displaced small scale
food producers
– resulting in unrest, violence
• Boom made possible by
pesticide spraying
– for Boll Weevil
• At first, sprayed only few
http://www.dep.state.fl.us/waste/categories/cleansweeppesticides/images/Image5.jpg
times/season
• Insects develop resistance to
insecticide
– Requires spraying more
Pesticide Treadmill
• By mid-1960s were spraying 10
times/season
• Pesticides killed natural insect
predators
• Eventually spraying 40 times/season
– costing 50% of production
• Cost too high, leading to Bust
• Now wasted, eroded soils
– ghost towns
• Cotton boom- bust increased hunger
http://www.sciencemuseum.org.uk/antenna/nontoxiccotton/images/cotton.jpg
– left economic ruin
– environmental devastation