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Environment vs Food. Myth To feed the hungry we are pushing production onto marginal land –destroying rainforests –causing erosion –poisoning the environment.

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Presentation on theme: "Environment vs Food. Myth To feed the hungry we are pushing production onto marginal land –destroying rainforests –causing erosion –poisoning the environment."— Presentation transcript:

1 Environment vs Food

2 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

3 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 billion tons/yr. –220,000 die each year from pesticide poisoning Amazon Deforestation (purple)

4 Africa Traditional agriculture preserved semi-arid land –diverse mix of crops, trees and livestock 19 th century colonists view: –Land is a mine to extract wealth from Monoculture of export crops without rotation –quickly depleted soil Peanuts, cotton Best land for Europeans – worst land for Africans 9726E5A35423/0/CottonField.gif African cotton

5 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

6 Agriculture in Africa

7 U.S. Soil Destruction 30% of farmland abandoned since 18 th 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 Export boom in 1970s –increased erosion in Corn Belt 39% –in three years Dustbowl 1930s

8 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

9 Global Soil Degradation

10 Rain Forests Rainforests 7% of land –50% of plant and animal species Source of –Beauty –CO 2 sink –Pharmaceuticals –Chocolate, cashews, bananas, brazil nuts, cortisone, quinine Amazon rainforest

11 Rain Forest Destruction In 20 th 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


13 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

14 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 –Cattle ranching Slash and burn maize, Peru

15 Rainforests of the World

16 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

17 Deforestation: Central America Most of the tropical rain forest has been affected by: –Logging –Banana Plantations –Cattle Ranching

18 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

19 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. –300,000 farmworkers/ yr California lettuce

20 US Geological Survey 1997

21 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

22 Pesticides in Developing Countries Protection for workers low Regulations lax Toxicity education poor Mexican girl drinking from pesticide container

23 Pesticides Despite 10x increase in toxicity –crop losses have doubled from insect pests 0.1% pesticides reaches pests. – Rest into environment

24 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 times/season Insects develop resistance to insecticide –Requires spraying more pesticides/images/Image5.jpg

25 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 –left economic ruin –environmental devastation toxiccotton/images/cotton.jpg

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