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 billion tons/yr. –220,000 die each year from pesticide poisoning Amazon Deforestation (purple)
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 E5A35423/0/CottonField.gif African cotton
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
Agriculture in Africa
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
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
Global Soil Degradation
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
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
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
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
Rainforests of the World
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
Deforestation: Central America Most of the tropical rain forest has been affected by: –Logging –Banana Plantations –Cattle Ranching
Deforestation: Indonesia tropical fires created huge smoke cloud –thousands of square miles Fires blamed on poor –clearing land Actually, most from –Logging –plantations
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
US Geological Survey 1997
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 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
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