APES 5.1 & 5.3-5.4

5.1: TRAGEDY OF THE COMMONS

Examples of tragedy of the commons: overgrazing, overfishing, water and air pollution, Overuse of groundwater, pesticide runoff

Why tragedy of the Commons happens: When no one owns the resource, no one directly suffers the negative consequences, people assume others will Overuse the resource if they don’t, and there is no penalty for overusing resources

Overall effect of tragedy of the commons: Externalities

How to solve the tragedy of the commons: Private land ownership, fees/taxes for use, and fines/criminal charges for pollution or shared air/soil/water resources

5.3: THE GREEN REVOLUTION

The green revolution: The shift in agriculture away from small, family operated farms to large, industrial-scale agribusiness (mechanization, GMOs, irrigation, fertilizers, pesticides)

Pros of the green revolution: Increases efficiency of lands, short-term profitability, and food supply, decreased world hunger and increased earth's carrying capacity

Cons of the green revolution: soil erosion, biodiversity loss, and ground/surface water contamination

Mechanization: Increased use of tractors for plowing and tilling fields, and combines for harvesting

Pros of mechanization: Increased yield and profits

Cons of mechanization: increased reliance on fossil fuels, heavy machinery compacts soil, decreasing H2O holding capacity and making topsoil more prone to erosion

High-Yield Variety crops: Hybrid, or genetically modified crops that produce a higher yield (amount of crops produced per unit of area)

Hybrid: cross-pollinating different species, or parent plants with ideal traits

GMOs in high-yield variety crops: crops with new genes spliced into their genome

Pros of GMOs: Genes for drought tolerance, pest resistance, faster growth, and larger fruit/grain and increased profitability with fewer plants lost to drought, disease, or pests

Con of GMOs: Crops are genetically identical so genetic diversity is decreased and susceptibility to diseases or pest is increased

Fertilizers in the green revolution: The shift from organic fertilizers like manure and compost to synthetic fertilizers (man made ammonium, nitrate, phosphate)

Con of synthetic fertilizers: Production requires fossil fuels

Pro of irrigation: Makes agriculture possible in many parts of the world that naturally too dry

Cons of irrigation: Depletes groundwater sources, especially aquifers and drowns roots from over watering, causing soil salinization

Con of pesticides: Chemicals can wash off of crops and runoff in local soil or waters, killing non-target species

Components of the green revolution: Mechanization, High-yield variety crops, GMOs, synthetic fertilizers, irrigation, and pesticides

5.4: IMPACT OF AGRICULTURAL PRACTICES

Cons of tilling: Increases erosion by loosening topsoil as it breaks up leftover root structure from harvest, loss of organic matter and topsoil nutrients over time, increased particulate matter in the air, and sediments in nearby water, increasing Turbidity

Slash and burn: cutting down vegetation and burning it to clear land for agriculture and return nutrients in plants to soil