APES Unit 5

Tragedy of Commons

Suggests that individuals will use shared resources in their own self-interset rather than keeping with common good, thereby depleting the resources.

Externalities

Negative costs associated with human actions, that aren’t accounted for in the price (unintended side-effects)

green revolution 

shift in agriculture away from small, family owned farms to large, industrial scale agribusiness 

positive effects of the green revolution 

greatly increases efficiency of lands, short-term profitability, and food supply; decreased world hunger and increased earth’s carrying capacity for humans 

negative effects of the green revolution

soil erosion, biodiversity loss, ground and surface water contamination

mechanization

increasing use of tractors for plowing and tilling of fields

positives and negatives of mechanization of farming 

positive is increases yield and profits, negative is increased reliance on fossil fuels and makes topsoil more prone to erosion 

high yield variety crops

hybrid, or genetically modified crops that produce a higher yield (amount of crop produced per unit of area)

GMOs

genetically modified crops that have genes for drought tolerance, pest resistance, faster growth, and larger fruit/gain

positives and negatives of GMOs 

positives are increased profitability with fewer plants lost to drought, disease, or pests, and larger plant sizes; negatives are decreased diversity and susceptibility to diseases as GMO crops are genetically identical 

synthetic fertilizer

part of green revolution with shift from organic fertilizers (like manure and compost) to synthetic fertilizers

positives and negatives of synthetic fertilizer

positive is increased yield and profits with more key nutrients added to soil, negatives are excess nitrate and phosphate washing into water and causing eutrophication and fossil fuel use for production

irrigation

drawing water from the ground or nearby surface waters and distributing it on fields to increase plant growth 

positives and negatives of irrigation

positive is it makes agriculture possible in many parts of the world that are naturally dry; negatives are it depletes groundwater and causes soil salinization

pesticides

chemicals sprayed on crops that kill weeds, insects, rodents and pests that eat or damage crops 

positives and negatives of pesticides

positive is increased yield and profits with fewer plants lost to pests, negatives are it can wash off crop s in runoff and kill or harm non-target species in local soil or water