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HUMAN POPULATION & SUSTAINABILITY

HUMAN POPULATION & SUSTAINABILITY. HUMAN POPULATION - HISTORY. Homo sapien sapien “wise man” 250,000 – 500,000 years ago Hunter-gather populations considered stable at 3 million prior to the development of agriculture (35,000 – 40,000 years ago). HUMAN POPULATION - HISTORY.

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HUMAN POPULATION & SUSTAINABILITY

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  1. HUMAN POPULATION& SUSTAINABILITY

  2. HUMAN POPULATION - HISTORY Homo sapiensapien“wise man” 250,000 – 500,000 years ago Hunter-gather populations considered stable at 3 million prior to the development of agriculture (35,000 – 40,000 years ago)

  3. HUMAN POPULATION - HISTORY Agricultural Revolution – the development and domestication of traditional farming techniques (Mesopotamia ~10,000 years ago) Led to the development of civilizations and could support larger populations. Human population growth is exponential 2, 4, 8, 16, 32, 64, 128, 256, 512

  4. HUMAN POPULATION - GROWTH Population still regulated by limiting factors due to environmental conditions • Water • Food • Arable land • Space • Disease

  5. HUMAN POPULATION - GROWTH Advancements in medicine, industrial manufacturing, and commercial large scale farms increased the population growth rate. More people = more resources = more water, air, food, shelter, clothing, energy, minerals, medicine, space. Has the human population already passed the carry capacityof Earth?

  6. HUMAN POPULATION - RESOURCES A supply that benefits humans • water, land, air, ore, life Natural resources: the resources the Earth provides • 2 Types of Natural Resources • Renewable • Nonrenewable

  7. HUMAN POPULATION - RESOURCES RENEWABLE • Natural resources that can be used indefinitely, reused, or recycled • Sun, water, fertile soil, nitrogen, carbon, living things NONRENEWABLE • A resource that exists in a fixed amount • Can be replaced but the process takes hundreds of millions of years • fossil fuels, gemstones, silver, uranium, biodiversity

  8. RESOURCES - SUSTAINABILITY • Renewable resources are replaced through natural processes • Humans must not use the resources faster than they can be replaced • Sustainable yield: the replacement of renewable resources at the same rate they are consumed

  9. RESOURCES - AGRICULTURE Sustainable Agriculture / Aquaculture • Farming using principles of ecology, natural • Does not abuse or overuse available resources • Efficient use of resources; space, water, nutrients • Limits environmental impact • Ensure long term use of land and productivity • Economical profit

  10. RESOURCES - AGRICULTURE Sustainable Methods • Fuel efficient / man powered machines • Organic pesticides and herbicides • Crop rotation, cycling different crops • Organic fertilizers, composting • Biocontrols, natural predators • Crop integration, polycultures • Drip irrigation or native food crops

  11. RESOURCES - AGRICULTURE Commercial / Industrial Agriculture • Machines, equipment, transportation • Pesticides and herbicides • Large areas clear cut for farms • Monoculture • Irrigation systems • GMOs

  12. RESOURCES - AGRICULTURE Problems with Commercial / Industrial • Excessive tilling, erosion • Nutrient depletion, no more nutrients in soil • Clear cutting large areas, slash’n’burn • Poor irrigation, waste of water • Salinization or desertification – “dead” soil • GMOs weak against disease • Chemical herbicides/pesticides hurt ecosystem

  13. RESOURCES – FOSSIL FUELS Chemicals formed by heat and pressure from dead plants & organisms • Primary source of energy for the U.S. • Coal, oil, and natural gas • Takes millions of years to form • Non-renewable • Produce pollution • CO2, NOx, SOx, Mercury, etc

  14. RESOURCES - NUCLEAR Uses the energy released in the process of nuclear fission, where a radioactive atom is split or decays into two smaller atoms. Advantages • High Energy outputs • Large supply • Emits 1/16 amount of Carbon Dioxide as coal • Moderate land use Disadvantages • High cost • Thermal pollution from the nuclear power plants • Accidents (Chernobyl and 3 mile Island) • Radioactive waste

  15. RESOURCES - SOLAR Solar Energy • Passive Solar Heating: Capturing sunlight directly and converting it to heat • Active Solar Heating: using solar panels to collect heat • Photovoltaic Cells (PV cells): solar energy is converted into electrical energy, silicia • Problems: expensive to buy

  16. RESOURCES – GEOTHERM / HYDRO Geothermal Energy • Energy produced by naturally occurring steam and hot water • Only available in geologically active areas Water Energy • Hydroelectric Power: the power of falling water turns turbines that produce electrical energy • Hydrotidal Power: power of the rising and receding tides moves turbines producing electrical energy

  17. RESOURCES - WIND Wind Energy • Wind turbines convert mechanical energy of the wind to electrical energy • A large portion of the US’s energy could be supplied by wind farms in Texas, North and South Dakota • Problems: Must have constant wind, unattractive and kills birds, transportation • FASTEST growing market

  18. RESOURCES - BIOMASS Biomass • Renewable resource • Includes wood, dried crops and dried fecal matter from animals • Wood is a primary source of energy for 50% of the world • Biogas: mix of methane and CO2 from animal waste that is used for cooking fuel • Gasohol: mix of gasoline and ethanol that can be used as fuel

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