topic 3 – human population, carrying capacity, and resource use
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Topic 3 – Human Population, Carrying Capacity, and Resource Use. Topic 3.1- Population Dynamics. Current Human Population. There are about 7 billion people living on Earth For about 200,000 years, there were between 1-15 million people on Earth. Milestones. 1 Billion: 1804 2 Billion: 1927 - PowerPoint PPT PresentationTRANSCRIPT
Topic 3 – Human Population, Carrying Capacity, and
Resource UseTopic 3.1- Population Dynamics
Current Human Population
• There are about 7 billion people living on Earth
• For about 200,000 years, there were between 1-15 million people on Earth
Milestones• 1 Billion: 1804• 2 Billion: 1927• 3 Billion: 1960• 4 Billion: 1974• 5 Billion: 1987• 6 Billion: 1999• 7 Billion: 2012
Demographics• If you reduce the worlds population to a village of
100 people, how many would:• Be Male• Be White• Be Christian• Live in substandard housing• Be able to read• Be malnourished• Be without access to safe water• Have internet access• Have a college education• Have HIV• Be US citizens• Control 1/3 of the wealth
Predicted Growth• Some predict a
stabilization of human population, while others predict a continued increase
Calculating Rates• Crude Birth Rate (CBR)
• The number of live births per 1000 people
• Equation:
Calculating Rates• Crude Death Rate
(CDR)• The number of deaths
per 1000 people
• Equation:
• Natural Increase Rate (NIR)• CBR-CDR
Calculating Rates• Fertility
• The average number of births per women of child-bearing age
• Equation:
Calculating Rates• Doubling Time
• The amount of time it takes for a population to double
• Equation:
Population Pyramids
Population Pyramids
Population Pyramids
Population Pyramids
Demographic Transition Model
Topic 3 – Human Population, Carrying Capacity, and
Resource UseTopic 3.2- Resources – Natural Capital
Natural Capital
• Natural resources/natural assets
• Can become natural income• Goods or
services
Resources• Non-renewable• Cannot be replenished
at the same rate they are used
• Renewable• Can be replenished at
the rate they are used via human processes
• Replenishable• Non-living resources
that can be replenished via natural processes
Nature of a Resource
• The value of a resource changes with human technology/culture
Sustainability• Using resources at a
rate that allows natural regeneration
• Living within the means of nature
• Development that meets the needs of the present without compromising the ability of future generations to meet their own needs
Topic 3 – Human Population, Carrying Capacity, and
Resource UseTopic 3.3 – Energy Resources
Making Energy
• Electricity is delivered to homes and businesses via alternating current (AC)
• AC power is generated when electromagnets are spun using a turbine
Energy Sources Worldwide
• 90% of the worlds energy comes from fossil fuels.
Fossil Fuels
Nuclear Power
Wind Power
Hydropower
Solar Power
Geothermal Power
Biofuels
Oil Palms
Future Solutions• Hydrogen
• Nuclear Fusion
• Carbon Sequestration
Topic 3 – Human Population, Carrying Capacity, and
Resource UseTopic 3.4 – Soil Systems
Soil
• Soil is eroded rock, nutrients, decaying organic matter, and water
Soil Formation• Soil is produced by:• Weathering of rock• Deposition of sediments by erosion• Decomposition of organic matter in dead organisms
• Soils generally have distinct horizons:• A horizon• Humus (decaying organic matter with mineral particles)
• E horizon• Not always present, pale layer where minerals have been leached
• B horizon• Organic matter and mineral deposits
• C horizon• Weathered rock/bedrock
Soil Horizons
• Soil type depends on the particle size• Sand = Biggest• Silt = Medium• Clay = Smallest
Soil Texture
Soil Texture
Soil TypesPotential to hold organic matter
Drainage Water holding capacity
Air Spaces
Plants and animals
Primary Productivity
Sandy Soil
Low Very Good
Low Large Few Low
Clay Soil Low Poor Very High
Small Few Very Low
Loam Soil
Medium Good Medium Medium
Many High
Nutrients• Macronutrients• Nitrogen (needed for
chlorophyll)• Phosphorous (needed
for photosynthesis)• Potassium (needed
for fruiting and growth)
• Calcium• Magnesium• Sulfur
• Micronutrients• Boron• Copper• Chloride• Iron• Manganese• Zinc
nutrients
• Atmospheric Nitrogen has to be ‘fixed’ (usually by bacteria) for plants to use it.
Nitrogen cycle
• Water erosion• Wind erosion• Acidification• Groundwater use• Pollution• Desertification• Climate change• Overgrazing• Deforestation• Roads
Soil Degradation
Soil Degradation
Soil Degradation
• Mechanical/physical barriers
• Organic farming• Afforestation• Contour plowing• Terracing• Crop rotation• Soil conditioners
Soil conservation