3.1 – Population Dynamics IB Topics 3.1.1-3.1.4. Current Human Population There are about 7...

3.1 – Population DynamicsIB Topics 3.1.1-3.1.4

Topic 3 – Human Population, Carrying Capacity, and Resource Use

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…

http://www.toby-ng.com/graphic-design/the-world-of-100

/

Predicted Growth Some predict

a stabilization of human population, while others predict a continued increase

Global Population Forecast

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

3.2 – Resources – Natural CapitalIB Topics 3.2.1-3.2.7

Topic 3 – Human Population, Carrying Capacity, and Resource Use

Natural CapitalNatural

resources/natural assets

Can become natural incomeGoods or

services

Resources Non-renewable

Cannot be replenished at the same rate they are used

Renewable Living resources that

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 ResourceThe 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

Sustainable development

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Ex: fishing, hunting, energy

3.3 – Energy SourcesIB Topics 3.3.1-3.3.3

Topic 3 – Human Population, Carrying Capacity, and Resource Use

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 Worldwide85% of the

worlds energy comes from fossil fuels.

Energy Production in Wisconsin

Pollution from Energy in Wisconsin

Renewable Energy in Wisconsin

Energy Production Examples: WI:

Pleasant Prairie Coal Plant 1190 MW Oak Creek Coal Plant 1135 MW Point Beach Nuclear Plant 1033 MW

Other Examples: Three Gorges Dam 22,500 MW Hoover Dam 2080 MW Nellis Solar Power Plant 14MW (70,000 panels) Big Wind Turbine 1.6 MW Typical Geothermal Plant 40 MW

Energy Source

Description Pros Cons

Fossil Fuels

Nuclear

Wind

Hydro

Solar

Geothermal

Biofuels

Fossil Fuels

Nuclear Power

Wind Power

Hydropower

Solar Power

Geothermal Power

Biofuels

Oil Palms

Future Solutions Hydrogen Nuclear Fusion Carbon

Sequestration

3.4 – Soil SystemsIB Topics 3.4.1 – 3.4.5

Topic 3 – Human Population, Carrying Capacity, and Resource Use

SoilSoil 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

Soil Horizons 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 Texture

Soil type depends on the particle sizeSand = BiggestSilt = MediumClay = Smallest

Soil Texture

Soil TypesPotential to hold organic matter

Drainage

Water holding capacity

Air Spaces

Plants and animals

Primary Productivity

Sandy Soil

Clay Soil

Loam Soil

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

NutrientsMicronutrients

BoronCopperChloride IronManganeseZinc

Nitrogen cycle Atmospheric Nitrogen has to be ‘fixed’ (usually

by bacteria) for plants to use it.

Soil DegradationWater erosionWind erosionAcidificationGroundwater usePollutionDesertificationClimate changeOvergrazingDeforestationRoads

Soil Degradation

Soil Degradation

Soil ConservationMechanical/

physical barriersOrganic farmingAfforestationContour plowingTerracingCrop rotationSoil conditioners