Chapter 4

I. Energy Resources

A. What are resources?1. Diff types of resources

a. Capital: $ or machines used to

produce goods or svcs

b. Human: people who perform tasks

c. Natural: materials in the natural environment that people value &

use to satisfy their needs

2. Nonrenewable Resourcesa. Can’t be replaced – a limited supplyb. Minerals formed in earth’s crust over millions of yrsc. Ex: iron, gold, copper, oild. Fossil Fuels: formed from remains of ancient plants/animals

- Main energy source of industrialized countries!!!

- Coal, oil, natural gas

Fossil Fuels

Advantages Disadvantages Future?

Oil

Natural Gas

Coal

3. Nuclear Energy

• Produced by fission – splitting of uranium atoms in a nuclear reactor, release stored energy

Pros Cons

How nuclear power works

4. The problem of nonrenewable resources – how can we

prolong the inevitable?a. New technology to find more

b. Recycle

c. Reduce overall consumption - conserve

d. Increase energy efficiency

6. Renewable Resources – constantly regenerated or replaced by environment

a. Examples: soil, forests, water, sun, wind

b. Human activities can interfere with renewal - deforestation, oil spill etc

c. Renewable energy sources

Advantages Disadvantages Future?

Wind

Solar

Water

Geothermal

Three Gorges Dam China

Larry Hagman's Solar Ranch

7. Alternative Fuels?

Advantages Disadvantages Comments?

ethanol

Alternatiave Fuel Comparison

B. Energy Sources1. Availability

a. Few countries have sufficient supply - must import

b. Oil/natural gas unevenly distributed over the world

- over ½ oil supply in SW Asia- lrg reserves of natural gas in Eurasia- coal is more evenly distributed –

but what’s the problem?

2. Distribution of Resources

a. Uneven distribution affects where people live, economic activities, trade networks

b. Population centers develop near resources or near easy means of transportation

c. When few resources available, people migrate to develop trade

Population Living on Less Than US$2 per Day2002

Percent

50

7875

41

23 20

World South Asia Sub-SaharanAfrica

East Asia and thePacific

Latin Americaand the

Caribbean

Middle Eastand North

Africa

Source: World Bank, World Development Indicators 2006.

II. Water ResourcesA. Water on Earth – our most precious

resource!

1. Distribution

a. 97% in oceans; 3% fresh

- most fresh water tied up in glaciers

b. Water Cycle

- amt of water stays constant thanks to repeating cycle, but physical

state changes : gas liquid solid

Water Cycle

2. Surface Watera. Water flows from high to low

- headwaters – 1st & smallest streams formed from the runoff of a

mt, eventually forming rivers- tributaries – small streams or rivers

that flow into larger stream or river- watershed or drainage basin – the

entire region drained by a river and its tributaries

b. Surface water may collect in lakes- lakes provide water supplies, fish, and recreation opportunities

- lakes can also reduce severity of climate on their shores

c. Lake salinity (saltiness)- may collect minerals from runoff

- as water flows in & evaporates, mor minerals build up. Saltiness

d. Estuaries – semi-enclosed bodies of water, seawater, and freshwater formed where a river meets an inlet of the sea

- mix of seawater/freshwater

- make good harbors

- rich in fish/shellfish

- shelters for animals

Estuaries

e. Wetlands – landscapes that are covered with water for at least part of a year

- bogs, coastal marshes, wooded swamps

- rich in fish, shellfish, birds, native plants

- migrating birds depend on wetlands for food, water & rest

- threatened by drainage projects (farmland, housing, industrial

sites). Over ½ US original wetlands destroyed

- FL Everglades, Okavango delta in Africa

The Florida Everglades

Hippos in the Okavango Delta - Botswana

Wetlands

3. Ground Watera. Water found below ground

b. Plant roots reach down to absorb this water

c. Water table – the groundwater level at which all the cracks and spaces in rock are filled with water

- rises/falls w/ rainy/dry season

- excessive drop in water table (thanks to drought or irrigation) may lead to subsidence or sink holes

d. Water Scarcity

- see article in packet

B. Floods1. occur when rivers carry more water than stream channels can hold (heavy rain, snow melt)

a. Erodes landb. Destroys vegetationc. Drown people/livestockd. Destroy cropse. Disrupt/destroy infrastructure

2. Human activity leads to increased floodinga. Vegetation cleared = increased

surface runoffb. flooding if rainwater can’t sink into

soilc. flood damage increasing with

population increase in flood plain- fertile farm land, water transport, waterpower, water supply

III. Natural ResourcesA. Soil & Forests

1. Soil Building

a. Rocky sediment + organinc matter

b. Humus – broken-down plant & animal matter in soil

c. Minerals in soil depend on parent rock

d. Soil formation is slow (up to 100s of yrs)

e. Leaching – the downward mvmt of minerals and humus in soils

- cause by excessive rain

- low fertility

2. Sustaining soil reservesa. Soil erosion can be controlled via contour plowing – plowing fields across a hill rather than up and down a hill

b. Crop rotation – the practice of planting different crops in a field in alternating years

can prevent soil exhaustion – a condition in which soil has lost nutrients and becomes

nearly useless for farming

c. Soil salinization – salt buildup in the soil can occur as salt is present in irrigation water

B. Forests

1. protect soil from erosion, provide habitats for many species,

provide useful products (wood, rubber, oils, medicines)

2. Deforestation – destruction or loss of forestsa. Rainforests being cleared at rapid rate

- for wood, farmland, ranch land

3. Reforestation – replanting of a forest programs are increasing in some

areas

Deforestation

C. Air & Water

1. Air

a. Threatened by pollution/acid rain

- smog & acid rain are short term issues

- increased greenhouse gas emissions contribute to global warming –

long term issue

b. ozone layer can be damaged by pollution

2. Water

a. Traditionally, aqueducts – artificial channels for transporting water – have carried water to dry areas

b. Where groundwater is the only source of water, wells are dug to extract water

from aquifers – rock layers where groundwater is plentiful

c. Areas with little rainfall might rely on fossil water – groundwater that is not replenished by rain

- nonrenewable form of water

- found mostly in desert areas