geog101 chapt05 lecture
TRANSCRIPT
Overview
Resource Terminology Energy Resources and Industrialization Nonrenewable Energy Resources Renewable Energy Resources Nonfuel Mineral Resources Land Resources Resource Management
Resource Terminology
Natural resource Physically occurring, exploitable material that a
society perceives to be useful Renewable resources
Replaced by natural processes Perpetual
From sources that are virtually inexhaustible Potentially renewable
Can last indefinitely if natural replacement rate is not exceeded
Resource Terminology
Nonrenewable resources Exist in finite amounts
May be reusable
Resource reserves Some have been identified, others undiscovered Proved reserves
Can be extracted profitably from known deposits Subeconomic
May become economic with improved technology or increased prices
Energy Resources and Industrialization
Energy is used to make all other resources available
Wood Predominant source of fuel for most of human history
Fossil fuels Economic base of wealth in industrialized countries
Correlation between energy consumption and gross national income per capita
Nonrenewable Energy Resources
Crude oil Coal Natural gas Oil shale and tar sands Nuclear energy
Crude Oil
Almost 40% of commercial energy consumed Refined into waxes, tars, and various fuels Largest reserves are in the Middle East OPEC
Organization of Petroleum Exporting Countries
U.S. imports about 66% of oil consumed Pessimists: production could peak by 2010 Optimists: supplies will last far into the future
Advances in exploration and production
Coal
Very large world supplies China and the U.S. are dominant producers Electric power generation, coke for steel
production, home heating and cooking Rank: reflects transformation of organic material
Lignite through bituminous coal to anthracite Grade: based on content of waste materials Bulky and not as easily transported as oil
Major heavy industrial centers on or near coal fields
Natural Gas
Efficient, versatile, burns cleanly Mostly for industrial and residential heating Flows easily and cheaply by pipeline Liquefied natural gas (LNG)
Liquefied by refrigeration for storage or transport Russia and the Middle East contain 2/3 of the
world’s proved reserves
Oil Shale and Tar Sands
Oil shale Sedimentary rock rich in organic material (kerogen)
Extracted and converted into a crude oil by distillation Enormous world reserves
Rich deposits in Green River Formation (CO, UT, WY)
Tar sand Sand and sandstone saturated with heavy oil
Mined, crushed, and heated to extract petroleum Resources many times larger than conventional oil
Major deposits in Alberta
Monetary and environmental costs
Nuclear Energy
Nuclear fission Controlled splitting of an atom to release energy About 20% of electricity in the U.S. Recent revival of interest in nuclear power worldwide No new plants ordered in the U.S. since 1979
High costs, safety concerns, lack of safe storage for radioactive waste, potential terrorist targets
Nuclear fusion Combining two atoms to release energy Technological problems with controlled fusion
Tremendous potential if overcome
Renewable Energy Resources
Biomass fuels Hydropower Solar energy Geothermal energy Wind power
Biomass Fuels
Energy from organic material produced by plants, animals, or microorganisms
Wood Source of most biomass energy Key source of energy in developing countries
Ethanol Alcohol produced from plants
Brazil: ethanol derived from sugarcane U.S.: most ethanol derived from corn
Waste Fermenting crop residues, animal and human refuse
Hydropower
Flowing water drives turbines Location-specific About 7% of electricity in the U.S.
Vast majority of electricity in Pacific Northwest Environmental and social costs
Reservoirs flood land, alter streamflow patterns, trap silt Displacement of people, disruption of ecosystems
Solar Energy
Inexhaustible and nonpolluting Ultimate origin of most forms of utilized energy Chief drawback: diffuse and intermittent Hot water and space heating Electricity generation
Converting solar energy into thermal energy Photovoltaic (PV) cells
Convert solar energy directly into electrical energy
Geothermal Energy
Generated by harnessing the naturally occurring steam and hot water produced by contact with heated rocks in the earth’s crust
Usually where magmas are near the surface E.g., Iceland
Electricity generation, heating, and cooling Geothermal heat pumps
Wind Power
Windmills can turn turbines directly, do not use any fuel, can be built rather quickly
Technological advances in design Lowered cost of electricity generation
California dominated development in 1980s Since then, growth in other states and Europe
Chief disadvantage: unreliable and intermittent Aesthetic impact, hazard to birds
Nonfuel Mineral Resources
Ore Mineral deposit that can be extracted at a profit
Exploitation of a mineral resource Exploration, extraction, concentration,
smelting/refining, transporting, manufacturing Practicality and profitability of mining a deposit
determined by: Value, quantity available, richness of the ore,
distance to market, land acquisition and royalty costs
The Distribution of Nonfuel Minerals
Larger countries are more likely to contain commercially exploitable deposits Russia, China, Canada, the U.S., Brazil, Australia
Roughly half of the nonfuel mineral resources
Many types of minerals are concentrated in a small number of countries E.g., South Africa
Gold ore, chromium and platinum-group metals
Copper: A Case Study
Important to industrialized societies Conducts heat and electricity well, malleable,
resists corrosion Largest deposits found in western North
America, western South America, Australia Chile leads the world in production Demand outstrips supply
Significant price increase in recent years Grade of ores mined in the U.S. has decreased Increased recovery by recycling Spurred the search for substitutes
Land Resources
Soils Wetlands Forest resources
Soils
Formed by physical and chemical decomposition of rock material and decay of organic matter Formation equals or exceeds erosion under most
natural conditions Erosion is accelerated by removal of vegetation
Soil converted to a nonrenewable resource Pressures upon land have increased with
population growth E.g., clearing and conversion of tropical rain forests
has accelerated erosion
Soils
Desertification Conversion of arid and semiarid lands into deserts
Due to climatic change and human activity Africa is most at risk
Evidence of accelerated soil erosion is found in all parts of the world Recently at an all-time high in the U.S.
Soils
Secondary effects of soil erosion Croplands become less productive Siltation of streams and reservoirs accelerates Erosion-borne silt pollutes water supplies Danger of floods increases Costs of maintaining navigation channels grow
Salinization Concentration of salts in topsoil as a result of the
evaporation of surface water Occurs in poorly drained soils in dry climates Often as a result of improper irrigation
Wetlands
Vegetated land surfaces periodically or permanently covered by standing water
Inland Freshwater bogs, marshes, swamps, floodplains
Coastal Covered by either fresh or salt water Estuarine zone
Narrow area of wetlands along coastlines where salt water and fresh water mix
Wetlands
Perform a number of vital functions Trap and filter silt, pollutants, and nutrients that
rivers bring downstream Habitat and food for a variety of plants and animals Absorb floodwaters and help stabilize shorelines
Many wetlands have been lost or degraded
Forest Resources
Commercial forests Northern coniferous Temperate hardwood Tropical lowland hardwood
Serve a variety of purposes Timbering; soil and watershed conservation; wildlife
habitat; recreation; recycling of water, carbon, oxygen Clear cutting
All the trees removed from a given area Selective cutting
Medium and large trees cut singly or in small groups
U.S. National Forests
155 national forests Multiple Use Sustained Yield Act
Recreation, timber production, watershed protection, wildlife habitat preservation
Much timber has been cut in recent years Old growth forests in Washington and Oregon
Tongass National Forest Clear cutting and road building are endangering
wildlife habitats
Tropical Rain Forests
Some countries subsidize conversion of forests To farming, cattle ranching, mining, etc.
Millions of acres are cleared every year Brazil has the largest area of tropical rain forests
One of the highest rates of clearing Policy of developing the Amazon Basin
Global concerns about clearing tropical forests Oxygen and carbon balance Contribution to air pollution and climate change Loss of biological diversity
Resource Management
Sustainable development Satisfies current needs without jeopardizing the ability
of future generations to meet their own needs Sustainable use of resources
Using them at rates within their capacity for regeneration
Wise management of resources entails: Conservation Reuse Substitution