Earth’s Resources Chapter 4

Renewable and Nonrenewable Resources Renewable – replaceable in months or years Nonrenewable – takes millions of years to be replaced ▫Coal, oil, natural gas ▫Metals such as gold, copper, iron, uranium 6% of the world’s population lives in the US but we use 30% of the available resources The world’s population is still increasing

Fossil Fuels Coal ▫Plant material changed by heat and pressure  Starts as peat (decomposed plants)  lignite (sedimentary rock – aka brown coal)  bituminous coal (still sedimentary – aka soft coal)  Anthracite (metamorphic – aka hard coal) ▫Most coal used at power plants ▫Surface mining damages the landscape ▫Underground mining is dangerous ▫All mining produces waste and pollution ▫Burning coal releases sulfur (makes acid rain)

Fossil Fuels Petroleum and natural gas ▫Oil ▫Plants and animals buried in ocean sediments ▫The oil and gas moves into the permeable parts of the soil, like sandstone ▫Oil and gas do leak to the surface ▫Large quantities can get trapped (in an oil trap) and we tap into it with an oil drill

Tar Sands and Oil Shale Tar Sands ▫Clay and sand with water and tar (bitumen) ▫Very thick so it can’t be pumped but it can be mined but it takes a lot of energy ▫Results in large amounts of contaminated water Oil Shale ▫Rock that contains kerogen ▫Can be mined and the kerogen vaporized when heated ▫Also contains minerals which have to be removed before it can be used (which is expensive)

Mineral Deposits Ore ▫Useful metallic metal mined for a profit (has to be enough of it in one place to make mining it profitable) ▫Gold, silver, copper, mercury, lead, platinum, and nickel Igneous Hydrothermal Solutions Placer Deposits

Nonmetallic Minerals Building materials and industrial materials Gravel and sand limestone Used as fertilizers Usually need processing before they can used which adds to their cost (on top of the mining)

Energy Sources Solar ▫No mining required ▫No waste or pollution produced ▫Solar panels collect heat and transfer it to pipes of water or air ▫Technology is currently expensive and you need a back up heating unit ▫Large scale requires lots of land in sunny places

Energy Sources Nuclear Energy ▫Radioactive material provides the energy ▫Heavy atoms (like uranium 235) are bombarded with neutrons  the nuclei splits into smaller nuclei which gives off energy  Those nuclei hit other nuclei and start a chain reaction (which can be controlled using neutron absorbing rods)  The heat released is used to turn steam turbines which produce electricity ▫Where should the wastes be stored? How should they be transported? ▫What of there is an accident?

Energy Sources Wind Energy ▫Wind turns the turbines used to make electricity ▫Produces noise pollution ▫Requires large tracts of land

Energy Sources Hydroelectric ▫Falling water turns turbines to produce energy ▫Dams are used to control the flow of water  Requires changing the direction of a river (harms the environment)  Silt builds up behind the dam so eventually the water stops flowing (usually years)  The river has to be large and running quickly if a dam is going to be able to produce power

Energy Sources Geothermal ▫Using underground hot water  Hot water runs turbines to make electricity ▫Areas with recent volcanic activity are usually hot enough ▫The hot water may not be renewed and new wells have to be drilled every years until the field is depleted

Energy Sources Tidal Power ▫Uses a dam at an estuary or coastal area where tides enter ▫The tide moves the turbine that makes energy

Water Covers 71% of the Earth’s surface ▫most of it is salt water ▫Less than 1% of the water on Earth is usable freshwater Pollution ▫Point source – comes from a specific location (sewage pond on a farm) ▫Nonpoint source – pollution from many places all coming together (run off from everyone's lawn in the spring when fertilizer is put out) ▫What problems does pollution cause? (page 109)

Air Components of Atmosphere ▫Nitrogen, oxygen, and water vapor ▫Carbon dioxide and methane are a small part of the atmosphere but they make a big difference ▫Ozone – blocks UV radiation Pollution ▫Carbon monoxide, nitrogen oxide, soot, sulfur dioxide ▫Smog, acid rain, global warming ▫Chlorofluorocarbons (CFCs) were destroying the ozone layer but we eliminated them and the ozone is repairing itself

Land Resources Mining ▫500,000 mines in the US ▫causes soil erosion, destroys vegetation, pollutes freshwater Agriculture ▫Irrigation uses up freshwater and cause salination of the soil ▫How else could we feed this many people? Forestry ▫Clear cutting results in soil erosion and a loss of wildlife ▫We are trying to replace the forests we have cut down (less than 1% of the old growth forests in the US are still standing) Landfills ▫Contaminate groundwater (a key source of freshwater)

Conservation How much energy does to take to get a pudding cup into your lunch box? Does that get recycled? The careful use of our resources combined with recycling It is easier to stop pollution than clean it up

Water Pollution Clean water act (1972) ▫Reduce point source pollution ▫Increase the number of sewage plants Safe Drinking Act (1974) ▫Set a maximum level of pollutants allowed in drinking water ▫Public water sources tested regularly ▫Bottled water is not tested and not regulated as well as public drinking water

Air Pollution Clean Air Act (1970) ▫National Ambient Air Quality Standard  Carbon monoxide, ozone, lead, sulfur dioxide, nitrogen oxides, and particles  Even though we use more energy our air pollution levels have decreased since 1970  Power plants clean the air more before releasing it  Use lower sulfur coal  Increased use of non-fossil fuel energy sources

Land Resource Use Farming ▫Soil conservation  No till farming prevents soil erosion  Contour plowing reduces runoff  Strip cropping prevents to soil from losing nutrients  Reduction in pesticide use  Use natural fertilizers such as compost Forestry ▫Selective cutting  Maintains diversity of vegetation and habitats  Prevents soil erosion Landfills ▫Use liners under new landfills ▫Resource conservation and recovery act (1976)  Decreased unsafe dumping of toxic substances