CHAPTER 2 HUMAN ACTIONS Section 2 Using Resources Wisely Notes 2-2

Atmospheric Resources Atmosphere has a direct effect on our health Gives us O 2 Upper atmosphere contains O 3, ozone Protects from UV rays Atmosphere can’t be used up Important to understand what human activities do to it. Air quality and Sustainability Hard to clean up the air because it moves around Rules have been made about emissions Banned lead in gasoline in 1996 Clean Air Act started in 1970 and has been updated over the years myths-and-facts myths-and-facts

Atmospheric Resources Air Pollution Forms are smog, acid rain, greenhouse gases, particulates Causes asthma and allergy sufferers to not breathe easily Causes global climate change Smog: Gray-brown haze over a city Formed by air pollutants like: ozone, nitrogen oxides and volatile organic compounds

Air Pollution Acid Rain: Air pollution combines with rain to form acids Damages leaves, changes chemistry of soils and surface water Can release toxic elements from the soil and allow them to move through the biosphere Greenhouse Gases: Carbon dioxide, water vapor, methane

Air Pollution Particulates: Tiny pieces of ash and dust Released by industrial processes and diesel engines Cause breathing issues when inhaled into the lungs Some acids, organic chemicals, metals, soils and dust Key Question: What are the major forms of air pollution? Smog, acid rain, greenhouse gases and particulates

Freshwater Resources Usually freshwater is considered renewable It, however, is being used at an alarming rate Only 3% of water is fresh (1% is liquid) Water Pollution Can be affected by harmful material Point source: where pollution enters the water source Factory or an oil spill Nonpoint source: pollution enters from many smaller sources Grease and oil from roads, chemicals released into air by factories and cars

Water Pollution Industrial and Agricultural Chemicals PCBs used in industry until 1970 Can still be found in parts of the Great Lakes and coastal regions Heavy metals like lead and mercury Pesticides and Insecticides DDT (caused raptor’s eggs to soften) Biological Magnification Pollutant is picked up by a primary producer Gets carried through the food web to the highest trophic level Can reach 10 million times its original concentration

Water Pollution Sewage: Large amounts of sewage in water ways can cause bacteria and algae to grow They use of water’s oxygen and cause “dead zones” Can also carry organisms that carry disease Water Quality and Sustainability Plant buffers of trees and plants to help absorb excess nutrients and filer out pollutants Watershed: groundwater, streams and rivers that drain into the same body of water Cutting pollution rates by using predators and parasites instead of chemicals on fields Less poisonous sprays and crop rotation

Soil Resources Topsoil: Mineral and nutrient rich soil at surface Absorbs and holds water, but allows extra to drain Low in salts Can be renewable but must be well managed Dust Bowl Soil Erosion Wind or water takes the topsoil away When it is left bare between plantings Desertification: loss of topsoil Caused by farming, overgrazing or drought Plant roots hold soil in place

Soil Resources Deforestation: Loss of forests There less than half of the old growth forests They have never been cut Can lead to severe soil erosion Topsoil in the rainforest is very thin and not very fertile Once trees are cut down, the soil is only useful for a couple of years Soil Sustainability No till farming: leave the soil with plants in it Crop rotation: planting different crops each year Contour Plowing: planting across the slope of the land Selective Cutting Forests: picking some trees to cut down, not all the trees