Introduction to Geography Arthur Getis, Judith Getis, & Jerome D. Fellmann

Human Impact on the Environment Chapter 12

Overview Ecosystems Impact on Water Impact on Air & Climate Impact on Land & Soils Impact on Plants & Animals Solid Waste Disposal

Ecosystems Biosphere Ecosystems Food chain & renewal cycles Troposphere Hydrosphere Upper reaches of the earth’s crust Ecosystems Self-sustaining units that consist of plants, animals, and physical features Food chain & renewal cycles

Impact on Water Availability of water Modification of streams “Scarcity” Modification of streams Channelization Water Quality

Water Pollution Agricultural sources Fertilizers Biocides Eutrophication Biocides Animal wastes

Other Sources of Water Pollution Industry PCBs Thermal pollution Mining Municipalities & residences

Impact on Air & Climate Air pollutants Acid rain Photochemical smog Carbon dioxide, carbon monoxide, hydrocarbons, nitrogen oxides, particulates, sulfur oxides Acid rain Sulfuric & Nitric acids Photochemical smog Depletion of the ozone layer CFCs

Greenhouse Effect Gases serve as an insulating barrier trapping infrared radiation that would otherwise be reradiated The greenhouse effect is natural An enhanced greenhouse effect could lead to global warming Evidence: 20th century very warm Winter temperatures in the Arctic have risen since the 1950s Glaciers are thinning & retreating

Potential Effects of Global Warming Ocean expansion Melting ice caps & Greenland ice sheet Possible changes in precipitation Shifts in plant & animal ranges Likely loss of biodiversity Increase in water pollution More respiratory illness Spread of some infectious diseases

Controlling Air Pollution Montreal Protocol of 1987 Kyoto Protocol of 1997

Impact on Land & Soils Landforms produced by excavation Mines, pits, ponds, canals, etc. Landforms produced by dumping Often a result of excavation Surface depressions Subsidence after resource extraction Water, oil, gas Coal, salt, gold

Soil Issues Erosion Deforestation Desertification Salinization

Impact on Plants & Animals Threatened species Habitat disruption Hunting & Commercial Exploitation Exotic Species

Solid Waste Disposal Municipal waste Landfills Incineration

Hazardous Waste Over 400 hazardous substances according to the EPA Low-level waste Decays in less than 100 years High-level waste Can remain radioactive for over 10,000 years Yucca Mountain