Human Geography

Jerome D. FellmannMark BjellandArthur GetisJudith Getis

Human Geography

Chapter 13

Human Impacts on Natural Systems

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Photo by Mark Bjelland

Human Geography 11e

Physical Environments and Cultural Impacts

• Environment • Biosphere

– The thin film of air, water, and earth within which we live, including the atmosphere, surrounding waters, and the upper reaches of the earth’s crust

Human Geography 11e

Climates, Biomes, and Change

• Biomes– A major ecological community, including

plants and animals, occupying an extensive earth area

• Climate Change– Change in the earth’s climate system,

whether natural or caused by humans

• Global Warming

Human Geography 11e

Climates, Biomes, and Change

• Humans have significantly altered the chemical composition of the atmosphere since the advent of the Industrial Revolution around the year 1750

• The Greenhouse Effect is the result of specific gases partially capturing the long-wave heat energy radiated the earth

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Human Geography 11e

Climates, Biomes, and Change

• Acid Rain– Pollutants that are created by burning

fossil fuels and that change chemically as they are transported through the atmosphere and fall back to earth as acidic rain, snow, fog, or dust• Pollutants are chiefly oxides of sulfur and

nitrogen• The sources of pollution are vehicles,

industry, power plants and ore smelting facilities

Human Geography 11e

Climates, Biomes, and Change

• The Trouble with Ozone– Ozone blocks the cancer-causing

ultraviolet (UV) light that damages the molecule of heredity and cell control•However, the Ozone shield now

appears in danger of destruction by chemicals released into the air by humans

Human Geography 11e

Land Use and Land Cover

• Tropical Deforestation

• Desertification• Soil Erosion

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© David Rose/Panos Pictures

Human Geography 11e

Land Use and Land Cover

• Tropical Deforestation– The tropical rain forest biome is feeling the

pressures of • Growing population numbers • The need for more agricultural land • Expanded demand for fuel and commercial wood • Forest destruction for the expansion of grazing land

– When tropical rainforest is cleared, vegetation will be less effective releasing oxygen in the atmosphere

– Forest destruction changes surface and air temperatures, moisture content, and reflectivity

Human Geography 11e

Land Use and Land Cover

• Desertification– The spread of desert-like landscapes into

arid and semiarid environments– Accelerates because of human activity,

mainly overgrazing, deforestation for fuel wood, clearing of original vegetation for cultivation, and burning

• Soil Erosion– Accelerated soil erosion quickly removes

tropical forest soils from deforested areas

Human Geography 11e

Water Supply & Water Quality

• Patterns of Availability, and Water Use and Abuse– The problem is not with the global

amount of water but with its distribution and the variability of precipitation from year to year

– Regional water sufficiency is also a function of the size of the population using the water and the demands it places on the resource

Human Geography 11e

Garbage Heaps and Toxic Wastes

• Solid Wastes and Rubbish– Landfill Disposal– Incineration– Ocean Dumping

• Toxic Wastes– Radioactive Wastes

• Exporting Waste

Human Geography 11e

Prospects and Perspectives

• Link to Culture and Human Geographic Patterns

• Diverse Systems of Exploitation of the Environment