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(page 122). Chapter 6: The Environment . Section 6.1: An Interconnected Planet. Currently the world population is 6.5 billion people. We have gotten to this population size with the help of medical care, technology, and sanitation.
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(page 122) Chapter 6: The Environment
Section 6.1: An Interconnected Planet • Currently the world population is 6.5 billion people. We have gotten to this population size with the help of medical care, technology, and sanitation. • As organisms part of an ecosystem, we depend on the environment for resources such as food, water, air, space, shelter, and fuel. • As human population increases, the impact of human activities on the environment increases.
Two Types of Resources • Renewable resources—natural resources that can be replaced at the same rate at which they are consumed What are some examples of these? • Ex. Fresh water, solar energy, fish, trees, wind etc…
These resources are continually being replenished as long as the demand for them is low • Trees are an example of a renewable resource that is quickly becoming a nonrenewable resource
Two Types of Resources • Nonrenewable resources—resources that form at a rate that is much slower than the rate at which they are consumed What are some examples of these? • Ex. fossil fuels—nonrenewable energy resources that formed from the remains of organisms that lived long ago (oil, natural gas, coal) • They are nonrenewable because it takes millions of years for them to form
Air Pollution • Problem: Burning of fossil fuels from power plants, industries, and vehicles releases pollutants like carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen oxides (NO2 and NO3) into the air
Results of Air Pollution • Air pollution causes respiratory problems for people • Acid rain—precipitation that has an unusually high concentration of sulfuric or nitric acids, which is caused by pollution • This damages wildlife in lakes and forests
1908 1968
Results of Air Pollution • Destruction of the ozone layer, which protects the Earth from the sun’s ultraviolet (UV) rays • Cause: Chemicals from refrigerator coolants and aerosols from spray cans have damaged the ozone layer • More risk for skin cancer in people
Results of Air Pollution • Global warming—gradual increase in the average global temperature • Cause: Excessive amounts of Greenhouse gases • CO2 absorbs solar energy and traps heat within the atmosphere
Results of Air Pollution • Greenhouse Effect—warming of the atmosphere that results from greenhouse gases • With increasing carbon dioxide levels, temperatures increase also • Ex. Inside of a hot car on a sunny day
More prevalence of natural disasters, polar ice caps melting, animal behavior is altered (bird migration patterns), sea level increase
Water Pollution • Problem: Water resources are quickly becoming contaminated with runoff from roads, pesticides, industrial waste, landfills, etc…
Results of Water Pollution • Organisms are running out of useable water • Organisms are becoming poisoned • Excessive nutrients from fertilizers are being run off into bodies of water causing algal blooms • Overpopulated alga deplete the water of oxygen and cause aquatic organisms to suffocate
Soil Damage Problem: • Erosion—process in which the materials of Earth’s surface are moved by wind, gravity, or water
Solutions for Soil Damage • Contour plowing to create temporary dams • Planting cover crops to hold topsoil in place • Crop rotation to allow topsoil from washing away
Ecosystem Disruption • Habitat Destruction and Deforestation—clearing of forests • 50% of the world’s tropical rain forests have been cut down for timber, farmland, and pastureland. Unfortunately this is the place of greatest species diversity
Loss of biodiversity—variety of species in a given area • Without certain species, others cannot survive • Introduction of invasive (non-native) species • Ex. Kudzu and poison ivy competing with native plant species • Extinction—death of every member in a species
Solutions for the Future • Conservation—protecting existing natural habitats • 5% of Costa Rica is protected by the government • Restoration—cleaning up and restoring damaged habitats • Reduce Resource Use • Recycle waste • Only 16% of waste is sent to landfills, everything else is recycled • Alternative sources for energy • Electricity, solar, wind, water power • Hybrid cars, ethanol powered cars • Education