16.1 human population growth and natural resources key concept as the human population grows, the...
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16.1 Human Population Growth And Natural Resources
KEY CONCEPT As the human population grows, the demand for Earth’s resources increases.
16.1 Human Population Growth And Natural Resources
Objectives
• Summarize the current state and effects of human population growth
• Explain the importance of effective resource management
16.1 Human Population Growth And Natural Resources
Earth’s human population continues to grow.
• Earth’s human carrying capacity is unknown.
16.1 Human Population Growth And Natural Resources
• Technology has helped to increase Earth’s carrying capacity.– gas-powered farm equipment– medical advancements
16.1 Human Population Growth And Natural Resources
The growing human population exerts pressure on Earth’s natural resources.
• Nonrenewable resources are used faster than they form.– coal– oil
16.1 Human Population Growth And Natural Resources
• Renewable resources cannot be used up or can replenish themselves over time.– wind– water– sunlight
• Growing use of nonrenewable resources may lead to a crisis.
• Resources must be properly managed.
16.1 Human Population Growth And Natural Resources
• An ecological footprint is the amount of land needed to support a person.
• The land must produce and maintain enough– food and water– shelter– energy– waste
16.1 Human Population Growth And Natural Resources
• Several factors affect the size of the ecological footprint.– amount and efficiency of resource use – amount and toxicity of waste produced
16.1 Human Population Growth And Natural Resources
Give 3 examples of how technology has influenced human population growth
• Advances in medicine have reduced infant mortality and prolonged life spans
• Industrial technologies have made transportation and agriculture more productive and easier, allowing for easier food production and distribution
• Plumbing and sewage treatment have improved sanitation, reducing incidence of water born illness
16.1 Human Population Growth And Natural Resources
What is the difference between renewable and nonrenewable resources
Renewable Resources
• Can be replenished by Earths natural processes
Nonrenewable Resources
• Are difficult to replenish in a time span meaningful to humans
16.1 Human Population Growth And Natural Resources
What factors can limit the growth of the human population?
• Disease• Drought• Overexploitation of limited resources• Crop pests• War
16.1 Human Population Growth And Natural Resources
KEY CONCEPT Fossil fuel emissions affect the biosphere.
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Objective
• Describe the sources, types, and effects of pollution
• Explain how air pollution contributes to acid rain
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Pollutants accumulate in the air.
• Pollution is any undesirable factor added to the air, water, or soil.
• Smog is one type of air pollution.– sunlight interacts with
pollutants in the air– pollutants produced by fossil
fuel emissions– made of particulates and
ground-level ozone
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
• Smog can be harmful to human health.• Acid rain is caused by fossil fuel emissions.
– produced when pollutants in the water cycle cause rain pH to drop
– can lower the pH of a lake or stream– can harm trees
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Air pollution is changing Earth’s biosphere.
• The levels of atmospheric carbon dioxide rise and fall over time.
• High levels of carbon dioxide are typical of Earth’s warmer periods.
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
• The greenhouse effect slows the release of energy from Earth’s atmosphere.– sunlight penetrates Earth’s atmosphere– energy is absorbed and reradiated as heat– greenhouse gases absorb longer wavelengths– Greenhouse
gas moleculesrereleaseinfraredradiation
methane (CH4) water (H2O)
carbon dioxide(CO2)
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
• Global warming refers to the trend of increasing global temperatures.
North Pole
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Name and describe 2 ways in which pollution affects ecosystems
• Pollution can result in smog and acid rain
• Smog is caused by the interaction of sunlight with pollutants produced by fossil fuel emissions
• Acid rain results from the mixture of these emissions with water
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
How does the greenhouse effect keep Earth warm?
• Infrared energy Radiating from Earths surface is absorbed by greenhouse molecules such as water, carbon dioxide, and methane.
• This energy, also called heat, is then released and absorbed by other molecules of Earths surface or the atmosphere.
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Explain how a build-up of CO2 in the atmosphere could increase Earths global temperature.
• With more greenhouse molecules in the atmosphere, less heat would be allowed to escape, causing Earth to become warmer.
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Greenhouse gasses are found close to earths surface and high above in the atmosphere. Name 2 important functions of greenhouse gasses at Earths surface.
• At Earths surface water vapor condenses to form precipitation which is part of the hydrologic cycle
• Carbon dioxide is a necessary reactant for photosynthesis
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
Ocean producers such as phytoplankton are an important part of food webs, but they require a specific temperature range to survive. How might increased water temperature affect these ocean food webs?
• If increased water temperatures kill the phytoplankton, the lowest trophic levels will be gone and the food webs will probably collapse
16.2 Air Quality
16.1 Human Population Growth And Natural Resources
KEY CONCEPT Pollution of Earth’s freshwater supply threatens habitat and health.
16.3 Water Quality
16.1 Human Population Growth And Natural Resources
Objectives
• Describe how water pollution affects ecosystems
• Explain how biomagnification causes accumulation of toxins in food chains
16.3 Water Quality
16.1 Human Population Growth And Natural Resources
Biomagnification causes accumulation of toxins in the food chain.
• Pollutants can move up the food chain.– predators eat contaminated
prey– pollution accumulates at
each stage of the food chain• Top consumers, including
humans, are most affected.
16.3 Water Quality
16.1 Human Population Growth And Natural Resources
How do PCBs affect bird populations through biomagnification?
• PCBs travel up through trophic structure of an ecosystem and accumulate in large amounts in the eggs of large birds.
• PCBs can negatively impact growth and development within the egg, causing – Genetic mutations– Deformities– Death
• The population of birds may crash as a result
16.3 Water Quality
16.1 Human Population Growth And Natural Resources
Would a buffalo or a mountain lion be more affected by biomagnification? Why?
• A mountain lion would be more affected because it is higher on the food chain and would ingest more contaminants from its food supply
16.3 Water Quality
16.1 Human Population Growth And Natural Resources
How does the biomagnification pyramid compare with the energy pyramid?
• They are opposite
• Energy decreases as you move up the food chain, but pollution increases
16.3 Water Quality
16.1 Human Population Growth And Natural Resources
KEY CONCEPT The impact of a growing human population threatens biodiversity.
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
Objectives
• Assess the consequences of loss of biodiversity
• Explain how loss of habitat and introduced species affect ecosystems and biodiversity
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
Preserving biodiversity is important to the future of the biosphere.
• The loss of biodiversity has long-term effects.– loss of medical and technological advances– extinction of species– loss of ecosystem stability
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
Loss of habitat eliminates species.
• Habitat fragmentation prevents an organism from accessing its entire home range.– occurs when a barrier forms within the habitat– often caused by human development
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
• Habitat corridors are a solution to the problem.
– corridors can be road overpasses or underpasses– allow species to move between different areas of
habitat
16.1 Human Population Growth And Natural Resources
Introduced species can disrupt stable relationships in an ecosystem.
• An introduced species is one that is brought to an ecosystem by humans.– accidental– purposeful
• Invasive speciescan have anenvironmentaland economicimpact.
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
Invasive species often push out native species.
Burmese python (Florida Everglades) & mice (Australia)
kudzu (southeastern United States)
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16.1 Human Population Growth And Natural Resources
List reasons that biodiversity is important to humans
• A loss of diversity could mean a loss of food, medicine, and economic activity
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16.1 Human Population Growth And Natural Resources
How does habitat fragmentation affect migrating bird populations?
• Birds need large areas of land or water on which to rest and feed during long migrations.
• If these habitats aren’t available they may not be able to complete a migration
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
What types of damage can introduced species cause?
• Introduced species can disrupt ecosystems, threaten human health, and physically dominate or overtake waterways and human-made structures
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
How could continued fragmentation reduce biodiversity?
• If species are cut off from habitats they need for survival or reproduction, they could become extinct, thereby reducing biodiversity
16.4 Threats to biodiversity
16.1 Human Population Growth And Natural Resources
Due Wednesday: In your Study guide WorkbookChapters 13 & 14
Pages Numbers
133 1-5
134 10
135 All
137-144 All
145-146 1-6
147 1-5
148 7-10
150 6-13
151 1-4
152 6-9
153-154 1 & 4
Chapters 15 & 16
Pages Numbers
155-156 All
157 1-4
158 All
161 5-6
162 all