Slide Human impact on Ecosystems

As the human population grows, the demand for Earth’s resources increases... Earth’s human population continues to grow.. Earth’s human carrying capacity is unknown... The growing human

I As the human population grows, the demand for

Earth’s resources increases

A Earth’s human population continues to grow

1 Earth’s human carrying capacity is unknown

2 Technology has helped to increase Earth’s carrying

capacity

a gas-powered farm equipment

b medical advancements

B The growing human population exerts pressure on

Earth’s natural resources

1 Nonrenewable resources are used faster than they form

a coal

b oil

2 Renewable resources cannot be used up or can replenish

themselves over time

4 Resources must

be properly managed

C Effective management of Earth’s resources will help

meet the needs of the future

1 Earth’s resources must be used responsibly

2 Careless use of resources makes them unavailable to

future generations

3 Easter Island is

an example of irresponsible resource use

4 An ecological footprint is the amount of land needed to

support a person

5 The land must produce and maintain enough

a food and water

b shelter

c energy

d waste

6 Several factors affect the size of the ecological footprint.

a amount and efficiency of resource use

b amount and toxicity of waste produced

II.Fossil fuel emissions affect the biosphere

A Pollutants accumulate in the air

1 Pollution is any undesirable

factor added to the air, water, or soil

2 Smog is one type of air

pollution

a sunlight interacts with

pollutants in the air

b pollutants produced by fossil

fuel emissions

c made of particulates and

ground-level ozone

3 Smog can be harmful to human health.

4 Acid rain is caused by fossil fuel emissions

a produced when pollutants in the water cycle cause

rain pH to drop

b can lower the pH of a lake or stream

c can harm trees

A Air pollution is changing Earth’s biosphere

1 The levels of atmospheric carbon dioxide rise and fall

over time

2 High levels of carbon dioxide are typical of Earth’s warmer

periods

3 The greenhouse effect slows the release of energy from

Earth’s atmosphere

a sunlight penetrates Earth’s atmosphere

b energy is absorbed and reradiated as heat

c greenhouse gases absorb longer wavelengths

d Greenhouse

gas molecules rerelease

infrared radiation

methane ( CH 4 ) water (H 2 O )

carbon dioxide

(CO 2 )

4 Global warming refers to the trend of increasing global

temperatures

North Pole

III Pollution of Earth’s freshwater supply threatens

habitat and health

A Water pollution affects ecosystems

1 Pollution can put entire freshwater ecosystems at risk

2 Indicator species provide a sign of an ecosystem’s health.

a amphibians

b top predators

B Biomagnification causes accumulation of toxins in the

2 Top consumers, including

humans, are most affected

IV The impact of a growing human population threatens

biodiversity

A Preserving biodiversity is important to the future of the

biosphere

1 The loss of biodiversity has long-term effects

a loss of medical and technological advances

b extinction of species

c loss of ecosystem stability

1 Habitat fragmentation prevents an organism from

accessing its entire home range

a occurs when a barrier forms within the habitat

b often caused by human development

2 Habitat corridors are a solution to the problem.

– corridors can be road overpasses or underpasses

– allow species to move between different areas of

habitat

C Introduced species can disrupt stable relationships in an

3 Invasive species often push out native species.

a Burmese python (Florida Everglades)

4 Invasive species often push out native species.

a mice (Australia)

a kudzu (southeastern United States)

V Conservation methods can help protect and restore

ecosystems

A Sustainable development manages resources for

present and future generations.

1 Sustainable development meets needs without hurting

future generations

a resources meet current needs

b resources will still be available for future use

2 The timber industry has started to adopt sustainable

B Conservation practices focus on a few species but

benefit entire ecosystems

1 The Endangered Species Act

works to protect individual species from extinction

2 A listed species is often called

an umbrella species

a the habitat in which the

species lives must be protected

b other species are protected

because they share the ecosystem

1 The Environmental Protection Agency (EPA) was created

a Clean Air Act

b Clean Water Act

c Endangered Species Act

4 The National Park

Service helps manage public lands

5 The park system

includes over 390 areas, covering 84 million

acres

6 There are several ways that people can help protect the

environment

a control population growth

b develop sustainable technology and practices

c protect and maintain ecosystems