Transcript carrying capacity

List 4 Environmental Problems you’re concerned about
List 4 Environmental Problems you’re concerned about
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Climate change
Global warming
Sea level rise
Species extinction
Endangered species
Habitat destruction
Desertification
Ozone depletion
Acid rain
Oil spills
Air pollution
Deforestation
What is the ultimate cause
of these problems?
Human Population Growth
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
How Do Living Things Grow in Nature?
Logistic Growth
Animal Population
Exponential Growth
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
How Does human Population Grow?
1. What type of growth pattern (logistic growth or
exponential growth) is exhibit by human population?
Exponential growth
2. What is the carrying capacity for human population?
Human population have not reached the
carrying capacity yet.
3. What are the limiting factors for human growth?
Food, water, space, diseases.
4. In 1650 the world population reached 0.5 billion people. How long did it take for the
200 years
population to double? ________________________
75 years
How long did it take for the population to double a second time? ______________
51 years
And a third time? _____________________________________
5. Based on your graph, in what year will the population reach 8 billion? 2020
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
How Does human Population Grow?
Industrial
Revolution
begins
Agriculture
begins
Plowing
and
irrigation
Bubonic
plague
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
The Earth’s Carrying Capacity
Prior to 1950, the death rate was high, which kept the numbers of humans from increasing rapidly. In the 19th Century,
the agricultural revolution increased food production. The industrial revolution improved methods of transporting food
and other good. In the 20th Century, advances in medicine, sanitation and nutrition have decreased the death rates
further. These factors combined to produce the rapid growth of the human population in the 20th century.
As with any population, humans are also limited by factors such as space, amount of food and disease. The carrying
capacity is the number of individuals that a stable environment can support. Authorities disagree on the maximum
number of people that the earth can support, though the numbers generally range for 8 to 10 billion. As the population
approaches its limit, starvation will increase. Some countries have a much higher growth rate than others. Growth rate is
the number of people born minus the number of people that die. Compare the growth rates of the following countries
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
1. What factors contributed to the world’s overall population growth in the last 150 years?
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The agricultural revolution has increased the food production.
The industrial revolution improved methods of transporting for goods and food
Advances in medicine, sanitation, and nutrition decreased the death rates.
2. What are limiting factors? List 3 limiting factors for humans.
Limiting factors are biotic or abiotic factors that limits the size of a population.
Three limiting factors for humans are space, amount of food & water, and diseases.
3. What is carrying capacity?
What is the estimate human carrying capacity on Earth?
Carrying capacity is the number of individuals that a stable ecosystem can support.
The estimate human carrying capacity is between 8 and 10 billions of people.
4. What will happen when the human population exceeds the earth’s carrying
capacity?
Starvation will increase.
5. What is the effect of human population growth on natural resources?
As human population increases, natural resources will decrease because a growing
demand on natural resources.
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
Regents Questions
1. The average life expectancy of humans in the United States increased from 63.3 years in 1943 to 77.6
years in 2003. This, combined with other factors, has led to an increase in population.
State one factor that contributed to the described increase in human life expectancy in the United States.
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2. Which factor is primarily responsible for the destruction of the greatest number of habitats?
A) extinction of species
B) loss of biodiversity
C) human population growth
D) water pollution
3. The negative effect humans have on the stability of the environment is most directly linked to an
increase in
A) predation and disease
B) supply of finite resources
C) human population size
D) recycling activities by humans
4. Which of the following long-term changes could directly cause the other three?
A) depletion of resources
B) increasing human population
C) global warming
D) pollution of air and water
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
Regents Questions
5. Ecologists are concerned that the human population has outgrown the capacity of many ecosystems on
the Earth. Which natural limiting factor will most likely prevent further human population growth in
many parts of the world?
A) democracy
B) political intervention
C) food supply
D) social intervention
6. The increased growth of the human population over the past 300 years is most likely due to
A) a decrease in pesticide use
B) the removal of natural checks on the population
C) a decrease in the amount of farmland
D) the elimination of predator populations
Objective: Understand How Human Population Growth Relates to Environmental Problems
Key Words: logistic growth, exponential growth
Population Growth
•In a new environment the population increase quickly, but it stabilizes when it reaches the carrying
capacity of that environment.
•Human population is growing rapidly. Result of medical knowledge and education, which have decreased
the death rate from disease.
•Earth’s human carrying capacity could be reached soon. Result could be catastrophic: famine, disease or
wars.
The graphs at the right show the size of the human population
in relation to food production per acre in four different
countries over the same period.
Which country survived the longest without the need for food
imports?