growth of human populations

the rate of growth

Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960.

human population numbers

Human population growth over the past 10,000 years has been tremendous (Figure 1.1). The entire human popula- tion was estimated to be 5 million in 8000 B.C. 300 million in A.D. 1 1 billion in 1802 3 billion in 1961 7 billion in 2011 As the human population continues to grow, different factors limit population in different parts of the world. What might be a limiting factor for human population in a particular location? Space, clean air, clean water, and food to feed everyone are limiting in some locations.

instructional diagrams

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questions

human population reached its first billion in which year?

``````a) 8000 b.c.

b) a.d. 1

-->  c) 1802

d) 1961
``````

in 2011, the human population increased to _____.

``````a) 1 billion

b) 3 billion

c) 5 billion

-->  d) 7 billion
``````

by the end of the 21st century, the human population is estimated to reach

``````-->  a) 10 billion

b) 9 billion

c) 8 billion

d) stay the same
``````

which can contribute to overpopulation?

``````a) high mortality rate

-->  b) low mortality rate

c) decreased birth rate

d) none of the above.
``````

human population grows because

``````a) much of the human population is young and will have children.

b) people are living much longer than in the past.

c) more children survive to have children than in the past.

-->  d) all of these
``````

the rate at which the human population is growing is decreasing.

``````a) true

-->  b) false
``````

limiting factors on human population in local regions include

``````-->  a) space, clean air, clean water and food.

b) disease.

c) predators.

d) nothing. there are as yet no regions where human population is limited.
``````

limiting factors on human population worldwide include

``````a) space, clean air, clean water and food.

b) disease.

c) predators.

-->  d) nothing. there are as yet no limiting factors on human population growth worldwide.
``````

by the end of the 21st century, the human population is expected

``````a) to decrease by 3 billion.

-->  b) to increase by more people than were even alive in 1960.

c) to increase by 10.1 billion.

d) none of the above.
``````

as for future population growth

``````a) the population is decreasing.

b) the rate of growth of the population is decreasing.

-->  c) the rate that the rate the population is growing is decreasing.

d) none of the above.
``````

diagram questions

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