human population

human population

How quickly is the human population growing? If we look at worldwide human population growth from 10,000 BCE through today, our growth looks like exponential growth. It increased very slowly at first, but later grew faster and faster as the population increased in size ( Figure 1.1). And recently, the human population has increased at a faster pace than ever before. It has taken only 12 years for the worlds population to increase from six billion to seven billion. Considering that in the year 1804, there were just one billion people, and in 1927, there were just two billion people (thats 123 years to increase from 1 to 2 billion), the recent increase in the human population growth rate is characteristic of exponential growth. Does this mean there are unlimited resources? Worldwide human population growth from 10,000 BCE through today.

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five stages

On the other hand, if you look at human population growth in specific countries, you may see a different pattern. On the level of a country, the history of human population growth can be divided into five stages, as described in Table 1.1. Some countries have very high birth rates, in some countries the growth rate has stabilized, and in some countries the growth rate is in decline. Stage 1 2 3 4 5 Description Birth and death rates are high and population growth is stable. This occurred in early human history. Significant drop in death rate, resulting in exponential growth. This occurred in 18th- and 19th-century Eu- rope. Population size continues to grow. Birth rates equal death rates and populations become stable. Total population size may level off. The United Nations and the U.S. Census Bureau predict that by 2050, the Earth will be populated by 9.4 billion people. Other estimates predict 10 to 11 billion.

future growth

There are two different beliefs about what type of growth the human population will undergo in the future: 1. Neo-Malthusians believe that human population growth cannot continue without destroying the environment, and maybe humans themselves. 2. Cornucopians believe that the Earth can give humans a limitless amount of resources. They also believe that technology can solve problems caused by limited resources, such as lack of food. The Cornucopians believe that a larger population is good for technology and innovation. The 5-stage model above predicts that when all countries are industrialized, the human population will eventually level out. But many scientists and other Neo-Malthusians believe that humans have already gone over the Earths carrying capacity. That means, we may have already reached the maximum population size that can be supported, without destroying our resources and habitat. If this is true, then human overpopulation will lead to a lack of food and other resources. Overpopulation may also lead to increased disease, and/or war. These problems may cause the population of humans to crash. If these issues are not controlled, could the human population go extinct? Which of the above theories makes sense to you? Why?

instructional diagrams

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questions

planet earth has unlimited resources.

a. true

-->  b. false

the human population is running out of resources, so it shows logistic growth.

a. true

-->  b. false

how long did it take for the human population to increase from 6 billion to 7 billion people?

a) 1 year

-->  b) 12 years

c) 25 years

d) 50 years

how long did it take for the human population to increase from 1 billion to 2 billion people?

a) about 25 years

b) about 50 years

c) about 100 years

-->  d) over 120 years

which is the first stage of human population growth?

a) population size continues to grow.

b) birth rates equal death rates and populations become stable.

-->  c) birth and death rates are high and population growth is stable.

d) total population size may level off.

which is the last stage of human population growth?

a) population size continues to grow.

b) birth rates equal death rates and populations become stable.

c) birth and death rates are high and population growth is stable.

-->  d) total population size may level off.

by the year 2050, how many people will inhabit the planet?

a) about 7 billion

b) about 8 to 9 billion

-->  c) about 9 to 11 billion

d) over 15 billion

diagram questions

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