population clock
TRANSCRIPT
Population Clock
http://www.census.gov/main/www/popclock.html
Human Numbers Through Time: A.D. 0
Taken from Nova online
300 million
A.D. 1000
310 million
1800
1 billion65% Asia, 21% Europe, 1% North America
1927
2 billion
1960
3 billion
1974
4 billion
1987
5 billion
1999
6 billion62% Asia, 12 % Europe, 12% Africa, 9% Latin America, 5% N. America
2050
Population will more than likely will reach 9 billion peopleNearly all growth will take place in developing countries
PGR: increase in a country’s population during a period of time (1 year).
PGR = birth rate – death rate
+ +
immigrants emigrants
Rapid PGR: Africa and Middle EastSlowest PGR: Europe and North America
Average Annual Population Growth Rate, 1980-98
1980: 4.4 Billion2000: 6 Billion
Population (shown in millions)
In the past few decades…
• Death rates have declined – Living longer in both industrial and developing countries
immunization, health care, technology– Avg life expectancy: 78
• Birth rates have declined– Parents are choosing to have less children– Access to family planning– More women starting families later in life
* PGR remain high though because birth rates have not fallen as much as death rates
• PGR have started to decline• But will continue to increase because the population
base has become larger. • Growth rates tend to be higher in low and middle-
income
Population Growth Rate
Population momentum• Phenomenon that occurs when a large proportion of a country’s
population is of childbearing age. • Occurs in low-income countries• More than a third of the population is under the age of 15
Why so many children?
• Fear their babies may die• Need laborers to work• Ensure that they themselves will
be cared for in their old age• Lack access to education and to
family planning
To reduce fertility rates
1. Greater access to primary health care and family planning services
2. Receive a basic education (esp. girls and women)
3. Have government serviced that help protect them when sick, old, unemployed
Are we going to reach a carrying capacity?
• Carrying capacity: number of individuals the environment can support over a long period of time
• Some say we have already exceeded the carrying capacity
• Others say billions more can be sustained on earth
• Consensus– World population will continue to grow until after
the middle of this century– Peak of some 9 billion– Perhaps declining in the latter years
What controls population size?
• Density-Independent Factors– Weather, floods, fire– Reduce population by the same proportion
regardless of size
• Density-Dependent Factors– Shortages of food, shelter– Triggered by increasing population density
In groups of 2 or 3, answer the following (in complete sentences)
1. What do you think daily life might be in your town in 2050 when there are 9.2 billion people on this planet?
2. What types of technological changes will be needed to accommodate the world’s growth?
3. What do you think will be the greatest environmental concerns at that time?
4. Do you see population growth becoming a major political issue by 2050? Why or why not? What types of population issues might people be talking about at that time?