04-17-2007, 11:43 AM
Human Population Growth
According to an article by Joel E. Cohen in the September 2005 issue of Scientific American:
"... The year 2005 is the midpoint of a decade that spans three unique, important transitions in the history of humankind.
* Before 2000, young people always outnumbered old people. From 2000 forward, old people will outnumber old people.
* Until approximately 2007, rural people will have always outnumbered urban people. From approximately 2007 forward, urban people will outnumber rural people.
* From 2003 on, the median woman worldwide had, and will continue to have, too few or just enough children during her lifetime to replace herself and the father in the following generation.
The century with 2000 as its midpoint marks three additional, unique, important transitions in human history.
* First, no person who died before 1930 had lived through a doubling of the human population. Nor is any person born in 2050 or later likely to live through a doubling of the human population. In contrast, everyone 45 years or older today has seen more than a doubling of human numbers from three billion in 1960 to 6.5 billion in 2005. The peak population growth rate ever reached, about 2.1 percent a year, occurred between 1965 and 1970. Human population never grew with such speed before the 20th century and is never again likely to grow with such speed. Our descendants will look back on the late 1960s as the most significant demographic event in the history of the human population ...
* Second, the dramatic fall since 1970 of the global population growth rate to 1.1 or 1.2 percent a year today resulted primarily from choices by billions of couples around the world to limit the number of children born. ... Never before the 20th century has a fall in the global population growth rate been voluntary [ as opposed to plagues, wars, etc ] ...
* Finally, the last half a century saw, and the next half a century will see, an enormous shift in the demographic balance between the more developed regions of the world and the less developed ones. Whereas in 1950 the less developed regions had roughly twice the population of the more developed ones, by 2050 the ratio will exceed six to one.
... By 2050 the world's popuylation is projected to reach 9.1 billion, plus or minus two billion people, depending on future birth and death rates. ... humans are already growing enough cereal grains to feed 10 billion people a vegetarian diet. ... ".
According to an article by Joel E. Cohen in the September 2005 issue of Scientific American:
"... The year 2005 is the midpoint of a decade that spans three unique, important transitions in the history of humankind.
* Before 2000, young people always outnumbered old people. From 2000 forward, old people will outnumber old people.
* Until approximately 2007, rural people will have always outnumbered urban people. From approximately 2007 forward, urban people will outnumber rural people.
* From 2003 on, the median woman worldwide had, and will continue to have, too few or just enough children during her lifetime to replace herself and the father in the following generation.
The century with 2000 as its midpoint marks three additional, unique, important transitions in human history.
* First, no person who died before 1930 had lived through a doubling of the human population. Nor is any person born in 2050 or later likely to live through a doubling of the human population. In contrast, everyone 45 years or older today has seen more than a doubling of human numbers from three billion in 1960 to 6.5 billion in 2005. The peak population growth rate ever reached, about 2.1 percent a year, occurred between 1965 and 1970. Human population never grew with such speed before the 20th century and is never again likely to grow with such speed. Our descendants will look back on the late 1960s as the most significant demographic event in the history of the human population ...
* Second, the dramatic fall since 1970 of the global population growth rate to 1.1 or 1.2 percent a year today resulted primarily from choices by billions of couples around the world to limit the number of children born. ... Never before the 20th century has a fall in the global population growth rate been voluntary [ as opposed to plagues, wars, etc ] ...
* Finally, the last half a century saw, and the next half a century will see, an enormous shift in the demographic balance between the more developed regions of the world and the less developed ones. Whereas in 1950 the less developed regions had roughly twice the population of the more developed ones, by 2050 the ratio will exceed six to one.
... By 2050 the world's popuylation is projected to reach 9.1 billion, plus or minus two billion people, depending on future birth and death rates. ... humans are already growing enough cereal grains to feed 10 billion people a vegetarian diet. ... ".