Name: Yuzhu Gong Due Date: 2015/11/08
Article Title: Human Population Grows Up
Author/Source: Scientific American
Article Title: Human Population Grows Up
Author/Source: Scientific American
A: List major ideas, concepts or key points - point by point
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.
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.
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 the first absolute increase in population by one billion people took from the beginning of time until the early 19th century, one billion people will be added to today’s population in only 13 to 14 years.
Poor countries’ populations grow faster than rich countries’ populations because birth rates in poor countries are much higher.
This crossover in the proportions of young and old reflects both improved survival and reduced fertility.
The more powerful influence, however, is reduced fertility, adding smaller numbers to the younger age groups.
Early efforts to calculate Earth’s human carrying capacity assumed that a necessary condition for a sustainable human society could be measured in units of land.
This approach has many problems. Perhaps the most serious is its attempt to establish a necessary condition for the sustainability of human society in terms of the single dimension of biologically productive land area.
Other one-dimensional quantities that have been proposed as ceilings on human carrying capacity include water, energy, food and various chemical elements required for food production.
The difficulty with every single index of human carrying capacity is that its meaning depends on the value of other factors.
Attempts to quantify Earth’s human carrying capacity or a sustainable human population size face the challenge of understanding the constraints imposed by nature, the choices faced by people and the interactions between them.
Human population size drop by billions when the climate becomes unfavorable, they may regard a much larger population as sustainable when the climate is favorable.
A plot of land may have a low carrying capacity, not because of low soil fertility but because it is sacred or inhabited by ghosts.
No scientific estimates of sustainable human population size can be said to exist.
Major cities were est. in regions of exceptional agricultural productivity. If the urban population doubles in the next half a century from 3 billion to 6 billion, while the world's rural population remains roughly constant at three billion, and if many cities expand in area rather than in density, agricultural lands could be removed.
Urbanization will interact with the transformation of human societies by aging.
Cities raise the economic premium paid to younger, better-educated workers whereas the mobility they promote often weakens traditional kin networks that provide familial support to elderly people.
Better education in youth is associated with better health in old age.
One obvious strategy to improve the sustainability of the coming wave of older people is to invest in educating youth today, including education in those behaviors that preserve health and promote the stability of marriage.
Another obvious strategy is to invest in the economic and social institutions that facilitate economic productivity and social engagement among elderly people.
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.
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.
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 the first absolute increase in population by one billion people took from the beginning of time until the early 19th century, one billion people will be added to today’s population in only 13 to 14 years.
Poor countries’ populations grow faster than rich countries’ populations because birth rates in poor countries are much higher.
This crossover in the proportions of young and old reflects both improved survival and reduced fertility.
The more powerful influence, however, is reduced fertility, adding smaller numbers to the younger age groups.
Early efforts to calculate Earth’s human carrying capacity assumed that a necessary condition for a sustainable human society could be measured in units of land.
This approach has many problems. Perhaps the most serious is its attempt to establish a necessary condition for the sustainability of human society in terms of the single dimension of biologically productive land area.
Other one-dimensional quantities that have been proposed as ceilings on human carrying capacity include water, energy, food and various chemical elements required for food production.
The difficulty with every single index of human carrying capacity is that its meaning depends on the value of other factors.
Attempts to quantify Earth’s human carrying capacity or a sustainable human population size face the challenge of understanding the constraints imposed by nature, the choices faced by people and the interactions between them.
Human population size drop by billions when the climate becomes unfavorable, they may regard a much larger population as sustainable when the climate is favorable.
A plot of land may have a low carrying capacity, not because of low soil fertility but because it is sacred or inhabited by ghosts.
No scientific estimates of sustainable human population size can be said to exist.
Major cities were est. in regions of exceptional agricultural productivity. If the urban population doubles in the next half a century from 3 billion to 6 billion, while the world's rural population remains roughly constant at three billion, and if many cities expand in area rather than in density, agricultural lands could be removed.
Urbanization will interact with the transformation of human societies by aging.
Cities raise the economic premium paid to younger, better-educated workers whereas the mobility they promote often weakens traditional kin networks that provide familial support to elderly people.
Better education in youth is associated with better health in old age.
One obvious strategy to improve the sustainability of the coming wave of older people is to invest in educating youth today, including education in those behaviors that preserve health and promote the stability of marriage.
Another obvious strategy is to invest in the economic and social institutions that facilitate economic productivity and social engagement among elderly people.
B: Summarize the author's main point or idea
Summary of Author's Main Points:
There are a lot of changes in human population's demographics. By 2050, the divide between developed and developing countries will be bigger. The world's population will be older, bigger, more urban, and slower-growing. In contrast, 51 countries or areas, most of them economically more developed, will lose population between now and 2050. Slowing population growth everywhere means that the 20th century was probably the last in human history in which younger people outnumbered older ones. This crossover in the proportions of young and old reflects both improved survival and reduced fertility. Humans have been worrying about overpopulation since ancient times. Many megacities were established in regions of exceptional agricultural productivity, typically the floodplains of rivers, or in coastal zones and islands with favorable access to marine food resources and maritime commerce. Right now the most densely settled half of the planet’s population lives on 2 to 3 percent of all ice-free land. No one knows the path to sustainability because no one knows the destination, if there is one. But we do know much that we could do today to make tomorrow better than it would be if we do not put our knowledge to work.
Summary of Author's Main Points:
There are a lot of changes in human population's demographics. By 2050, the divide between developed and developing countries will be bigger. The world's population will be older, bigger, more urban, and slower-growing. In contrast, 51 countries or areas, most of them economically more developed, will lose population between now and 2050. Slowing population growth everywhere means that the 20th century was probably the last in human history in which younger people outnumbered older ones. This crossover in the proportions of young and old reflects both improved survival and reduced fertility. Humans have been worrying about overpopulation since ancient times. Many megacities were established in regions of exceptional agricultural productivity, typically the floodplains of rivers, or in coastal zones and islands with favorable access to marine food resources and maritime commerce. Right now the most densely settled half of the planet’s population lives on 2 to 3 percent of all ice-free land. No one knows the path to sustainability because no one knows the destination, if there is one. But we do know much that we could do today to make tomorrow better than it would be if we do not put our knowledge to work.
C: Reaction to the article
My Own Thoughts on the Topic:
Populations are growing world wide, there are problems associated with that, for instance, the resources, because if we have more people on the planet and everybody needs food to survive, then eventually we are going to reach a carrying capacity, which at that time, the population decreases. And also the economic burden imposed by elderly people will depend on their health, on the economic institutions available to offer them work, and on the social institutions on hand to support their care. Troubles emerge when it comes to overpopulation, what domestic and international political institutions will be used to resolve conflicts? What social and demographic arrangements will influence birth, health, education, marriage, migration and death? We still need to figure out these problems as population increases. Virtually everything that needs doing from a population point of view needs doing anyway.
My Own Thoughts on the Topic:
Populations are growing world wide, there are problems associated with that, for instance, the resources, because if we have more people on the planet and everybody needs food to survive, then eventually we are going to reach a carrying capacity, which at that time, the population decreases. And also the economic burden imposed by elderly people will depend on their health, on the economic institutions available to offer them work, and on the social institutions on hand to support their care. Troubles emerge when it comes to overpopulation, what domestic and international political institutions will be used to resolve conflicts? What social and demographic arrangements will influence birth, health, education, marriage, migration and death? We still need to figure out these problems as population increases. Virtually everything that needs doing from a population point of view needs doing anyway.