Europe and Japan—birth rates are declining due to couples choosing to have fewer or no children.
Russia - The end of the Soviet Union caused economic collapse. Death rates have risen dramatically and the birth rate is among the lowest in the world.
Africa - the AIDS epidemic has hit Africa the hardest. In Zimbabwe, Botswana, Zambia and Namibia, up to 39% of the population is HIV positive. More than 2/3 of the 15 yr. olds now living will die of AIDS before age 50. Life expectancy in Botswana has dropped to 31.6 years.
AIDS in South Africa
Population Density Around the World
Note that population is not distributed equally around the globe.
Crude Birth Rate - Number of births in a year per thousand. (Not adjusted for population characteristics such as number of women of childbearing age.)
Total Fertility Rate - number of children born to an average woman in a population during her life
Zero Population Growth - Occurs when births plus immigration in a population equal deaths plus emigration. ZPG Is a rate of 2.1 children per couple, not 2.0, because some people do not have children and some children do not survive to reproductive age.
Decline in Fertility Rates Worldwide
Fertility rates have declined everywhere except in Africa.
China’s one child policy has decreased the fertility rate from 6 in 1970 to 1.54 in 2010.
Education and socioeconomic status are usually inversely related to fertility in wealthier countries.
Birth Reduction Pressures
In developing countries, higher income often means families can afford more children, thus fertility often increases, rather than decreasing as it does in developed countries.
In less-developed countries, adding another child to a family usually does not cost much, while in developed countries, raising an additional child can carry significant costs.
A Century of US Birth Rates
Could We Have a Birth Dearth?
Most European countries, as well as Japan, Singapore and Taiwan, are experiencing negative growth rates.
There are concerns in all these countries about a lack of young people to be soldiers, workers, and taxpayers.
One reason that birth rates may have dropped in developed countries is that toxins and endocrine disrupters that are pollutants interfere with sperm production. Sperm numbers and quality have fallen by half in the last 50 years.
Pattern of falling death rates and birth rates due to improved living conditions accompanying economic development.
Pre-Modern Society - Poor conditions keep death rates high; birth rates are correspondingly high. (Stage I)
Economic Development brings better standard of living thus death rates fall. Birth rates stay constant or even rise. (Stage II)
Demographic Transition (continued)
In a mature industrial economy, birth rates begin to fall as people see that most of their children survive. (Stage III)
Populations continue to grow due to population momentum.
Developed Countries - Transition is complete and both death and birth rates are low and population is in equilibrium. (Stage IV)
Demographic Transition Happening Now?
Four conditions necessary for demographic transition:
improved standard of living
confidence that children will survive
improved status of women
availability and use of birth control
Some demographers think that a demographic transition is taking place now in developing nations.
Demographic Transition Now?
Others take a more pessimistic view. Lester Brown warns that poorer countries may be caught in a demographic trap.
The population is growing so rapidly that there are not enough resources to complete modernization and enter stage IV.
Still other demographers believe that in order for the demographic transition model to work, resources must be distributed more equitably.
They believe that the world has enough natural resources, but inequitable social and economic systems cause maldistribution.
Many rich countries, when they were colonial powers, extracted the wealth from countries that were their colonies. Some of the world’s poorest countries had rich resources and adequate food supplies before they were impoverished by colonialism.
We should consider the rights of other species.
Perhaps, rather than asking what is the maximum number of people that Earth can hold, we should instead ask what is the optimum number of people at which we can provide a fair and decent life for all humans while causing the minimum impact on other species.