BESC 201 9 30 2013 Lecture 13 Outline of Last Lecture I International Environmental Policy Outline of Current Lecture II Chapter 6 Central Case Study III Our World At Seven Billion IV Demography Current Lecture 9 30 2013 Human Population Central Case Study China s One Child Policy The People s Republic of China is the world s most populous nation Chinese women gave birth to 5 8 children in her lifetime Chinese leaders realized that the nation might not be able to feed its people if their numbers grew much larger A control program was put in place beginning with education increased accessibility to contraception and abortion and eventually more enforced policies Growth rate dropped from 2 8 to 1 8 Most controversial social experiments in history Led to a trend of preferences of sons over daughters because they don t carry on the family name and are married of Our World at Seven Billion Most population growth is occurring in poverty stricken developing nations that are ill equipped to handle it Although the rate of human population growth is slowing our absolute numbers are still increasing The human population is growing rapidly Even if growth rate remains steady population size will increase by greater increments with each successive generation The growth rate of the human population has declined to 1 2 since the 1960s These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Can roughly estimate doubling times with a handy rule of thumb o Take the number 70 and divide it by the annual percentage growth rate Is there a limit to human population growth It s difficult to estimate the carrying capacity for humans because we are a successful species and have repeatedly overcome predicted limits by developing new technologies and ways to secure resources Under the view that many economists hold resource depletion due to population increase is not a problem if new resources can be found or created to replace depleted ones Unless the availability and quality of all resources keeps pace forever with population growth the average person in the future will have less space and a lower quality of life Population is one of the several factors that affect the environment IPAT Model represents how our total impact I on the environment results from the interaction among population P affluence A and technology T I P x A x T A fourth factor can also be added sensitivity S to denote how sensitive a given environment is to human pressure Demography Demography the application of principles from population ecology to the study of statistical change in human populations Demography is the study of human population Demographers study population size density distribution age structure sex ratio and rates of birth death immigration and emigration of people Population size A population s environmental impact depends on its density distribution and composition Population density and distribution Population density is highest in regions with temperate subtropical and tropical climates and lowest in regions with extreme climate biomes Human population is dense along seacoasts and rivers and less dense away from the water Age Structure Age structure describes the relative number of individuals of each age class within a population Age structure diagrams population pyramids are visual tools scientists use to illustrate age structure Populations are aging in many nations dramatic shift in age structure will challenge China s economy health care system families and military forces because fewer working age people will be available
View Full Document
Unlocking...