1 / 12

Human Population Growth

Human Population Growth. Christina Hull 210 The Dynamic Earth Dr. Michael Sandy. Present Population Status. In 2000, the world had 6.1 billion human inhabitants.

heloise
Télécharger la présentation

Human Population Growth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Human Population Growth Christina Hull 210 The Dynamic Earth Dr. Michael Sandy

  2. Present Population Status In 2000, the world had 6.1 billion human inhabitants. In the last 50 years, world population multiplied more rapidly than ever before, especially in underdeveloped and poverty-stricken countries.

  3. Fertility • The current growth of population is driven by fertility.  • Fertility is largely controlled by economics and by human aspirations. • The high fertility of a developing world can be partially explained by the large number of hands needed to perform low-technology agricultural tasks. In these areas, families with large numbers of children realize an enhanced economic status. • As technology improves, parents realize that having more children decreases rather than increases their standard of living.

  4. Mortality • In the developing world, the death rate has dropped, more or less continuously, since the start of the industrial revolution. • Personal hygiene and improved methods of sanitation have played a major role and preceded the impact of modern medicine and, in particular, the development of antibiotics capable of reducing death due to infection. • The combination of decreasing death rate due to the march of progress in sanitation and medicine, along with the fluctuating birth rate due to economic changes, has led to a profound change in the population growth curve in the developed world. This change is called the Demographic Transition.

  5. The Demographic Transition • Stage 1: Birth rates and death rates are both high. No demographic transition has occurred. • Stage 2: Standards of hygiene and more modern medical techniques began to drive the death rate down, leading to a significant upward trend in population size. The birth rate remained high, as much of the economy was based on agriculture. • Stage 3: Urbanization actively discouraged from having large families. In response to these economic pressures, the birth rate started to drop, ultimately coming close to the death rate. • Stage 4. The last stage of the demographic transition in Europe was characterized by a higher, but stable, population size. Birth and death rates were both relatively low and the standard of living became much higher than during the earlier periods. The developed world remains in the fourth stage of its demographic transition.

  6. The Demographic Transition

  7. The Demographic Transition Projected World Population Growth

  8. Future Global Population Growth • An eventual world population of 8-12 billion is expected by the end of the century.  • According to a report from the United Nations Population Fund, based on 1998 analyses, projections for the future global population are being revised downward.  The projection for 2050 now is 8.9 billion, substantially lower than the 1996 projection of 9.4 billion.  • The major reason for the lower projection is good news: global fertility rates have declined more rapidly than expected, as health care, including reproductive health, has improved faster than anticipated, and men and women have chosen to have smaller families.  • About one-third of the reduction, however, is due to increasing mortality rates in sub-Saharan Africa and parts of the Indian subcontinent. The most important factor is HIV/AIDS, which is spreading much faster than previously anticipated.

  9. Future Global Population Growth

  10. Is There Carrying Capacity For Human Beings? • Such growth cannot continue. If it does, every square foot of the Earth's surface will be taken up by a human within the next few hundred years. • Experience with other species tells us that resource limitations and/or habitat degradation will force the human population curves to approach an upper limit, or the carrying capacity.

  11. What Can Be Done? • Increase human productive capacities through technology and innovation • Reduce numbers and expectations of people through such means as family planning and vegetarian diets • Change the terms of people’s interactions through improved planning and government to enhance social justice.

  12. References • http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html • http://www.prb.org/Content/NavigationMenu/PRB/Educators/Human_Population/Population_Growth/Population_Growth.htm

More Related