1 / 49

Increasing Human Population

Increasing Human Population. The Greatest Environmental Problem Spring 2012, Lecture 2. US Census Bureau Population Estimate. Click link below to see Latest Census Bureau Estimate of U.S. and World Populations. United State Population Clock. World Population Clock.

afya
Download Presentation

Increasing Human Population

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. Increasing Human Population The Greatest Environmental Problem Spring 2012, Lecture 2

  2. US Census Bureau Population Estimate Click link below to see Latest Census Bureau Estimate of U.S. and World Populations United State Population Clock World Population Clock

  3. United Nations Population Division – 2012 Estimates In thousands

  4. 2050 Population Estimates In thousands

  5. Thomas Malthus (1798) “An Essay on the Principle of Population” • Populations grow geometrically while supporting resources grow arithmetically • Population, if not purposefully checked (“preventative checks”), would outpace resources and lead to unplanned “positive checks” that would return population to sustainable levels

  6. Significant Developments and Human Population

  7. Recent Population Explosion • Detailed look at the last thousand years

  8. Crop Yield and Fertilizer Input • “Green revolution”: • high-yielding crop varieties • chemical fertilizers • pesticides • irrigation • mechanization Global Fertilizer use

  9. Humans Have: • Transformed or degraded 39-50% of the Earth's land surface • Increased atmospheric CO2 concentration by 40% • Overexploited or depleted 22% of marine fisheries • 44% more are at the limit of exploitation

  10. New South Wales, Australia Figure shows the trend in the total catch for marine fisheries in NSW since 1984–85.

  11. Changes Due to Man • About 20% of bird species have become extinct in the past 200 years, almost all of them because of human activity • Man uses more than half of the accessible surface fresh water • On many islands, more than half of plant species have been introduced by man • On continental areas, man has introduced 20% or more of the plant species present

  12. Human Activities • Over 50% of terrestrial nitrogen fixation is caused by human activity • Use 8% of the primary productivity of the oceans (25% for upwelling areas and 35% for temperate continental shelf areas)

  13. Changes Due To Man

  14. Population and Availability of Renewable Resources Total Per Capita 1990 2010 Change (%) Change (%) Population (millions) 5,290 7,030 33 Fish Catch (million tons) 85 102 20 -10 Irrigated Land 237 277 17 -12 (million hectares) Cropland (million hectares) 1,444 1,516 5 -21 Rangeland and Pasture 3,402 3,540 4 -22 (million hectares) Forests (million hectares) 3,413 3,165 -7 -30 Source: Postel, S. "Carrying capacity: Earth's bottom line." State of the World, 1994.

  15. Regional population patterns: Population density Consortium for International Earth Science Information Network.

  16. World 40 years Africa 23 years Kenya (fastest) 20 years Latin America 30 years Asia 36 years Doubling Times

  17. Doubling Time Map - 2000

  18. Worldwide Fertility, 2005 • Children per woman

  19. Reduction in Childhood Death Rates • DDT used against mosquitoes that transmit malaria • Childhood immunization used against cholera, diphtheria, etc. • Antibiotics used against bacterial infections

  20. Demographic Transitions • When a country moves from stage 1 of the demographic model to stage 2, a population explosion occurs • This transition occurs when technology and medical care improvements decrease a countries death rate dramatically while the birth rate stays the same; this causes the natural rate of increase to increase rapidly

  21. Demographic Transition -Sweden “Rate of Natural Increase”

  22. Demographic Transition -Mexico “Rate of Natural Increase”

  23. National Age Structures • The proportion of individuals in different age groups has a significant impact on the potential for future population growth • Mexico – large fraction of young people likely to reproduce in the near future • Sweden – even distribution of population through all age groups, and many people beyond prime reproductive years • United States – even distribution except for bulge due to post WWII baby boom

  24. Age Structures • Each horizontal bar is a five-year cohort • Blue = pre-reproductive, yellow – reproductive, and orange – post-reproductive

  25. People over 100 years old in U.S. 4,000 in 1970

  26. People over 100 years old in U.S. • 79,086 in 2010

  27. People over 100 years old in U.S. Projected 597,547 thousand in 2050

  28. Trends in U.S. Population

  29. 2008 Population Projections

  30. Global Income Distribution, 1960 - 1989 Source: United Nations Development Programme, Human Development Program, 1992 (New York, Oxford University Press, 1992)

  31. Global Income Distribution Graphic

  32. Global Wealth Pyramid, 2011

  33. Food Distribution Animation http://vimeo.com/moogaloop.swf?clip_id=8812686

  34. China - 20% of world’s population • Potential for rapid population growth • 2000:1,263,637,531

  35. China: "one-child-per-couple" policy since 1979 • Rewards for having only one child: grants, additional maternity leave, increased land allocations. Children get preferential treatment in education, housing, and employment. • Couples punished for refusing to terminate unapproved pregnancies, for giving birth when under the legal marriage age, and having an approved second child too soon. • Penalties include fines, loss of land grants, food, loans, farming supplies, benefits, jobs and discharge from the Communist Party. • In many provinces sterilization is required after the couple has had two children.

  36. China’s Population Policy Children per woman: 1970: 5.01 1995: 1.84 Population still growing! Population in 2000: 1.3 billion Projected for 2025: 1.5 billion Use of abortion Forcible abortions and sterilization Infanticide Criticisms:

  37. China 2025 • Approaching stabilization • 2025:1,394,638,699

  38. China 2050 • Possible decline in population • 2050:1,303,723,332

  39. India 2000: 1,006,300,297

  40. India 2025 • 2025 predicted: 1.396.046.308 • The base is narrower than the top

  41. India 2050 • 2050 predicted: 1,656,553,632 • A definite “baby-boom” shape • Note disparity male/female numbers

  42. U.N. Conference on Population (Cairo, 1994) "Programme of Action" (182 nations) Goal: to stabilize human population at 7.8 billion by 2050 1. Provide universal access to family-planning and reproductive health programs. 2. Recognize that environmental protection and economic development are not necessarily antagonistic. Promote free trade, private investment and development assistance. 3. Make women equal participants in all aspects of society - by increasing women's health, education, and employment. 4. Increase access to education. Provide information and services for adolescents to prevent unwanted pregnancies, unsafe abortion, and the spread of AIDS and sexually transmitted diseases. 5. Ensure that men fulfill their responsibility to ensure healthy pregnancies, proper child care, promotion of women's worth and dignity, prevention of unwanted pregnancies, and prevention of the spread of AIDS and sexually transmitted diseases.

  43. United Nations Population Fund (UNFPA) • Programs to improve: • Pre- and post-natal mother's health • Access to voluntary family planning programs and contraception • STD and HIV education and prevention • U.S. funding withheld for many years because of UNFPA’s support of China’s policies • U.S. funding restored for F.Y. 2000 at level of $25 million

  44. Slowing Population Growth • The HIV epidemic is measurably slowing population growth • Nowhere is this more evident than in sub-Saharan Africa, a region of 800 million people, where the epidemic is spiraling out of control • If a low-cost cure is not found soon, countries with adult HIV infection rates over 20 percent, such as Botswana, South Africa, and Zimbabwe, will lose one fifth or more of their adult population to AIDS within the next decade

  45. Slowing Population Growth • When the United Nation's demographers did their biennial update of world population numbers and projections in October of 1998, they reduced the projected global population for 2050 from 9.4 billion to 8.9 billion – in 2009, it is 9.1 billion • Of this 500 million drop, two thirds was because of falling fertility - that's the good news • The bad news is that one third of the fall was the result of rising mortality from AIDS

More Related