Environmentalists argue that you are living when the critical decisions will be made that affect the long-term status of

2. Environmentalists argue that you are living when the critical decisions will be made that affect the long-term status of the planet, driven by human population This graph shows that as resources are depleted, global food production and industrial output falls, leading to a drop in population after 2030This graph shows that as resources are depleted, global food production and industrial output falls, leading to a drop in population after 2030

5. Population--Density People are unevenly distributed over the globe. Populations are clumped at all spatial scales. At the largest scales- lowest populations in extreme biomes such as deserts, deep rainforest, and tundra- high pop in subtropical and tropical climates from Europe to China to Mexico to Southern Africa to India. At small scales, we cluster in certain neighborhoods and individual families.People are unevenly distributed over the globe. Populations are clumped at all spatial scales. At the largest scales- lowest populations in extreme biomes such as deserts, deep rainforest, and tundra- high pop in subtropical and tropical climates from Europe to China to Mexico to Southern Africa to India. At small scales, we cluster in certain neighborhoods and individual families.

10. 5 great things to do this week How many people were there on earth when you were born? http://www-popexpo.ined.fr/eMain.html What is your ecological footprint? http://www.earthday.org/footprint/index.asp Have the salmon come in yet? Visit Nimbus Hatchery, Hwy 50 The smell of autumn Visit Stebbins Cold Canyon Reserve Hear a world�s leading ecologist speak Illka Hanski; Storer Lecture; 4:10PM Th,

15. Demographic transition is happening around the world

16. 1998 UN Population Projections:

18. Contraceptive programs work

19. Decreasing poverty works

20. Human Population

21. What is Human Carrying Capacity?

22. Example Quiz questions Recent trends in human population suggest that it is increasing linearly increasing at a rate that is increasing decreasing because of an aging population structure Increasing more than linearly, but decreasing in the rate that it is increasing Closing in on a carrying capacity threshold The total population that can be sustained by the environment of a species is called the: Carrying capacity Population maximum Density ceiling Maximum fecundity True / False. Most African countries are not any where near completing the process of demographic transition in human population growth.

24. Some key related issues from Chapter 1 Thomas Malthus and An Essay on the Principle of Populations Paul Ehrlich and The Population Bomb Garrett Hardin and The Tragedy of the Commons Wackernagel and Rees and The Ecological Footprint

25. Learning objectives for human population segment You should be able to: Describe past, current and predicted future human population size. Describe the geographical distribution of human populations, including the geography of wealth and education Describe what limits populations and carrying capacity Explain demographic transition Explain population doubling time and recent trends in population doubling times Understand forces driving population growth and changes in growth rates Enunciate arguments for and against funding the UNFPA

26. The Opposing View The "Sucker" Punch of the Overpopulation Myth --- Kevin Roeten ; http://www.opinioneditorials.com/guestcontributors/kroeten_20060921.html Myth #1: �Population growth is adding overwhelming numbers of humans to a small planet.� In fact, even though we cluster together to exchange goods and services, humans occupy only 1-3% of the earth�s land surface. If you allotted 1250 ft2 to each person, all the people in the world would fit into the state of Texas. But forecasts of eventual world population size have been steadily falling. In 1992, the World Bank predicted 10 billion by the year 2050. In 1996, the UN predicted 9 billion. If the observed trend continues, the next estimate will be much lower. Myth #2: �Overpopulation is Causing Global Warming.� In fact, 79 scientists issued the �Leipzig Declaration� saying ��there does not exist today a general scientific consensus about�greenhouse warming.� It�s interesting that many respected climatologists vigorously dispute a global warming danger. Myth #3: �Overpopulation causes ozone depletion.� Actually there�s enough information here for a whole column, but S. Fred Singer (atmospheric physicist) calls the ozone scare a �misuse of science�. Myth #4: �The world�s forests are disappearing because of overpopulation�. In fact, annual forest growth today is more than 3.5x what it was in 1920. Now, trees are growing 33% faster than they are being cut. Myth #5: �Air pollution is the result of overpopulation, and acid rain, a byproduct of air pollution, is destroying lakes, rivers, and forests.� Actually in the US, air pollution is declining significantly. The National Acid Precipitation Assessment Program recently reported �no widespread forest or crop damage in the US� related to acid rain. Myth #6: �Many plants and animals are disappearing because of the growth in human numbers.� This claim has no scientific data whatsoever to support it. Actually, some species such as blue whales, spotted owls, and black footed ferrets have been found to be more numerous than was once thought. Myth #7: �Overpopulation is threatening the world�s food supply.� According to the Food and Agriculture Organization, world food supplies exceed requirements in all areas. Myth #8: �Overpopulation is the chief cause of poverty.� Problems are almost always due to bad economic policy. The Ethiopian famine, for instance, was caused by its government confiscating the food stocks of traders and farmers and exporting them to buy arms. Myth #9: �Overpopulation causes war and revolution.� The most war-torn continent on earth�Africa�is also one of the least densely populated. 

27. Current Population------

30. Most future growth is predicted to occur in developing countries of Africa and Asia and, contrary to the past, will be mostly urban populations

31. Ethical Issues If you believe that human population pressure drives most of our current environmental concerns, and that these concerns speak to global welfare, then it is in the interest of all of humanity to slow population growth and stabilize it at a level lower than the current 6 billion If you believe that population is a source of innovation, industry, power and wealth, then the developed world asking the developing world to slow growth is cultural imperialism.

32. The background for this problem arises from the population crisis of Europe in the 18th and 19th centuries (Industrial Revolution).

33. 4) Human Demography Demography - vital statistics about people, such as births and deaths Two demographic worlds Less-developed counties represent 80% of the world population, but more than 90% of projected growth Richer countries tend to have negative growth rates

34. Fertility and Birth Rates Fecundity - physical ability to reproduce Fertility - the actual production of offspring Crude birth rate - number of births per year per thousand people Total fertility rate - number of children born to an average woman during her reproductive life Zero population growth (ZPG) - occurs when births + immigration just equal deaths + emigration

35. Factors to consider for predicting population growth Birth /Fertility rate Mortality rate (particularly juvenile mortality) Average age of first reproduction Age structure of the population

40. Factors to consider for predicting population growth Birth / Fertility rate Age structure of the population Mortality rate (particularly juvenile mortality). Decreasing globally Average age of first reproduction Increasing age of first reproduction lengthens generation time and slows growth

42. Leeuwenhoek, 1679 Estimated maximum human population to be 13.4 billion Extrapolated density of Holland, which he presumed to be saturated, to the rest of the world. Just about dead on the median estimate today

43. Living off reserves arguments Ehrlich et al (1993). <<< 5.5 billion. We are currently maintaining agricultural yields at the expense of fossil fuels and topsoil. Yield without these would be much less Pimentel et al. 1994. 3 billion Using only solar energy to meet the needs of the world

44. Single resource constraints DeWit (1967) 1,027 billion All photosynthetic potential of earth placed into plant growth and all of this plant growth set to feed humanity

45. Satirical projections Fremlin (1964) 1,000,000,000,000,000,000 120 people/ sq m, body heat alone would raise the temperature to 1000 C, this would challenge our ability to cool earth. Buildings would melt, water would boil off and we would all die.

46. Bottom Line We do not have sufficient forecasting ability of technology to know when we hit the ceiling for energy that can be applied toward human consumption. We know there is a ceiling. Cessation of human population growth will be because: Humans choose zero population growth, or Humans lack the ability to stem a population decline (ie disease, war)

47. Bottom Line The level of a sustainable human population is largely a matter of quality of life. Many more people can be supported through existing energy supplies if we do not: Use energy for transportation Use electricity at all Eat meat

49. Consumption: FOOD Production, globally continues upward Productivity per acre has stopped increasing in US, but many regions continue to improve Fewer acres in production in US and Europe than 100 years ago.

50. Meat is expensive Every 16 kg of grain fed to an animal in a feedlot produces ~ 1 kg of edible meat. Eating grain directly results in 21 times more calories and 8 times more protein than meat consumption

51. Sustainability and Resources Sustainability - we should use resources in ways that do not diminish them Resources - anything that is useful for creating wealth or improving our lives Sustainable development: �meeting the needs of the present without compromising the ability of future generations to meet their own needs�*

52. Review Population has reached 6.5 billion The world strongly varies with respect to density, population growth and the timing of demographic transition. For the purposes of this class, we will assume that population increase has to reach some stability � we can�t double forever. Population control is fraught with social justice issues. Many factors contribute to less than maximum reproductive rate; reproductive choice is one of these reasons Demographic transition naturally happens as people shift their livelihoods from rural agriculture to urban jobs. The UN now thinks population may stabilize at < 10 billion. The world remains dominated by young people.