Objectives:

1. Objectives: Discuss the major environmental problems and their root causes. Warm Up: What do you think are the largest environmental problems today? Climate change. Loss of biodiversity. Loss of our ozone shield.

2. The two root causes of these problems are • Overpopulation. • Over consumption.

3. POPULATION U.S. 305,457,863World 6,731,400,28010.20.08 The Earth’s human population is increasing by: 2.5 people / sec., 150 people/min, 9,000/hr., 214,000 / day, 78 million/year. U.S. = 4.6% of the world’s population, we consume 40% of the resources.

5. Objectives: Discuss the effect of a growing human population. Begin the histogram lab. Warm Up: In which specific ways does a growing human population have an impact on our planet? Increase poverty, starvation, increase in crime, increases extinction & decreases biodiversity & forests, increases pollution, increases class distinction.

6. PROBLEMS OF OVERPOPULATION 1. Shortage of fuel wood: Can be a matter of life & death. a. used to cook food (some can’t be eaten raw) b. used to boil water (waterborne diseases common) 25 million people/yr, most of them children die of diseases contracted from dirty water. (Lima Peru 1991 1st cholera epidemic in Western Hemisphere in more than 75 years.) 2. The Urban Crisis. By 2020 almost 1/4 of the world’s city dwellers will be homeless.

7. 3. Social Unrest: Conflicts between groups for scare resources. Water rights, food riots, illegal immigration. 4. Environmental Refugees: Millions of people in search of food. Host countries overwhelmed: provide education, health care & jobs.

8. Soil infertility as a result of intensive farming = decreasing the carrying capacity of the land which may take hundreds of years to recover if it can. • The flood of environmental refugees is a good argument for helping other countries solve their environmental problems & reduce their population growth. •  Overall = Resource depletion, environmental degradation & threats to the ecological support systems that we all depend on.

9. TO ACHIEVE A SUSTAINABLE FUTURE, THE PROBLEMS OF OVERPOPULATION AND OVERCONSUMPTION MUST BE SOLVED. Deep societal changes include: 1.Improved social, educational & economic status for women (birth control & women’s rights are often interdependent.) 2. Improved status for children. 3.Acceptance of calculated choice as a valid element in life in general & fertility in particular. 4.Social security. 5.Knowledge, availability, & use of effective & acceptable means of birth control.

10. THEORY OF DEMOGRAPHIC TRANSITION Stage 1: Birth & Death rates are both high in pre-industrial societies, & population grows slowly if at all. Stage 2: When health care improves, the population size increases. Birth rates continue to be high, and people are living longer. The population increases by about 3 percent each year, which means that it doubles every 25 years and is 30 times, its original size by the end of 100 years. Stage 3: Birth rates fall until they roughly equal death rates, and population growth slows down and stops.

11. 1. For 99% of human history we were hunter/gathers. Population was stable at approximately 1 million people. (Detroit has 1 million people.) 2.The agricultural revolution occurred 10,000 years ago. Due to increased carrying capacity & storage of food the population grew slowly. It took from 10,000 years until about A.D. 1804 for human population to reach 1 billion people. 3. Population doubled between 1800 and 1930 to 2 billion. (130 years) 4. 1975 to 4 billion (45 years) 5. 1987 to 5 billion (12 years) 6. October 12, 1999 6 billion (12 years ) 7 billion by 2008, & 8 billion by 2019? 1/10th of all people are alive today.

12. Humans are living longer due to improvements in nutrition, & better sanitation. Declining mortality, not rising fertility is the primary cause of most population growth. Life expectancy has risen from 40 to 65.5 yrs. This century. There is a direct correlation between life expectancy & income. The global intrinsic rate of growth has decreased to 1.4%. This means the population will double again in about 50 years. U.S. = 0.8% Legal immigration of 800,000 people/yr. + even more people illegally is making our total growth rate larger. Globally = 38 million refugees.

13. PROS FOR HAVING CHILDREN 1. Having children is rewarding. (Pleasure, pride & comfort.) 2. The only source of income for the elderly in countries without social security. Provides a source of current income & help with chores. 3. Where infant mortality is high people need to have more children to insure that at least a few will survive. 4. Status. 5. Continuity & a need to replace those who die or are incapacitated. 6. Birth control may be taboo in the culture or religion. 7. Male pride. 8. People will provide answers to our current problems & extend the global carrying capacity.

14. NPP (Net primary productivity) = total amount of solar energy converted into biochemical energy through photosynthesis minus the energy needed by those plants for their own metabolic requirements. (Measure of food resources available on Earth.) NPP without human influence = 150 billions tons of organic matter per year. Humans have caused a 12% decline in NPP through deforestation. Humans utilize approx. 27% of the NPP for their own purposes (food, building material, energy, etc.) or by converting productive land to other uses. Together this represents 40% of the NPP or carrying capacity. Therefore: 100% x 6 billion (current population) = 15 billion people = Theoretical maximum 40% (leaving none for other consumers)

15. Histograms: graph of population distribution by age. A – Example of a stable population in a MDC. B – Example of a population with momentum built in due to the enormous # of children. Typical of LCD’s.