Human population growth
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This document discusses human population growth trends over time. It notes that the global human population reached 1 billion in 1830, 2 billion in 1930, 3 billion in 1960, 4 billion in 1975, 5 billion in 1987, 6 billion in 1999, and 7 billion in 2011. It also provides estimates of current birth and death rates worldwide. The document then discusses factors that have allowed unprecedented human population growth, such as advances in agriculture, medicine, and public health. It examines some potential problems associated with high population growth, especially in developing countries, including environmental degradation and resource scarcity. Finally, it outlines the demographic transition process and considers predictions for future global population size and stability.
Human population growth
- 1. Human Population Growth Dr. Mark A. McGinley Honors College and Department of Biological Sciences Texas Tech University
- 3. Human Population Growth • Reached 1 Billion – 1830 • Reached 2 Billion – 1930 • Reached 3 Billion – 1960 • Reached 4 Billion – 1975 • Reached 5 Billion – 1987 • Reached 6 Billion – 1999 • Reached 7 Billion – 2011
- 4. Current Estimated Human Population • Monday February 4, 2013 – 1:40 PM • World 7,064,109,760 people • http://www.census.gov/main/www/popclock. html
- 5. Approximate Estimates Worldwide • 5 births per second • 2 deaths per second • dN/dt = 3 individuals per second • = 10,800 inviduals per hour • Add new Lubbock (N = 230,000 ind) in less than 1 day!!!
- 6. Human Population Growth • As human population size has increased there has not been a decline in the per capita growth rate – As populations have gotten larger humans have not been forced to have lower per capita birth rates – As populations have gotten larger humans have not been forced to have higher per capita death rates
- 7. What’s Up With Humans? • Humans can alter the world in ways that no other species on the planet can. – 1. increase food production • Agriculture – Irrigation, fertilization, farm more area, mechanization, crop improvement • Interestingly, the proportion of people who are starving on the planet is about the same to day as it was in the mid 1800s (20%)
- 8. What’s Up With Humans? – 2. Modern medicine • Decreased juvenile mortality • Increased longevity – 3. Better public health • Waste disposal • Clean water – 4. Don’t worry too much about predators • Occasional shark or cougar attack
- 9. Human Population Growth Problem? • Benefits of Population Growth?? • Disadvantages of Population Growth??
- 11. Human Numbers Through Time • http://www.globalchange.umich.edu/globalch ange2/current/lectures/human_pop/human_ pop.html • http://www.youtube.com/watch?v=4BbkQiQy aYc
- 12. Where is Human Population Growth Occurring? • Most population growth is occurring in developing countries.
- 13. Potential Problems With High Human Population Growth Occurring in Developing Countries • Environmental problems – Most developing countries located in the tropical regions – Habitat destruction, overharvesting, and pollution can cause extinction in the two most diverse ecosystems on the Earth • Tropical Rainforests • Coral Reefs
- 15. Hunger
- 17. Childhood Obesity in the USA
- 18. Weight Loss Products • Weight Loss is a 60 Billion Dollar industry in the USA
- 19. Pudgy Pets
- 21. World Poverty
- 22. Child Labor
- 23. Urbanization
- 24. Urbanization- India Photo by Honey Blakeman
- 25. Human Population Growth • Human populations have basically stabilized in developed countries but are still increasing in developing nations • Why??
- 27. Demographic Transition • Pre-industrial societies – High per capita death rates offset by high per capita birth rates • Slow population growth • Transitional societies – Per capita birth rates have remained high while per capita death rates have fallen • Rapid population growth • Post-industrial societies – Low per capita death rates and per capita birth rates • Slow population growth
- 28. What Causes Per Capita Birth Rates to Decline in Industrialized Societies?
- 29. Literacy Rate vs. Birth rate
- 31. Fertility Rate vs GDP
- 32. What Will Happen to Human Population Size in the Future??? • Human demographers predict that once all countries have completed the demographic transition that Earth’s population will stabilize. – When and how large?
- 33. Factors Increasing Mortality Rates HIV/AIDS
- 34. HIV in Africa