environmental sciences: towards a sustainable future chapter 5 the human population: demographics
TRANSCRIPT
Ch. 5 Outline The world population explosion including
the United States. What about your state? Different population growth rates in
developed and developing nations. Consequences of exploding populations. Dynamics of population growth.
As of Oct 27, 2009….World Population: 6,793,208,538U.S. Population: 307,796,653
Where do you find the greatest population densities?
Major Shifts in Sustainabilitynatural systems displaced by human ones
Paleolithic Time of early humans (40,000 to 10,000 yrs ago) hunter-gatherers, settlements were small and short-lived
Neolithic Revolution (12,000 yrs ago in Middle East after colder and drier climate occurred) development of animal domestication and agriculture, more reliable efficient and abundant food source allowed for specialization of labor and permanent settlements permitting better care and protection leading to greater population growth
Industrial Revolution (1800’s to present) modern science and technological advancements energized by fossil fuels, first coal then oil and gas expanding economies, global commerce, larger cities, exploitation of natural resources and POLLUTION
The Next Revolution…a return to GREEN
Environmental Revolution (1960’s…NOW?) revolution implies an overthrow of “business as usual” to sustainable development, finding ways to limit degradation of natural resources and keep ecosystem cycles intact
Average Number of Children, Grandchildren, and Great Grandchildren
In America West Germany Africa
14 5 258…wow!
Developing country: generally used to describe a nation with a low level of material well being (low GNI, low GDP non industrialized)
The World Bank considers all low- and middle- income countries as "developing". In 2008, countries with Gross National Income (GNI) per capita below US$11,905 were considered developing.
Developed country: used to describe countries that have a high level of development /industrialization (high GNI or high HDI)
World Bank considered high income developed countries with GNI per capita above US$11,905 in 2008.
Some use other criteria such as Human Development Index (HDI), or Kofi Annan, former UN Secretary General, defined a developed country as “one that allows all its citizens to enjoy a free and healthy life in a safe environment."
Growth of Cities
Within the last year, over half of the world’s population now live in “cities” (including shanty towns)
Reasons for the Human Population Explosion…better health conditions Causes of disease recognized Improvements in nutrition Discovery of antibiotics Improvements in medicine Increase in number of women who actually
reach child-bearing age Short doubling times in some countries
Consequences of Exploding Populations
More PopulationCauses
deforestationresource depletionloss of agricultural landbiodiversitydiseasepest resistancepopulation migrationirrigation/water shortagesWetlands degradation
Basic Human Needs are already limited
Drinkable Water Edible Food Safe Housing Health Care An Education A Job
Developing or Developed Nations? High fertility rates High consumptive lifestyles: use 80%
of world’s wealth Intense poverty Eat high on the food chain
Developing or Developed Nations? Long doubling times High environmental degradation Twenty percent of the world’s
population
Global Conditions for a Sustainable Population Lower fertility rates Improve the lives of people Protect the environment
The Meaning of Absolute Poverty
Malnutrition Illiteracy Disease Squalid
surroundings High infant
mortality Low life expectancy
17 million children under5 die each year
Resolving the Problems of Population Growth and Land Availability
Subdividing farms Opening more land for agriculture Move to cities Engage in illicit activities Move to other countries
How do these “solutions” aggravate the problems?
4 Phases of Demographic TransitionPhase I primitive stability‖ high CBR, high CDRPhase II epidemiologic transition declining CDRPhase III significant population growth declining CBR from declining fertility ratesPhase IV ―modern stability‖ low CBR and CDR
developed countries have completed the demographic transition developing countries are in Phase II and III
Calculating Fertility Rates and Doubling Times
(CBR - CDR)/10 = Rate of Increase or decrease in population as a percentage (because now the rate would be per 100 instead of per 1000)
70/ Rate of Increase = Doubling Time (in yrs)
Calculating Fertility Rates and Doubling Times: Practice
Country CBR /1000
CDR /1000
Annual Rate of Increase
Doubling Time
Kenya 40 15 2.5% 28 yrs
Mexico 22 5 1.7% 41 yrs
USA 14 8
Denmark 12 10
0.6% 117
0.2% 350
3 Important American Environmental Organizations
1886 Audubon Society founded 1892 Sierra Club incorporated (John
Muir as president) 1935 The Wilderness Society founded
Dec 2007 IPCC Intergovernmental Panel on Climate Change
Released 4th climate change summary for policy makers scientifically showing that “warming of our climate system is unequivocal” and mostly caused by “anthropogenic GHG concentrations”
Please view your American Environmental Movement Timeline document
Add these 3 international events to your timeline…