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Human Population and Its Impact
Are there too many of us? – Core Case Study p. 122-123
http://www.eahdfoundation.org/world_live_clock.php
http://www.census.gov/population/www/popclockus.html
Human Population Growth
• ~10K yr ago – 5 million (start of agriculture)
• 1927 – reached 2 billion
• 1974 – another 2 billion (47 yr)
• 1999 – another 2 billion (25 yr)
Population Regulated
Agricultural Advances
Range Expansion &Adaptation
SanitationMedical AdvancesIndustrialization
Sources of Growth
• Developed countries – 0.1%/yr increase
• Developing countries – 1.5%/yr increase
• China & India – 36% global population and rapidly growing economies
• Changes in birth and death rate
• Changes in reproductive contribution
Tracking the U.S. Baby Boom
Based on this U.S. should be stable
Is U.S. Population Declining?
Immigration increases population size
Immigrants adopt resource use habits of new country
Challenges of Slowing Population Growth - China
• Could not support growing population• Instituted One-Child Policy – reward if
followed it• Problem – “little emperors/empresses”,
“bride shortage”, kidnappings for brides• Solution – allow >1 child if…..• Future Problem – age imbalance (31% of
population >60 yr old; potential slowing of economy