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