env science quiz 4

• agriculture

• health care

what has driven recent population growth?

0.2 hectares

how many hectares does each human need to support life

100 hectares

how many hectares did pre-agricultural communities (hunter-gatherer) require? 

population crashes

• disease

• famine

• resource depletion

• climate

• isolation

Cahokia mounds

example of population crash

methods to control population

• policy

• education

education method to control population

women who are given a secondary education are more likely to have less children

empowerment of women

• access to birth control

• education

• employment

overpopulation issue or consumption issue

I = PAT

I = PAT

I — Impact

P — Population

A — Affluence

T — Technology

how to use I = PAT

Impact = Population x Affluence x Technology

conservation

careful management of natural resources

preservation

set aside undisturbed areas. maintaining pristine state.

ecosystem services

• provisioning services

• regulating services

• cultural services

• supporting services

provisioning services

• consumables that are directly provided

• resources that are directly used

• examples: freshwater, animals, wood, medicine, wild edibles

regulating services

• natural processes that favor human development

• examples: climate, water filtration, waste removal

cultural services

• not essential but improve quality of life

• examples: spiritual, recreational, educational

supporting services

• provide fundamental conditions that other services depend on

• examples: soil formation, photosynthesis, nutrient, and water cycling

dangers of valuing ecosystems

1. ecosystem disservices

2. managing for some species results in loss of others

3. artificial substitute to natural sources