Earth at Night from Shuttle
•1200—400 million people•1300—400 million people•1400—350 million people•1500—450 million people•1600—550 million people•1700—600 million people•1800—900 million people•1900—1.5 billion people•2000—6.0 billion people•2010—7+ billion people
Lag phase
Exponentialgrowth
Exponential growth
J-Curve
2 4 6 8 10 etc.
2 2 2 2 etc.
Linear Growth
Time
#’s
2 4 8 16 32 etc.
2 4 8 16 etc.
Exponential Growth
Time
#’s
Biotic Potential
Logistic Growth/ S-Curve
Carrying Capacity•“Niche spaces”•Limiting Factors
Limiting factors•Density dependent•Density independent
Density dependent factors•Habitat•Food•Water•Shelter•Etc
•Disease•Behavior
Density independent factors•Climate (?)•Geology•Geography•Etc
# live births
Mid-year population BR = x 1000
# Deaths
mypDR = x 1000
BR - DR10
APGR =
20 - 810
APGR = = 1.2 %
10010
11011
12112
133Etc
#’s
Time
APGR70DT =
1.2 %70
DT = = 58.33 years
1954 = 2.7 billion; Current = <7 billion
# Immigrants - # Emigrants myp
Net Migration =
x 1000
Net migration10
Adjusted Growth Rate =
+ APGR
Adjusted GR70
Adjusted DT =
#Births = 40,000#Deaths = 20,000Mid-year population = 2,000,000 Immigrants = 12,000 Emigrants = 2,000
40,000
2,000,000BR = x 1000
40,000,000
2,000,000BR = = 20
20,000
2,000,000DR = x 1000
20,000,000
2,000,000DR = = 10
20 - 1010
APGR = = 1%
1.0 %70
DT = = 70 years
12,000 - 2,0002,000,000
Net Migration =
x 1000
10,000,0002,000,000
Net Migration =
= 5
510
Adjusted Growth Rate =
+ 1.0
0.5
Adjusted Growth Rate =
+ 1.0= 1.5%
1.570
Adjusted DT = = 46.66 years
TFR= Total Fertility Rate
Replacement TFR• In developed countries, 2.1•In less developed countries 2.5-3.3
AMA= Average Marrying Age
AMA TFR
MDC’s LDC’s
APGR 0.5 2+
DT 140 yrs 35 yrs
TFR 2.3 3.5+
AGE STR Uniform Bottom heavy
Human Population Carrying Capacity•Unknown•Quality of life
Should population growth be slowed?•Ecologists •Economists
How to slow growth•Education of women•Economic development•Empowerment of women•Family planning•Reproductive laws
Disease•Infectious disease•Non-infectious
Infectious disease•Direct•Vector transmitted•Endemic•Epidemic•Pandemic
Disease•Acute•Chronic
Control of Non-human Populations•Hunting/harvesting•Trapping•Poisoning•Introduced pathogens/predators
Control of Non-human Populations•Hunting/harvesting•Trapping•Poisoning•Introduced pathogens/predators
Birth Control•Abstinence•Rhythm method•Barrier methods•Hormonal methods•Spermicides•Sterilization•Abortion
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