1: Human Population

Question 1

Overview of World Population

Answer 1

 Current statistics
 world population = 7.1 billion
 net gain of ~80 million this year
 net gain of ~1 billion in the next 12-13 yrs
 population may reach 9-10 billion by 2050
 Big questions
 Will population continue to rise indefinitely, or will it eventually taper off?
 What factors control population growth and what regions will be most affected?
 Will the Earth’s resources be able to support these numbers of people?

Question 2

History of Population Growth (Before end of 16th century)

Answer 2

 slow growth with occasional fluctuations from
plagues, pestilences, and famines
 high birth rates, but high death rates

Question 3

History of Population Growth (After end of 16th century)

Answer 3

 much faster growth

 causes: declining death rates from improvements in (1) medical care, (2) sanitation, and (3) diet

Question 4

Population Distribution (6 most populated countries)

Answer 4

 China (1.3 billion) 
 India (1.2 billion) 
 United States (314 million) 
 Indonesia (242 million) 
 Brazil (197 million) 
 Pakistan (177 million) 
(50% of world population)

Question 5

Distribution of population growth

Answer 5

• highest rates in less developed countries, lowest rates in more developed countries
• reason: difference in birth rates

Question 6

Population growth less developed countries

Answer 6

economies mostly agricultural and large families are a form of human social security

Question 7

Population growth more developed countries

Answer 7

need for large families not present; more expensive; delay in starting families; family planning/abortion, etc

Question 8

Population growth and resource consumption: Thomas Malthus

Answer 8

“Essay on the Principles of Population (1798)”

• population pressure will eventually outpace agricultural production
• did not go as far to predict an imminent catastrophe

Question 9

Population growth and resource consumption: Paul Ehrlich

Answer 9

“The Population Bomb (1968)”

- predicted that hundreds of millions would starve to death during the 1970s and 80s.

Question 10

What actually happened to population growth/agriculture in the 70s/80s?

Answer 10

Food production rose faster than population growth
- possible result of the “green revolution” which transformed agriculture after 1945. (plant breeding, irrigation development, etc)

Question 11

/year of population leveling off

Answer 11

10-11 billion by 2100.

Question 12

Problems of resources supply remain

Answer 12

Population growth, increasing standards of living, and the spread of technology to developing parts of the world will bring new challenges in the future.

Question 13

How many people die every day from famine

Answer 13

25,000 die every day = 9 million per year

Question 14

Human population growth is probably not exponential but closer to…

Answer 14

a logistic (“S”) curve.