California State University Long Beach 

Population and environmental change

• Economic and population growth vs. sustainability

 
 
• Are there physical limits to growth?
• With growth, there is environmental degradation
• Increased resource consumption
• Increased pollution
• Decreased natural habitats
• Increased crowding/urbanization
• Inadequate individual food, space, and resources
• Infectious diseases
• Violence and warfare

Population growth (people)

• Initially slow growth of human population
• Predators
• Disease
• Insufficient food
• It took 3-4 m.y. to reach 500 million population in ~1650 A.D.

 
• Improved agricultural methods, the industrial revolution, exploration/emigration to new lands
• 1 billion people by 1830 (doubled in 180 years)

 
• Public health measures, immunization, reduced infant mortality, insecticides (DDT), and the "green revolution"
• 2 billion people by 1930 (doubled in 100 years)
• 4 billion people by 1976 (doubled in 46 years)

 
• Present world population: over 6,300,000,000 people
• World population currently doubling every ~45 years
• 8 billion people by 2021?

 
• Exponential growth, not a linear increase
Think about it!

Population growth (where?)

• Developed, industrialized nations
• I.e., Europe, USA, Canada, Japan, etc.
• Decreased birth rate and death rate
• The "demographic transition"

 
• Developing nations
• Former European colonies, independent after WWII
• Rapid decrease in death rate
• Increased population growth rate
• 1940: 2/3’s of world’s population
• 1990: 3/4’s of world’s population

 
• Highest population growth rates in:
• Africa
• Southwest Asia
• Latin America

Population related societal strains

• Imbalanced distribution of wealth
• Gross National Product (GNP) per capita
• Less than $500/year for half the world’s population
• Greater than $20,000/year for 10% the world’s population
• Population growth rate inversely proportional to wealth!
 
• Food supply
• Over 50% of world get less than 100% of required calories
• Over 25% of world get less than 90% of required calories
• Limited Resources
• All these people need food, shelter, medicine, and space to live
• How much longer can we provide for all of the world's population without running out of resources?
• Food, energy, fertilizer, building materials...
• Good news about population problem
• World growth rates declining since 1970s
• Why?
• Governments involved in family planning
• Economic development (locally)
• Lower mortality rates -> decreased number of children
• Better education
• Higher status for women

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For any questions or problems with these pages contact>
John Francis
Email: jfrancis@csulb.edu
Phone: 562-985-4928
written by R. Behl.
Last changes:31Oct. 1997