1. Section 2 Changing Population Trends
Chapter 9
Section 2
Changing Population Trends
Environmental Science
Spring 2011

2. Objectives Describe 3 problems caused by rapid human population growth
Compare population growth problems in more-developed countries and less developed countries
Analyze strategies countries may use to reduce their population growth
Describe worldwide population projections into the next century

3. Infrastructure
Infrastructure: basic facilities and services that support a community
Public water supplies, sewer lines, power plants, roads, subways, schools, hospitals

4. Infrastructure
Populations with high rates of growth create environmental and infrastructure problems
Symptoms of overwhelming population growth include suburban sprawl, overcrowded schools, polluted rivers, barren land, inadequate housing
Mumbai, India

5. Problems of Rapid Growth
Rapidly growing population uses resources faster than the environment can renew them

6. Problems of Rapid Growth
Shortage of Fuel-wood:
In many of poorest countries wood is main fuel source
When populations stable people use fallen tree limbs
In rapid population growth deadwood does not accumulate fast enough to provide enough fuel
People begin to cut down trees and vegetation resources are cleared
Lack of fuel- cannot cook food, boil water (often unsafe), leads to people suffering from disease and malnutrition

7. Problems of Rapid Growth
Unsafe Water:
In places that lack infrastructure local water supply may be used for drinking, washing, sewage disposal
Water supply becomes breeding ground for organisms that cause diseases such as dysentery, typhoid, cholera
With expanding populations, water systems cannot expand fast enough to keep up with growth

8. Problems of Rapid Growth
Impacts on Land:
Arable land: land that can be used to grow crops
Increasing populations may have a shortage
Need to make tradeoff between competing uses for lands such as agriculture, housing, natural habitats
Urbanization: movement of people from rural areas to cities

9. A Demographically Diverse World
Not every country is progressing through each stage of the demographic transition according to the model
Ex. Modern industries, incomes remain low
Ex. Stable and educated populations, little industries
Ex. Remain in second stage of model

10. A Demographically Diverse World
Least developed countries: show few signs of development and in some cases have increasing death rates, while birth rates remain high

11. Managing Development and Population Growth
Countries are realizing that continued population growth can limit their economic development
Many countries favor stabilizing population growth through investments in development, especially through improvements in women’s status

12. Growth Is Slowing World population = 6 billion
Still growing
Fertility rates are declining world wide
If these rates continue most countries will have replacement level fertility rates by 2050
If so world population growth would eventually stop

13. Review Describe 3 problems caused by population growth
Compare population growth in more developed countries to population growth in less developed countries
Describe worldwide population projections for the next 50 years
Do you think that simply changing birthrates will cause a nation to undergo further development?