1. ENVIRONMENTAL SCIENCE
The Human Population: Demographics
Part II Different Worlds

2. Part 2 Different Worlds Objectives
Distinguish between high, middle, and low income countries.
Compare population growth in rich and poor nations.
Discuss the problems that different populations present for the environment.

3. The Disparity Among Nations
There is tremendous disparity among the nations on Earth with respect to economics, resources, and health care.
The World Bank, a United Nations agency, divides nations into three main economic categories based on average per capita gross national product.
High income, highly developed, industrialized countries – 1998 gross national product per capita of $9,361 or above (average of $25,510)
Examples: U.S., Canada, western Europe, Japan, and some Arab states

4. The Disparity Among Nations
The World Bank, a United Nations agency, divides nations into three main economic categories based on average per capita gross national product. Cont’d
Middle income, moderately developed countries – 1998 gross national product per capita of $761 - $9,360 (average of $2,950)
Examples: Many Central American countries, northern African countries, eastern Europe, and countries of the former U.S.S.R.
Low-income countries – 1998 gross national product per capita less than $760 (average of $520)
Examples: Many nations of central Africa, and central Asia

5. The Disparity Among Nations
The high-income countries are are usually referred to as developed countries and the middle and low-income countries as developing countries.
The developed countries hold just 20% of the world’s population, yet control about 80% of the world’s wealth.
The distribution of wealth within countries is also disproportionate.

6. The Disparity Among Nations
In developed countries,between 10% and 15% of the people are recognized as poor; about 60% of people in developing nations are considered poor.
It is among the poorest people (globally speaking) that population growth is the greatest.

8. Population Growth in Rich and Poor Nations
The developed world, with a population of 1.18 billion in 2001, is growing at a rate of 0.1% per year; developing nations, with a population of 4.97 billion in 2001, is growing at a rate of 1.7% per year.
About 94% of world population growth is occurring in developing nations.
Total fertility rate – the average number of children each woman has over her lifetime – is the major determining factor for population growth (except for high mortality events).

9. Population Growth in Rich and Poor Nations
A total fertility rate of 2.0 will result in a stable population, higher rates will result in growth, lower rates will result in a shrinking population (not counting immigration patterns).
Replacement level fertility is the fertility rate that will just replace the population of parents, which is slightly higher than 2.0 because of infant and childhood mortality as well as the fact that some women in the population do not reproduce.

10. Population Growth in Rich and Poor Nations
The replacement level fertility is 2.1 for developed countries and slightly higher in developing countries (due to higher infant and child mortality rates).
Total fertility rates in developed nations have declined (average of about 1.5 – U.S. is 2.1) as well as in developing nations, although their average is still 3.2, some have a rate of 6.0.
The percentage of the world’s population living in developing countries will continue to climb – perhaps to over 90% by 2075.

12. Different Populations Present Different Problems
Increasing global populations put increasing pressure on the environment through demands for food, energy, and water resources as well as the production of wastes.
The demand each individual puts on the environment depends on what that individual consumes.
As consumption increases, so does the negative impact on the environment.

13. Different Populations Present Different Problems
The average American places 20 times the demand on the environment as does an average individual from some developing nations.
Environmental impact is proportional to the population multiplied by the affluence of the population’s lifestyle, moderated by the stewardly action of the population.
Three key issues that must be addressed are 1.) population growth, 2.) highly consumption-oriented lifestyles, and 3.) inattention to stewardship.