Key issue # 1: Where is the worlds population distributed?

Answer:
Global population is concentrated in a few places. Humans avoid area that are too wet, too dry, too cold, or too mountainous. The capacity of Earth to support a much larger population depends heavily on peoples ability to use sparsely settled lands more effectively.

Summary:
Humans are not distributed evenly across Earth's surface. Geographers identify regions where population is clustered and where it is sparse, or spread out.

Population Concentrations:
Two-thirds of the world population is clustered in East Asia, South Asia, Southeast Asia, and Western Europe. This data can be displayed on a cartogram, which depicts the size of countries based population rather than land area. The four regions have some similarities that may explain why so many people live there. Most of these areas have easy access to an ocean or water supply, fertile soil, and a temperate climate.

Sparsely Populated regions:
Humans avoid clustering in certain physical environments. Few people live in regions that are too wet, too dry, too cold, or too mountainous. The portion of Earth's surface occupied by permanent human settlement is called the ecumene. Approximately three-fourths of the world's population lives in only 5% of Earth's surface.

Population Density:
Density can be defined as the number of people occupying an area of land. Geographers use arithmetic density, physiological density, and agricultural density to describe the distribution of people in comparison to available resources. Arithmetic density, or population density, is the total number of people divided by the total land area. Physiological density is the total number of people supported by a unit area of arable land, or land good for farming. The higher the physiological density, the greater the pressure that the people place on the land for food. Agricultural density is the ration of the number of farmers to the amount of arable land. This helps account for economic differences between regions.

Article:
http://www.nationalatlas.gov/articles/people/a_popchange.html


This article provides information about population growth and how people are distributed across the United States. It states that many states population grew rapidly between 1990 and 2000 although they did grow at different rates. Also, it is stated in the article that most Americans lived in the states with the highest populations and that only 3% of the total population lived in the 10 least populated states.