The idea of “cultural landscapes” is most closely associated with the twentieth century environmental geographer Carl Sauer. Sauer argued that all geographic regions, even those which might appear to be unaffected by mankind’s influence, have been impacted by the growth of the human population. His work was important for spreading the significance of environmental studies in the field of geography.

The Fertile Crescent is a region of land between the Tigris and Euphrates rivers in the Middle East (much of modern day Iraq, Syria, and Jordan). It is often referred to as the “cradle of civilization” because it was in these fertile floodplains that the first agricultural communities and later civilizations began to appear. In the thousands of years since then, however, the region (according to Marsh) has been ruined by overuse by mankind. What was once a fecund floodplain is now mostly an arid desert. Marsh uses the example of the Fertile Crescent to support his theory that mankind negatively impacts the environment, especially as population grows.

The “carrying capacity” of an area refers to the maximum number of people who can be realistically sustained by the geography of that area. This number can be affected by access to food, water, shelter, and other significant factors. The “carrying capacity” can often be quite difficult to compute and is extremely fluid and changeable. This is because most “areas” do not solely sustain themselves (think of how it is common for people in the United States to buy mangoes grown in South Asia), but rather exchange sustaining goods with other “areas.”

George Perkins Marsh is one of the most well-regarded geographers and environmentalists of the nineteenth century. In his seminal work Man and Nature (1864), Perkins argued that mankind has a destructive influence on the condition of the environment. His ideas were initially on the fringe of accepted geographic theory, but over the years Marsh has come to be revered as a visionary.

HIV/AIDS rates in Sub-Saharan Africa have reached more than 25% in some countries, severely decreasing the populations of these areas. While all of these factors decrease popuations, none are nearly as threatening as the prevalence and expansion of HIV/AIDS.

The global annual natural increase rate is approximately 88,000,000 people per year. The answer choice '1.2 percent' yields an answer of approximately 88,000,000.

The answer choice '12 percent' is a poor choice because it yields an answer of 888,000,000, which is approximately 10 times greater than the actual natural increase rate.  

The answer choice '0.12 percent' is also a poor choice because it yields and answer of 8,800,000, which is nearly 10 times less than the actual natural increase rate.

The answer choices '12 million' and '120 million' are not the best answer choices available because they are not closest to 88 million.

The dependency ratio would increase. The dependency ratio is the ratio of economically-dependent people in a society (those younger than 16 years old or over 65 years old) to the people they depend on (people who are economically productive individuals from 16-65 years old). As the "Baby Boomers" retire, they will rely upon younger generations.

The fertility rate would not increase as the population ages, because the aging "Baby Boomer" generation will not be having more children. Similarly, the rate of natural increase will not increase because the aging of the "Baby Boomers" should not increase the birth rate or decrease the death rate. The childhood mortality rate will not be affected by the aging "Baby Boomers" because the aging of this generation does not directly affect the health of young children. The independency ratio is not a real term used by geographers.

Great Britain had many colonies, including India, United States, and Canada. Since Great Britain had so many colonies, the nation was known as "the empire on which the sun never sets." Mexico did not become one of these colonies.

Since Australia's colonization by the British government in the eighteenth century, the vast majority of Australia's population has lived along the coastlines. The interior of Australia, known as the Outback, is largely barren land with few natural resources or advantages. The natural harbors and resource-rich locations were first settled by European colonists and are still the home of Australia's significant population centers.

Fertility rates rise and fall for a variety of reasons and differ greatly for a variety of reasons. Western Europe has for the last few decades had the lowest fertility rates in the world, which could have a variety of causes, including secularization, which made the religious encouragement for larger families less important.