The odometer-like references to population growth have become a staple in any essay about population. Some scholars say that when looking at population, we must focus on the numbers, namely limiting them. Others argue that population numbers are the symptom of much more complex problems rather than the cause of them.

Since 1960, when the global population was less than half its current number, many experts became concerned about the consequences of a human population growing unchecked. Since that time concerted international efforts have helped bring down birth rates. There have been major gains in access to food and clean water, and the rate of population growth has been slowed significantly. Impressive as some gains have been, many problems related to, or magnified by population still exist across the world today. It is estimated that the global population will reach nine billion by 2050, a three billion jump from today.

There is a growing concern today about increasing unemployment, urbanization, pandemic disease, economic disparity, consumerism and environmental degradation across the world. Increasingly, the impact is being felt world-wide and not just in the areas of higher population density. This is not surprising in a "globalized" world whose nations are being brought closer and closer together by economics and culture and through technology. In this "small world," the definition of population issues is getting larger to include those most closely associated with the "north" or the industrialized nations, such as urban sprawl and consumption.