Of course, some theories are less focused on the pessimistic hypothesis that the world’s population will meet a detrimental challenge to sustaining itself. Cornucopian theory scoffs at the idea of humans wiping themselves out; it asserts that human ingenuity can resolve any environmental or social issues that develop. If we need more food, the theory why do my nostrils burn contends, agricultural scientists will figure out how to grow it, as they have already been doing for centuries. After all, in this perspective, human ingenuity has been up to the task for thousands of years and there is no reason for that pattern not to continue . Fort McMurray, Alberta, is the hub that services the Athabasca Tar Sands.

The population composition includes the sex ratio as well as the population pyramid (Figure 20.4). The fertility rate of a society is a measure noting the number of children born. The fertility number is generally lower than the fecundity number, which measures the potential number of children that could be born to women of childbearing age. Sociologists measure fertility using the crude birthrate ; just as fertility measures childbearing, the mortality rate is a measure of the number of people who die.

Recently, experts have tried to curb the spread of suburban sprawl, or at least create urban areas that are developed more purposefully. This is known as “smart growth.” City planners create communities that are designed for more walking and less dependency on cars. Some developers recover old communities in downtown urban areas, rather than develop the next piece of farmland or wilderness. Many city residents move to suburbs, a situation known as suburban migration. Homes in suburbs are usually larger than homes in cities, and suburbs usually have more parks and open spaces.

What the Highway Act created instead was suburban sprawl. A town is generally larger than a village, but smaller than a city. Some geographers further define a town as having 2,500 to 20,000 residents. Utilizing the metropolitan area population of urban areas in the United States, we find that the U.S. lacks an actual primate city. With the New York City metropolitan area population at approximately 21 million, second-ranked Los Angeles at 16 million, and even third-ranked Chicago at 9 million, America lacks a primate city.

Earth’s human population is growing quickly, especially in peripheral countries. Factors that impact population include birth rates, mortality rates, and migration, including immigration and emigration. There are numerous potential outcomes of the growing population, and sociological perspectives vary on the potential effect of these increased numbers.