Discuss how the growth of the human population is a dangerous and ominous threat for the world’s near future.

Question

What will be an ideal response?

Answer 1

The human population has recentlygrown with unprecedentedspeed. Between1950 and 1990 it doubled in just 40 years. The rate ofgrowth has declined since 1990, so that the population iscurrently doubling about every 58 years.Never before in human history has the population doubledin the life span of a single individual, yet today everyoneover 60 has experienced such a doubling.

Since no one knows what the population figures in thefuture will be, the United Nations makes a range of projections.In its most recent projection, its middle estimatesees world population reaching 8.9 billion by 2050. Its highestimate puts the population at 10.6 billion by 2050, itslow estimate at 7.4 billion, which assumes that the world’speople will quickly move to below-replacement levels offertility (the number of children per couple).

If the fertility rate falls only to replacement level (orabout 2.1 children per couple), the population will stillgrow for 70 years. This is due to the disproportionatenumber of children and young reproductive-age people intoday’s population, which is a result of recent populationgrowth. This is referred to as the “demographic bulge,” or“population momentum.”

Population projections differ widely by country. Inone group of about 33 countries, including Spain, Japan,Russia, and Germany, populations are projected to remainstable or to shrink because of falling fertility rates. Anothergroup of countries, including Lesotho and Swaziland, havedeclining population due to a rising death rate. Other countries,including China and the United States, have reducedfertility to replacement level, but their population is stillexpanding due to the demographic bulge just described.Still other countries, especially in Africa and other lessdeveloped areas, continue to increase their population rapidly,even though the rate of growth is decreasing. If downwardtrends continue, their population growth could slowto replacement level by 2050.

From 2000 to 2100, the placement of the world’s populationis expected to shift dramatically, as Europe’s sharedeclines from 12.0 to 5.9 percent, and as Africa’s almostdoubles, from 13.1 to 24.9 percent. North America willgrow until 2050 from migration; after that the UN projectsno further migration. By 2100 the UN projects a high estimateof 14 billion people, a middle one at 9 billion, and alow of 5.6 billion.

The absolute size of the world’s population is one elementin the human footprint; another is the impact that individualsmake depending on their levels of consumption.Citizens of developed countries consume much more thando citizens of developing countries. If China reaches whatthe consumption levels were in the United States in 2005,the human impact on Earth will likely double. So levelsof consumption are as important as the sheer numbers ofhumans in measuring theirimpact on the biosphere.