Population
Introduction
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It might be argued that without the multiplier of population none of the problems we confront would be of sufficient magnitude to qualify as global. Certainly if population were stable, many global issues would be far more manageable.
World population exceeded six billion in 1999 – doubling from three billion in 1960 – and is currently increasing by 80 to 85 million people each year. Depending upon the choices we make over the next few decades, demographers at the United Nations project world population in 2050 could be anywhere 7.3 billion to 10.7 billion. It is important to note that these scenarios assume fertility will decline significantly in the future.
A number of factors drive this growth. At the most basic level, it is because far more people are born each year than die. Advances in nutrition and health care have increased survival rates and longevity for much of the world, and shifted the balance between births and deaths.
Another is population "momentum". Even though fertility rates have come down worldwide – from an average of six children per woman in 1950 to 2.9 children per woman in 2000 – there are many more people of childbearing age today than ever before. Roughly half the world’s population is under age 25, so as those three billion people start families over the next few decades, world population will likely increase by several billion.
Another reason for continued high levels of population growth is that fertility rates remain relatively high in some populous regions like Africa and South Central Asia. Broadly speaking, population growth is higher in those regions because levels of income and education are lower there.
Decisions about family size are often based on economic factors, and in poorer societies, having numerous children may be an important asset. They provide support and security in parents’ old age, help raise food, haul water, care for younger siblings, and gather fuel wood. Children may also work for wages outside the home, be indentured, or even sold to help support the family.
Birth rates are also closely linked to education. The more education people have, the more economic options they generally have, and the fewer children they are likely to want or need. In the areas of the world where education levels are highest – Europe, Japan, China, the former Soviet Bloc, and North America – fertility is correspondingly lowest.