- Populations increase as people are born or immigrate into a country, and decrease as people die or emigrate. Rates of population growth, usually expressed as a percentage, vary greatly. In the late twentieth century, growth rates in many European nations were extremely low, and in some parts of Eastern Europe and the former Soviet Union the growth rate was negative—that is, populations were declining in number. On the other hand, in some African and Latin American nations, the growth rate was around 4 percent, which is a doubling time of less than twenty years. The United States, as inboof the year 2000, had a growth rate of about 1 percent per annum.
- This ever-increasing growth rate is mostly due to an unprecedented decline in death rates. South Asia, the Middle East, and North and sub-Saharan Africa are the regions with the fastest-growing populations, while in Europe, the Russian Federation, North America, and Japan, population growth is stable or declining. However, reductions in death rates are likely to be reversed by the global AIDS pandemic.
- Population growth is the change in a population over time, and can be quantified as the change in the number of individuals of any species in a population using "per unit time" for measurement. In biology, the term population growth is likely to refer to any known organism.
- The increase in the average length of a human life affected the amount of children they could reproduce during their reproductive years. In addition, improvements in basic health meant that many if not all of the offspring would survive until they too, could have children. Whereas many babies used to die as infants, modern medicine coupled with better nutrition during pregnancy made it possible for a mother to give birth to many healthy children. It became common to see multigenerational families, with grandparent and great grandparent surviving to see their descendants. The population growth occurred quite rapidly because people did not have fewer children, and surviving until old age became common. However, as Western nations were just beginning to realize it was time to have fewer children, less developed countries began to pick up on many of these advances, and their populations exploded in growth as well.
- As the century begins, natural resources are under increasing pressure, threatening public health and development. Water shortages, soil exhaustion, loss of forests, air and water pollution, and degradation of coastlines afflict many areas. As the world’s population grows, improving living standards without destroying the environment is a global challenge.Most developed economies currently consume resources much faster than they can regenerate. Most developing countries with rapid population growth face the urgent need to improve living standards.
- In order to minimize current and future population growth, a global effort will have to be undertaken by the countries who can afford to do so. This means educating those in less affluent countries regarding the function and usage of various birth control methods in addition to an understanding of the broader scope of the causes and problems of population growth. It is important to realize that many places of the world are still without technologies such as internet and television, or may not have access to educational resources. Education is the first key step in a solution to population growth, because choices regarding reproduction are unlikely to be altered without an awareness of population problems. People need to have fewer children in order for the population growth to slow down.