The six-billionth human being on earth is projected to make his or her appearance at noon - that's presumably Eastern Daylight Time - on Tuesday, Oct. 12. This estimate may be off by some hours or days, but there's no doubt we're about to pass a population milestone.
It took from whenever homo sapiens first emerged until 1800 for world population to reach 1 billion, but only 130 years more to reach 2 billion. Thereafter, growth reached dizzying speeds - 30 years for the third billion, 14 years for the fourth, 13 years for the fifth, and 12 years for the sixth.
Two questions urgently demand attention: How did this startling acceleration occur, and what does it portend?
How it happened is simple: Death rates declined and birth rates didn't. Especially after 1950, modern medicine found ways to keep people, particularly children, from dying, and the United States and other foreign-aid givers spread these life-saving practices throughout the world.
Medicine was also finding ways to keep people from being born, but the application of those ways has encountered a multitude of political, cultural, and religious objections. These are slowly being removed. The rate of population growth peaked about 1970. The number of people is nearing its peak now. Even though the birth rate is going down, the number of births is going up. More women are having fewer babies. It will take at least a generation to slow the momentum of population growth.
This has enormous and dimly foreseen implications. Growth is occurring almost entirely in the third world, increasing population pressures in countries ill-equipped to handle them. These pressures are felt, in the form of immigration, in industrialized countries, especially the US, which is the only major country with much experience in handling large-scale immigration. Pressure for immigration, legal or not, is already high and will go higher. Immigration policy will become an increasingly controversial issue in American politics.
Foreign aid will be part of the controversy. The argument will be that, by making life more attractive at home, economic development will reduce the urge to leave. The 21st century presidents who make this argument for larger foreign aid programs will not mention that it was foreign aid that caused the problem in the first place. It was foreign aid that improved public health, which made population growth possible.
The new immigrants will be different from the ones we have been used to historically. Those came mainly from Europe - Germans, Poles, Irish, Italians, Scandinavians, Jews. For some time now, most immigrants have come from Asia and Latin America, with growing numbers from Africa. This will continue.
It will bring about a major shift in the ethnicity of the American people and the electorate. California can already see the time when Euro-Americans will be outnumbered by Hispanics and Asians. Texas, Florida, and New York are not far behind. These are the largest states, those with the most political clout.
This will be reflected in representation in Congress and in the character of congressional districts. Already a contentious issue in state legislatures, the boundaries of congressional districts will become more so.
All of these trends, taken together, are going to make the US a different nation, possibly one our grandparents would not recognize. This is not to say it will be better or worse, only different.
It is worth noting in this connection that immigrants typically are the most energetic members of the societies from which they come. They are the ones with the drive and initiative to undertake the difficult, frequently dangerous journey to the US - sometimes dodging the Immigration and Naturalization Service after they get here.
A population of 6 billion - 7 billion in a couple more decades - even though nearing stability, will also have profound effects internationally.
Overcrowding degrades environmental sanitation and public health. Polluted water and air make bad health worse. The pressure to increase food leads to overgrazing and overfarming and produces less food instead of more.
There are ways to deal with these problems. Desalination can make sea water fit for drinking and irrigation. Genetically altered plants and animals can produce more foodstuffs per acre. Some of these new techniques will encounter cultural resistance just as did programs to reduce birth rates. Most of them will require huge amounts of capital that may not be forthcoming.
Earlier demographers, notably Thomas Robert Malthus 200 years ago, postulated that the tendency of population to expand to the limit of subsistence made human survival dependent on war, famine, and pestilence. We have done a little better than that, but we are not home free and the challenge is growing.
It's going to be an interesting century.
*Pat M. Holt is a Washington writer on foreign affairs. He is the author of 'Secret Intelligence and Public Policy' (Congressional Quarterly Press, 1995).
(c) Copyright 1999. The Christian Science Publishing Society