World population today - 4,721,880,000. Gain in past year - 82,077,000 (largest in history). World population in 1900 - 1,650,000,000.
US Census figures in new study indicate birthrates are declining over most of world, but the population time bomb is still ticking.
More and more demographic speculation centers on the supposed race between food and population. Communist China, with a population of 1.059 billion, is the most populous nation on Earth. It has instituted a birth-control, baby-quota system using elaborate social and community pressures. In the world at large, discussions of nuclear war are coupled with another supposed threat, galloping population increase.
The world population increase rises each year, a just-issued study by the US Census Bureau declares, despite a near-stationary percentage growth rate. The record one-year increase of 82 million on June 30, 1983, represents a 1.75 percent growth rate. This is within, or a little below, the 1.7 to 1.8 percent increase of other recent years. The world's annual growth has declined over much of the past 30 years: It peaked at 2.2 percent in the 1954-55 baby boom, then declined for 10 years, and has remained steady since.
In a recent warning, Gen. Maxwell D. Taylor, chairman of the Joint Chiefs of Staff in 1962-64, said ''a forgotten factor'' in Central America is ''unchecked population growth.. . . We must remember that, concurrently, these same conditions that frustrate us in Central America are present in virtually every other country in Latin America. . . .''
According to studies by the Population Reference Bureau Inc., the world's population increase is 1.8 percent. Of this, the figure for more developed countries is 0.6 percent and of less developed countries, 2.1 percent. As examples, the United States figure is 0.7 percent and its next-door neighbor Mexico is 2.6 percent. Recent studies show illegal immigration from Mexico into the US at a near peak. A tightening of controls is proposed in a bill now hanging fire in Congress.
Former Sen. Robert Taft Jr. (R) of Ohio, in testimony to the Senate Appropriations Committee last March, charged that the problem of instability in the developing world is ''closely related to overpopulation.''
Here are figures from the Census Bureau's new annual global report:
* Five biggest nations have 52 percent of the world's population: China; India, 750 million; Soviet Union, 272 million; US, 234 million; and Indonesia, 160 million.
* The five greatest contributors to the 1982-83 increase were India, with 15. 5 million; China, 15 million; Indonesia, 3.3 million; Brazil, 3 million; Bangladash, 2.9 million.
* European nations added only 1.5 million over 12 months, and five lost population: East Germany, Hungary, Denmark, Malta, and West Germany.
* US population rose from just over 232 million to nearly 234.2 million in 12 months.
* The highest growth rate was 10.7 percent in the United Arab Emirates on the Persian Gulf, due to large numbers of immigrant workers.
About 1 in 5 people on Earth live in mainland China. Unofficial reports say the government is intervening increasingly to reduce growth. It has introduced extraordinary social controls. Baby quotas are given communities, factories, and to families with the goal set at one child per couple. The government argues that if something isn't done, the current total of around a billion population will grow to 4 billion in 100 years - about the size of the whole world today. Even with China's social controls, observers believe, its population will keep increasing for another 20 years.