‘Rising Wind of Migration’ Foreseen : Growth: High birthrates could produce a huge population seeking jobs in the industrial nations, U.N. agency says.

Raising the specter of relentless migration pressures in the next century, the U.N. Population Fund reported Wednesday that an estimated 70 million people now work legally or illegally in countries other than those in which they were born, their numbers augmented every year by about 2 million more immigrants and refugees.

During the late 1980s, the U.N. agency said in its annual report, the United States accepted an average of 603,000 permanent immigrants a year, an influx topped only by the great waves from Europe in the first two decades of this century, when the United States had almost no restrictions on immigration.

Three countries--the United States, Canada and Australia--admitted a total of more than 8 million settlers during this period. In the United States, 44% came from Asia, which has supplanted Europe as the main source of immigrants to America.

The U.N. agency, which funds and coordinates family planning projects throughout the world, painted a future in which high birthrates in the developing world would produce an enormous population that would seek jobs in the countries of the industrial world with their relatively low birthrates, population declines and aging citizens.

“Like a gradient between high and low pressure in the atmosphere,” the annual report said, “the result could be a rising wind of migration, circling toward the north.”

As an example, the U.N. Population Fund said, the labor force of Central America is expected to increase by 50.5 million between now and 2025, while the North American labor force remains the same, except for immigration. Similarly, the North African labor force is expected to increase by 56.6 million, while the labor force in Europe declines by 14.5 million.

It is obvious where the unemployed of Central America and North Africa will head in these cases.

Differences between the rich and poor countries in family planning are enormous. The British colony of Hong Kong and the former West Germany have the lowest fertility rates in the world--1.4 children per woman, not enough to keep their populations at current levels. Rwanda, on the other hand, has the highest fertility rate. Women there have an average of eight children.

As for the world population in general, Nafis Sadik, a Pakistani who is executive director of the U.N. Population Fund, told a news conference in London that the rapidly growing numbers of people threaten an economic and ecological catastrophe. She called the problem the “nightmare of the 1990s.”

In a similar vein, Catherine S. Pierce, a U.N. Population Fund official, told a news conference in Washington that, if the projected world population of 10 billion in the year 2050 “consumed at United States levels in 1987, world oil reserves would be burned up within five years.”

Repeating estimates issued in past years, the annual report said that the world population would reach 5.48 billion a few months from now, 6 billion in 1998, 10 billion in 2050 and 11.6 billion in 2150 before starting to decline. In the first decade of the 21st Century, the U.N. agency said, world population will increase by a record 97 million a year.

In a statement, the Sierra Club said that the U.N. report makes clear the need for stronger family planning programs throughout the world.

“This report confirms the worst fears of scientists and environmentalists,” said Nancy Wallace, director of the club’s population program. “Past inaction on population is creating a graveyard for all the progress and hopes of today’s generation.”