At the turn of the 21st century, scholars will no doubt tally up in amazement the number of studies published since 1980 with ''2000'' in their titles. The latest, released today, is ''Forecast 2000: George Gallup Jr. Predicts the Future of America.''
At first blush, this book seems just another blurp from the megatrenders. It paints gruesome pictures of muggings in city parks, nuclear devices set off by terrorists in New York City, and fashionable coke-snorting women. And it offers ''practical'' solutions ranging from the selfish (we're told to escape nuclear terrorism by moving to the countryside) through the improbable (we can abolish pockets of unemployment by relocating the unemployed) and into the downright odd (we can reduce world hunger by eating peanut butter and banana sandwiches for lunch).
But Mr. Gallup (president of the Gallup polling organization and son of George Gallup Sr., its founder) is no mere tub-thumper. Two things make this a useful book. One is his earnest concern. This is the prose of a man who really likes America and longs to see it survive - and who writes, with an almost Old Testament fervor, that ''I'm sufficiently convinced that our society is heading in a dangerous direction that I feel compelled to sound a note of extreme urgency.''
The other strength lies in Gallup's well-respected survey technique. This book is based largely on polls of American opinion leaders - ''the most comprehensive set of surveys ever attempted'' of its sort, he tells us. Some 1, 346 ''pacesetters,'' drawn from Marquis's Who's Who in America, were asked about the state of the United States and the world in the year 2000. All of them, says Gallup, ''hold key positions in government, science, business, the arts, or other fields.''
That's an impressive collection of movers and shakers. With help from writer William Proctor, Gallup organizes their responses into nine ''Future Forces'' akin to the ''megatrends'' identified in John Naisbitt's best seller: the nuclear threat, overpopulation, economic pressures, technological progress, the ''environmental emergency,'' crime and violence, the ''faltering family,'' personal health, and political issues. His respondents comment on the current significance of each ''force'' - and on its probable significance in 2000.
In seven of the nine areas, these leaders admit to large measures of optimism. They see even the No. 1 problem - the nuclear threat - diminishing in importance by 2000. But in two areas the future looks particularly bleak. While only 16 percent see overpopulation as one of the top problems today, 38 percent see it as such by 2000. And environmental pollution jumps from 39 percent today to 55 percent in 2000. Interestingly, as Gallup notes, the ''lack of sufficient energy resources wasn't even mentioned'' by these leaders: They put protecting the environment well ahead of tearing it up to search for energy.
In other areas, too, the book mines some fascinating nuggets. Gallup notes that one-third of the respondents saw ''decline in family structure, divorce, and other family-oriented problems'' as major problems today. At the same time, less than 3 percent of them thought that ''strengthening family relationships is an important consideration.'' Gallup's conclusion: ''It's obvious that we're confused and ambivalent in our feelings about marriage and the family.''
Confused, too, is the view of religion. After citing poll results showing that America, second only to India, is ''the most religious nation in the world, '' he notes that only 29 percent of these opinion leaders thought that organized religion is ''giving adequate answers.'' ''We lack deep levels of individual spiritual commitment,'' he concludes. Yet ''the two basic ingredients identified by our opinion leaders'' as essential to a sound future, he finds, are ''mature commitment'' coupled with ''better education.''
America's ''pacesetters,'' then, are optimistic wherever they think technology is on their side - but far less so on such knotty, peopley issues as population and the environment. That's a most telling distinction. These opinion leaders, apparently, are looking at a future where solutions can't be entrusted solely to technological advances. They may be pointing us to a truth long known but sometimes overlooked: The knottiest problems need the broadest vision that, rising above the technological, emphasizes such old humanistic values as education and commitment.