Global Warning ... Global Warming.

Only a confident writer can admit at the beginning of a book that he has taken on "an inordinately complex subject." For most writers, the global warming issue is simple: More C|O.sub.2~ means a warmer climate means global disaster. Their books are long on politics (often well disguised) and short on real science. This one isn't. And, more to his credit, the author has made reason entertainingly readable, without the cheap tricks and props of doomsday politics.

Benarde once was asked the question that all Americans sampling from the buffet of environmental problems want to know: "Do I have to worry?" In this book the Temple University professor of epidemiology explains, "It's more important to know how to worry." The book's five parts tell readers how to worry in reasonable scientific fashion.

The benefit of Benarde's approach is that it depolarizes and depoliticizes the debate over global warming. Without endorsing President Bush's go-slow-and-more-research method, he demonstrates how it could be a reasonable approach.

His fascinating history of climate modeling leads Benarde to conclude that for all their value, "At this point, we are in thrall to model predictions." It is possible, he says, that Michael E. Schlesinger of Oregon State University was right when he suggested that models might be more sensitive than nature.

Despite long, detailed chapters on the complexities that create this debate, Benarde in the end notes what may be the most critical obstacle: "Long-term planning, especially preventive planning, has never been our strong suit."

In his final paragraph, Benarde quotes the British statesman Edmund Burke, "The public interest requires doing today those things that men of intelligence and good will wish, five or 10 years hence, had been done." That doesn't mean rushing out and throwing a few billion dollars at the most fashionable "solution." It does mean doing what Benarde has done--writing clearly, critically, and honestly about the facts and theories. It also means reading this book.