ANN ARBOR—How will global warming affect the planet? What caused the space shuttle Columbia to disintegrate during re-entry? When and where will earthquakes and other natural disasters strike? Scientists can’t always answer such questions with certainty, and that sometimes confuses the rest of us. Faced with scientific uncertainty, policy makers often hedge, asking for more and more data before making crucial decisions about the future. But uncertainty need not frustrate or paralyze us, says Henry N. Pollack, professor of geophysics at the University of Michigan. “It’s impossible to eliminate uncertainty from our lives, either as individuals or as a society,” Pollack said. “But rather than treating uncertainty as an excuse for inaction, we should recognize it as a stimulus for creativity, problem solving and scientific progress.” In his new book, “Uncertain Science . . .Uncertain World” (Cambridge University Press, 2003), Pollack explores uncertainty in various contexts, from the laboratory to the stock market to the battlefield, and shows readers how to use their everyday experiences to evaluate and understand uncertain science. Aimed at a general audience and written in non-technical language, the book pays special attention to the issue of global climate change, explaining how climate scientists are able to work and make progress even in an environment of uncertainty. “Probably no other scientific topic has been more regularly in the spotlight in recent years, and intense debate has swirled around the subject,” said Pollack, an award-winning teacher and an internationally recognized expert on the temperature of the Earth, both today and in the geological past. “Scientists and policy makers have argued over the reality of climate change, the causes, the consequences, and the political, economic and social responses to it. As a complex, global-scale, slowly developing phenomenon, climate change displays many of the fascinating facets of scientific uncertainty.” Several themes run through the book:

· Uncertainty will always be with us and will always affect our understanding of the past and our vision of the future. · Because uncertainty never disappears, decisions about the future—big and small—must be made in the face of uncertainty. · Predicting the long-term future is difficult, but we can make mid-course corrections to accommodate new developments. · Uncertainty, far from being a barrier to progress, actually promotes it. “I hope this book will help non-scientists recognize that it’s possible to see through the veil of uncertainty,” Pollack said, “and that by embracing uncertainty, we can surmount the challenges of this new century.”