Postcard after postcard came addressed to Naomi Oreskes after she wrote her first book on how scientists study the movement of continents.

A groundswell of attention, perhaps? Not exactly. Her mother wrote them all, dashing off each postcard after finishing a chapter. Outside the worlds of science and academia, the book didn't attract much attention.

But 12 years later, the Manhattan-raised historian is traveling a much more public path, drawing both praise and condemnation. She's a fierce defender of scientists and a leader in the vanguard of those who strongly advocate that the world must acknowledge and deal with global warming.

"Professor Oreskes has turned vilified scientists into the heroes they deserve to be," says John Abraham, an associate professor at the University of St. Thomas in St. Paul, Minn. She's performing a service regarding global warming by showing "how a few organized and influential people were able to confuse the country long after the science was settled," he says.

Oreskes, a professor of history and science studies at the University of California, San Diego, acknowledges that she's trying to save the world. Earlier, though, her goal was simpler. She wanted to understand scientists by studying their past, in terms of both their findings and their funding....