Far too often, SF writers with no taste for homework set their cautionary tales in so distant a future that the process of shattering an ecosphere becomes a side issue.

John Brunner never tells us exactly when The Sheep Look Up is taking place, but it seems to be no later than 1980 or 1990—the very point at which all the "minor" environmental crises are beginning to converge into a disaster. It's the process that concerns Brunner, because an ongoing process can be stopped. Sheep has more political punch than any other ecological disaster novel I've read, precisely because its concrete details suggest concrete action.

Brunner has done his homework, and the novel's background is scrupulously built up from a collage of current data and careful extrapolation. (p. 63)

That the environment is delicately balanced is hardly a new insight. Yet Brunner scatters characters and climaxes in every direction—there's...