Aimed at a lay reader, The Crowded Greenhouse is the collaborative effort of John Firor, director emeritus of the National Center for Atmospheric Research, and his wife, population expert Judith Jacobsen. The first three chapters (written by Jacobsen) deal with population issues, and the second three chapters (written by Firor) assess climate change. This volume proceeds from the assumptions that the earth is finite, that human population cannot grow indefinitely, and that humans must act now to avoid negative environmental consequences from population growth.