This volume is dedicated to the memory of Roger R.D. Revelle (1909-1991), renowned oceanographer and student of the earth and its processes. Dr. Revelle worked at the forefront of efforts to understand the possible warming effects of greenhouse gases. A scientist of diverse talents, Dr. Revelle received the National Medal of Science from President Bush in 1990 . . . "for his pioneering work in the areas of carbon dioxide and climate modification, oceanographic exploration presaging plate tectonics, the biological effects of radiation on the marine environment, and studies of human population growth and food supplies." The Water Science and Technology Board and the Committee on Climate Uncertainty and Water Resources Management were honored that Dr. Revelle chose to participate in the colloquium that is the basis for this volume. His insights and humor will be greatly missed.