Dr Henry F. Diaz is a Research Meteorologist in the Earth System Research Laboratory at the National Oceanic and Atmospheric Administration (NOAA). He has worked on a variety of climate issues at NOAA over the last 15 years, particularly the impact of climatic variation on water resources of the western United States. He is recognized as an expert on the El Nino Southern Oscillation (ENSO) phenomenon and coedited El Nino: Historical and Paleoclimatic Aspects of the Southern Oscillation, also published by Cambridge University Press (1992). Dr Richard Murnane is the Program Manager for the Risk Prediction Initiative (RPI) and a Senior Research Scientist at the Bermuda Institute of Ocean Sciences (BIOS), where he leads RPI's efforts to transform science into knowledge for assessing risk from natural hazards. Dr Murnane's own research focuses on tropical cyclones, climate variability, and the global carbon cycle. Before joining the RPI and BIOS in 1997, Dr Murnane was on the research staff of Princeton University in the Program in Atmospheric and Oceanic Sciences.