Following the highly publicized 1998 E1 Niño event, interest in how climatic events in the tropics affects global climate has grown. However, an understanding of the long-term natural variability in tropical climates is only beginning to emerge. Long-term instrumental records documenting tropical ocean climate are sparse or non-existent in some areas. Therefore, scientists depend upon proxy climate records. The isotopic signatures of coral skeletons offer a suite of proxy records for potentially reconstructing past tropical climate over the last few centuries. Our ability to model and understand current climate and to predict future climate conditions depends on a solid understanding of past climate.