Stable isotope analysis of two separate corals from Nauru Island in the warm pool of the western tropical Pacific confirm that coral oxygen isotopes are a robust recorder of environmental variables. Coral Δ13O faithfully records interannual variability even when strongly influenced by kinetic effects. Interannual to decadal variability of coral Δ13C remains enigmatic; only one of the two corals exhibits the expected light-Δ13C response in the interannual band. Coral Δ18O from this region has a great similarity to global instrumental temperature records reflecting the impact of the Pacific warm pool and variations of the Indonesian Low in concert with El Ni¿o-Southern Oscillation on global climate. Since 1896, coral Δ18O has exhibited a cumulative decrease of 0.7?, which reflects a combination of warming and more frequent El Ni¿o events (precipitation) affecting the surface waters of this region. ¿ 1999 American Geophysical Union