Surface-temperature trends and variability in the low-latitude North Atlantic since 1552

Sea surface temperature variability in the North Atlantic Ocean recorded since about 1850 has been ascribed to a natural multi-decadal oscillation superimposed on a background warming trend(1-6). It has been suggested that the multidecadal variability may be a persistent feature(6-8), raising the possibility that the associated climate impacts may be predictable(9). However, our understanding of the multidecadal ocean variability before the instrumental record is based on interpretations of high-latitude terrestrial proxy records(7,8). Here we present an absolutely dated and annually resolved record of sea surface temperature from the Bahamas, based on a 440-year time series of coral growth rates. The reconstruction indicates that temperatures were as warm as today from about 1552 to 1570, then cooled by about 1 degrees C from 1650 to 1730 before warming until the present. Our estimates of background variability suggest that much of the warming since 1900 was driven by anthropogenic forcing. Interdecadal variability with a period of 15-25 years is superimposed on most of the record, but multidecadal variability becomes significant only after 1730. We conclude that the multidecadal variability in sea surface temperatures in the low-latitude western Atlantic Ocean may not be persistent, potentially making accurate decadal climate forecasts more difficult to achieve.