The role of secular warming relative to decadal and spatial variability in ocean temperature is examined from long-term Sea Surface Temperature (SST) records off California, from other regions of the North Pacific, and from the Indian Ocean. The Pacific Decadal Oscillation (PIDO) index of basin-scale variability accounts for 18-48% of the variability in these SST series. The warming trend in SST is now associated with similar levels of variability. Near-surface temperature variations throughout the California Current System are similar between regions, including the waters over the Santa Barbara Basin. Changes in the abundances of planktonic foraminifera from Santa Barbara Basin sediments show that the warming trend has had a substantial impact on marine populations relative to other interannual- to decadal-scale changes. Time series that began after 192 5 may underestimate the cold extremes of decadal-scale ocean variability and its modulation of marine populations while records since 1977 lie within an anomalously warm period.