IMAGES core MD01-2416 (511N, 1681E) provides the first centennial-scale multiproxy record of Holocene variation in North Pacific sea-surface temperature (SST), salinity, and biogenic productivity. Our results reveal a gradual decrease in subarctic SST by 3-51C from 11.1 to 4.2 ka and a stepwise long-term decrease in sea surface salinity (SSS) by 2-3 p.s.u. Early Holocene SSS were as high as in the modern subtropical Pacific. The steep halocline and stratification that is characteristic of the present-day subarctic NorthPacific surface ocean is a fairly recent feature, developed as a product of mid-Holocene environmental ch ange. HighSSS matched a salient productivity maximum of biogenic opal during Bølling-to-Early Holocene times, reaching levels similar to those observed during preglacial times in the warm mid-Pliocene prior to 2.73 Ma. Similar productivity spikes marked every preceding glacial termination of the last 800 ka, indicating recurrent short-term events of mid-Pliocene-style intense upwelling of nutrient-rich Pacific Deepwater in the Pleistocene. Such events led to a repeated exposure of CO2-richdeepwater at the ocean surface facilitating a transient CO2 release to the atmosphere, but the timing and duration of these events repudiate a long-term influence of the subarctic NorthPacific on global atmosph eric CO 2 concentration. r 2004 Elsevier Ltd. All rights reserved.