These data indicate that the sensitivity of the carbon system may be large, and indicate the presence of large positive feedbacks to amplify the modest and gradual energy forcings into major climate shifts. Evidence suggests that nutrient uptake efficiency in high latitude, high nutrient regimes has changed, and that there have been large changes in export flux from the surface ocean. It is convenient to assume that the ocean was in a steady state before human influences, but we cannot know this assumption is true without studies that evaluate the system before the perturbation began. Often the period of modern observations began after the injection of valuable transient tracers such as radiocarbon and tritium. Paleoclimatic studies can help us reconstruct the evolution of transient tracers through studies of tree rings.
Paleoceanographic measurements can cover both millennial and shorter time scales.
We must be cautious about pigeon-holing the time scale of some processes. The best paleoceanography is done by iterative forays between proxy development in the modern ocean, investigation of paleo archives, and consideration of the implications for modern biogeochemistry. In some cases we have major discrepancies between proxies. Future proxy development may depend on the availability of archived samples. It is imperative that we take advantage of this presence to improve our global database of geochemical tracers.