The transfer of photosynthetically produced organic carbon from the surface to subsurface waters draws CO₂ out of the atmosphere, thereby reducing the Earth's greenhouse effect. Previous estimates of the strength of this biological carbon pump have large uncertainties. Furthermore, current earth system models have incomplete representations of export pathways and a large intermodal spread. Here we combine multiple decades of hydrographic observations, including phosphate, dissolved inorganic and organic carbon, total alkalinity, and dissolved oxygen, with a global biogeochemical inverse model to estimate organic carbon export. Our top-down inversion, which implicitly accounts for all export pathways, is higher than the upper limit of previous estimates, suggesting they have either ignored or vastly underestimated the importance of various carbon export processes such as zooplankton migration and particle injection pumps.