The movement of carbon between the atmosphere, oceans and continents or carbon cycle regulates Earth s climate, with the ocean playing a major role in carbon sequestration. A new study finds that the shape and depth of the ocean floor explain up to 50% of the changes in depth at which carbon has been sequestered there over the past 80 million years. While these changes have been previously attributed to other causes, the new finding could inform ongoing efforts to combat climate change through marine carbon sequestration.