Force-feed plankton blooms
Plankton are one of the most important carbon sinks on Earth. Although they are some of the ocean's smallest organisms, as a group they absorb carbon dioxide by the ton and also produce a significant portion of the Earth's oxygen. Thus, some scientists have proposed placing huge wave-powered pumps on the swells of the Pacific Ocean that would force the nutrient-rich water in the colder depths to mix with the warmer surface waters, essentially acting as a feedlot for large plankton blooms.