The oceans affect the climate in numerous ways, some of which are poorly understood and therefore cannot be accurately modeled in computer climate programs. A. Estimates of future conditions are entered into supercomputers to calculate climate possibilities at various places on Earth. B. The ocean's capacity to absorb carbon dioxide remains great despite recent reductions of marine plant nutrients such as iron. C. Oceans absorb a great deal of carbon dioxide from the air through limestone production and the photosynthesis of phytoplankton. D. Ocean circulation is strongly controlled by wind and by the sea's balance of salt and heat. E. Gases are stored in the sea in the form of shells and hydrates, but gases stored in these ways can be recycled to the atmosphere where they may cause warming. F. The ocean holds and moves a great deal of heat, and as ocean water evaporates, it produces clouds, snow, and ice, which all affect global temperatures.