The El Niño weather phenomenon happens because of the unstable interaction of ocean surface temperatures with the lower atmosphere of the tropical Pacific Ocean in processes that are so complicated even modern science does not fully understand it. The process has to do with worldwide dynamics of the ocean and atmosphere, including oceanic waves crossing the entire planet, currents, and global circulation of the atmospheric. About the only thing that scientists have concluded with much certainty is that neither sunspots nor volcanic eruptions seem to influence El Niño.