ENSO stands for El Niņo/Southern Oscillation. It is a periodic warming or cooling effect of the Pacific Ocean near the equator that heats the earth and produces climate changes effects. The great El Niņo of 1998 caused $25 billion in damage in the United States alone.
PDO stands for Pacific Decadal Oscillation. It is a El Niņo-like phenomena discovered in 1996 that also affects climate change.
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