Read here. More often than not, we think of El Niño (or La Niña) events as contemporary climatic conditions. But researchers have determined that the ENSO climate behaviors were also important in climate history, on both sides of the Pacific Ocean.
[It should be remembered that climate models are incapable of correctly predicting these events despite their massive influence on the world's climate. After spending $79 billion on climate research that's a pretty sad statement.]
"The nine researchers conclude that "the finding of similar century-scale variability in climate archives from two El Niño-sensitive regions on opposite sides of the tropical Pacific strongly suggests that they are dominated by the low-frequency variability of ENSO-related changes in the mean state of the surface ocean in [the] equatorial Pacific." And that "century-scale variability," as they describe it, suggests that global warming typically tends to retard El Nino activity, while global cooling tends to promote it."
