El Niño over the ages: Is El Niño something new and unusual in the Earths climate?
No. El Niño has been occurring at least since people started putting thermometers in the ocean around the middle of the nineteenth century. Moreover, archived documents left by the Spanish colonists in Peru confirm that El Niño impacts such as occur now (flooding, marine life disturbances, etc.) have been felt in Peru ever since the first conquistador (Francisco Pizarro) set foot there in the early 16th century. And, as far as we can tell from paleo-climatic indicators such as geological evidence & tree rings, El Niño has been occurring for at least thousands of years, probably much as it has during this century. It will probably continue to occur as long as our climate system works the way it has since the most recent ice sheets of the late pleistocene receded (i.e., needing to get rid of excess tropical heat).
