Study Shows El Nino Is Active in Cold Weather, Dating to Ice Age

El Nino, the bane of farmers and insurance companies the world over because of its ability to generate extreme weather, dates back to the last Ice Age, researchers said Friday.

They said their findings showed that El Nino, a circulation pattern in the Pacific that affects weather the world over, is not just active during warm weather.

Tammy Rittenour of the University of Nebraska in Lincoln and colleagues at the University of Massachusetts looked at soil samples taken from the dried-up beds of ancient lakes in New England.

The cores, dating from between 17,500 to 13,500 years ago, show patterns that look like the modern three-year to five-year cycles of El Nino, the team reported in this week’s issue of the journal Science.

“It was previously thought that El Ninos were a warm-weather phenomenon that began only 5,000 years ago,” Rittenour said in a statement.

“Our findings have pushed the record of El Nino activity back to 17,500 years ago. This is remarkable because at that time all of Canada and most of the northern United States was covered by a large ice sheet.”

Julie Brigham-Grette of the University of Massachusetts said this showed the weather pattern was active during cold periods in world climate as well as warmer times.

“El Nino-like climate change can happen under all sorts of conditions, even when the Northern Hemisphere is covered with large ice sheets,” she said in a statement.