Saturday, April 8, 2006
Scientist Forecasts 'super El Niño'
By John Fleck
Copyright © 2006 Albuquerque Journal; Journal Staff Writer
One of the country's leading climate scientists says there is "a good chance" for a "super El Niño" next winter, a powerful warming in the Pacific Ocean linked to wet winters in the Southwest.
In a draft paper circulated to colleagues, NASA climate researcher James Hansen blames global warming for increasing the chance of extreme El Niños.
When they happen, such extreme El Niños can wreak weather havoc worldwide, from deep drought in Australia to flooding in California.
Hansen's new paper drew a flurry of attention among scientists because of his standing as one of the nation's most prominent climate scientists. But the most common reaction was caution.
"The graveyard is filled with missed El Niño forecasts," said Mickey Glantz at the National Center for Atmospheric Research in Boulder, Colo.
Scientists also questioned Hansen's El Niño-global warming link, noting researchers' predictions on the subject vary widely. "There is no consensus," said University of New Mexico climate researcher Dave Gutzler.
One of the strongest reactions came from Mark Cane, at Columbia University's Lamont-Doherty Earth Observatory in New York. "I strongly believe that most of what Jim Hansen writes about El Niño there is incorrect," Cane said in a phone interview Friday.
Hansen, head of NASA's Goddard Institute for Space Studies in New York City, sent a March 29 e-mail to a list of colleagues describing "a draft paper that I intend to submit for publication within a few days" and including a link to the paper on a public Web site. University of Colorado science policy researcher Roger Pielke Jr. made it public late Thursday afternoon on his blog.
Hansen could not be reached for comment Friday.
El Niño and its counterpart, La Niña, act like a global climate seesaw, tipping back and forth every few years as temperatures and winds across the equatorial Pacific shift.
When the seesaw tips to the warm side El Niño New Mexico and the Southwest generally have wet winters. When the seesaw tips to the cool side La Niña, which we are experiencing now things here tend to be dry.
Similar patterns of extreme wet weather or drought follow La Niña and El Niño over large parts of the globe, which makes forecasting the phenomena of critical importance.
"Predicting El Niño ... both on the seasonal time scale and for the next century is a key societal need," French climate researcher Eric Guilyardi recently wrote.
In his draft paper, Hansen argues that ocean conditions now, including a significant warming off the coast of Peru, are similar to those that preceded the extreme El Niño in the winter 1997-98 the strongest in the 20th century.
The 1997-98 event brought, in Cane's words, "worldwide notoriety" to El Niño, including a famous "Saturday Night Live" sketch in which the late Chris Farley played a bombastic professional wrestler known as "El Niño."
In the United States, California felt the brunt of El Niño's wrath, suffering massive flooding. New Mexico received above-average precipitation.
Hansen's prediction is at odds with a forecast issued Thursday by the federal government's Climate Prediction Center, which noted significant uncertainty in the computer climate models used to forecast what will happen next winter. None of the 20 models surveyed by federal forecasters are predicting as strong an El Niño as Hansen suggests.
Gutzler urged patience, saying that there is no need for a 2006-07 El Niño forecast now anyway, and by September the forecast will be more clear. "Let's wait till the end of summer," he said.