Disasters“Iconic” El Niño may bring more than rain to California

Published 20 November 2015

A few weeks ago in the hills north of Los Angeles, heavy rain set off widespread mudslides that blocked roads and covered highways, burying hundreds of vehicles and bringing much of Los Angeles’ infamous traffic to a standstill. For Californians, these mudslides are just one of many recent harbingers signaling the imminent arrival of a “monster” El Niño — an El Niño that started bubbling up from unusually warm temperatures in the tropical Pacific last summer. In Southern California, a strong El Niño usually signals rain, and given that California is now in the throes of a severe drought, it seems like that should be a good thing, even if it comes with risk of floods. But the reality of climate is more complex and counter-intuitive than it first appears, and Californians should be careful what they wish for.

A few weeks ago in the hills north of Los Angeles, heavy rain set off widespread mudslidesthat blocked roads and covered highways, burying hundreds of vehicles and bringing much of Los Angeles’ infamous traffic to a standstill.

For Californians, these mudslides are just one of many recent harbingers signaling the imminent arrivalof a “monster” El Niño — an El Niño that started bubbling up from unusually warm temperatures in the tropical Pacific last summer.

In Southern California, a strong El Niño usually signals rain. Given that California is now in the throes of a severe drought, it seems like that should be a good thing, even if it comes with risk of floods. But the reality of climate is more complex and counter-intuitive than it first appears.

“It turns out,” when it comes to explaining climate in a place like California, “there are details you’d like to be able to smooth out as not part of the big picture — but those details are the big picture,” says Scott Steinschneider, a postdoctoral research fellow at the Columbia Water Center.

A “Poster-child” El Niño
Columbia University’s Earth Institute notes that The El Niño/Southern Oscillationis a semi-periodic climate pattern that cycles every two to seven years, depending on the warmth of ocean temperatures in the South Equatorial or Central Pacific. In the El Niño phase, warmer than average sea surface temperatures set off chain reactions in the climate around the world, impacting everything from the quality of fishing to the global price of chocolate, coffee, rice, and sugar and the inflation targets of the European Central Bank. The warmer the temperatures, the more dramatic the impact. By contrast, the Pacific’s cooler phase (“La Niña”) has different effects.

Lisa Goddard, the director of Columbia University’s International Research Institute for Climate and Society and one of the world’s leading experts on the El Niño/La Niña cycle, expects that this year’s El Niño will be “an iconic event” comparable to the 1997-98 season. “This is a kind of poster-child El Niño,” she says. “The garden variety events no one really looks at because they’re not very interesting. It’s the iconic events that we’re used to looking at. And this one is icon-worthy.”

She adds that this year’s El Niño may still not turn out to be as big as the 1997-1998 season, but “it’s a contender.”