Climate scientists are all pretty well on board with the prediction that this coming winter is going to be a severe El Niño season. And for those who did not live in Northern California during the winter of '97/'98, that means we're in for some serious, non-stop rain, and a period of dreariness that will be the opposite of this shiny, sunny summer we just had. But now at least one scientist is linking El Niño to spikes in overall average temperatures around the globe, and suggesting that 2015 is going to be a doozy of high-temperature sweating, and devastation, like we've never seen.
As discussed today on the NYT's Upshot blog, climate-change skeptics have been quick to point out that cooling trends have prevailed over the last decade, defying models that suggested overall warming year over year. But cycles of El Niño and La Niña, in which Pacific Ocean surface temperatures alternately warm and cool, may be the best explanation for the recent dips, since La Niña seasons have prevailed since 1998, and El Niños have been mild to moderate. A severe El Niño is likely not only to mean a wet winter for the West and South, but it could cause severe droughts in Australia and bring high temperatures roaring back across the globe next year.
And, it could affect whether for years to come, too.
But El Niño has the potential to do more than offer a one-time jolt to climate activists. It could unleash a new wave of warming that could shape the debate for a decade, or longer. In this chain of events, a strong El Niño causes a shift in a longer cycle known as the Pacific Decadal Oscillation, which favors more frequent and intense El Niños during its “warm” or “positive” phase. The oscillation has been “negative” or “cool” since the historic El Niño of 1998.
Climate scientists don’t fully understand the exact mechanics of this phenomenon. “But the suspicion is certainly that it is related to El Niño events,” Mr. Trenberth said. “The switch to the current negative phase was probably triggered by the 97-98 El Niño.” The question is whether this fall’s El Niño “might kick the P.D.O. into a positive phase.” If it does, a result would be faster warming, at least doubling the rate of surface temperature increases.
Expect weather events to shape a lot of the debate heading into the 2016 election. And expect not to be basking on a blanket in the park next January or February. Like not even once.