It's usually warranted to go find the
ORIGINAL article, and not just the news blurb to see what they are talking about.
And when you do that, you'd find they did not address ENSO (El Nino, or also referred to as Interdecadal Pacific Oscillation - IPO) as a factor in that paper.
And if you DID a little research, you'd find that the
author of the work YOU linked (John Fyfe, 2013) has a NEW article published THIS year (April 2015) where they DID look at the IPO and its influence vs. 'models'. Guess what they found!??
The recent slowdown in observed surface warming has been attributed to decadal cooling in the tropical Pacific [1,4,5], intensifying trade winds5, changes in El Niño activity [6,7], increasing volcanic activity [8–10] and decreasing solar irradiance[7]. Earlier periods of arrested warming have been observed but received much less attention than the recent period, and their causes are poorly understood. Here we analyse observed and model-simulated global T fields to quantify the contributions of internal climate variability (ICV) to decadal changes in global-mean T since 1920. We show that the Interdecadal Pacific Oscillation (IPO) has been associated with large T anomalies over both ocean and land. Combined with another leading mode of ICV, the IPO explains most of the difference between observed and model-simulated rates of decadal change in global-mean T since 1920,and particularly over the so-called ‘hiatus’ period since about 2000. We conclude that ICV, mainly through the IPO, was largely responsible for the recent slowdown, as well as for earlier slowdowns and accelerations in global-mean T since 1920, with preferred spatial patterns dierent from those associated with GHG-induced warming or aerosol-induced cooling. Recent history suggests that the IPO could reverse course and lead to accelerated global warming in the coming decades.
I know, that's a LOT of words to read. But they've basically shown that models UNDERestimated warming in the late 20th century, due to predominant El Nino cycles of the ENSO/IPO; the models are OVERestimating warming in the last 15 years due to predominant La Nina cycles. Overall, when the proper ENSO is used in the models, they are ACCURATE. And the conclusion here is that if we revert to a dominant El Nino period, we are going to experience accelerated warming.
http://www.nature.com/nclimate/journal/v5/n6/full/nclimate2605.html
Last I checked, 2015 > 2013, and when the SAME AUTHOR is correcting his prior work with updated information/data, it's a good idea to look at the more recent works....
EDIT: If you are REALLY interested in understanding this, I can link you graphs that mirror their basic analysis - their paper is rather technical, and I don't believe it is free/open access. But it's not difficult to link the plots which show precisely the effects they identified, using the data on the WoodForTrees site.
