Thing is, Anthony has already posted a number of articles about Trenberth and Fasullo (2013). There is this one by Bob Tisdale, which I wrote about here. And this one and this one - both also by Bob Tisdale. Perennially Puzzled Bob Tisdale was trying to argue that Trenberth and Fasullo were cheating or something silly like that. (Since I wrote the main article, Anthony has elevated his piece to a "sticky", which just shows what HotWhopper readers know from past experience, Anthony's memory is not that great.)
In this latest WUWT article (archived here), Anthony wrote this, as if it was the first article about the Trenberth Fasullo paper at WUWT, instead of the fourth in a just a little over a month:
From the “settled science” department. It seems even Dr. Kevin Trenberth is now admitting to the cyclic influences of the AMO and PDO on global climate. Neither “carbon” nor “carbon dioxide” is mentioned in this article that cites Trenberth as saying: “The 1997 to ’98 El Niño event was a trigger for the changes in the Pacific, and I think that’s very probably the beginning of the hiatus,”
This is significant, as it represents a coming to terms with “the pause” not only by Nature, but by Trenberth too.
For anyone who knows of Kevin Trenberth's work, to say that
Kevin Trenberth has been publishing papers about the oceans for more than forty years. He knows more about oceans than all the purported hundreds of thousands of WUWT readers combined. John Fasullo is younger, but if you combine them, they have more than 55 person years of science between them.
If Anthony Watts is interested in tracking the history of discovery of the Pacific Decadal Oscillation, he could do a lot worse than starting with the following two seminal papers by Kevin Trenberth, going back nearly 25 years:
Trenberth, Kevin E. "Recent observed interdecadal climate changes in the Northern Hemisphere." Bulletin of the American Meteorological Society 71, no. 7 (1990): 988-993.
Trenberth, Kevin E., and James W. Hurrell. "Decadal atmosphere-ocean variations in the Pacific." Climate Dynamics 9, no. 6 (1994): 303-319.
Since we're tracking back history, this 1981 paper might be of interest - though it's probably peripheral to the subject, it was cited in Mantua, Hare et al (1997).
Trenberth, Kevin E., and Daniel A. Paolino Jr. "Characteristic patterns of variability of sea level pressure in the Northern Hemisphere." Monthly Weather Review 109, no. 6 (1981): 1169-1189.
What caught my eye was the opening sentence, particularly given Anthony's opening comments about Dr Trenberth "finally admitting to ... cyclic influences":
The atmospheric circulation is characterized by various "centers of action" which are spatially interdependent.Since I've plugged the references here, I'll add the PDO paper:
Mantua, Nathan J., Steven R. Hare, Yuan Zhang, John M. Wallace, and Robert C. Francis. "A Pacific interdecadal climate oscillation with impacts on salmon production." Bulletin of the American Meteorological Society 78, no. 6 (1997): 1069-1079.
Back to the Nature article - here are some key excerpts discussing the "hiatus" in surface temperature rise in recent years:
Trenberth, ... estimated that aerosols and solar activity account for just 20% of the hiatus. That leaves the bulk of the hiatus to the oceans, which serve as giant sponges for heat. And here, the spotlight falls on the equatorial Pacific.
...Just before the hiatus took hold, that region had turned unusually warm during the El Niño of 1997–98, which fuelled extreme weather across the planet, from floods in Chile and California to droughts and wildfires in Mexico and Indonesia. But it ended just as quickly as it had begun, and by late 1998 cold waters — a mark of El Niño’s sister effect, La Niña — had returned to the eastern equatorial Pacific with a vengeance. More importantly, the entire eastern Pacific flipped into a cool state that has continued more or less to this day.
This variation in ocean temperature, known as the Pacific Decadal Oscillation (PDO), may be a crucial piece of the hiatus puzzle. The cycle reverses every 15–30 years, and in its positive phase, the oscillation favours El Niño, which tends to warm the atmosphere (see ‘The fickle ocean’). After a couple of decades of releasing heat from the eastern and central Pacific, the region cools and enters the negative phase of the PDO. This state tends towards La Niña, which brings cool waters up from the depths along the Equator and tends to cool the planet. Researchers identified the PDO pattern in 1997, but have only recently begun to understand how it fits in with broader ocean-circulation patterns and how it may help to explain the hiatus.
One important finding came in 2011, when a team of researchers at NCAR led by Gerald Meehl reported that inserting a PDO pattern into global climate models causes decade-scale breaks in global warming3. Ocean-temperature data from the recent hiatus reveal why: in a subsequent study, the NCAR researchers showed that more heat moved into the deep ocean after 1998, which helped to prevent the atmosphere from warming6. In a third paper, the group used computer models to document the flip side of the process: when the PDO switches to its positive phase, it heats up the surface ocean and atmosphere, helping to drive decades of rapid warming7.
A key breakthrough came last year from Shang-Ping Xie and Yu Kosaka at the Scripps Institution of Oceanography in La Jolla, California. The duo took a different tack, by programming a model with actual sea surface temperatures from recent decades in the eastern equatorial Pacific, and then seeing what happened to the rest of the globe8. Their model not only recreated the hiatus in global temperatures, but also reproduced some of the seasonal and regional climate trends that have marked the hiatus, including warming in many areas and cooler northern winters.
...That was investigated by Trenberth and John Fasullo, also at NCAR, who brought in winds and ocean data to explain how the pattern emerges4. Their study documents how tropical trade winds associated with La Niña conditions help to drive warm water westward and, ultimately, deep into the ocean, while promoting the upwelling of cool waters along the eastern equatorial region. In extreme cases, such as the La Niña of 1998, this may be able to push the ocean into a cool phase of the PDO. An analysis of historical data buttressed these conclusions, showing that the cool phase of the PDO coincided with a few decades of cooler temperatures after the Second World War (see ‘The Pacific’s global reach’), and that the warm phase lined up with the sharp spike seen in global temperatures between 1976 and 1998 (ref. 4).
The article goes on to discuss the work of Mark Cane, who proposes that global warming may lead to extended La Ninas. Other scientists' work suggests that global warming may lead to more El Ninos. Time (and more research) will tell.
Now you'll be wondering why Anthony Watts mentioned the Atlantic Multidecadal Oscillation. So am I. It isn't mentioned in the Nature article although it is mentioned in Trenberth and Fasullo (2013). Maybe Anthony actually read a scientific paper (not likely).
From the WUWT comments
There aren't any stand out comments, so I'll award the comment of the day to Anthony Watts himself for his opening comments about Kevin Trenberth, who was arguably very influential in shaping the understanding of what we know today as the Pacific Decadal Oscillation.
Most WUWT readers will be in for a big shock when the next El Nino arrives.
DirkH doesn't have a clue about climate models and says:
January 16, 2014 at 4:10 am
“The simplest explanation for both the hiatus and the discrepancy in the models is natural variability.”
No, that’s nonsense. The simplest explanation is that the theory is falsified, and that the models are wrong. In fact, EVERYTHING points at the models being wrong, false and useless. Not ONE thing points to the models being right, correct, or useful. There are simply no such reports. We should see thousands of triumphant papers confirming again and again that the models got this right and that right after many years of painstaking development, but we NEVER see any such report.
That’s like celebrating the 100,000th Lancaster bomber built and shipped over the Atlantic while not one of them ever made it through the Kammhuber line.
johnmarshall is a "scientists don't no nuffin'" denier and says:
January 16, 2014 at 4:12 am
Trenberth getting a reality hit?
One of his problems is a complete misunderstanding of latent heat which is where much heat has been used for in cooling at the surface and has stupid graphic in AR4 which uses a flat earth with 24/7 sunlight and no idea from where radiated energy comes from.
Chris Marlowe says:
January 16, 2014 at 4:29 am
The smartest of these guys will be looking for an exit strategy and will eventually look the other way if anyone suggests they were once on the bandwagon beating the drum.
Stephen Richards is a conspiracy nutter and says:
January 16, 2014 at 4:36 am
What I don’t want is for these guys to remain in place when this whole scam is exposed. Like Erlich they will just keep coming back with another scare for money scheme.
M Courtney struggles to understand climate and energy accumulation and says:
January 16, 2014 at 4:46 am
Not sure that this report does fully recognise the impact of natural cycles.
It seems to think that the cooling phase of the PDO exactly balances the warming from Greenhouse gases over several decades when the emissions have varied.
That raises two questions:
1 How come the balancing is so precise – are our emissions coupled to the PDO or is their effect swamped by the PDO?
2 If the PDO can match the magnitude of AGW on th ecool sided, can it match the magnitude of AGW on the warm side? If so, how do we know any of the 20thC warming was manmade?
Ivor Ward misunderstands what's written and thinks that Kevin Trenberth agrees with Bob Tisdale that there are leprechauns burning coal fires in the oceans and says:
January 16, 2014 at 5:02 am
So essentially he is saying that Bob Tisdale is right and he was wrong. Why does Trenberth not just say that and get it over with?
Jim Cripwell is about right (except when it comes to Australia's PM Tony Abbott) when he says (excerpt):
January 16, 2014 at 5:12 am
Unfortunately, what is written on WUWT carries little weight with our politicians and the MSM.
graphicconception also mistakenly thinks that Kevin Trenberth attributes global warming to leprechauns like Bob Tisdale does, and says:
January 16, 2014 at 5:24 am
The temperature graph is a kind of integration of the PDO Index graph.
(You need to add 0.6 to the Index, cumulate and then scale. Where do I collect my Nobel Prize?)
So as Bob Tisdale has been saying, if I understand it correctly, PDO variations are not just oscillations about a mean. They leave a resultant change.
evanmjones knows nothing about science either. I bet he thinks a fake sceptic invented the PDO when he says:
January 16, 2014 at 5:29 am
Yeah, they finally discovered the PDO. Sort of like a professional secretary discovering the Shift key. Bloody amateurs.
Now they need to “discover” that their panic was due to a positive PDO and, consequently, their “projections” were at least twice too high. Then maybe they can learn the rest of the alphabet . . .
I can't say I agree with clivebest when he says:
January 16, 2014 at 5:56 am
The graphic above shows that we have only just entered a new 30 year long cool period of the PDO. This means that there will be no further warming until ~2030. Warming may well then resume after 2030, but whichever way you look at it, climate sensitivity looks to be about one half of current IPCC estimates. How is the IPCC going to keep the egg off its face for the next 15 years ?
Conspiracy nutter Timothy spawned an idiot in David Ball, who says:
January 16, 2014 at 6:13 am
“Now, after having wasted at least 30 years of public money and time due to our false ideology, we return you to your regularly scheduled viewing,…..”
January 16, 2014 at 6:26 am
At some point the deadenders will attack the wavering warmists and excommunicate them from the treasure hunt known as carbon tax revenue. The only question is whether it will be a peaceful process or a North Korean-style purge.
Clay Marley is mistaken if he thinks Bob Tisdale invented the "sloshing" ENSO. Unlike Bob, who thinks the oceans will keep warming forever, Clay is hopeful that Earth's temperatures will one day return to "normal". He says "it has to end...":
January 16, 2014 at 6:38 am
First I’d heard the term “sloshing” is in Tisdale’s posts and book. It isn’t intended to be a scientifiky term. That Trentberth uses it probably means at least that he is reading Tisdale, which would be a good thing. But he is hoping/praying for another strong El Niño that would start the warming again.
Tisdale is saying that a strong El Niño will cause a rapid SST rise over much of the earth. After the event, SST’s cool slowly. If the El Niño events come frequently enough there isn’t enough time between them to cool completely. Thus we see a stairstep warming with slight cooling between events. This is what has been happening since around 1918.
It has to end though. We can’t keep getting strong El Niños until the oceans boil. So there must be some process that slows and weakens the El Niños and allows the rest-of-world to get back to lower temps.
Richard M says that Dr Trenberth "don't know nuffin'" about oceans and could learn a thing or two from Perennially Puzzled Bob. This one is runner-up comment of the day - after Anthony's opening comment:
January 16, 2014 at 7:15 am
Trenberth doesn’t realize that El Niño events might not quite work the same during a -PDO. As Tisdale has demonstrated it is the after effects of the El Niño during a +PDO that have a lot to do with the step up warming that occurs even after the following La Niña. I have a feeling that the changes in circulation in a -PDO will eliminate that effect (didn’t see it during the 2009-2010 El Niño). That is probably why the global temperature falls during a -PDO.
I wonder how many copies of Tisdale’s books will find their way to NCAR? Or, should I say …. have found their way?
These WUWT-ers aren't just scientifically illiterate. They are deluded. Here's another one from Economic Geologist who says:
January 16, 2014 at 7:42 am
I think Trenberth is reading Tisdale, but will never give him credit. The AGW crowd will slowly morph their scientific positions as their predictions continue to fail, and no-one will be held accountable for all the money wasted on useless, misguided research. And no-one in the skeptic camp will be acknowledged for having seen the weaknesses in the climate community’s science. There’s no justice in this world.
Oh - that's more than enough. I can't be bothered reading the rest. You can read more here if you want to.