Note: Dr. Judith Curry also has an essay on this important paper. She writes:
My mind has been blown by a new paper just published in Nature.
Just when I least expected it, after a busy day when I took a few minutes to respond to a query from a journalist about a new paper just published in Nature [link to abstract]:
This has important implications for IPCC’s upcoming AR5 report, where they will attempt to give attribution to the warming, which now looks more and more like a natural cycle. See updates below. – Anthony
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Guest essay by Bob Tisdale
The recently published climate model-based paper Recent global-warming hiatus tied to equatorial Pacific surface cooling [Paywalled] by Yu Kosaka and Shang-Ping Xie has gained a lot of attention around the blogosphere. Like Meehl et al (2012) and Meehl et al (2013), Kosaka and Xie blame the warming stoppage on the recent domination of La Niña events. The last two sentences of Kosaka and Xie (2013) read:
Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas increase.
Anyone with a little common sense who’s reading the abstract and the hype around the blogosphere and the Meehl et al papers will logically now be asking: if La Niña events can stop global warming, then how much do El Niño events contribute? 50%? The climate science community is actually hurting itself when they fail to answer the obvious questions.
And what about the Atlantic Multidecadal Oscillation (AMO)? What happens to global surface temperatures when the AMO also peaks and no longer contributes to the warming?
The climate science community skirts the common-sense questions, so no one takes them seriously.
UPDATE
Another two comments:
Kosaka and Xie (2013) appear to believe the correlation between their model and observed temperatures adds to the credibility of their findings. They write in the abstract:
Although the surface temperature prescription is limited to only 8.2% of the global surface, our model reproduces the annual-mean global temperature remarkably well with correlation coefficient r = 0.97 for 1970–2012 (which includes the current hiatus and a period of accelerated global warming).
Kosaka and Xie (2013) used the observed sea surface temperatures of the central and eastern equatorial Pacific as an input to their climate model. By doing so they captured the actual El Niño-Southern Oscillation (ENSO) signal. ENSO is the dominant mode of natural variability on the planet. In layman terms, El Niño and La Niña events are responsible for the year-to-year wiggles. It’s therefore not surprising that when they added the source of the wiggles, the models included the wiggles, which raised the correlation coefficient.
Table 1 from Kosaka and Xie (2013) is also revealing. The “HIST” experiment is for the climate model forced by manmade greenhouse gases and other forcings, and the “POGA-H” adds the tropical Pacific sea surface temperature data to the “HIST” forcings. For the modeled period of 1971-1997, adding the ENSO signal increased the linear trend by 34%. Maybe that’s why modeling groups exclude the multidecadal variability of ENSO by skewing ENSO to zero. That way El Niños and La Niñas don’t contribute to or detract from the warming. Unfortunately, by doing so, the models have limited use as tools to project future climate.
UPDATE2 (Anthony): From Dr. Judith Curry’s essay – she writes at her blog:
The results in terms of global-average surface temperature are shown in Fig 1 below:
In Fig 1 a, you can see how well the POGA H global average surface temperature matches the observations particularly since about 1965 (note central Pacific Ocean temperatures have increasing and significant uncertainty prior to 1980).
What is mind blowing is Figure 1b, which gives the POGA C simulations (natural internal variability only). The main ’fingerprint’ of AGW has been the detection of a separation between climate model runs with natural plus anthropogenic forcing, versus natural variability only. The detection of AGW has emerged sometime in the late 1970′s , early 1980′s.
Compare the temperature increase between 1975-1998 (main warming period in the latter part of the 20th century) for both POGA H and POGA C:
- POGA H: 0.68C (natural plus anthropogenic)
- POGA C: 0.4C (natural internal variability only)
I’m not sure how good my eyeball estimates are, and you can pick other start/end dates. But no matter what, I am coming up with natural internal variability associated accounting for significantly MORE than half of the observed warming.
The paper abstract:
Recent global-warming hiatus tied to equatorial Pacific surface cooling
Yu Kosaka & Shang-Ping Xie Nature (2013) doi:10.1038/nature12534
Despite the continued increase in atmospheric greenhouse gas concentrations, the annual-mean global temperature has not risen in the twenty-first century1, 2, challenging the prevailing view that anthropogenic forcing causes climate warming. Various mechanisms have been proposed for this hiatus in global warming3, 4, 5, 6, but their relative importance has not been quantified, hampering observational estimates of climate sensitivity. Here we show that accounting for recent cooling in the eastern equatorial Pacific reconciles climate simulations and observations. We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model. Although the surface temperature prescription is limited to only 8.2% of the global surface, our model reproduces the annual-mean global temperature remarkably well with correlation coefficient r = 0.97 for 1970–2012 (which includes the current hiatus and a period of accelerated global warming). Moreover, our simulation captures major seasonal and regional characteristics of the hiatus, including the intensified Walker circulation, the winter cooling in northwestern North America and the prolonged drought in the southern USA. Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas increase.
Pamela Gray says:
“Stephens argument is similar to Ulric’s. They both are unknowingly making the elephant’s trunk wriggle through the sheer number of tiny and large variables…”
Oh sure, solar wind speed polar air pressure, which shifts the jet stream, which when south inhibits the trade winds.
Ulric Lyons:
At September 2, 2013 at 10:00 am you say to me
No, I will not bite.
I will “carry on” only if and only when you answer any of the points or questions I put to you. Otherwise I will not waste effort on your arm-waving assertions.
I am now writing to draw the attention of others to your evasiveness.
Richard
Ulric Lyons says:
September 2, 2013 at 10:27 am
My last comment the symbols didn’t post; “solar wind speed *dictates* polar air pressure”.
@richardscourtney
I dealt with all your points.
Ulric, was it you that pointed readers to the solar wind data and you contention that low temperatures are part and parcel of low solar wind? Were you referring to a random non-connected observation, not uncommon with two noisy sets of data, or implicitly telling the reader that one drives the other? If the later, I assume you use such proposed connections consistently in your forecasts. Correct me if I am wrong. And while we are at it, want to describe your forecast methodology?
Then solar wind speed should dictate air pressure in other places as well. There are several macro semi permanent pressure systems around the globe. Does it?
“..or implicitly telling the reader that one drives the other? If the later, I assume you use such proposed connections consistently in your forecasts.”
Yes, but the connection is the result of the forecast, it is not used in it.
“Then solar wind speed should dictate air pressure in other places as well. There are several macro semi permanent pressure systems around the globe. Does it?”
Yes, ENSO.
“And while we are at it, want to describe your forecast methodology?”
Not in comments, I would need to present a full case, and seeing there is still a planetary talk D-notice in effect here, I really would not want to get cut off in mid stream.
To consider:
The reader is cautioned regarding stated connections in proposed solar-atmospheric pressure systems. The commentators proposing these connections should link to papers, readily available and not behind paywalls, they use to support their thesis.
The reader is also cautioned regarding these papers, that solar parameter data sets are currently under broadly supported and well-qualified efforts to reconcile disparate data sets. It is likely that “recent increased solar activity” data sets will be reconciled to solar indices that do not show such an increase, thus calling into question papers that demonstrate correlations using these pre-reconciled data sets. A case in point, highly regarded scientists whose previous papers depended on pre-reconciled data sets are now highly engaged and supportive of the very endeavor that will call into question their interpretations made earlier.
The reader should also regard efforts to expand the well-known and mathematically plausible but observationally undetectable relationship between the approximate 11-year solar cycle and Earth temperature, to long term temperature trends with equal caution.
In other words, think.
Pamela Gray says:
“The commentators proposing these connections should link to papers, readily available and not behind paywalls, they use to support their thesis.”
No, I’ll link straight to the OMNI solar data thanks as I did earlier, and you’ll see that the plasma speed graph that I linked to earlier was direct from here and not from a “paper”: http://omniweb.gsfc.nasa.gov/form/dx1.html
And show me where there are “disparate data sets” of solar wind measurements.
http://www.leif.org/research/Solar%20Wind%20at%20Earth%201883-2007.pdf
Ulric, proper citation of papers pro and against is a requirement of any introduction of a proposed hypothesis. What papers are you citing please?
To be clear, we are talking about extended temperature trends and their connection with solar parameters, not the well-known reactions to solar blasts, which are temporary affects (out to 4 or 5 days post-impact) rising above a constant stream of buzzy noisy little waves of background solar wind.
Pamela Gray says:
“What papers are you citing please?
I am citing original OMNI data, Leif’s Ap index from 1844, and original AO/NAO/ENSO data.
“To be clear, we are talking about extended temperature trends and their connection with solar parameters, ”
I’m not, I am mapping the noise that makes the trend.
“not the well-known reactions to solar blasts, which are temporary affects”
What effects?
Temporary changes in atmospheric pressure systems on Earth, clearly documented and widely accepted, even down to sea level. And it is tiny though measurable. Which begs the question: Does it drive weather pattern variations for days, weeks, months, years, decades? Not above natural variability entirely intrinsic in Earth-bound systems. In other words, these rare solar-atmospheric pressure events pale in comparison to pressure changes seen when the solar wind is doing anything else. Which is what it does most of the time. Only rarely does it ahhchooo!
http://www.technologyreview.com/view/424665/solar-wind-changes-atmospheric-pressure-over-south-korea/
Temperature trends are statistical averages of daily noise. They are not two separate systems. Go ahead and study the noise. It is what I would do.
“Not above natural variability entirely intrinsic in Earth-bound systems.”
All the dominant stuff like daily/weekly AO and hence jet stream displacement is solar forced, otherwise I would not be able to forecast and hindcast at such scales.
Here is the South Korea study pdg. Critical analysis of contents required.
http://arxiv.org/pdf/1107.1841.pdf
Again, papers please. I can readily find papers. How come you can’t or won’t?
Pamela Gray says:
September 2, 2013 at 12:31 pm
“Again, papers please. I can readily find papers. How come you can’t or won’t?”
Because I can make better sense of the raw data myself.
Okay, so you say that you are using the AO to forecast (I am assuming so correct me if I’m wrong). Who doesn’t. But you are “investigating” what causes the AO system to vary in SLP and probably also to split and shift. Everyone knows that all of these changes can be used to predict weather with a rather high, IE about .8 correlation out to about 7 days, degree of accuracy. Again who doesn’t use it. But you are saying that its parameters (SLP, shape(s), and location) are primarily solar driven even to the level of its daily noise. Correct?
http://www.nc-climate.ncsu.edu/climate/patterns/NAO.html
Goodness this is fun!
Hell, I’s still in my jammies!
Some food to eat while we discuss. By the way large wave 1 and 2 Rossby Waves propogate up into the stratosphere so be careful when you attribute stratospheric changes to top down solar influences.
http://www.appinsys.com/GlobalWarming/AO_Regime.htm
Gotta go to town in a bit. Clearly we have lots to chew on with my last reference and many papers so step up to the plate Ulric. Papers please. Delivered on a silver platter no less.
Pamela Gray says:
“Okay, so you say that you are using the AO to forecast (I am assuming so correct me if I’m wrong).”
Yes wrong, the forecast tells me what the AO will do, not the reverse. I am looking at largely negative AO conditions from around January 7th 2014, severe at times, till at least February 20th.
I have not missed a single significant individual cold shot in the last 3 winters, and have not over forecast a single one either.