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.
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OK. So how well would this model simulate the CET temperature during the latter part of the 17th and early 18th Century when the temp rose by about 2 deg C when there was no “human warming due to CO2”. I am skeptical that even half of the more recent temps are due to AGW given the model is again one that is driven primarily by CO2. The model output, without changing any of the no doubt vast number of “fitting” parameters, will therefore need to be validated from this point on.
UK US…..opinion piece? You’re being too nice. It’s mere speculation. If you want the pats on the back all you have to say is:
Cooling is a temporal fluke
Warming is the truth
Repeat, try to keep those checks coming in a few more years…
So what I am getting out of this they now have a working model that “proves” your book as much as one of their models can. Congratulations when will you get the due credit I wonder.
Wow, ENSO has a massive influence on global temperature? Thank you, Captain Obvious! You can be paid for telling people this? This is getting more and more like the ‘battle’ against Heliocentrisim centuries ago; the proponents of AGW are pouring forth increasingly ludicrous reasons and theories as to why none of the warming the ‘holy’ models prophesied has occurred, never daring to admit the blindingly obvious – the models are wrong – ’cause that’d be heresy.
It seems we have crossed the threshold into Pathological Science.
Good eyes, Judith. And thanks for posting that graph. It wasn’t readable in the Nature preview.
Add to this the Eschenbach Effect, which caps the tropical SSTs at a max of 31C, and we have another constraint on CO2 warming. The radiative effect of increasing CO2 pushes against the development of clouds and thunderstorms in the ITCZ which “chimney” the heat up into the upper atmosphere where it escapes to space.
What I gather from those charts is this: We are due for a volcano.
Is it the “d”…or the “u”…or the “h” that is confusing or surprising? So giving the computer model the observations of the very thing that holds onto or coughs up heat onto land “surprisingly” traces the land temperature data. Who would have thought that a trained model could do that? I am boggled. Just boggled.
Reported in The Guardian, but they don’t bother showing the POGA C chart; focus is all on the “hiatus”.
Still, next time some alarmist tells you there is no pause in the surface temperature you call label them a denier and state that “even The Guardian acknowledges a hiatus in warming”.
Actually we haven’t had “freakish” (cool word Bob) La Nina’s. It’s been more like La Nada. So I don’t think the oceans are soaking up heat like they did before. When we return to El Nino’s and the belching up of all that heat, we won’t get much more than a gag here and there.
_ _ _
Multidecadal Climate (including AMO) is simple.
Details:
Multidecadal Solar-Terrestrial-Climate 101
_ _ _
Sorry can’t edit, Guardian again. This seems to be the closest they come to acknowledging the warm period (by implication)…
Now lets see, 40s to 70s was cooling. 2000+ was more cooling, the “hiatus”.
Hmmmm, that leaves an unmentioned period of 2 decades or so; a period between two cooling periods; a period where the cycle was on the other side of cooling, the uncooled phase of the cycle, better known as… as… head… in… sand…
This is not rational, in two respects. Using only the local measure of ENSO is arbitrary as the effects of a Nino will reach further afield to regions where there is no Nina effect to force such a return swing. It’s like saying that now ENSO is the sole measure of natural variation. And secondly, how can such multi-decade trends in natural variability, be internal variation, when naturally, Earth’s ocean-atmosphere systems tend to work towards stability?
La Nada…..(LOL)……let me say it again…Pathological Science.
Remember they made the recent La Nina episodes deeper and longer:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
The thing is though, the big up steps in global warming arise out of multi-year La Nina episodes, I hope these folks don’t think we are really in for such a rise just round the corner, I’ll be surprised if the Nino’s can keep pace with falling global temp’s through the next four years.
Alarmists seem to have the same problem as the Labour party does in Australia, something is only correct when they say it, despite skeptics saying it already for years.
at the end of your paper you said,
“I’m not sure how good my eyeball estimates are, and you can pick other start/end dates.”
ok, then I will.
from 1960 to 2010 the 5-year running mean variability is negative .02 (-.02) global
compare that to
http://www.woodfortrees.org/plot/hadcrut4gl/last:500/mean:13/plot/hadcrut4gl/last:500/trend/plot/rss/last:500/mean:13/plot/rss/last:500/trend
Hmmmmm Would Michale Mann be considered a pathological scientist?
“Pathological science, as defined by Langmuir, is a psychological process in which a scientist, originally conforming to the scientific method, unconsciously veers from that method, and begins a pathological process of wishful data interpretation (see the Observer-expectancy effect, and cognitive bias).”
Kosaka and Xie describe their approach as being novel. A paper that explores the heart of this issue was published back in 2008 by Compo et al.
Compo,G.P., and P.D. Sardeshmukh, 2008: Oceanic influences on recent continental warming. Climate Dynamics, in press.
The abstract reads
“Evidence is presented that the recent worldwide land warming has occurred largely in response to a worldwide warming of the oceans rather than as a direct response to increasing greenhouse gases (GHGs) over land. Atmospheric model simulations of the last half-century with prescribed observed ocean temperature changes, but without prescribed GHG changes, account for most of the land warming. The oceanic influence has occurred through hydrodynamic-radiative teleconnections, primarily by moistening and warming the air over land and increasing the downward longwave radiation at the surface. The oceans may themselves have warmed from a combination of natural and anthropogenic influences.”
Ulric you are joking right? If Earth’s ocean-atmosphere systems tended to work towards stability it would stop working the way it does, which is similar to the atmosphere. The atmosphere thankfully moves around because it is in a pressure system battle that waxes and wanes. Oceans are no different. Warm and cold water flow up and down and around like a lava lamp, fighting each other for space, as the entire system waxes and wanes its heat content via the conveyor belt currents beneath, and on the surface through calm or choppy seas, keeping it quietly just below the surface or peeling it off and shoving it elsewhere. Stable? Hardly.
I think JC has a typo in her statement:
■POGA H: 0.68C (natural plus anthropogenic)
That probably should read: “POGA H: 0.86C”
By my estimate, it’s from -0.47°C (1975) to +0.35°(1998), which is delta T of 0.82°C – close enough for eyeball work to 0.86°C.
That’s how she gets natural internal variability being “significantly more” than half the observed warming (0.68 is NOT significantly more than half of 0.4, right?).
If one looks at the history of ENSO over the past 60 years, there were more La Ninas (blue) by far during the 1960s to mid-1970s global cooling scare period than during the 1980s-1990s foundation of the global warming scare.
http://www.esrl.noaa.gov/psd/enso/mei/ts.gif
As I was just commenting in another thread, El Ninos (/ La Ninas) are largely how temperature change is expressed in the climate system. High solar forcing charges up and allows a strong El Nino afterwards. Weak does not, like I can already tell that no El Nino in the latter part of this decade will exceed the warmth of the 1998 El Nino (short of data fudging) as this cycle wasn’t as strong as the solar cycle preparing it.
Back in 1997, warmists were predicting more frequent El Ninos from warming, and the 1997-1998 El Nino was supposed to be exceeded by still stronger ones, with La Ninas supposed to go away, as implied in an article published at the time: http://news.bbc.co.uk/2/hi/science/nature/25433.stm . That didn’t happen, so now they are trying to change their story.
Regarding these two sentences of Kosaka and Xie:
“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.”
The first sentence is true in itself, although it neglects why there have been more La Ninas (the reason being reduced solar activity and GCR change, although the small percentage difference so far is minor compared to the tens of percent difference in GCR levels which occurred during the Little Ice Age and which may soon occur again in coming decades).
The second sentence is just kowtowing to what is politically in favor, helping the article get published but not likely true. Rather the end of the Modern Maximum of solar activity and a Grand Minimum comes in all probability.
The Kosaka and Xie paper implied estimate of only 0.4C of 0.68C or thus only 60% of global warming being from natural causes is from models treating the effect of cosmic ray variation as 0%, rather than what is seen in http://s24.postimg.org/rbbws9o85/overview.gif
(As strong as the preceding link is for all from temperature to clouds / humidity / sea level, extra exactness on still smaller timescales neither I nor apparently anyone else has managed, although I have a hypothesis, needing more work, that the ENSO oscillation’s El Ninos & La Ninas could be closely predicted, if solar activity could be guessed in advance, via modeling the ENSO as a semi-independent oscillation where an oscillation occurs in any case but its amplitude and timing is determined by prior external solar/GCR forcing).
Bob Tisdale,
Your articles are always worth reading. I’ve watched over the years as you have mastered the subject, and surpassed all but a very small handful of specialists. You are a real asset to the knowledge base.
What I don’t understand is why all readers don’t give your articles 5 stars. The reason must be that there is always a grumpy True Believer who is the fly in the ointment.
Anyway, keep ’em coming. I always learn something that I didn’t know before I started reading.
@John Blake –
I’d extend that invitation to stop breathing specifically to the alarmists. Don’t they know each one of them emits 500 kg of CO2 every year? Unconscionable of them. /sarc