Note: Above graph comes from this source and not the paper below. Only the abstract is available. (Note from 2016: The link to the graph died, the image was recovered from the Wayback Machine and an edit made to restore it on Oct 31, 2016)
A new peer-reviewed climate study is presenting a head on challenge to man-made global warming claims. The study by three climate researchers appears in the July 23, 2009 edition of Journal of Geophysical Research. (Link to Abstract)
Full Press Release and Abstract to Study:
July 23, 2009
Three Australasian researchers have shown that natural forces are the dominant influence on climate, in a study just published in the highly-regarded Journal of Geophysical Research. According to this study little or none of the late 20th century global warming and cooling can be attributed to human activity.
The research, by Chris de Freitas, a climate scientist at the University of Auckland in New Zealand, John McLean (Melbourne) and Bob Carter (James Cook University), finds that the El Niño-Southern Oscillation (ENSO) is a key indicator of global atmospheric temperatures seven months later. As an additional influence, intermittent volcanic activity injects cooling aerosols into the atmosphere and produces significant cooling.
“The surge in global temperatures since 1977 can be attributed to a 1976 climate shift in the Pacific Ocean that made warming El Niño conditions more likely than they were over the previous 30 years and cooling La Niña conditions less likely” says corresponding author de Freitas.
“We have shown that internal global climate-system variability accounts for at least 80% of the observed global climate variation over the past half-century. It may even be more if the period of influence of major volcanoes can be more clearly identified and the corresponding data excluded from the analysis.”
Climate researchers have long been aware that ENSO events influence global temperature, for example causing a high temperature spike in 1998 and a subsequent fall as conditions moved to La Niña. It is also well known that volcanic activity has a cooling influence, and as is well documented by the effects of the 1991 Mount Pinatubo volcanic eruption.
The new paper draws these two strands of climate control together and shows, by demonstrating a strong relationship between the Southern Oscillation and lower-atmospheric temperature, that ENSO has been a major temperature influence since continuous measurement of lower-atmospheric temperature first began in 1958.
According to the three researchers, ENSO-related warming during El Niño conditions is caused by a stronger Hadley Cell circulation moving warm tropical air into the mid-latitudes. During La Niña conditions the Pacific Ocean is cooler and the Walker circulation, west to east in the upper atmosphere along the equator, dominates.
“When climate models failed to retrospectively produce the temperatures since 1950 the modellers added some estimated influences of carbon dioxide to make up the shortfall,” says McLean.
“The IPCC acknowledges in its 4th Assessment Report that ENSO conditions cannot be predicted more than about 12 months ahead, so the output of climate models that could not predict ENSO conditions were being compared to temperatures during a period that was dominated by those influences. It’s no wonder that model outputs have been so inaccurate, and it is clear that future modelling must incorporate the ENSO effect if it is to be meaningful.”
Bob Carter, one of four scientists who has recently questioned the justification for the proposed Australian emissions trading scheme, says that this paper has significant consequences for public climate policy.
“The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions. The available data indicate that future global temperatures will continue to change primarily in response to ENSO cycling, volcanic activity and solar changes.”
“Our paper confirms what many scientists already know: which is that no scientific justification exists for emissions regulation, and that, irrespective of the severity of the cuts proposed, ETS (emission trading scheme) will exert no measurable effect on future climate.”
—
McLean, J. D., C. R. de Freitas, and R. M. Carter (2009), Influence of the Southern Oscillation on tropospheric temperature, Journal of Geophysical Research, 114, D14104, doi:10.1029/2008JD011637.
This figure from the McLean et al (2009) research shows that mean monthly global temperature (MSU GTTA) corresponds in general terms with the Southern Oscillation Index (SOI) of seven months earlier. The SOI is a rough indicator of general atmospheric circulation and thus global climate change. The possible influence of the Rabaul volcanic eruption is shown.
Excerpted Abstract of the Paper appearing in the Journal of Geophysical Research:
Time series for the Southern Oscillation Index (SOI) and global tropospheric temperature anomalies (GTTA) are compared for the 1958−2008 period. GTTA are represented by data from satellite microwave sensing units (MSU) for the period 1980–2008 and from radiosondes (RATPAC) for 1958–2008. After the removal from the data set of short periods of temperature perturbation that relate to near-equator volcanic eruption, we use derivatives to document the presence of a 5- to 7-month delayed close relationship between SOI and GTTA. Change in SOI accounts for 72% of the variance in GTTA for the 29-year-long MSU record and 68% of the variance in GTTA for the longer 50-year RATPAC record. Because El Niño−Southern Oscillation is known to exercise a particularly strong influence in the tropics, we also compared the SOI with tropical temperature anomalies between 20°S and 20°N. The results showed that SOI accounted for 81% of the variance in tropospheric temperature anomalies in the tropics. Overall the results suggest that the Southern Oscillation exercises a consistently dominant influence on mean global temperature, with a maximum effect in the tropics, except for periods when equatorial volcanism causes ad hoc cooling. That mean global tropospheric temperature has for the last 50 years fallen and risen in close accord with the SOI of 5–7 months earlier shows the potential of natural forcing mechanisms to account for most of the temperature variation.
Received 16 December 2008; accepted 14 May 2009; published 23 July 2009.
UPDATE: Kenneth Trenberth of NCAR has posted a rebuttal to this paper. Which you can read here:
http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/FosteretalJGR09.pdf
Thanks to WUWT reader “Bob” for the email notice. – Anthony
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Bob Tisdale (04:15:29) :
Bob, if there are any points in this report that could be improved by input via WUWT, we should move to implement them in order to make it better and stronger.
The entire AGW community attempt to destroy it.
I think it is extremely important to kill the AGW hoax with a single report.
Therefore I think it’s important to have the publishers of the report involved in the discussion here.
Do you agree?
Personally, I’m skeptical of this report for the exact same reasons I’m skeptical of AGW. The climate is still a complex, dynamic system. While I tend to agree with some of its conclusions that doesn’t change the fact they are probably missing many components and interactions.
I suspect we are still a long way from understanding exactly what drives ENSO. We understand how it manifests itself but I have yet to see anything that nails all the factors. Clearly, CO2 could play a part although I think the Lindzen paper does more to douse the CO2 significance. And, of course, the sun is probably involved in one way or another. 😉
I hope this paper plays a part in getting climate science off the CO2 hysteria and back to a more sane approach where all factors are considered while conducting the research and BEFORE making conclusions.
O.T. Ramp up of Solar Cycle 24:
Today a Cycle 23 spot (big word) emerged.
“A small sunspot is developing inside the circled region. Its magnetic polarity identifies it as a member of old Solar Cycle 23. Credit: SOHO/MDI”
http://www.spaceweather.com
The ENSO is strongly correlated with the SOI and the ENSO is strongly correlated with the Tropics temperatures (and even more correlated with the Tropics troposphere temperatures than the surface). So, one would expect to find a close relationship between the two.
But even if you pull the ENSO or SOI influence out of the temperature series, there is still a general trend upward leftover in the residuals.
In addition, the SOI itself doesn’t provide as good of a reconstruction as the ENSO itself and any reconstruction performs much better if you add the AMO as one of the variables and if you add CO2 as one of the variables to account for the general upward trend leftover.
Here is a really nice reconstruction of Hadcrut3 Tropics temperatures going back to 1871. R^2 is 0.782 and the correlation coefficient is 0.88. The upward trend leftover would translate to about 1.7C of warming by 2100.
http://img23.imageshack.us/img23/5207/hacruttropics.png
If one applies the same process this paper has done adding the radiosonde lower troposphere temps (from 1958 is the data I have) to the RSS tropics temps from 1979 onward, the reconstruction is similar.
[I haven’t adjusted these reconstructions for volcanoes because I just don’t see any need to do so, they hardly show up at all – I could plug a few tenths of C here or there but it would just be a plug which needs to be done less often in climate science.]
There is still a general warming trend leftover which would be about 1.2C by 2100.
http://img136.imageshack.us/img136/9021/hadat2rsstropics.png
Nice to see in publication, but hardly a hypothesis. The Joes (D’Aleo & Bastardi) have been basically arguing this point for years.
These cycles follow bigger cycles. In order to get a real forecast, what meteorologist are supposed, and expected to do it well, one must have a wider perspective. So we cannot say, as it would be the same, “solar forcing”,ENSO.
No, let us remember the bigger cycles and their: “correlation”?, “coincidence”? with climate.
Following Socrates´ mayeutic method, we should ask ourselves: What was the cause of ENSO, PDO, etc.? because, if we don´t, we get entangled in any “new age science” binary “algorithm” computer game.
Bill D .. nothing Tamino says can detract from the relationship shown in Figures 7(a), (b) and (c) of the paper.
Jeff L .. I completely agree with you that Joe D’Aleo has been talking about this subject for quite a while. He’s one of the frequent commentators but he’s not the only one. Search Joe’s ICECAP and you’ll find an article on the 1976 Pacific Climate shift from me on 3 Oct 2007 and Joe refers to my work on this subject on 10 Oct 2007 and again on 28 April 2008.
@Anthony
Better secretely clever than openly dump.
Anyhow the papers “hypothesis” is falsified. Forget it.
@Tisdale
Concerning the Pacific SSTs, Niño is essentially a phenomenon within the thermocline. Besides of the desastrous mathematics of the paper the idea that a phenomon distributing heat BETWEEN two reservoirs (upper ocean, atmosphere) could produce a warming of both doesnt make sense.
REPLY: It is Tamino’s opinion that the paper’s hypothesis is falsified, but his opinion has no weight unless he writes a letter of rebuttal or paper to JGR. So many people, including “Tamino” tell me that my opinion here doesn’t matter, fair enough, so what is good for the goose is good for the gander. Let Tamino follow procedure of JGR/peer review and get it published. Until then it is just one of many opinions about the paper. – Anthony
Ron de Haan says:
http://www.climatescience.org.nz/images/PDFs/mclean_defreitas_carter_jgr_2009.pdf
Bill D says:
Ouch!! Quite a thorough debunking indeed! In fact, all that they seem to have shown is basically what many of us have been saying for quite some time, which is that the variability in the temperature data (especially the satellite data) about the general trend is strongly influenced by ENSO with a several month delay.
So, we have this peer reviewed report that suggests ENSO plays a very strong role in climate. Ok.
We also had a report from WUWT about a week ago that shows solar activity impacts La Niña and El Niño events in the tropical Pacific Ocean.
http://www.nsf.gov/news/news_summ.jsp?cntn_id=115207&org=OLPA&from=news
John McLean says:
And, nothing does. Almost everybody agrees that the ups-and-downs in the temperature (especially the lower tropospheric one measured by satellites) is due in very large part to ENSO. However, this says nothing about what the overall trend is due to…And, in fact, Tamino shows that if you add in a HUGE artificial linear trend of ~10 C / decade to the data, you get precisely the same result!
” John Finn (01:19:37) :
I broadly agree with this paper apart, that is, with the assumption that this leaves very little room for CO2. There is still an underlying trend – even allowing for ENSO/PDO fluctuations.”
Sure, but it’s probably due to the rebound from the LIA, as Akasofu and others have argued.
@Anthony
The paper is not worth a formal rebuttal. One can not take care of each stupidity even if it passed peer review.
Independent from the formal process you certainly understood what went wrong and what Tamino demonstrated in his post (in partcular since you had very similar problems before). Why not putting a little warning under the post saying that the paper is unfortunately plain wrong?
REPLY: Well the “plain wrong” part remains to be seen. Tamino has made mistakes before, but is loathe to allow them to see the light of day. McIntyre has knocking him down a peg or two on several occasions. Look at the comment by Basil for example. Rather than take the Obama “there’s no time we must do this now” stance, I’ll get some other opinions in. Besides, WUWT is one of hundreds of blogs carrying this paper.
As for the “not worth a formal rebuttal” that speaks volumes about academic laziness. If truth truly matters, then it is worth a rebuttal, if the goal is smear, then that has certainly been accomplished. – Anthony
Anthony Watts says:
Well, I think we already know that peer review is an imperfect filter. Its purpose is to increase the signal-to-noise ratio in the literature, not to block out all bad papers.
However, there is something else going on here too: The paper itself emphasizes the correlation between ENSO and detrended global temperatures. There are a few fairly mild statements about how this might also account for long term trends (and better refereeing would have caught that these statements are not supported by what the paper presents). However, the strongest statements in regards to the longer term trends are made in the press release, not the paper itself. Needless to say, their press release is not peer reviewed.
Nick, you wrote:
“They actually do the correlation on year-to-year differences. This turns any steady trend into a constant.”
“What they have done, is taken out, by differencing, any trend, before they even start.”
I haven’t read the paper yet, so I don’t have my own understanding of what they did, just what you are here describing. Now you are a smart guy, and maybe you are trying to say something else, but…
Differencing does not “take out” a trend. The “constant” is the trend.
Example:
I happen to have HadCRUT3 data open in gretl on my desktop. A simple trend through the data (regressing against time) yields a slope of 0.000366025 (this is monthly). If I take the average of the first difference, I get 0.00055131. Different, yes, but just different ways of looking at the (monthly) rate of change, i.e. “trend”. Now you can argue the merits of using either approach, but to claim that the differencing method “removes” (my word, but I think it captures the sense of what you are alleging here) the trend is incorrect.
Incidentally, another way to compute the “trend” here would be to fit a “smooth” to the data with HP smoothing, difference it, and calculate the average. The result? 0.00038539. Not much different than the “linear” trend. But this approach is far superior, in my view, because it preserves the non-linearity of natural cycles in the data, and can be used to calculate “trends in trends” i.e. systematic variation in the data around the linear trend line.
As a case in point about “trends in trends” here is an image of the “trend in the trend” in HadCRUT3 since 1979 (e.g. the “satellite era”):
http://i32.tinypic.com/21k9cmo.jpg
I’ve converted from the monthly data to a decadal equivalent by multiplying by 120. The average decadal “trend” computed this way (since 1950), is 0.094731. The “linear trend” (from regressing against time) is 0.11572428 (decadal equivalent), which I think is ballpark close to IPCC calculations.
Here’s a thought, for you. If you look at my image, I imagine you might see an upward slope to the trend of trends. Is that evidence of AGW? I don’t know, but I kind of doubt it. I rather think that we’re just looking at “natural climate variability” here. But assume that it is evidence of AGW. From a linear regression through the “trend in trends,” like this:
http://i26.tinypic.com/6ydrf5.jpg
we’re looking at an increase of from roughly 0.06 to 0.13 since 1950. At that “rate of change in the rate of change,” it would about double from 0.13 to 0.26 over the next century, which implies about a 2° C increase over a century.
But all of this could just be natural climate variability, and there is no reason to think that the linear regression in the second image will continue that trend for 100 years. In fact, with the “trend of trends” currently below zero, a linear trend will continue to decline for some time.
Bottom line, though, is that differencing does not remove the trend. It merely looks at the trend differently, and in conjunction with a technique like HP smoothing, more profoundly than just running linear trends through the undifferenced temperature data.
I see I misstated my charts. They go back to 1950, not 1979.
Anthony Watts says:
Well, in time I am sure that there will indeed be comments written on the paper. However, in the meantime, I think anyone who has taken mathematics up through calculus can easily confirm that what Tamino says is in fact correct.
And, just to re-emphasize: Tamino does not disagree with the main hypothesis of the paper (as opposed to that of the press release) that ENSO accounts for much of the up-and-down fluctuations in temperature. In fact, as he noted, he himself has pointed this out before. Rather, he disagrees with their statement that they have shown that “perhaps” it accounts for the overall multidecadal trend too. To quote Tamino explicitly:
Basil says:
But, the constant is then completely irrelevant to the subsequent correlation computation. So, from the point of view of computing correlations, you have indeed taken out any effect of the trend. The correlation that you get is identical even when you add a fake linear trend of 10 C / decade to the original temperature data!!
So this can account for 80% of the warming. GISS Step 1 can account for 10% of the GISS warming. Hmm.
@Anthony
So the answer to my original question ist: None
REPLY: Well then if we are all just too “stupid”, your word, why frequent here? I simply prefer to get more information. The paper took weeks or months to produce, to dismiss it wholesale in 24 hours isn’t reasonable. It may very well be that there is a math error. However that does not negate the entire paper. I’m interested in seeing what others say about it, because one anonymous blogger does not a total falsification make.
You could do well to learn some manners also. – Anthony
@Basil
read the press release at least:
“The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions. ”
The “little room” refers to correlation. Constants do not correlate.
NigelHarris (02:34:28) :
There is a confusion here between variability and long-term trend. No great surprise that ENSO events can explain a lot of the short-term fluctuations in global temperature, but how can they explain a rise over 50+ years? This study is actually designed in such a way that any long-term near-linear change in temperature is excluded from consideration.
So, the IPCC says the increase from CO2 will not be monotonic, which is how they explain away the fact that global temps today are similar to the late 1970’s. Now you’re telling us that CO2 acts as a “long-term near-linear change”.
Whew, there’s some logic I can believe in.
Anyone following this issue knows about the strong correlation between temps and ENSO. Here is a WUWT post by Bill Illis from Feb-09 saying much the same thing but going a step farther to demonstrate the correlation between ENSO and trade winds. http://wattsupwiththat.com/2009/02/17/the-trade-winds-drive-the-enso/
We also have cause to believe that the peer review process is not nearly so rigorous as it should be. While we see a strong bias toward pro-AGW studies, we have to allow that a deficiency in academic rigor in the process can cut both ways.
In order for realists to have/maintain/increase their credibility, they need to subject papers supporting their hypotheses to the same level of scrutiny as those that the AGWers use supporting theirs.
As Anthony suggested, a look-see by McIntyre should easily confirm/deny the claims by Tamino that the correlation this paper demonstrates is just with the variability, not with the trend.
Personally, I am going to hold off on popping the champagne corks until the results are in. To do otherwise invites criticism from the AGWers if the study is flawed. If there is egg to be found on faces, let it not be ours.
“According to the three researchers, ENSO-related warming during El Niño conditions is caused by a stronger Hadley Cell circulation moving warm tropical air into the mid-latitudes. During La Niña conditions the Pacific Ocean is cooler and the Walker circulation, west to east in the upper atmosphere along the equator, dominates.”
I had all of that backwards. I thought El Niño conditions caused weakened trade winds, stronger return (Walker) circulation which tends to wind-shear hurricanes, preventing their formation. Now I am totally confused.
Ron de Han: You wrote, “I think it is extremely important to kill the AGW hoax with a single report.”
That’s a nice thought, but I believe it’s impossible.
For sure this switch affected temperature changes in Alaska, mean annual temperature increased 3F from 1975-1978
http://climate.gi.alaska.edu/ClimTrends/Change/TempChange.html
And since 1978 temperatures have been flat.
http://climate.gi.alaska.edu/ClimTrends/Change/7708Change.html