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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Oh geez, now you’ve done it. I send my regards to your moderators, who will no doubt be snipping some very rabid comments. 😉
pretty interesting
It will be interesting to see how the AGW activists receive this paper and its peer reviewed findings…..
I expect that the AGW mob will try to ignore it in its entirety, whilst attacking the reputation of the Scientists that produced it.
How long will it take before the GW boys realize the rug has been pulled out from under them? Will it have any influence on the cap and trade movement?
I sure hope so!!!!
But-but-but-but what about the models?
Data and Empirical Observation trump Models.
Man made CO2 as a climate forcing agent (at 385PPM+) is increasingly occupying the margins…
1. Low sensitivity for C02, negative feedbacks from other systems.
2. Substantial saturation of the spectrum that CO2 absorbs at 385PPM+.
3. Lack of visible impact of Human Emissions on the measured rate of CO2 rise suggests natural drivers for CO2 rise.
Hopefully the AGW myth will begin to die.
Refreshingly sensible.
Anthony,
I must apologize for my lack of education. I am trying. I was the one who in an earlier comment suggested instrument error for the 1998 blip in satellite measured temperatures. I have since found several references (including this one) referring to an El Nino event causing the jump. This large of a jump in such a short period of time seemed wrong to me because I have been steeped in the slow CO2-driven-3-degrees-per-hundred-year rise in temperature as the source of the coming disaster. I now realize the differences of time constant and scale between land and ocean affects on the atmosphere and that of carbon dioxide capture of IR radiation. I need to find a reference that will explain how such a small effect will send the climate into instability while the much larger and faster ocean and land contributions average out to nothing in the same time frame.
Is there no plot of the SOI index beyond 2004?
REPLY: There is, this is just an example graphic. I’ll see if I can locate a better example. – Anthony
REPLY2: I have located and inserted a better example. – Anthony
Do ENSO events really affect global temperature? Or do they just shift heat around so that it ends up in places where it gets noticed? I don’t see ENSO events adding or removing energy from the system.
It will be interesting to see if the major newspapers pick up on it, given the left-green bias evident in most science/climate reporters, dont count on it.
We should email all the politicians involved in carbon tax / cap & Trade etc and beat them over the head with the string of reports which undercut the IPCC sensitivity, positive feedback junk science on which Carbon taxes etc are based.
“”REPLY2: I have located and inserted a better example. – Anthony””
Yes. You can see how global temperatures have at least levelled out.
The current El Niño seems to be fizzling out early. More cooling?
WOW. I’ve never seen it stated so clearly. Is this the breakthrough paper we’ve been expecting?
An ENSO flip in 1976? Changes in ENSO, solar forcing and volcanic activity causing most of the climate variability? I have heard this all before. And I *still* believe it to be true.
Jeff Alberts (22:33:51) :
…………………………….
Do ENSO events really affect global temperature? Or do they just shift heat around so that it ends up in places where it gets noticed? I don’t see ENSO events adding or removing energy from the system.
– Good point. If India gets a weaker/stronger monsoon they just get on with it, they don’t go insane.
– Nice match for 1998 event BTW.
Well, I’ve read the paper. It shows that fluctuations in global temp correlate well with ENSO and volcanoes, but we knew that. And they have observed, as many have, that the pattern of El Nino’s changed somewhat after 1976. What this analysis doesn’t tell you much about is trends. The variation that they analyse for is dominated by fluctuation rather than trend. Or it would be, but they do more. They actually do the correlation on year-to-year differences. This turns any steady trend into a constant. So the analysis would not even see a trend due to AGW, and can’t possibly rule it out.
“I don’t see ENSO events adding or removing energy from the system.”
I don’t think that is the inference, rather enso events are a manifestation of the heat transfer from the oceans to the atmosphere and it is this process which has been the primary proximate driver of the warming that has made AGW people so over-excited. The point is that CO2 has not been a significant contributor to the warming atmosphere.
“During La Niña conditions the Pacific Ocean is cooler and the Walker circulation, west to east in the upper atmosphere along the equator, dominates.”
Really introducing the physically impossible Walker cell concept into this weakens this paper tremendously. The Walker cell has been demonstrated a “physical miracle”. On Africa for instance observations run counter to the Walker cell supposed effects -cf Leroux “Meteorology and climate of tropical Africa”.
As long as this kind of poor atmospheric circulation models are still used by either the AGWists or the realists -not that realists obviously-, we are unlikely to get real progress.
“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.” To steal a phrase from David Kay … ‘We Were Almost All Wrong’ .. and so are the models. Once again, a “global concensus” was wrong.
I wonder if the step changes Bob Tisdale talked about ENSO providing can explain the trends in temperature. If he isn’t busy tinkering around with more animations, I would love to hear from him on this. 🙂
Anthony – If you haven’t got a copy of the paper – I have it.
Anthony, just for fun, if it is not too difficult, could you overlay your favorite global temp graph on the ENSO graph? That would visually display the claim made in the paper (if I understand the contention being made). Or, if you have already done that on another post, would you please point me there? Thank you.
“Do ENSO events really affect global temperature? Or do they just shift heat around so that it ends up in places where it gets noticed? I don’t see ENSO events adding or removing energy from the system.”
Yes, they might. The reason is that they may affect clouds and convection. These processes might be significant elements both in the absorption of heat from the Sun, and transfer of heat out from the earth. They can therefore do more than move heat around.
I think the argument is very roughly like this. Suppose we had two objects with relatively poor conductivity at the same temperature. So they both cool at the same rate. We now set up some arrangement on one of them that makes the heat distribution uneven. The left hand part of one is very hot, the right hand part is very cool. The total heat content remains the same.
This one will cool faster, because heat transfer is a function of temperature difference, and we have raised the temperature difference for the left hand part. So you might have the feeling that whatever it is that moves the heat content from right to left is ‘just moving heat around’, and that is true, but this does not mean it does not have any effect on heat loss from the body as a whole.
Nick Stokes
I think you miss the point. The analyses effectively takes out the ENSO effect, which over many years pretty much accounts for all temperature change. IE the global temperature now is approaching that of 1975. If there was a trend left then that might be said to be the AGW signal. Unfortunately for the trolls this team are saying that there is little or no trend left for the GWs to cling on to. See what they mean?
“[…] if the period of influence of major volcanoes can be more clearly identified and the corresponding data excluded from the analysis […]”
I hope the (ultimate) goal is to “include properly” rather than “exclude” (which seems a sensible interim strategy).
–
Time to track down a copy of this paper…