ENSO Myth 5 – ENSO Only Adds Noise to the Instrument Temperature Record…

…and We Can Determine its Effects through Linear Regression Analysis, Then Remove Those Effects, Leaving the Anthropogenic Global Warming Signal

This is the 5th post in the series about myths and failed arguments about the El Niño-Southern Oscillation—myths that were created by proponents of the hypothesis of human-induced global warming. The intents of these myths are obvious: they downplay and obscure the very obvious roles Mother Nature has played in global warming. Links to past posts about other myths and a listing of future posts are provided at the end of this one. This series of posts are reprints from my book Who Turned on the Heat?

For four years, I’ve searched for signs of an anthropogenic warming signal in the global satellite-era sea surface temperature record. It’s difficult if not impossible to find (1) if you divide the global oceans into logical subsets and (2) if you understand the role that strong El Niño events played in that warming. In this post, we’ll illustrate the impacts of those strong El Niños on GISS Land-Ocean Temperature Index (LOTI) data, which is the merger of land surface air temperature and sea surface temperature anomaly data.

The title of this myth is long, but self-explanatory: “ENSO Only Adds Noise to the Instrument Temperature Record and We Can Determine its Effects through Linear Regression Analysis, Then Remove Those Effects, Leaving the Anthropogenic Global Warming Signal.” The flawed assumption that perpetuates this myth is that the year-to-year wiggles associated with El Niños and La Niñas ride on top of a warming signal created by manmade greenhouse gases. The realities are, (1) strong El Niño events are responsible for the vast majority of the warming, and (2) ocean heat content data indicates El Niños are fueled naturally. If this subject is new to you, refer to my illustrated essay “The Manmade Global Warming Challenge” [42MB] for an overview.

This myth has been discussed in a number of posts at my blog Climate Observations, many of which were cross posted at WattsUpWithThat. Most recently, an overview of the flaws of this myth was presented in the video included in the post The Blatant Errors in the SkepticalScience Video “Global Warming over the Last 16 Years”, which was cross posted at WUWT here. My YouTube video included in that post is On the SkepticalScience Video “Global Warming over the Last 16 Years”. This post is a further discussion of the flaws in the SkepticalScience video—a more detailed look at those errors in the SkepticalScience argument is planned for next week.

The following is Chapter 7.5 from my book Who Turned on the Heat? For those with copies, it starts on page 459. I also discovered a typo, which I struck and corrected in this post.

7.5 ENSO Only Adds Noise to the Instrument Temperature Record and We Can Determine its Effects through Linear Regression Analysis, Then Remove Those Effects, Leaving the Anthropogenic Global Warming Signal

The relationship between ENSO events and global surface temperatures is known. During an El Niño event, some places around the globe warm in response and other places cool. The warming exceeds the cooling, so global temperatures, as a whole, warm in response to an El Niño event. On the other hand, during a La Niña event, the cooling around the globe exceeds the warming and, as a whole, global temperatures cool in response to a La Niña event. Early work on the relationship between ENSO and weather (temperature and precipitation) around the globe, as noted earlier in the book, include Berlage (1976) Southern Oscillation and World Weather, Newell and Weare (1976) Factors Governing Tropospheric Mean Temperature, Angell (1981) Comparison of Variations in Atmospheric Quantities with Sea Surface Temperature Variations in the Equatorial Eastern Pacific, Pan and Oort (1983) Global Climate Variations Connected with Sea Surface Temperature Anomalies in the Eastern Equatorial Pacific Ocean for the 1958–73 Period.

Somewhere along the line, possibly Jones in the 1989 book The influence of ENSO on global temperatures [not available online], a study used a statistical tool such as correlation or regression analysis to determine the linear relationship between an ENSO index and global temperature. With that factor and an appropriate time lag between the ENSO index and global surface temperatures, they then crossed a hurdle. They subtracted the scaled ENSO index from the global temperature data and claimed the difference was caused by manmade greenhouse gases.

That is, with a statistical tool, they used an ENSO index and global surface temperatures to determine how much global surface temperatures warmed and cooled in response to the ENSO signal represented by the ENSO index. They also determine the time lag between the change in the ENSO index and the response in global surface temperatures. For example, let’s say a study determined that global surface temperatures varied 0.18 deg C for every 1.0 deg change in the ENSO index and that global surface temperatures lagged the ENSO index by 3 months. Further, let’s say the study also included a dataset called Aerosol Optical Depth (AOD) to account for the sun-shading effects of volcanic aerosols spewed into the stratosphere by explosive volcanic eruptions. ENSO and volcanic aerosols are the two primary causes of the year-to-year wiggles in the global surface temperature record. Like before, also for the example, we’ll exclude polar data, so we’ll only examine the GISS Land-Ocean Temperature Index data from 65S-65N.

As a reminder, the Arctic temperature data is also impacted by a phenomenon called polar amplification, which skews the data. As also noted before, GISS, for all intents and purposes, deletes sea surface temperature data in areas of seasonal sea ice in both polar oceans. They then replace it with land surface temperature data, which will exaggerate the long-term warming there because land surface temperatures vary much more than sea surface temperatures. There’s no need to include those biases in our discussion.

Figure 7-14The three datasets are shown in Figure 7-14. Note that I haven’t scaled the volcanic aerosol data, and that it shows a dip of about 0.15 deg C in 1991 in response to the eruption of Mount Pinatubo. Climate studies have estimated the impact of Mount Pinatubo to have been in the range of 0.2 to 0.5 deg C. I’ll show you what they missed—later.

The climate studies that attempt to remove the impacts of ENSO and the volcanic eruptions, very simply, then subtract the scaled and lagged ENSO index and Aerosol Optical Depth data from the global surface temperature data and assume the warming shown is caused by anthropogenic greenhouse gases. See Figure 7-15. It’s nonsense, but there are a good number of studies that attempt to show this. Why is it nonsense?

Figure 7-15There are two very obvious erroneous assumptions made by those studies. First, they assume the ENSO index represents the all of the effects of the entire ENSO process. We know that’s not correct. The ENSO index only represents the effects of ENSO on the variable or variables being measured. For NINO3.4 sea surface temperature anomalies, the ENSO index only represents the impacts of El Niño and La Niña on the sea surface temperatures of a small region along the equatorial Pacific. The Southern Oscillation Index only represents the effects of ENSO on the sea level pressures of Tahiti and Darwin, Australia. Those ENSO indices do not account for the effects of the warm surface waters in the tropical Pacific that are left over after an El Niño and they do not account for the warm subsurface waters that are returned to the west Pacific and East Indian Ocean by Rossby waves. The Multivariate ENSO Index, which includes a number of other different variables, also fails to capture these important aspects of ENSO.

The second erroneous assumption—maybe it’s actually the second and third erroneous assumptions—is they assume the effects of ENSO on global surface temperature are proportional or linear to the ENSO index and that those effects are all the same sign. We know the effects of ENSO on global sea surface temperatures are NOT proportional to the ENSO index. The sea surface temperatures of the East Indian and West Pacific Ocean warm in response to an El Niño but fail to cool during the trailing La Niña event. Also, we’ve already shown and discussed a number of times that there are places around the globe that warm in response to an El Niño and some that cool in response to an El Niño, and vice versa for a La Niña. As a reminder, the map in Figure 7-16 presents the correlation of GISS Land-Ocean Temperature Index data with NINO3.4 sea surface temperature anomalies, with a 3-month lag.

Figure 7-16

Let’s smooth the ENSO- and volcano-adjusted GISS Land-Ocean Temperature Index data with a 13-month running-average filter, Figure 7-17, and see what we can see. You may have noticed the upward shifts during the 1986/87/88 and 1997/98 El Niño events in the “raw” (unsmoothed) data (Figure 7-15), but they stand out remarkably well in the smoothed data. The periods before, between, and after the 1986/87/88 and 1997/98 El Niño events (highlighted in blue) still show signs of ENSO-related variations, but they’re inversely related to the NINO3.4 data. Stop and think about that for a moment. Considering the different time lags and when and where global surface temperatures are impacted by ENSO at those assorted time lags, it’s very logical that there are noticeable ENSO related signals visible that are the opposite sign after you remove the major variations of the same sign. In fact, you should expect to see them.

Figure 7-17

We can show the inverse relationship between ENSO and the ENSO- and volcano-adjusted GISS surface temperature data, by scaling and inverting the NINO3.4 sea surface temperature anomalies. In Figures 7-18, 7-19 and 7-20, the NINO3.4 data was scaled by a factor of 0.12, which is less than the scaling factor we used when we originally adjusted the data; then we used a scaling factor of 0.18. The NINO3.4 data in the three upcoming figures has not been lagged. This helps to show the timing of the upward shifts, which occur during the transitions from El Niño to La Niña. The upward shifts trail the NINO3.4 data by a couple of months. The lagged relationship between the inverted NINO3.4 data and the adjusted GISS Land-Ocean temperature stands out best in Figure 7-20, but it can also be seen in Figure 7-19, for the period between the 1986/87/88 and 1997/98 El Niño. You’re probably asking yourself why I’m using three graphs of the same two datasets. In Figure 7-18, I’ve offset the NINO3.4 data by -0.15 deg C, to show how well the adjusted GISS data and the inverted and scaled NINO3.4 data agree before the 1986/87/88 El Niño. The NINO3.4 data is offset -0.05 deg C in Figure 7-19 to show how well the two datasets agree between the 1986/87/88 and 1997/98 El Niño events. Then, in Figure 7-20, the inverted and scaled NINO3.4 sea surface temperature anomalies were offset +0.15 deg C to show how well that inverted NINO3.4 data now agrees with the ENSO- and volcano-adjusted GISS Land-Ocean Temperature Index data after the 1997/98 El Niño. The changes in the offsets provide a very rough approximation of the shifts in surface temperatures caused by the 1986/87/88 and 1997/98 El Niño events.

Figure 7-18


Figure 7-19


Figure 7-20

It all makes sense, and there was no need to rely on greenhouse gases to explain the warming of land plus sea surface temperatures from November 1981 to March 2012, for the latitudes of 65S-65N. If you’re not aware, the latitudes of 65S-65N cover about 90% of the planet, and the GISS data north of 65N and south of 65S has been modified by their deletion of sea surface temperature data and replacing it with land surface temperature data.

Recall that in Figure 5-14 7-14 we assumed the eruption of Mount Pinatubo only cooled global surface temperatures by about 0.15 deg C. We also noted that climate studies determined that global surface temperatures cooled 0.2 to 0.5 deg C in response to the volcano. Some of those studies removed the linear effects of ENSO to determine the response of global temperatures to Mount Pinatubo. They assumed incorrectly that the response of global surface temperatures to ENSO were all the same sign. They didn’t bother to consider the fact that there are areas around the globe that cool in response to El Niño and warm in response to La Niña AND that these inverse effects may be strongest at a different time lag. Now, if you would, please scroll back up to Figure 7-19. Note how well the scaled and inverted NINO3.4 data agrees with the ENSO- and volcano-adjusted GISS Land-Ocean Temperature Index data at the time of the Mount Pinatubo eruption. The adjusted GISS land plus sea surface temperature data is cooling in response to the string of El Niño events from 1991 to 1995. The studies appear to have overestimated the response of global surface temperatures to the eruption of Mount Pinatubo, because they failed to notice that the ENSO-adjusted surface temperatures (which were adjusted for surface temperature response to ENSO with the same sign) were cooling in response to the El Niño events.

Let’s look at the climate model hindcasts for the period of 1999 to 2000 that were and will be used by the IPCC in the 4th and 5th Assessment Reports, Figure 7-21. The data has been detrended to approximately “zero” before and after the responses to the 1991 eruption of Mount Pinatubo. I’ve also presented the Aerosol Optical Depth data required to account for the actual dip and rebound caused by it. The multi-model ensemble mean of the climate models prepared for the IPCC’s upcoming 5th Assessment Report more than doubles the response needed to explain the dip and rebound.

Figure 7-21


In summary, ENSO is a coupled ocean-atmosphere process and its effects on Global Surface Temperatures are not represented by an ENSO index. ENSO indices cannot account for the impacts of the warm water released by an El Niño event, returned to the West Pacific and redistributed from there. Therefore, any scientific papers that attempt to determine manmade global warming by removing the linear effects of ENSO with a scaled and lagged ENSO index and subtracting it from global surface temperatures are fatally flawed. Papers that make this error-filled, misleading effort include:

Foster and Rahmstorf (2011) Global Temperature Evolution 1979–2010

Fyfe et al (2010) Comparing variability and trends in observed and modelled global-mean surface temperature

Lean and Rind (2009) How Will Earth’s Surface Temperature Change in Future Decades?

Lean and Rind (2008) How Natural and Anthropogenic Influences Alter Global and Regional Surface Temperatures: 1889 to 2006

Fawcett (2008) Has the world cooled since 1998?

Santer et al (2001) Accounting for the effects of volcanoes and ENSO in comparisons of modeled and observed temperature trends

Thompson et al (2008) Identifying signatures of natural climate variability in time series of global-mean surface temperature: Methodology and Insights

Trenberth et al (2002) Evolution of El Niño–Southern Oscillation and global atmospheric surface temperatures

Wigley, T. M. L. (2000) ENSO, volcanoes, and record-breaking temperatures


Trenberth et al (2002) is a widely cited paper about ENSO. I’ve used it as a reference in this book. Only a very small portion of that paper makes the error discussed in this chapter. Trenberth et al also provide a disclaimer in the second paragraph of their Conclusions, (their paragraph 52, my boldface):

The main tool used in this study is correlation and regression analysis that, through least squares fitting, tends to emphasize the larger events. This seems appropriate as it is in those events that the signal is clearly larger than the noise. Moreover, the method properly weights each event (unlike many composite analyses). Although it is possible to use regression to eliminate the linear portion of the global mean temperature signal associated with ENSO, the processes that contribute regionally to the global mean differ considerably, and the linear approach likely leaves an ENSO residual.

The ENSO “residuals” are a significant contributor to the warming of Global sea surface temperatures during the satellite era, as we’ve shown throughout this book.

A more recent paper, Compo and Sardeshmukh (2010) Removing ENSO-Related Variations from the Climate Record, seems to be a very important step in the right direction. They write (my boldface):

An important question in assessing twentieth-century climate is to what extent have ENSO-related variations contributed to the observed trends. Isolating such contributions is challenging for several reasons, including ambiguities arising from how ENSO is defined. In particular, defining ENSO in terms of a single index and ENSO-related variations in terms of regressions on that index, as done in many previous studies, can lead to wrong conclusions. This paper argues that ENSO is best viewed not as a number but as an evolving dynamical process for this purpose.

Note: While Compo and Sardeshmukh made a step in the right direction, they missed a very important aspect of ENSO. They overlooked the significance of the huge volume of warm water that is left over after certain El Niño events, and they failed to account for its contribution to the warming of global Sea Surface Temperature anomalies since about 1975/76.



Why should you be interested? As noted in the post, the sea surface temperature records indicate El Niño and La Niña events are responsible for the warming of global sea surface temperature anomalies over the past 30 years, not manmade greenhouse gases. I’ve searched sea surface temperature records for more than 4 years, and I’ve searched ocean heat content records for more than 3 years, and I can find no evidence of an anthropogenic greenhouse gas signal. That is, the data indicates the warming of the global oceans has been caused by Mother Nature, not anthropogenic greenhouse gases.

I’ve recently published my e-book (pdf) about the phenomena called El Niño and La Niña. It’s titled Who Turned on the Heat? with the subtitle The Unsuspected Global Warming Culprit, El Niño Southern Oscillation. It is intended for persons (with or without technical backgrounds) interested in learning about El Niño and La Niña events and in understanding the natural causes of the warming of our global oceans for the past 30 years. Because land surface air temperatures simply exaggerate the natural warming of the global oceans over annual and multidecadal time periods, the vast majority of the warming taking place on land is natural as well. The book is the product of years of research of the satellite-era sea surface temperature data that’s available to the public via the internet. It presents how the data accounts for its warming—and there are no indications the warming was caused by manmade greenhouse gases. None at all.

Who Turned on the Heat? was introduced in the blog post Everything You Ever Wanted to Know about El Niño and La Niña… …Well Just about Everything. The Free Preview includes the Table of Contents; the Introduction; the beginning of Section 1, with the cartoon-like illustrations; the discussion About the Cover; and the Closing.

Please buy a copy. (Credit/Debit Card through PayPal. You do NOT need to open a PayPal account.) Simply scroll down to the “Don’t Have a PayPal Account” purchase option. It’s only US$8.00.



1. El Niño-Southern Oscillation Myth 1: El Niño and La Niña Events are Cyclical. Refer also to the cross post at WattsUpWithThat for comments.

2. El Niño-Southern Oscillation Myth 2: A New Myth – ENSO Balances Out to Zero over the Long Term. And please see the WattsUpWithThat cross post.

3. Myth – ENSO Has No Trend and Cannot Contribute to Long-Term Warming. The WattsUpWithThat cross post is here.

4. ENSO Myth Number 4 – The Variations in the East Pacific and the East Indian-West Pacific Sea Surface Temperatures Counteract One Another.See the WUWT cross post here for more comments.


Myth – The Effects of La Niña Events on Global Surface Temperatures Oppose those of El Niño Events

Failed Argument – El Niño Events Don’t Create Heat

Myth – El Niño Events Dominated the Recent Warming Period Because of Greenhouse Gases

Myth – The Warm Water Available for El Niño Events Can Only be Explained by Anthropogenic Greenhouse Gas Forcing

Myth – The Frequency and Strength of El Niño and La Niña Events are Dictated by the Pacific Decadal Oscillation


The Sea Surface Temperature anomaly data are available through the NOAA NOMADS website:




GISS Land-Ocean Temperature Index data are available through the KNMI Climate Explorer.

And the GISS aerosol optical depth data can be found here.

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April 11, 2013 7:02 am

I get that ENSO cannot be seen as noise in a global temperature signal. But what has accounted for the strong El Nino warming episodes in recent decades, with less impactful cooling episodes? I understand that ENSO provides “natural” warming, but the strength and number of them is what might be considered unnatural. I’m inferring that your hypothesis is that the recent warming is just a cycle within natural variability, and that temperatures are likely to cool in the future. I see that as a valid hypothesis, but still a hypothesis just like greenhouse gases. It may even be that both are correct.

April 11, 2013 7:06 am

ENSO represents the tail end of the ocean conveyor. Energy from the sun 1000 years ago that was trapped in the deep oceans and modified by the heat of the earth’s core along the ocean floor is finally brought to the surface in the eastern Pacific in a series of pulses. What we are seeing in ENSO is a history of earth’s climate from as far back as the time of the Vikings, and how it affects our climate today.
The problem with modern Climate Science is that it takes an extremely simplistic, short term view of the climate system. Climate is assumed to be a linear system and no allowance is made for large scale oscillators like the oceans. Thus, natural effects such as ENSO are seriously underestimated.
This leads to the problem as documented by the IPCC. Climate Scientists are unable to explain the observed changes in climate by from their simplistic models, so the only answer they are able to find is that human activity is the cause.
What is overlooked by the IPCC and Climate Scientists is that there is actually a much simpler explanation. The explanation is that the simplistic Climate Models are wrong, that the Natural Climate system is much more variable than allowed for in their models.
Unfortunately experts are typically the last people to admit their errors. The error is clear when looking at the Paleo records the past million years. For the past million years our climate has been anything but stable. Except for the 90% of the time when the land is mostly covered with 2 miles of ice, Climate has been unstable and highly variable.
The unstable and highly variable climate of the interglacials is well modeled by Chaos theory, something the climate models do not recognize and do not account for. The earth shows a long history over the past 600 million years of two stable temperatures; 11C and 22C. These are the two climate attractors. Earth’s temperature for most of the time circles one or the other attractor.
However, on occasion the orbit becomes unstable and tries to transition from one attractor to the other. Our current interglacials in one of those situations. As Marcott shows, we reached the peak of the interglacial 8000 years ago and our temperature “orbit’ is decaying and we are falling back into the 11C attractor.
As we do ice will again cover the land outside the tropics. Most of the major cities of the word will be buried, not underwater as Gore would suggest, but under ice. Miles of ice. This ice will erase all signs that these cities or their inhabitants every existed. 90 thousand years from now, at the start of the next interglacial, will humans if they exist even remember we once had a civilization? Will they look up at the moon and ask if one day we might go there?

Theo Goodwin
April 11, 2013 7:11 am

Mr. Tisdale,
Your work is nothing short of miraculous. I cannot think of another book or article that does as good as job as this one of explaining how and why ENSO must be treated as a natural process. In addition, you reveal the fundamental error of Alarmism, treating natural processes as statistical noise.
Readers who are new to your work will not understand that you were in the forefront of the battle to get Alarmists to take seriously the concept of natural processes. Today, many Alarmists talk about natural processes, as do many scientists who are not Alarmists, but only a year ago getting climate scientists to talk about natural processes was like pulling teeth.
Watching your work grow has been an inspiration to me. It should inspire all lovers of science and the real world. It is a stake in the heart of modelers. Every lover of science will want to own your books.
You should always emphasize your criticisms of Trenberth and others. You are far too kind to Trenberth but maybe that is the most effective kind of criticism.

April 11, 2013 7:33 am

What Chaos theory also tells us is that the earth’s temperature may transition to 22C instead of 11C, though the paleo record says this is less likely. The difference in energy resulting from our orbital mechanics has not been sufficient in the past million years to complete the transition.
The only thing we can really say for sure is that nothing will hold temperatures at the present 15C, because the climate system has no evidence of an attractor at that temperature. Either things will get much colder or they will get much warmer, but they are highly unlikely to stay as they are.
The question for most humans will be this: Do you want to live in a warmer world in the future or a colder world, because the natural climate system dictates that we are very unlikely to remain at the present temperatures.

Bill Illis
April 11, 2013 7:54 am

The question is does the ENSO leave lasting impacts (or just short-term ones) and what is the physical explanation for that.
The AMO cycle provides a very good representation of whatever those lasting impacts might be.

Theo Goodwin
April 11, 2013 7:56 am

Brian says:
April 11, 2013 at 7:02 am
Mr. Tisdale does not have a supercomputer, graduate assistants, the ability to undertake large scale experiments or anything that buckets of grant money can buy. For that reason, he cannot be expected to create and test rigorously formulated physical hypotheses. His two great achievements, in this essay, are to show that ENSO is best treated as a natural process and that Alarmists have failed to do so. He has put the ball in the Alarmist’s court. They do have the means to create rigorously formulated hypotheses from Mr. Tisdale’s work and to design and carry out experiments to confirm them. That is where the debate stands at this time.

Theo Goodwin
April 11, 2013 8:04 am

Bob Tisdale says:
April 11, 2013 at 7:49 am
“Theo Goodwin, thanks for all the kind words.”
Hey, I got a notice from Bob Tisdale!
It was not kindness that motivated my words but an appreciation for absolutely first rate citizen science. Also, you really have a talent for presenting science. Everything that you write scores really high on the memorability scale. I believe it is memorable because it points so directly to the real world.

April 11, 2013 8:18 am

Bob, I appreciate the reply. Shouldn’t the last 31 years be more heavily considered though, since AGW proponents point to most of the temperature rise during that period? The last 31 years may in fact be a naturally El Nino heavy phase, but I’m not sure pointing to data back to 1871 disproves AGW. The paper you referenced may have addressed this, but I couldn’t tell from the abstract.
Theo, I understand what you are saying. In my amateur opinion, he has done a great job of showing that ENSO cannot be discounted as noise. I also think that he has yet to disprove that ENSO may be just a natural mechanism by which unnatural warming is manifesting itself. Sure the ball is in the alarmist court, but I still see it as an open question.

Theo Goodwin
April 11, 2013 8:35 am

Brian says:
April 11, 2013 at 8:18 am
“I also think that he has yet to disprove that ENSO may be just a natural mechanism by which unnatural warming is manifesting itself.”
Give him a billion dollars and I bet he can give you a knock down “proof” in five years, though “proof” really doesn’t belong to science.
“Sure the ball is in the alarmist court, but I still see it as an open question.”
He has not suggested that it is not an open question. Claiming that ENSO is a natural process does not mean that manmade warming does not affect the process to some degree.

Paul Vaughan
April 11, 2013 8:44 am

Bill Illis (April 11, 2013 at 7:54 am) wrote:
“The AMO cycle provides a very good representation of whatever those lasting impacts might be.”

New light indicates need for a deep rethink.
Multidecadal climate waves perfectly match multidecadal heliosphere waves.
There are very serious defense implications, for example in planning to maintain a strategic edge in shielding against the threat of intercontinental ballistic missiles potentially coming from upstream in the zonal westerlies.
This certainly isn’t just about climate.

April 11, 2013 9:36 am

Bob, thanks for the more thorough explanation. I’m not questioning that there have been strong, completely naturally driven El Ninos in the past century and a half. And from this I think it is reasonable to assume that the last 31 years are also completely naturally driven. I am just pointing out the possibility that the more recent ones have a manmade component.
I will have to have a good look over that last link. The image you linked to shows that at least a portion of El Nino is fueled naturally, and I don’t think even the most alarmist CAGW believer would refute that. But it doesn’t prove that unnatural warming is not involved in the strength of each El Nino. and that’s why I believe that the warming seen in recent decades is still an open question. I appreciate all of the work you do in promoting your ideas on the issue.

April 11, 2013 9:40 am

Normally I don’t learn article on blogs, however I would like to say that this write-up very forced me to check out and do it! Your writing style has been amazed me. Thank you, quite great article.

S. Meyer
April 11, 2013 12:05 pm

Dr Tisdale: Thank you for another thought-provoking post. It is always a pleasure, evn though way over my head.. I have been trying to reformulate your conclusions in my head in a simplistic way, so that I can wrap my head around it. Here is an analogy:
Consider three pots on a stove. Each pot sits on a hot plate. The hot plate for pot 1 is hotter than the hotplate for pot 2 which is hotter than the hotplate for pot 3. Pot 1 and 2 have overflow spigots that drain water when the level of water in the pot becomes too high. Pot 1 drains into pot 2 and pot 2 drains into pot 3. All pots are stirred by a Teflon-coated magnetic stirrer, but the stirrer in pot 1 is jumping about crazily, as these stirrers sometimes do.  Finally a pump pumps water from pot 3 to pot 1 to keep water levels approximately stable. Suppose that, at baseline, the three pots together receive as much energy as they give off.
Now, somebody measures the temperatures in all three pots over time and comes up with the idea that something other than the hot plates must be heating the pots. He tries to prove this by looking at the temperature curves. He wants to show that average temperatures in all three pots combined have been rising over time. The problem is that pot 1 will occasionally overflow and discharge some water into pot 2. The researcher thinks that the resulting temperature spike in pot 2 should not be counted and subtracts it from the curve. He also notices that the water in pot 2 cools after the initial spike. He thinks that this too should not be counted and removes that effect from the curve. However, he does not remove any such effects from pot 3. The result is a curve that shows increasing temperatures only after the described manipulation of the data.
The pots, of course, represent the various oceans. Pot 1 is the tropical ocean that is heated by the sun (the stove). As the water gets warmer it expands and eventually reaches an overflow spigot. Warm water leaves through that spigot and is drained into pot 2. This would be a niño event – warm water being discharged to cooler oceans. Pot 2 will eventually also drain some water into pot 3, making pot 3 warmer, while pot 2 is slowly cooling. This would be a niña.  Because of the crazy stirrer in pot 1 (chaotic weather) niños and niñas occur irregularly. 
Therefore, if you measure and “correct” temperatures during a time of frequent overflows caused by the chaotic stirrer you would show increasing temperatures, while, in reality you are just demonstrating erratic stirring. Or, in other words, you’d think that ocean temperatures overall are rising while, in reality, you simply had a predominance of niños caused by the chaos inherent in weather.

April 11, 2013 7:40 pm

Very good article Bob, thanks.
Who Turned on the Heat? is a must-read for those willing to understand Earth’s climate.

Pavel Belolipetsky
April 11, 2013 8:24 pm

This is nice post, but probably anticorrelation between adjusted temperatures and Nino34 are spurious. The reason is that it is hard to find precisely the scaled factor for the comparison of variances dependent and explanatory variables. It is shown on figure 7-14 that you have used 0.18 for scaling Nino34. In general this factor produces little bigger amplitude for El Nino then at GISS temperature reconstruction. For example, true responce for some El Nino event is 1 deg C, but using Nino34 index and your scaling factor will show 1.1 deg C (numbers are only for example). As a result adjusted temperatures will be 1-1.1=-0.1 deg C during this El Nino event. The same situation but with opposite sign is for La Nina. So anticorrelations shown on figures 7-18, 7-19, 7-20 may be spurious.
Nevertheless, described feature doesn’t contradicts the main ideas of your hypothesis, because I think presence or absence of anticorrelation on figures 7-18, 7-19, 7-20 are not very important. More important is that you arguments will be more convincing if you show the same features in instrumental records from the beginning of 20th century.
Also please add in your list of papers that make this error-filled, misleading effort our preprint:
Belolipetsky PV, Bartsev SI, Degermendzhi AG, Hsu HH, Varotsos CA (2013) Empirical evidence for a double step climate change in twentieth century. Preprint. http://arxiv.org/ftp/arxiv/papers/1303/1303.1581.pdf
(Now under review in Climate Dynamics)
I think it contains viable hypothesis about 20th century warming that is different to anthropogenic, solar and yours. And have some advantages over them.

April 12, 2013 2:55 am

Thanks Bob.

April 12, 2013 8:10 am

The notion that the global temperature is the linear sum of a warming “signal” and natural “noise” abuses these two terms. “Signal” and “noise” are communications theoretic terms but here are being used in reference to attempts at controlling the global temperature.
There is an asymmetry between communications and control that is not being recognized by those who are guilty of this abuse. In communications, the signal arrives at its destination after it was sent but in control the “signal” must arrive at its destination before it was sent. For it to arrive before it was sent this “signal” must travel at a superluminal speed but under Einsteinian relativity, this is not possible. It may be concluded that this “signal” does not exist.
When we are able to control a system such as the climate, this is not because a signal carries information to us about the future. It is instead because we have acquired an ability to infer a state of nature in the future from a state of nature in the present with a degree of reliability. It is inferences that carry the information to us that is required for control of a system and not a signal. As today’s climate models make no such inferences, we lack this information thus being incapable of controlling the climate.

April 12, 2013 9:01 am

Pavel Belolipetsky:
I am commenting on your post addressed to Bob Tisdale at April 11, 2013 at 8:24 pm
In it you say

our preprint:
Belolipetsky PV, Bartsev SI, Degermendzhi AG, Hsu HH, Varotsos CA (2013) Empirical evidence for a double step climate change in twentieth century. Preprint. http://arxiv.org/ftp/arxiv/papers/1303/1303.1581.pdf
(Now under review in Climate Dynamics)
I think it contains viable hypothesis about 20th century warming that is different to anthropogenic, solar and yours. And have some advantages over them.

I have read the pdf and it provides a curve fit to global temperature over the twentieth century produced by two “regime shifts” in the climate system. This does disagree with both the Tisdale and the IPCC explanations of climate change over the past century. However, the pdf does not provide a possible mechanism for the “regime shifts”.
Considering your claim of the “advantages” of your hypothesis, the “advantages” are paucity (i.e. “Occam’s Razor). However, the disadvantage of no suggested mechanism for your hypothesis prevents falsifiability of your hypothesis. This disadvantage does not mean your hypothesis is wrong but it provides the challenge of postulating what such a mechanism could be.
In my opinion, there would be benefit in an article on WUWT from you which is similar to the articles from Bob Tisdale. This would permit evaluation in public of your hypothesis which could be of benefit to all and especially to your work. I observe that English is not your first language and if you were to prepare such an article then it may be beneficial to seek assistance from an English-speaker in ‘polishing’ the language used in the article. Bob Tisdale may perhaps be willing to help you in this way because you are providing an alternative – but not dissimilar – hypothesis to his.

Paul Vaughan
April 12, 2013 11:24 am

Pavel Belolipetsky (April 11, 2013 at 8:24 pm) referred to:
Belolipetsky, P.V.; Bartsev S.I.; Degermendzhi A.G.; Hsu, H.-H.; & Varotsos C.A. (2013). Empirical evidence for a double step climate change in twentieth century.
The paper emphasizes steps centered ~1925/1926 & ~1987/1988, the latter of which Bob Tisdale has emphasized here:
North Pacific ocean heat content shift in the late 1980s
The 2 step-dates emphasized by Pavel Belolipetsky correspond with the maximum rate of change of the orange SCD (solar cycle deceleration) curve illustrated here:
This is illustrated directly as maxima of the blue curve at the top of p.4 here:
Solar-terrestrial volatility weaves
I recommend that Pavel Belolipetsky see Figure 4 here:
Wyatt, M.G.; Kravtsov, S.; & Tsonis, A.A. (2011). Atlantic Multidecadal Oscillation and Northern Hemisphere’s climate variability. Climate Dynamics.

Paul Vaughan
April 13, 2013 4:07 pm

@ Pavel Belolipetsky (April 11, 2013 at 8:24 pm)
Another noteworthy match with your step-dates is figure 4 here:
Tlatov, A.G.; & Makarov, V.I. (2005). 22-year variations of the solar rotation.

Pavel Belolipetsky
April 14, 2013 10:14 pm

Thank you for the post. You are right that main advantage of our hypothesis is simplicity. I can add two another advantages – symmetry on the time and homogeneity for two regions. By symmetry on the time I mean that explanations for the warming of the beginning and of the end of 20th century are the same. Symmetry allowed to fit linear regression coefficients by data from first part of century (before 1950) and obtain near the same reconstruction. By homogeneity for two regions I mean that time series in tropics and north middle latitudes are very different, but the way of warming is common – shifts at near the same moments.
We didn’t suggested any mechanism because we don’t know it and there are many possible variants. For example, Paul Vaughan in this thread suggested some relationships with solar variability. And our hypothesis emerged from analysis of time series. We have found that assumption of shifts allows for easiest (known for me) way to reconstruct temperature dynamics at considered regions. Of course there are some residuals between observed and reconstructed values. But they are quite homogeneously distributed during the century. This is not the case for reconstruction by anthropogenic forcing (e.g. Lean JL and Rind DH (2008) How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophys. Res. Lett., 35, L18701, doi:10.1029/2008GL034864.) So our aim now is to show the evidence for shifts and suggesting the reasons is another task.
You wrote that absence of suggested mechanism prevents falsifiability of our hypothesis. I quite agree with you that it is hard to falsify it. But I think that the reasons are not only the absence of suggested mechanism. I don’t know now how to prove or reject it. So I again quite agree with you that article on WUWT will be very useful. I have made several attempts to submit guest post, but they were not successful (there was no response). I think the reason is that texts were bad. I also tried to contact with Bob Tisdale – send reference to him, answered on his questions. But I think I didn’t manage to make him interested. The conversation may be found in comments to following post:
bobtisdale.wordpress.com/2013/03/25/trenberth-still-searching-for-missing-heat/ .
Now again I’m preparing a new text for submitting a guest post to WUWT. So if somebody wish to help with this I will be very glad. My email could be find in preprint.
Paul Vaughan:
Thank you for provided information. I have looked through links briefly but haven’t enough time to read carefully know.
Best wishes

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