Bob has asked me to carry this post, and I’m happy to do so. For those who want to criticize without contributing anything but criticism, I offer this insight: The only real mistake is the one from which we learn nothing. ~John Powell
-Anthony
Revised Post – On Foster and Rahmstorf (2011)
Guest post by Bob Tisdale
ABOUT THE ERROR-LADEN FIRST VERSION OF THIS POST
I displayed my very limited understanding of statistics in my post On Foster and Rahmstorf 2011 – Global temperature evolution 1979–2010. This was pointed out to me a great number times by many different people in numerous comments received in the WattsUpWithThat cross post. My errors in that portion of the post were so many and so great that they detracted from the bulk of the post, which was about the El Niño-Southern Oscillation. For that reason, I have added a third update to my earlier post on Foster and Rahmstorf (2011), which asks readers to disregard that post and the cross post at WUWT. That update also includes a link that redirects readers here.
I learned a lot from my mistakes. Many of those who commented provided detailed explanations of the methods used by Foster and Rahmstorf (2011). Thanks go to them.
When an author of a blog post makes a major mistake, it needs to be acknowledged and/or corrected, and I have done this multiple times for that portion of my earlier post about Foster and Rahmstorf (2011). Now I’m reposting an expanded version of the discussion of ENSO. If you’d still like to discuss the errors I made in the earlier post, please comment on that thread, not this one.
OVERVIEW
This post discusses the assumption made in the paper Foster and Rahmstorf (2011) “Global Temperature Evolution 1979–2010”that the variations in the global temperature record due to El Niño-Southern Oscillation (ENSO) can be estimated from an ENSO index. This post excludes all discussions of the statistical methods used by Foster and Rahmstorf in their paper. Please limit the comments on this thread to ENSO and surface temperature responses to ENSO.
INTRODUCTION
Foster and Rahmstorf (2011) attempted to remove from 5 global temperature datasets the linear effects of 3 factors that are known to cause variations in global temperature. The paper covered the period of 1979 to 2010. The intent of their paper was to show that anthropogenic global warming continues unabated in all of those datasets. The independent variables listed in the abstract of Foster and Rahmstorf (2011) are El Niño-Southern Oscillation (ENSO), volcanic aerosols, and solar variations.
Foster and Rahmstorf (2011) used independent measures for these three factors. Total Solar Irradiance and aerosol optical depth data were used to estimate the effects of solar variability and volcanic aerosols on global surface temperatures. This post does not pertain to them. This post initially discusses the attempt by Foster and Rahmstorf (2011) to use an ENSO index as a measure of the effects of ENSO on global surface temperature. What will then be discussed and shown is that an ENSO index cannot account for the effects of ENSO on global surface temperatures.
Foster and Rahmstorf (2011) also makes two more assumptions that have little basis in reality. They assume the rise in surface temperatures since 1979 was linear and that it was due to anthropogenic factors. The sea surface temperature record of the global oceans since 1982 clearly disagrees with these assumptions.
ENSO IS NOT AN EXOGENOUS FACTOR
The following two papers discuss the problems with the assumption made by Foster and Rahmstorf (2011) about ENSO. One of the papers was cited by them in their paper.
Foster and Rahmstorf (2011) cited Trenberth et al (2002) Evolution of El Nino–Southern Oscillation and global atmospheric surface temperatures”as one of their ENSO references. But Trenberth et al (2002) include the following 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 rise in Global Sea Surface Temperatures during the satellite era, as will be shown later in this post. Did Foster and Rahmstorf (2011) consider these residuals in their analysis? No.
A more recent paper was overlooked by Foster and Rahmstorf (2011). Compo and Sardeshmukh (2010) “Removing ENSO-Related Variations from the Climate Record” seems to be a 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 from certain El Niño events, and they failed to account for its contribution to the rise in global Sea Surface Temperature anomalies since about 1975/76.
ENSO IS A PROCESS NOT AN INDEX
I have discussed, illustrated, and animated the process of ENSO and its effects on global surface temperatures and lower troposphere temperatures for about three years. There are too many posts to list them all here. However, if the subject of ENSO is new to you, refer to the introduction post here. If you would prefer an introductory-level discussion about ENSO written by someone else, refer to the excellent answers to FAQ here by Bill Kessler of the NOAA Pacific Marine Environmental Laboratory. For those who believe La Niña events are the opposite of El Niño events refer to the posts here, here and here. And for those who believe ENSO is represented by an index, refer to the post here. I will provide a relatively detailed overview of the process of ENSO in the following.
ENSO is a coupled ocean-atmosphere process that periodically discharges heat to the atmosphere during an El Niño. The phrase “coupled ocean-atmosphere process” refers to the fact that many ocean and atmospheric variables in the tropical Pacific interact with one another. For that reason, a number of tropical Pacific variables are impacted directly by ENSO, including sea surface temperature, sea level, ocean currents, ocean heat content, depth-averaged temperature, warm water volume, sea level pressure, cloud amount, precipitation, the strength and direction of the trade winds, etc. I have presented the effects of ENSO on each of those variables in past posts. And since cloud amount for the tropical Pacific impacts downward shortwave radiation (visible light) there, I’ve presented and discussed that relationship as well. In fact, the videos included in the post here presented ISCCP Total Cloud Amount data (with cautions about that dataset), CAMS-OPI precipitation data, NOAA’s Trade Wind Index (5S-5N, 135W-180) anomaly data, RSS MSU TLT anomaly data, CLS (AVISO) Sea Level anomaly data, NCEP/DOE Reanalysis-2 Surface Downward Shortwave Radiation Flux (dswrfsfc) anomaly data, and Reynolds OI.v2 SST anomaly data.
During an El Niño, warm water from the west Pacific Warm Pool can travel thousands of miles eastward across the equatorial Pacific. Keep in mind that the equatorial Pacific stretches almost halfway around the globe. So as the convection, cloud cover, and precipitation all accompany that warm water, their relocation causes changes in atmospheric circulation patterns worldwide. In turn, this causes temperatures outside of the eastern tropical Pacific to vary, some warming, some cooling, but in total, the areas that warm exceed those that cool and global surface temperatures rise in response to an El Niño. The spatial patterns of warming and cooling during a La Niña are similar to an El Niño, but of the opposite sign. And all that a paper such as Foster and Rahmstorf (2011) can only hope to account for are the changes in global temperature that respond linearly to the changes in the ENSO index used in the analysis. As confirmation, a paper cited by Foster and Rahmstorf (2011) acknowledged that there are ENSO-related factors that impact global temperatures that are overlooked by linear regression analysis. See Trenberth et al (2002) linked above.
Because global spatial patterns for El Niño and La Niña events are similar but opposite, many persons believe that all of the effects of El Niño and La Niña events oppose one another. This is far from reality. A La Niña event is basically an exaggeration of the “normal” (or ENSO-neutral) state of the tropical Pacific, while an El Niño event is an anomalous state.
An El Niño can carry huge volumes of warm water from the surface and below the surface of the west Pacific Warm Pool eastward to the central and eastern equatorial Pacific. That warm water is not consumed fully by the El Niño, so it returns to the west during the La Niña. One of the ways the La Niña accomplishes this return of warm water is through a phenomenon called a slow-moving Rossby wave, which forms in the northeast tropical Pacific at about 5N-10N. After the 1997/98 El Niño, the Rossby wave is plainly visible in ocean heat content anomaly animations, and better still in sea level residual animations from the Jet Propulsion Laboratory.
I’ve highlighted the Rossby wave in screen captures from the JPL video in Figure 1. The upper right-hand cell shows the formation of the Rossby wave and the lower left-hand cell captures the Rossby wave travelling from east to west at approximately 5N-10N, carrying leftover warm water back to the western Pacific during the transition from the 1997/98 El Niño to the multiyear La Niña that followed.
Figure 1
The Rossby wave can be seen in the first 10 to 15 seconds of Video 1. And as you will note, if you allow the video to play through, there are no comparably sized Rossby waves carrying cool waters back to the western tropical Pacific at 5N-10N after the La Niña.
Video 1
And to further confirm this basic difference between El Niño and La Niña events, there are also no comparably-sized Rossby waves carrying cool waters back to the western tropical Pacific at 5N-10N after any La Niña event seen in the full version of the JPL animation, Video 2, which runs from 1992 to 2002.
Video 2
There are no ENSO indices presently in use that can account for the return of the warm water to the West Pacific during a La Niña event that follows an El Niño.
As I’ve noted in numerous posts, ENSO is also a process that redistributes the warm water that was leftover from the El Niño itself and enhances the redistribution of the warm water that resulted from the El Niño in waters outside of the eastern tropical Pacific. The redistribution carries that warm water poleward and into adjoining ocean basins during the La Niña that follows an El Niño. The impacts of this redistribution depend on the strength of the El Niño and the amount of water that was “left over”. Lesser El Niño events that are not followed by La Niña events obviously would not have the same impacts. There are no ENSO indices that can account for this redistribution and these differences.
La Niña events also recharge part of the warm water that was released during the El Niño. They accomplish this through an increase in downward shortwave radiation (visible light), and that results from the reduction in tropical Pacific cloud amount caused by the stronger trade winds of a La Niña. Sometimes La Niña events “overcharge” the tropical Pacific, inasmuch as they recharge more ocean heat in the tropical Pacific than was discharged during the El Niño that came before it. That was the case during the 1973/74/75/76 La Niña. Refer to Figure 2. Tropical Pacific Ocean Heat Content rose significantly during the 1973/94/75/76 La Niña, and that provided the initial “fuel” for the 1982/83 Super El Niño and the multi-year 1986/87/88 El Niño. The La Niña events that followed those El Niño only recharged a portion of the heat discharged by them. Tropical Pacific Ocean Heat Content declined until 1995. Then the 1995/96 La Niña event “overcharged” the Tropical Pacific Ocean Heat Content again and that provided the fuel for the 1997/98 “El Niño of the Century”.
Figure 2
Refer also to the introductory level discussion in the post ENSO Indices Do Not Represent The Process Of ENSO Or Its Impact On Global Temperature.
THE TREND OF THE EAST PACIFIC SEA SURFACE TEMPERATURE ANOMALIES HAS BEEN RELATIVELY FLAT FOR 30 YEARS
The East Pacific Sea Surface Temperature anomalies from pole to pole, Figure 3, are dominated by the variations in tropical Pacific caused by ENSO, and as a result, the variations in the East Pacific Sea Surface Temperature anomalies mimic ENSO, represented by the scaled NINO3.4 Sea Surface Temperature anomalies. The trend of the East Pacific Sea Surface Temperature anomalies is relatively flat at 0.011 deg C/Decade.
Figure 3
The reason the trend is so flat: warm water from the surface and below the surface of the west Pacific Warm Pool is carried eastward during an El Niño and spread across the surface of the eastern tropical Pacific, raising sea surface temperatures there. And during the La Niña events that follow El Niño events, the leftover warm water is returned to the western tropical Pacific. Due to the increased strength of the trade winds during the La Nina, there is an increase in upwelling of cool subsurface waters in the eastern equatorial Pacific, so the Sea Surface Temperatures there drop. In other words, the East Pacific is simply a temporary staging area for the warm water of an El Niño event. Warm water sloshes into this dataset from the western tropical Pacific and releases heat, and then the warm water sloshes back out.
WHAT EFFECT DOES THE WARM WATER HAVE WHEN IT RETURNS TO THE WESTERN TROPICAL PACIFIC DURING THE SUBSEQUENT LA NIÑA EVENT?
The warm waters released from below the surface of the West Pacific Warm Pool during a major El Niño are not done impacting Sea Surface Temperatures throughout the global oceans when that El Niño has ended, and they cannot be accounted for by an ENSO index. Keep in mind, during an El Niño like the 1997/98 event, a huge volume of water from below the surface of the west Pacific Warm Pool was spread across the surface of the eastern tropical Pacific. Consequently, warm water that had once been excluded from the surface temperature record, because it was below the surface, is now included in the surface temperature record. At the end of the El Niño, the trade winds push the warm water that’s now on the surface back to the western Pacific where it remains in the surface temperature record. The Sea Surface Temperature in the western Pacific rises as a result. Add to that the effects of the Rossby wave. As illustrated earlier, at approximately 5N-10N latitude, a slow-moving Rossby wave also carries leftover warm water from the eastern tropical Pacific back to the western Pacific during the La Niña. Ocean currents carry all of the leftover the warm water poleward to the Kuroshio-Oyashio Extension (KOE) east of Japan and to the South Pacific Convergence Zone (SPCZ) east of Australia, and the Indonesian Throughflow (an ocean current) carries the warm water into the tropical Indian Ocean. And as noted above, due to the increased strength of the trade winds during the La Nina, there is an increase in upwelling of cool subsurface waters in the eastern equatorial Pacific, so the Sea Surface Temperatures there drop. But that cooler-than-normal water is quickly warmed during the La Niña as it is carried west by the stronger-than-normal ocean currents that are caused by the stronger-than-normal trade winds. And the reason that water warms so quickly as it is carried west is because the stronger-than-normal trade winds reduce cloud cover, and this allows more downward shortwave radiation (visible sunlight) to warm the ocean to depths of 100 meters. This additional warm water helps to maintain the Sea Surface Temperatures in the West Pacific and East Indian Oceans at elevated levels during the La Niña and it also recharges the West Pacific Warm Pool for the next El Niño event. Refer again to Figure 2. (Keep in mind that the graph in Figure 2 is for the Ocean Heat Content for the entire tropical Pacific, not just the Pacific Warm Pool.)
And what happens when a major El Niño event is followed by a La Niña event? The Sea Surface Temperature anomalies for the Atlantic, Indian, and West Pacific Oceans (the Rest-Of-The-World outside of the East Pacific) first rise in response to the major El Niño; the 1986/87/88 and 1997/98 El Niño events for example. Then the Rest-Of-The-World Sea Surface Temperatures are maintained at elevated levels by the La Niña; the 1988/89 and 1998/99/00/01 La Niña events to complete the example. The results are the apparent upward shifts in the Sea Surface Temperature anomalies of the Atlantic, Indian, and West Pacific Oceans from pole to pole (90S-90N, 80W-180), as illustrated in Figure 14. Some have described it as a ratcheting effect, where the redistribution of warm waters during the major El Niño and La Niña events drive the surface temperatures up a notch.
Figure 4
In Figure 4, the dip and rebound starting in 1991 is caused by the volcanic aerosols emitted by the explosive volcanic eruption of Mount Pinatubo. And the reason the Rest-Of-The-World Sea Surface Temperature anomalies respond so little to the 1982/83 Super El Niño is because that El Niño was counteracted by the eruption of El Chichon in 1982.
To assure readers that the upward shifts in Rest-Of-The-World Sea Surface Temperature anomalies coincide with the 1986/87/88 and 1997/98 El Niño events, I’ve included an ENSO index, NINO3.4 Sea Surface Temperature anomalies, in Figure 5. The NINO3.4 Sea Surface Temperature anomalies have been scaled (multiplied by a factor of 0.12) to allow for a better visual comparison, and shifted back in time by 6 months to account for the time lag between the variations in NINO3.4 Sea Surface Temperature anomalies and the response of the Rest-Of-The-World data.
Figure 5
But the ENSO Index data is visually noisy and it detracts from the upward shifts, so I’ve removed it in Figure 6. But in it, I’ve isolated the data between the significant El Niño events. To accomplish this, I used the NOAA Oceanic Nino Index (ONI) to determine the official months of those El Niño events. There is a 6-month lag between NINO3.4 SST anomalies and the response of the Rest-Of-The-World SST anomalies during the evolution phase of the 1997/98 El Niño. So the ONI data was lagged by six months, and the Rest-Of-The-World SST data that corresponded to the 1982/83, 1986/87/88, 1998/98, and 2009/10 El Niño events was excluded and left as black dashed lines. All other months of data remain and are represented by the blue curves.
Figure 6
And to help further highlight the upward shifts, the average Sea Surface Temperature anomalies between the major El Niño events are added in Figure 7.
Figure 7
Based on past posts where I’ve presented the data the same way, some readers have suggested the period average temperatures are misleading and have requested that I illustrate the linear trends. Figure 8 shows how flat the trends are between the 1986/87/88 and 1997/98 El Niño events and between the 1997/98 and 2009/10 El Niño events.
Figure 8
Back to the East Pacific data: If we adjust the East Pacific Sea Surface Temperature anomalies for the effects of volcanic aerosols, Figure 9, the linear trend is slightly negative. In other words, for approximately 33% of the surface area of the global oceans, Sea Surface Temperature anomalies have not risen in 30 years.
Figure 9
Note: The method used to adjust for the volcanic eruptions is described in the post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World, under the heading of ACCOUNTING FOR THE IMPACTS OF VOLCANIC ERUPTIONS.
And if we adjust the Rest-Of-The-World Sea Surface Temperature anomalies for volcanic aerosols, Figure 10, we reduce the effects of the dip and rebound caused by the 1991 eruption of Mount Pinatubo. And the trend of the Rest-Of-The-World data between the 1986/87/88 and 1997/98 El Niño drops slightly compared to the unadjusted data (Figure 8), making it even flatter and slightly negative.
Figure 10
Note: In the second part of a two part series (here), I further subdivided the Rest-of-the-World (90S-90N, 80W-180) sea surface temperature data to isolate the North Atlantic, due to its additional mode of natural variability. The sea surface temperatures for the remaining South Atlantic-Indian-West Pacific data decay between the major El Niño events. In other words, the sea surface temperatures there drop; the linear trends are negative, just as one would expect.
In summary, ENSO is a coupled ocean-atmosphere process and its effects on Global Surface Temperatures cannot be accounted for with linear regression of an ENSO index as attempted by Foster and Rahmstorf (2011)–and others before them. We can simply add Foster and Rahmstorf (2011) to the list of numerous papers that make the same error. Examples:
Lean and Rind (2009) How Will Earth’s Surface Temperature Change in Future Decades?
And:
Lean and Rind (2008) How Natural and Anthropogenic Influences Alter Global and Regional Surface Temperatures: 1889 to 2006
And:
Santer et al (2001), Accounting for the effects of volcanoes and ENSO in comparisons of modeled and observed temperature trends
And:
Thompson et al (2008), Identifying signatures of natural climate variability in time series of global-mean surface temperature: Methodology and Insights
And:
Trenberth et al (2002) Evolution of El Nino–Southern Oscillation and global atmospheric surface temperatures
And:
Wigley, T. M. L. (2000), ENSO, volcanoes, and record-breaking temperatures
IS THERE A LINEAR “GLOBAL WARMING SIGNAL”?
Foster and Rahmstorf (2011) assumed that the global warming signal is linear and that it is caused by anthropogenic factors, but those assumptions are not supported by the satellite-era Sea Surface Temperature record as shown above. The El Niño events of 1986/87/88 and 1997/98 are shown to be the cause of the rise in sea surface temperatures since November 1981, not anthropogenic greenhouse gases.
CLOSING COMMENTS
This post illustrated and discussed the error in the assumption that regression analysis can be used to remove the impacts of ENSO on Global Surface Temperature. ENSO is a process that is not fully represented by ENSO Indices. In other words, the ENSO indices only represent a small portion of the impacts of ENSO on Global Surface Temperatures. Attempting to use an ENSO index as Foster and Rahmstorf (2011) have done is like trying to provide the play-by-play for a baseball game solely from an overhead view of home plate.
The assumption made by Foster and Rahmstorf (2011) that a linear trend provides an approximate “global warming” signal was shown to be wrong using Sea Surface Temperature data. When broken down into two logical subsets of the East Pacific and the Atlantic-Indian-West Pacific Oceans, satellite-era Sea Surface Temperature data shows no evidence of an anthropogenic global warming signal. It only shows upward shifts associated with strong ENSO events.
If Foster and Rahmstorf (2011) were to exclude ENSO from their analysis, it is likely their results would be significantly different.
A closing note: I have also been illustrating, discussing, and documenting the ENSO-related processes behind these upward shifts for three years, using the East Indian-West Pacific subset (60S-65N, 80E-180). I first posted about it on January 10, 2008 in a two-part series here and here. The WattsUpWithThat cross posts are here and here.
ABOUT: Bob Tisdale – Climate Observations
SOURCES
The NODC OHC data is available through the KNMI Climate Explorer, on their Monthly observationswebpage.
The Reynolds OI.v2 Sea Surface Temperature data used in the ENSO discussion is available through the NOAA NOMADS website here.
The Aerosol Optical Thickness data used in the volcano adjustments of the Sea Surface Temperature data in Figures 9 and 10 is available from the GISS Stratospheric Aerosol Optical Thickness webpage here.
“afiziquist says:
January 15, 2012 at 1:44 am
My general impression is that fewer and fewer are interested in climate change these days. The only people interested are those at these sites and alarmist sites (which are even less). The subject is very rarely mentioned in mass media anymore. maybe without noticing it it has virtually died.”
It may be dying in the news but it is alive and well at the EPA and almost all democrats (and some republicans) in congress. It’s like giving enough pain medicine to a cancer patient to make the pain goes away then claiming you/ve cured the patient. This scam is far from dead yet, we still have years to go before we can declare victory that the world has been spared from this evil.
Catastrophic events, by definition, are driven and powered by steep contrasts and slopes. The consequences of “global warming” are first and most felt at high latitudes, where they result in a reduction of the contrast with the far more stable tropics. Therefore science and logic predict that adding energy to the (current, actual) system will reduce severe weather and associated catastrophes.
Coincidentally, it happens that this is what history records.
You were saying?
R. Gates says:
January 15, 2012 at 5:35 am
“Now it could be that this is all part of a natural, longer term cycle, and we are now getting to top of a cycle, and ocean heat content will begin to fall, as certainly over the longer time frames, short of external forcing such as from anthropogenic warming, ocean heat content must not go up nor down, but average out. Thus, the “step ups” you’ve identified must have a “step down” period, or something else is going on that your analysis is not accounting for.”
WOW! In order for it to ‘average out’ it MUST go up and down!
Exp says:
January 15, 2012 at 2:51 am
(Bob T said:)
“It’s also so ingrained in people now due to the constant bombardment from the news for all those years that when they hear of the drought in Texas or flooding somewhere else in the world they think of manmade global warming.”
If you put enough extra energy into a system to heat up the whole by an average of around 1C, wouldn’t you expect that those (severe and catastrophic) events that rely on energy, thermodynamic processes and entropy for their existence to be enhanced and effected? To deny this is to deny science and logic. Attribution is very hard to quantify certainly But trying to imply and insinuate that this means there is no effect and also trying to misrepresents scientists by claiming they are citing AGW as sole or even primary cause is outright dishonest.
___________
Exp – YOUR post seems to me to be dishonest (your words) and aggressive. Perhaps you should re-read Bob’s words and respond to what he actually said.
A few comments related Foster and Rahmstorf
http://iopscience.iop.org/1748-9326/6/4/044022
Abstract:
“We analyze five prominent time series of global temperature (over land and ocean) for their common time interval since 1979: three surface temperature records (from NASA/GISS, NOAA/NCDC and HadCRU) and two lower-troposphere (LT) temperature records based on satellite microwave sensors (from RSS and UAH). All five series show consistent global warming trends ranging from 0.014 to 0.018 K yr−1. When the data are adjusted to remove the estimated impact of known factors on short-term temperature variations (El Niño/southern oscillation, volcanic aerosols and solar variability), the global warming signal becomes even more evident as noise is reduced. Lower-troposphere temperature responds more strongly to El Niño/southern oscillation and to volcanic forcing than surface temperature data. The adjusted data show warming at very similar rates to the unadjusted data, with smaller probable errors, and the warming rate is steady over the whole time interval. In all adjusted series, the two hottest years are 2009 and 2010.”
Foster and Rahmstorf have analyzed a warming segment of clearly cyclical warming and cooling data, and then suggest that this “global warming signal” can be extrapolated into the future. This is just more global warming alarmist nonsense. There has been no significant global warming for a decade. Earth temperature is probably at the top of the cycle and is about to decline – aka “global cooling”. Such cooling last occurred from about 1945-1975. Bundle up.
The Climategate emails provide so much evidence of fraudulent behavior by acolytes of the global warming “Cause” that reading their papers is a waste of time.
Finally, while the media may be slowly moving away from global warming hysteria, the wasteful use of very expensive, inefficient and ineffective “alternative energy” schemes such as wind power and corn ethanol is still embraced by most of our lawmakers. We are still paying the price and will do so until these ridiculous energy scams and their huge subsidies and compulsory-use mandates are stopped.
“This post excludes all discussions of the statistical methods used by Foster and Rahmstorf in their paper.”
“This post illustrated and discussed the error in the assumption that regression analysis can be used to remove the impacts of ENSO on Global Surface Temperature. “
P. Solar says: “These oscillatory events are only about distribution of heat. You argue as if they were a source of energy by themselves. ENSO can not keep pumping up global temps indefinitely without a source for that energy.”
You must have zipped through the discussion of La Nina events. Look for the words and phrases recharge, overcharge, reduction in cloud cover, increase in downward shortwave radiation, that relate to Figure 2.
And thanks for the kind words.
Mardler says:
January 15, 2012 at 5:55 am
“Bob’s response was fine but may I add that here in the UK our government is committed to spending £18bn/pa on CO2 generated “green” policies that will cripple our econamy forever…”
Only capitalists will shut down an unprofitable industry.
Allan MacRae said:
“Foster and Rahmstorf have analyzed a warming segment of clearly cyclical warming and cooling data, and then suggest that this “global warming signal” can be extrapolated into the future. This is just more global warming alarmist nonsense.”
______
Actually, that is one of the best and most important parts of their entire paper. Skeptics are always asking for specifc, verifiable predictions…well, here you have one. If the statistical filtering methods used by Foster and Rahmstorf can be validated by other scientists, then there is a very specifc prediction for the linear background (one short-term noise is filtered out) rise in temperatures caused by anthropogenic forcing. If making specific and verifiable predictions is “alarmist nonsense” to AGW skeptics, then it seems skeptics are practicing a different kind of science.
Babsy said:
“WOW! In order for it to ‘average out’ it MUST go up and down!”
____
A big insight for you apparently. It seems skeptics keep wanting to look for natural cycles that explain warming, and thus assume that things must go down eventually to counter the late 20th and early 21st century warmth. Or some of them are of the mindset that the climate is still pulling out of the LIA. Anything, absolutely anything, but anthropogenic influence. It would seem a middle course is more reasonable…recognizing shorter-term cycles (which becomes noise if you’re looking for a longer-term signal), but also see how humans are altering the atmosphere, hydrosphere, and biosphere on micro and macro ways, and that alteration has only increased with human population growth.
Bob:
I don’t believe it is your technical writing that makes all ENSO discussions difficult to grasp. You are doing a fine job but the subject itself which is difficult. Without a beginning, the story can be difficult to collate into a whole. Until the ENSO causative story can be told, as to initiators and actual mechanics involved (predicted), it is very difficult to assemble a satisfying mosaic. This is not your fault. You have done well clarifying a very fuzzy picture, but it is always going to remain fuzzy until the fundamentals are discovered and understood (predicted). Typical cutting edge science conundrum… I would say. Thanks for your labors, for what it is, as always. GK
There’s a very important distinction that has to be kept in mind, and the semantics of the discussion may well hide it.
Global temperatures almost certainly do not show a linear response with respect to the ENSO index. But that is a very different thing from claiming a linear trend from the ENSO. Those are two different items, albeit with similar wording. Confusing them would be misleading.
As an example of a non-linear response (artificial, but for illustration), assume that the response of a system to an input has a delay, and returns to normal slower than it responds to an input. If you put a square wave input into the system (input rises, holds for a bit, drops back to neutral), a delayed response with a tail will produce something like a soft decaying sawtooth response. This is non-linear, and will leave +/- residuals after regression, as a scaled or delayed square wave cannot match a sawtooth form. But – a very important point – this kind of non-linear response will, while swinging back and forth over time, have a zero average residual (no trend) – with small variations above and below neutral.
In other words – a non-linear response, which is certainly the case with ENSO and the multiple factors involved, does not necessarily indicate underlying trends in the response – it simply means that a linear regression will leave some residuals (+/-) from the non-linear response. Identifying and attributing linear trends is a completely separate discussion.
[ Side note – step changes: Tisdale in Fig. 7 shows step changes with linear sections of length 3, 9, and 11 years. Given the inherent variation (weather) and noise in the global temperature signal, the statistical requirement for a minimum of 17 years of global data to establish a linear trend (Santer 2011, http://muenchow.cms.udel.edu/classes/MAST811/Santer2011.pdf), and the restriction of temperatures to a much smaller and hence more variant section of the Pacific, this claim is simply not statistically meaningful. At all. ]
—
Tisdale claims that a series of La Niña’s “overcharged” the ocean heat content, and led to a 30 year warming. As support he points to the “step-changes” in the last 30 years (see previous side note). Some questions come to mind:
* Why has this not happened before? (http://www.esrl.noaa.gov/psd/enso/mei/ – 135 year ENSO record)
* Ocean Heat Content, by any records (http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/), has increased hugely over the last 30 years. That’s completely inconsistent with an ocean driven positive SST change from ENSO variations – both OHC and air temperatures are rising.
* What is the SST observational difference for this limited set of data between (a) ENSO induced “step changes” that are not statistically meaningful given the data variance, and (b) ENSO variance around a linear trend separately caused by, oh, greenhouse gas changes? [ Answer – none. ] See http://tamino.wordpress.com/2012/01/10/step-2/ and http://www.skepticalscience.com/its-a-climate-shift-step-function-caused-by-natural-cycles.htm for examples of overfitting a series of steps to what are actually linear trends with variations.
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Summary: Non-linear responses from complex processes do not, by themselves, indicate underlying linear trends – that’s two completely different uses for the terminology.
Step changes are not statistically meaningful over such a short timeframe. You can really closely fit data with (for example) a high order polynomial – but if you don’t have the data to support that many parameters, you are overfitting, and getting deceptive results.
There is no observational difference for SST’s between ENSO plus a separate linear trend and ENSO step-changes – and those step changes are (a) not statistically supportable, and (b) lack a physical mechanism.
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Bob Tisdale – It would be interesting to see your work extended with confidence intervals. I realize that’s a bit of statistical heavy lifting, but given the other issues with such claims (I’ve mentioned a few above) I don’t think you’re going to make much headway unless you can show how supportable your claims are.
Hats off to you Sir. This is what credible science is all about.
Bob,
I know this is a bit off topic but the decadel oscillations could very easily drive the “lag” between warming and cooling. I tend to think of these heat sinks as the buffer between times of solar heat uptick which keep the earth from warming fast to times of solar depression where heat is released to keep the planet warmer.
Maybe I’m to simplistic in this process but many of the lag times in gases and temp are explained in the time factor it takes for these to occur. Our time span in assessing these is so limited that simple observation may be a better predictor than the numbers.
Alan Statham says:
January 14, 2012 at 6:03 pm
Well go on then. Try and get this published in the scientific literature.
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Alan, he just did. In case you haven’t noticed, the publications which often publish such tripe as F&R aren’t viewed as valid any longer by a large portion of the population. If the ideologues wish to continue to publish in these nonsensical periodicals, so be it. But, its has long since passed that what is published in them was viewed as a euphemism for science. We’ve known for a long time they were hi-jacked by ideologues, it has been proven repeatedly and the last several years. If you want to find real climate science, you need to look at the blogs.
If you constrain yourself as to believing only rubbished periodicals, you’ll be left with the impression that we’ve dead polly bears floating about, a non existent ice cap, clouds being of no import to temps, temps continuing unabated, the passing of the Amazon, upside-down proxies, no MWP or LIA, …….well, the list goes on and on. Yeh, those are the places I’d go for some science knowledge…..
@ur momisugly Bob, well done. Keep hammering at the ENSO fallacies. The biggest problem in climate science is the belief that we know so much, when, clearly, we know so little. Thanks again.
R. Gates says:
January 15, 2012 at 10:17 am
“It seems skeptics keep wanting to look for natural cycles that explain warming, and thus assume that things must go down eventually to counter the late 20th and early 21st century warmth. ”
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One can only laugh at the short sighted warmers for their undying belief that man is the sole cause of everything… Even when the facts show that it has happened time and time again without mans help..
Science is the practice of good observation and documentation skills. Warmers have a problem with observation and documentation skills… Climate-gate anyone? When ones financing by BIG GOVERNMENT clouds their vision they become nothing more than a shill for those who crave power..
You belittle those who are observing and noticing things that warmers want silenced…. where sir did you learn science? it seems you may be practicing anything but… please remove the liberal blinders you have so firmly in place… the science is not settled like you would want us to believe.
R. Gates says:
January 15, 2012 at 10:17 am
Yeah! That struck a chord with ya, didn’t it?! I once read in a book “The mark of your ignorance is the depth of your belief in tragedy and injustice”. Here’s how it works; one makes a measurement then formulates a hypotethsis to explain the observation. The hypothesis follows the facts and not the other way around. With you, the temperature of the atmosphere is increasing (never mind there are data that indicate otherwise [Hide the decline!]) and for you the *ONLY* possible explanation of the observation is because ‘man’ is dumping CO2 in the atmosphere! If you, and ‘The Team’, can’t formulate a theory that accurately predicts future observations using identical parameters, then your theory is *WRONG*.
“R Gates says;
On a larger perspective, this residual heat issue, as you’ve identified so nicely in the Rossby waves, does raise the issue that I’ve brought up with you, and that’s that El Ninos have not been releasing as much heat as La Ninas have been storing over the past 30+ years. Now, even the fact that some of the residual heat from El Ninos continues to influence ocean SST’s after the formal El Nino period has ended, only highlights this point even more.”
When I see your name I am going to discipline myself not to read your nonsensical posts.
El Nino’s, La Nina’s don’t store anything. They are dynamic process that distribute OHC. La Nina’s don’t stop when La Nina starts and vise versa, at times one is more dominate. Bubbles in a boiling pot will have different attractors as it is thermodynamically mixed into the Heat Content of the whole pot.
R.Gates, although this site is open to both those that know and those ignorant like you and me, it is still a requirement to have some basic cognitive ability. You, on the other hand, either have none, or are just another warmist troll.
Markus said:
“El Nino’s, La Nina’s don’t store anything.”
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In general, more SW solar radiation enters the ocean during La Ninas that during El Ninos. This fact, leads to the general observation that ocean heat content tends to increase during La Ninas and of course decrease during an El Nino. Of course, the El Ninos have not been as good at releasing the heat during the past 30+ years as the La Ninas have been at storing it, and so ocean heat content has increased. Some say this imbalance is due to anthropogenic factors, and some say it is a “natural cycle”, but regardless, the imbalance exists, and right up to the latest reporting period for OHC, with it being a La Nina, OHC has gone up and is at its highest levels in the 30+ year period.
markus says:
January 15, 2012 at 11:25 am
Your reference to bubbles in a boiling pot reminds me of flying in clouds. Inside a cloud is different than outside a cloud with respect to both temperature and dew point. I think the R Gates crowd would wish us to believe that such variation isn’t possible and that we should think of the atmosphere and the oceans as static entities. They ain’t!
Bill H says:
January 15, 2012 at 10:46 am
R. Gates says:
January 15, 2012 at 10:17 am
“It seems skeptics keep wanting to look for natural cycles that explain warming, and thus assume that things must go down eventually to counter the late 20th and early 21st century warmth. ”
——————————————————————————–
One can only laugh at the short sighted warmers for their undying belief that man is the sole cause of everything… Even when the facts show that it has happened time and time again without mans help..
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There is a big gray area between the extreme of saying, “It is all natural cycles” to “Man is the sole cause of everything”. The truth is most likely somewhere in that gray area, and the difficulty is in finding out where. Added to this difficulty is the fact that the mixture of the two, “natural cycle” versus “anthropogenic” is likely changing as humans have increased their footprint on the planet…i.e. what the ratio of natural versus anthopogenic was during the 1940’s may be far different now as the impacts from human activity has increased greatly.
Looked at Foster and Rahmstorf. Pretty worthless paper. They are chasing ghosts with MEI, AOD, and TSI, and they have no idea what ENSO is. They could have found out by reading my book but instead they have six blind men in a room trying to learn about an elephant. They also have no idea what information is carried by the satellite record and imagine that using a linear trend will get rid exogenous influences that only they can detect. All-in-all a true IPCC-quality monster.
R. Gates says:
January 15, 2012 at 11:47 am
“i.e. what the ratio of natural versus anthopogenic was during the 1940′s may be far different now as the impacts from human activity has increased greatly.”
Until your ‘Team’ can demonstrate the mechanism of ‘anthropogenic’, and it be independently confirmed, it doesn’t exist!
There are a variety of confounding influences to sea height data that make untangling the sea temperature signal difficult. 1) temperature 2) salinity 3)winds, including trade winds 4)ocean current dynamics, 5) tides, 6) other long period waves, 7) eustatic changes from increases and decreases in ocean mass, 8) tectonic changes in sea floor configuration, although this is a very long period change. Not all of these would be involved in an ElNino index based on sea height, but you asked for reasons why SST is used.
I think Brian H also mentioned this, but weather is driven by contrasts in temperature (and water vapor content) and since AGW increases the polar temperatures and humidity more than it does in the tropics, then this ought to, logically, reduce extreme weather? You could argue that Hurricanes would be another matter completely, but there isn’t clear evidence of an increase there either.
Couldn’t help myself
“R. Gates says:
January 15, 2012 at 11:40 am In general, more SW solar radiation enters the ocean during La Ninas that during El Ninos”
The fanciful world of a warmist. Hard to see though that warm mist isn’t it. “The Sun knows when a El Nino has formed as switches off.” Really, R.Gates. Both La Ninas and El Ninos are local phenomenon resultant from external forcing, on the other hand the oceans have global aspects, just like the Sun.
Mate, you’re illogical. You’re calling cause before you know the effects.
R. Gates says:
January 15, 2012 at 11:47 am
“The truth is most likely somewhere in that gray area, and the difficulty is in finding out where.”
In your case it’s the difficulty in finding the gray matter.