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Climate Hustle

## Fritz Vahrenholt - Duped on Climate Change

#### Posted on 15 February 2012 by dana1981

German electric utility executive Fritz Vahrenholt is co-author (along with geologist Sebastian Lüning) of a book expressing "skepticism" regarding the human contribution to global warming, which predictably has been trumpeted by the usual climate denial enablers.  Why should we particularly care what Vahrenholt thinks about climate science?  That is something of a mystery - he has a PhD in chemistry and has worked in the energy sector for Shell Oil and wind turbine maker RePower.  Vahrenholt and Lüning both currently work for RWE Innogy, Germany's second-largest energy company (Vahrenholt as a manager, Lüning as a scientist in its oil and gas division).

Vahrenholt admits he has no expertise in climate science, but apparently his status as "Germany’s Top Environmentalist" (a title which Vahrenholt appears to have been awarded just recently by anti-climate think tanks and denialists) and his climate "skepticism" are sufficient for some people to take his climate claims seriously.

In an interview with Der Spiegel, Vahrenholt discusses why he chose to write a book rather than attempting to conduct and publish scientific research.

SPIEGEL: You make concrete statements on how much human activity contributes to climatic events and how much of a role natural factors play. Why don't you publish your prognoses in a professional journal?

Vahrenholt: Because I don't engage in my own climate research. Besides, I don't have a supercomputer in my basement.  For the most part, my co-author, geologist Sebastian Lüning, and I merely summarize what scientists have published in professional journals -- just as the IPCC does.

However, as we will soon see, the difference between Vahrenholt and the IPCC is that the latter accurately summarizes the body scientific literature, while the former misrepresents his sources and only listens to a few select "skeptic" scientists.

### Misrepresenting the IPCC

In the interview, Vahrenholt makes a statement about the IPCC which reveals that he simply has not done his research.

"The long version of the IPCC report does mention natural causes of climate change, like the sun and oscillating ocean currents. But they no longer appear in the summary for politicians. They were simply edited out."

Vahrenholt refers to the IPCC Fourth Assessment Report Summary for Policymakers (SPM).  The following quotes are taken directly from the SPM, which Vahrenholt claims has edited out all mention of natural causes of climate change.  The first quote is the first sentence in the SPM.

* "The Working Group I contribution to the IPCC Fourth Assessment Report describes progress in understanding of the human and natural drivers of climate change, observed climate change, climate processes and attribution, and estimates of projected future climate change."

* "Human and Natural Drivers of Climate Change

Changes in the atmospheric abundance of greenhouse gases and aerosols, in solar radiation and in land surface properties alter the energy balance of the climate system.  These changes are expressed in terms of radiative forcing, which is used to compare how a range of human and natural factors drive warming or cooling influences on global climate."

* "Changes in solar irradiance since 1750 are estimated to cause a radiative forcing of +0.12 [+0.06 to +0.30] W m–2, which is less than half the estimate given in the TAR."

* "It is very unlikely that climate changes of at least the seven centuries prior to 1950 were due to variability generated within the climate system alone. A significant fraction of the reconstructed Northern Hemisphere inter-decadal temperature variability over those centuries is very likely attributable to volcanic eruptions and changes in solar irradiance, and it is likely that anthropogenic forcing contributed to the early 20th century warming evident in these records."

* "The observed widespread warming of the atmosphere and ocean, together with ice mass loss, support the conclusion that it is extremely unlikely that global climate change of the past 50 years can be explained without external forcing, and very likely that it is not due to known natural causes alone."

There are more such examples.  Then there's Figures SPM.2 and SPM.4:

Figure SPM.2: Global average radiative forcing (RF) estimates and ranges in 2005 for anthropogenic carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and other important agents and mechanisms, together with the typical geographical extent (spatial scale) of the forcing and the assessed level of scientific understanding (LOSU). The net anthropogenic radiative forcing and its range are also shown. These require summing asymmetric uncertainty estimates from the component terms, and cannot be obtained by simple addition.  Additional forcing factors not included here are considered to have a very low LOSU. Volcanic aerosols contribute an additional natural forcing but are not included in this figure due to their episodic nature. The range for linear contrails does not include other possible effects of aviation on cloudiness.

Figure SPM.4 - Comparison of observed continental- and global-scale changes in surface temperature with results simulated by climate models using natural and anthropogenic forcings. Decadal averages of observations are shown for the period 1906 to 2005 (black line) plotted against the centre of the decade and relative to the corresponding average for 1901–1950. Lines are dashed where spatial coverage is less than 50%. Blue shaded bands show the 5–95% range for 19 simulations from five climate models using only the natural forcings due to solar activity and volcanoes. Red shaded bands show the 5–95% range for 58 simulations from 14 climate models using both natural and anthropogenic forcings.

Clearly the SPM explicitly discusses natural contributions to global warming, and explains that according to the body of scientific evidence, their contribution to the observed warming is small.  Frankly if Vahrenholt can't even accurately read the 18-page SPM, it's exceptionally difficult to take him seriously.  His subsequent comments in the interview reveal that he has been very selective about what scientific research he chooses to accept.

### Misrepresenting Global Warming

Early in the interview, Vahrenholt repeats a myth which has become increasingly popular amongst climate contrarians.

"It hasn't gotten any warmer on this planet in almost 14 years, despite continued increases in CO2 emissions. Established climate science has to come up with an answer to that."

Of course our first answer must point out that Vahrenholt's assertion is false.  Over the past 14 years, the average global surface temperature has warmed approximately 0.13°C, according to data from the NASA Goddard Institute for Space Studies.  And of course surface air warming only represents a very small percentage of global warming, which has continued uninterrupted:

Figure 1: Global heat content, data from Church et al 2011.

And of course there's the fact that the odd timeframe choice of 14 years conveniently begins at the peak of the strongest El Niño in a century (a.k.a. cherrypicking of short-term data).  This cherrypicking is illustrated by The Escalator, which was used by German newspaper Die Zeit to debunk this myth from Vahrenholt's book (Figure 2).

Figure 2: Die Zeit use of The Escalator

We should note that while we are flattered that Die Zeit has described Skeptical Science as "an internet platform close to the IPCC" in their figure caption, we are in no way affiliated with the IPCC.

The second answer to Vahrenholt's concern about the dampened surface warming over the past decade or so involves the fact that virtually every non-greenhouse gas effect acted in the cooling direction over that period.  Human aerosol emissions increased, blocking more sunlight.  Heat accumulated in the deep oceans.  The solar cycle went into an extended minimum.  There were a number of strong La Niña events.  Foster and Rahmstorf (2011) showed that when we filter out the latter two effects and that of volcanic activity, the warming of surface temperatures has not even slowed (Figure 2).

Figure 2: Average temperature changes recorded by 5 teams of scientists: 2 working on satellites (University of Alabama, Huntsville and Remote Sensing Systems) and 3 working with thermometers and ship/buoy measurements (UK Hadley Centre & Climate Research Unit, NASA Goddard Institute for Space Studies and the US National Climatic Data Centre. Foster and Rahmstorf (2011) statistical methods have been used to 'take out' the effects of volcanic eruptions, Pacific Ocean cycles and the Sun.

### Blaming the Sun

Like David Archibald, Vahrenholt exaggerates the solar influence on global temperature.

"In the second half of the 20th century, the sun was more active than it had been in more than 2,000 years. This "large solar maximum," as astronomers call it, has contributed at least as much to global warming as the greenhouse gas CO2."

In the second half of the 20th century, solar activity was also flat.  Vahrenholt does not seem to understand that the climate responds to increasing solar activity, not flat solar activity, even if at a relatively high level.  It's true that solar activity increased leading up to the mid-20th century, which contributed to the warming observed from about 1910 to 1940.  However, total solar irradiance (TSI) increased by less than 2 Watts per square meter (W/m2) leading up to 1940 (i.e. see Vieira 2011 and Jones 2012, with more recent reconstructions showing a smaller TSI increase of generally less than 1 W/m2 during this period).

We can estimate the equilibrium temperature response to this TSI increase by multiplying the radiative forcing by the climate sensitivity parameter (λ).

$\small \Delta T_{solar} = \lambda \Delta F = \lambda \times 0.7 \times \Delta (TSI)/4 = 0.175 \times \lambda \times \Delta (TSI)$

The solar radiative forcing for a 2 W/m2 increase in TSI is just 0.35 W/m2, compared to the ~1.6 W/m2 radiative forcing from increased CO2.  These radiative forcings will cause an equilibrium surface warming of approximately 0.3°C and 1.3°C, respectively.  So no, the increase in solar activity has not contributed nearly as much to global warming as the CO2 increase.

### Blaming Ocean Cycles and Galactic Cosmic Rays

When confronted with the flat TSI trend over the past ~60 years by the Der Spiegel interviewer (who did a nice job challenging Vahrenholt's many myths throughout the interview), Vahrenholt invoked ocean cycles and galactic cosmic rays (GCRs) to explain the observed global warming.

"There are two effects: the declining solar activity, as well as the fluctuations in ocean currents, such as the 60-year Pacific oscillation, which was in a positive warm phase from 1977 to 2000 and, since 2000, has led to cooling as a result of its decline. Their contribution to the change in temperature has also been wrongly attributed to CO2. Most of all, however, the last sunspot cycle was weaker than the one before it. This is why the sun's magnetic field has continued to weaken since 2000. As a result, this magnetic field doesn't shield us against cosmic radiation quite as well, which in turn leads to stronger cloud formation and, therefore, cooling. What else has to happen before the IPCC at least mentions these relationships in its reports?"

Once again Vahrenholt has misrepresented the IPCC report, which does discuss GCRs (i.e. here and here) and the Pacific Decadal Oscillation (i.e. here and here).  The IPCC report correctly notes that the body of scientific research has shown that GCRs have little if any effect on cloud cover and thus global temperature, and even if they did, like TSI, solar magnetic field strength has remained steady over the past ~60 years (as has GCR flux on Earth).  Oceanic oscillations are just that - oscillations switching between positive and negative states, moving heat around between the oceans and atmosphere.  Since both oceans and atmosphere are warming, it must be due to an external forcing, not an internal oscillation.

### Vahrenholt Misrepresents Kirkby and CERN

The following exchange between Vahrenholt and the Der Spiegel interviewer is very representative of the interview as a whole.

Vahrenholt: It's more than that. The Cloud Experiment, headed by physicist Jasper Kirkby, has been underway at the CERN particle research center near Geneva since 2006. The initial results of tests conducted in a chamber in which the earth's atmosphere was simulated showed that cosmic particles do indeed lead to the formation of aerosol particles for clouds.

SPIEGEL: But the aerosols demonstrated in the Cloud Experiment are much too small. They would have to grow before they could actually serve as condensation germs for clouds. Whether this happens in nature is still an open question. You present this as a fact.

Vahrenholt: You will find many correlations between cloud cover and cosmic radiation in the book. I'd like to know why the IPCC doesn't thoroughly examine this mechanism. My guess is that the answer to this question would jeopardize the entire foundation of the IPCC predictions.

Vahrenholt misrepresents the scientific evidence, in this case Kirkby and CERN's results, which Kirkby himself states "says nothing about a possible cosmic-ray effect on clouds and climate, but it’s a very important first step."  The interviewer catches Vahrenholt in this misrepresentation, and Vahrenholt responds by claiming some research exists which supports his myth, and that the IPCC is ignoring it.  In reality, the IPCC has discussed the issue in great detail, as demonstrated above.

### Vahrenholt is Indeed Duped

In short, we end the way we began, wondering why anybody takes Vahrenholt's comments on the climate seriously.  Not only does he lack expertise in the subject, but he clearly has not done his research, and misrepresents most of the sources he references.  Toward the end of the interview, Vahrenholt provides a comment which Der Spiegel used in the title of the article:

"...I feel duped."

Indeed Vahrenholt has been duped, by his own shoddy research, and has also duped many of his readers in the process.

Note: Vahrenholt and Lüning have published a response to some of the criticism of their work.  However, their response doesn't really contain any new information, and doesn't seriously address any of the criticms leveled in this post (in addition to completely missing the point of The Escalator, as other "skeptics" have).

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Comments 51 to 65 out of 65:

1. You are playing semantic games elsa, since you are using false logic (constructing a non sequitur) to arrive at a false conclusion (i.e. that "AGW is untestable in any meaningful way").

Since AGW is indeed testable, at the very least according to the well established and oft-repeated criteria I described in post #39, there's obviously something wrong with your logic (it's easy to see that the problem is a semantic flaw based on a false premise [*]).

[*] The false premise being your "All we can do is use (iv) as a starting point, which really amounts to assuming that the theory is correct...", which is bogus.
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2. Must say I love reading Elsa's posts.
She is quite adept at getting attention and finding some point that she can use as a goad to create responses that she can then use to find another point in order to continue the game.
Of course I never see her accepting that anything she thinks could be wrong or admitting that someone has adequately address her objection.
I am impressed with the patience of those who engage with her.
So I have a question for Elsa. Have you tried pitting your rhetorical skills against the leading theories of climate that do not have CO2 being the main forcing of climate through the increase of anthropogenic CO2? What about the accuracy of their models and predictions based on actual data. How well do their theories explain the paleodata- ice ages, LIA, MWP, and all the various other verifiable changes in climate and global/regional temp.
It has been over 30 years since AGW has been mostly accepted as a concern by scientists. And 20 years since there was strong political pressure to deny AGW. Certainly Lindzen, Spencer, Christie, and others have a robust theory with predictions that can be forecast and hindcast and compared to AGW theory. And you can put your same questions to them, and then compare.
Please advise of your conclusions regarding the alternate theory and where it is consistent and adequately accounts for all the actual data in every discipline that has data on climate.
It shouldn't take very long.
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3. "Oceanic oscillations are just that - oscillations switching between positive and negative states, moving heat around between the oceans and atmosphere. Since both oceans and atmosphere are warming, it must be due to an external forcing, not an internal oscillation."

This is incorrect. Changes in ocean circulations can change the distribution of radiatively active clouds and water vapor in the atmosphere and thus can cause an 'internal' radiative forcing (an actual change in total heat, not just a change in the location of heat).

see this paper for example:

http://www.mendeley.com/research/why-ocean-heat-transport-warms-the-global-mean-climate/
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4. Elsa, your line is that "observations contradict the theory of climate". Eg. "look little warming over past decade while CO2 goes up, ergo climate science is wrong". As has been pointed out this a/ not how to test observation versus model and b/ not what model predicts anyway.

Likewise, claiming a cherrypick 1940 to 1970 is ignored, when gosh, it was cooling! is wrong for same reasons. The model has no problem with that cooling. The period chosen has to do with explaining why it is steadily warming over a period when there is no natural factors to explain that except for the short term noise. The denialists just focus on the noise.
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5. elsa wrote: "while I can understand a relationship between two variables might be statistically significant I do not see how you could make the statement that the trend in temperature is so."

Then I can only conclude that you do not understand what the words 'statistically significant' mean in standard usage. A general overview on statistical significance in regards to temperature trends can be found here and here.

and: "Perhaps you can explain then how you would take step (i) without using (iv). From where would you derive a relationship between eg CO2 and temperature without actually carrying out (iv)?"

As others have noted, the relationship between CO2 and temperatures was established over a century ago... and decades before Arhenius first cited the possibility of anthropogenic global warming. You seem almost to be arguing that we cannot formulate any new theories without first going back and re-validating all previous knowledge. Obviously, new theories are based on our understanding of other things and thus in some sense all science could be described as one continuously evolving 'theory of everything', but if we are to separate out individual scientific theories (like AGW) then they must have distinct introductory points (Arhenius 1896 for AGW) as 'step i', founded on the state of science available at that point.

also: "sorry about the timing of posts which is to do with the need to log out if one's view of the blog is to be updated."

I'm not sure what you mean here... I update the view all the time without logging out. In most cases you should be able to just hit the browser's 'refresh' button. The only exception would be if you are still on the page displayed after you made a post... in which case refreshing might cause a duplicate post. However, you can just click to any other page and then back OR use the browser 'back' button to go back to your view of the page prior to posting. No need to log out,
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6. Interesting discussion re elsa, her comments and the valuable replies she received then how she handled them.

I know this get's pretty simple but elsa try out this short video:
Global Warming: It's Not About the Hockey Stick

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

However I came here for a different reason. Back to Vahrenholt's interview, answering question #4 his reply includes the following, when explaining why he doesn't trust the IPCC:

"...In one case, a Greenpeace activist's absurd claim that 80 percent of the world's energy supply could soon be coming from renewable sources was assumed without scrutiny. This prompted me to examine the IPCC report more carefully."
~ ~ ~

Does anyone know the background to this. . .
and the rest of the story?
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7. Martin#34:

I looked at Kirkby's video in its entirety. Some of your points are not quite so clear.

"Kirkby doesn't claim that cosmic rays lead to increases in cloud cover."

That claim was made numerous times in the prior literature; it is the basis of the entire idea for the CLOUD experiment. See anything by Svensmark and his popularizer, Nigel Calder.

"UV is neglected as an input in climate models, the sign for solar irradiance forcing is wrong."

UV is not neglected; Haigh 2011 is a model study using UV.

The case for UV variation flipping the sign of solar forcing is not clear. Consider this statement from the Max Planck Institute:

the UV radiation shortward of 400 nm contributes only about 8% to the magnitude of the total solar irradiance, it is responsible for about 60% of the variation of the total irradiance.

So most of the variation is in a wavelength range that is a minimal component of total solar output. Lots of folks spend all their time studying these questions; to show they've missed something this big would be quite an achievement indeed. But it hasn't appeared in the literature yet.

"think of Kirkby as a sceptic it might be more because of what he thinks is poorly understood"

Not true. Cosmic ray physics are reasonably well understood. What I have not understood in Kirkby's work is why they designed the experiment to model solar cosmic ray energies - not galactic cosmic ray energies. And I've discussed that with particle physicists at CERN who don't understand it either.

Then there is this important, yet neglected question: How can the same ionization effect be triggered by lower energy gamma rays?
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8. yes - this man Vahrenholdt is manager of one of the big energy companies here in Germany. This is typical and as I often quoted here at SKS, the EIKE institute of denialists (CFACT behind EIKE) stands behind everything there ... you know EIKE is fostering Svensmark (and Kirbky) in a very rare way - actually a good scientist with brilliant ideas, but, as you say the results of the CERN project CLOUD are too thin as that they were final. And even though: CO2 is warming the atmosphere (and other GHGs) and this CLOUD-effect - as we might call it - is perhaps a shortterm mitigation effect ... when it is over, CO2 and the other GHGs strike back ...

This does not go into the heads of some influential people ...

Moreover there is another interview with Prof. Eicke Weber Head of the Fraunhofer Institute in Freiburg/Germany in one of the online issues of WELT or SPIEGEL (I just do not know which one) who is being opposing the Vahrenholdt book ... etc. etc.
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9. Tonydunc, my apologies that I have not had time to get back to you sooner. The question you ask is, I think, do I consider the alternative explanations of global warming to be as unscientific as the general view expressed here. The answer is yes. The models that apparently explain warming via sunspots etc are equally poor and are not scientific in any way.
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10. Chris, you say that the way we should do things is:

(i) perform experiments/observations
(ii) formulate a theory
(iii) devise and perform experiments/observations to test the theory
(iv) compare results with predictions...
(v) refine or abandon theory...
(vi) repeat steps (iii-(vi)

I would mostly agree with you if we were dealing with a simple situation, eg just the force of gravity, where we could run an experiment over and over again. Unfortunately with climate we are dealing with complex phenomena with the added difficulty that we cannot run the experiment over and over again. That is why we need a starting point which is given to us by something other than measurements we have already taken, otherwise we can "refine" our theory as you put it but all we are doing is making the numbers work so the theory cannot be wrong.
This is what happens to the AGW theory for the period 1940 to 1970s. The facts do not fit the theory as the world cools in the face of rising CO2. So the AGW group has then to add other factors to make it work. But such a theory is no longer testable, it will always be right.
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11. 60, elsa,

Sort of like having a theory of classical mechanics, except the speed of light doesn't fit, so someone devises some crazy Theory of Relativity just to make the obviously flawed, broken and useless model of classical mechanics fit the observations (rather than doing the smart thing, and just plain starting over)?

And then other people develop more ideas, like quarks and string theory and everything else?

You're right, it's all completely crazy. Why keep expanding on what you know and further refining your understanding of a complex system, when you can instead oversimplify things and throw out everything you do know because the details don't line up perfectly the first time?

Why base a theory of climate on well-known, well-understand, and proven things like atmospheric chemistry and physics, and then try to understand the other factors that influence and complicate those physics, when you can instead simply invoke the powers of the Flying Spaghetti Monster?
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12. Elsa, the experiments/observations on which AGW theory are based are repeatable and could be run over and over again. As I pointed out the theory of AGW predates global observations.

"This is what happens to the AGW theory for the period 1940 to 1970s. The facts do not fit the theory as the world cools in the face of rising CO2."

This is simply incorrect, and is based on your ignorance of what the theory actually predicts and of the historical development of the theory.

CO2 radiative forcing is only one of the forcings that govern long term climate, as it says, for instance in the IPCC WG1 report. Does AGW theory say that temperatures cannot fall while CO2 levels rise? No, it doesn't.

"But such a theory is no longer testable, it will always be right. "

That is also nonsense. AGW theory makes falsifiable projections.
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13. I don't think that's correct elsa. The climate isn't so complex at the level which is relevant to global warming (it's fundamentally about energy flow into and out of the earth system and its contribution, together with some understanding of how this is manifest at the earth's surface where we all reside).

One does need to be careful switching back and forth between philosophy of science descriptions (e.g. in the (vi)-point schematic you reproduced in your post!) and the real world. However the fundamental theory of AGW arising from 19th century science (that increased atmospheric [CO2] results in a warming contribution) has been tested virtually to destruction. Simply put it's completely compatible with observations. We've gone through steps (i) to (iv), and everything is holding up - the essential theory hasn't needed to be refined very much, 'though it would be silly not to continue to incorporate new knowledge into our attribution of component contributors to surface temperature changes.

A more general theory is that the actual surface warming is the result of all of the external and internal contributions to surface temperature change, and that at equilibrium, a persisitent temperature change must result from an enhanced external forcing. Again the observations are entirely compatible with that.

I don't agree with your statement about "AGW for the period 1940-1970". The change in greenhouse forcing in the middle part of the last century was small. So [CO2] was 299 ppm in 1900, and hadn't even reached 320 ppm by 1960. It's the massive post-war industrialization that took off in the mid 1960's and has seen [CO2] levels race up towards 400 ppm that has resulted in the large late 20th century warming. So the lack of surface warming in the period 1940-1970 isn't surprising when one considers all of the contributions to warming including the (then) quite small greenhouse forcing.

The theory of greenhouse warming is eminently testable and falsifiable. We can determine the earth surface temperature projected from quantitation of natural attributions to temperature change and see that these cannot result in warming from the mid 20th century til now. All of the sub-components of the theory are testable and falsifiable (the absorption characteristics of greenhouse gases; top of the atmosphere radiative changes; predictions of atmopsheric water vapour concentrations; tropopause height variations and stratospheric temperature changes and so on)...
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14. I presume elsa would also decry those who had to come up with dark matter and dark energy to iron-out discrepancies in the standard model of cosmology.
Those dastardly scientists, eh ? They can only solve this problem by coming up with stuff that is very difficult to falsify, let alone prove !
In fact, I would go so far as to state :

The facts did not fit the theory, as the expansion of the universe accelerated and discrepancies were found with regards to the mass of large astronomical objects. So the big-bang group has then to add other factors to make it work. But such a theory is no longer testable, it will always be right.
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15. 'The facts do not fit the theory as the world cools in the face of rising CO2. So the AGW group has then to add other factors to make it work. But such a theory is no longer testable, it will always be right. '

Sorry but that is an appalling misrepresentation of the actual science. Its easy to be skeptical if you are just creating strawmen to pull down. Climate has never been about single factors - only popular articles go in for that kind of simplistic nonsense.

As to 40's to 70's - remember the "heading for an ice age"? Well that comes from aerosol work. For science in the early part of 20th century GHG were not thought to be an issue because of band saturation. Aerosols were hardly "added to model to fit the facts", while solar variations have dominated climate theory since inception for obvious reasons.

As to testability, well [snip], the modelling puts out hundreds of testable predictions covering a wide range of parameters from expected spectral changes through to temperature profiles for air/ocean, precipitation etc. Not predictions are equally robust but not testable? You must be joking!
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Moderator Response: I hope the part I snipped was a typo.
16. [To moderator - should have read "blow me down" which is vernacular here for "surprise me" (like "knock me down with a feather"). I see now that other connotations could be taken in other parts of the world. Sorry.]
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Moderator Response: The "down" part was missing. Changes the meaning rather drastically;)
17. Sphaerica
If I understand you correctly what you say is that the theory of relativity was invented to rescue classical mechanics in the same way that other factors are brought in to explain falling temperatures in the face of rising CO2 levels.

I would not agree with the comparison. Relativity left the previous theory as a special case of a more general theory. With the addition of other factors into the AGW theory there is no new more general theory developed, simply an additional factor to explain away facts that are inconsistent with the standard AGW theory. But by introducing such factors we render the theory untestable. What we have done when the theory "failed" was to decide that it must in fact be right, it just omitted one of the other variables that we should have included. Now it may well be a correct view, but it is not one that we can really test in a scientific way. As James Lovelock put it "The great climate science centres around the world are more than well aware how weak their science is. If you talk to them privately they're scared stiff of the fact that they don't really know what the clouds and the aerosols are doing. They could be absolutely running the show. We haven't got the physics worked out yet."

Sort of like having a theory of classical mechanics, except the speed of light doesn't fit, so someone devises some crazy Theory of Relativity just to make the obviously flawed, broken and useless model of classical mechanics fit the observations (rather than doing the smart thing, and just plain starting over)?

And then other people develop more ideas, like quarks and string theory and everything else?

You're right, it's all completely crazy. Why keep expanding on what you know and further refining your understanding of a complex system, when you can instead oversimplify things and throw out everything you do know because the details don't line up perfectly the first time?

Why base a theory of climate on well-known, well-understand, and proven things like atmospheric chemistry and physics, and then try to understand the other factors that influence and complicate those physics, when you can instead simply invoke the powers of the Flying Spaghetti Monster?
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18. Sorry the above post seems to contain a repeat of Sphaerica's comment.
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19. Elsa, as has been pointed out to you REPEATEDLY, the 40s-70s cool period is completely consistent with AGW theory, and pretty much always has been. Note that in the early 70s there was some discussion about whether sulphate aerosols would counteract CO2 radiative forcing to such a degree that we would get a mini ice age (note if you want to discuss the associated skeptic argument, please do so on the appropriate thread). This was before we had GCMs.

Now, what is your evidence that AGW theory has been modified to explain the 40s-70s cool period? Point to a paper where this modification was published.

Can I suggest that we ignore Elsa until this information is provided?
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20. "With the addition of other factors into the AGW theory there is no new more general theory developed, simply an additional factor to explain away facts that are inconsistent with the standard AGW theory. But by introducing such factors we render the theory untestable. "

Yet again, this is completely untrue, as a Discovery of global warming. Likewise, predictions are all testable. Repeating wrong assertions does not make them true. How are we supposed to discuss this when you persist in repeating what is demonstrably false?
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21. Dikran,
I would agree that it would be possible to set up experiments that were repeatable to demonstrate a link between CO2 and warming. But I don't agree that the observations on which AGW theory are based are repeatable and could be run over and over again. We cannot fix the CO2 concentration in the atmosphere at will to test its relationship with temperature still less the other factors that we don't even know about.
You state that my view is "based on your ignorance of what the theory actually predicts and of the historical development of the theory.
CO2 radiative forcing is only one of the forcings that govern long term climate, as it says, for instance in the IPCC WG1 report. Does AGW theory say that temperatures cannot fall while CO2 levels rise? No, it doesn't." This view you reiterate at 69.
But if you have a theory of warming that is consistent with both warming and cooling how are we to test it? What circumstances would show it was wrong? You say AGW theory is falsifiable, but it seems any situation can be brought withn the predictions that it makes.
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22. Elsa, just what observations do you think AGW theory is based on. Note that the core of the theory was fully fleshed out by Gilbert Plass in the 1950s. Please tell me which observations he used that are non-repeatable.

"But if you have a theory of warming that is consistent with both warming and cooling how are we to test it? "

Sorry again you are demonstrating ignorance of the theory and of the models used to test the theory. If we have data or projections for the other forcings, then we can use the theory to determine/project the plausible range of the response to the combined forcings. If the observations lie outside that range then the theory is falsified. It really isn't rocket science.
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23. Chris
the reason why I think your numbered (i) to (vi) approach is wrong in the case of AGW is that there is far more than one variable involved. we cannot tell if the warming that has happened since 1970 is because of CO2 or reductions in aerosols or something else altogether. Quite apart from the complete lack of any mathematical technique that would enable us to do such a thing if we could do it there would not be models there would only be one model. The fact that the models have widely differing assumptions but can each claim to be able to explain temperature changes ought to be a huge source of concern for the AGW "scientists" not a source of strength.
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24. "we cannot tell if the warming that has happened since 1970 is because of CO2 or reductions in aerosols or something else altogether.

Wrong again. In this is the realm of attribution studies. Beyond those discussed in AR4 (have you even read this?), you might like to look at Benestad and Schmidt 2009. So much for "complete lack of mathematical technique".

The models dont differ their view of climate but differ heavily in how to compute the physics. What "widely different assumptions" are you claiming that models make?

Oh, and further to the idea that other factors were added to the theory to make it work, perhaps you should look at the Broecker 1975 which is based on one of the earlier climate models and the first that I know of that made quantifiable predictions to test. It's opening line shows nothing added to make it work.
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25. I can't help but think that 'Elsa' is simply a troll. The name might be sweetly female, but the contrast between (feigned?) ignorance and a preparedness to delve into non-basic science is ringing alarm bells.

I suspect that engaging her would be akin to engaging a mini-Monckton, or indeed a tar baby.
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lest you think that it is only "denialists" that think along lines like the piece that you quote from me I would ask you to remember what james Lovelock had to say about the models: "The great climate science centres around the world are more than well aware how weak their science is. If you talk to them privately they're scared stiff of the fact that they don't really know what the clouds and the aerosols are doing. They could be absolutely running the show. We haven't got the physics worked out yet."
Turning to the two pieces that you list: B&S talk mainly about solar forcings so are not really relevant here. The broeker study makes some forecasts of warming throughout the years 1940 to 1970. Here it would appear it did not even get the direction right let alone the quantity. The final decade that they list (to 2010) also has the greatest temperature increase, yet we know from elsewhere on this site that the trend was flat for that period at least on the surface.
I would not agree with you that a model can differ on how to compute anything. You can feed in a set of assumptions to a model and look at the outcomes. The computation is a given, only the assumptions can be different.

Bernard J
I can assure you that I am not a troll. If someone provides proper logical answers to my detailed criticisms I will be happy to shut up and go away. Your post does not begin to do this.
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27. elsa#76: "my detailed criticisms"

Your criticisms are hardly detailed, nor are they really criticisms. You've quoted James Lovelock more than once and that begs the question: Do you know what his qualifications are, so that his opinion on climate modeling can be placed in proper context?

Why have you not quoted some of his other opinions?

"Polar bears will not become extinct, they will just go back to what they were, which is brown bears.

...By 2040, parts of the Sahara desert will have moved into middle Europe. We are talking about Paris. As far north as Berlin."

These are not the opinions of a knowledgeable researcher (polar bears will evolve back into brown bears?) The fact that you rely so heavily on this type of opinion, rather than substantive science, seriously hurts your credibility.
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28. Elsa - clouds and aerosols are uncertainties (again see the AR4 report) but with known limits. I frankly think Lovelock was both exaggerating and quoting dated information. This is not what I hear from private conversation with modellers. The physics is known, the modelling of it is the issue.

As to your interpretation of the other two papers? Huh? Did you get past an abstract? B&S was written to respond to claim about solar forcing but used ALL of the GISS forcings and shows a purely phenomenological approach to attribution. Lean & Rind do similar. The point is that your claim about "lack of mathematical technique" is wrong. Model approaches to attribution are in AR4.

Broecker wrote when temperatures were declining, pointing out the GHG forcings would soon overcome aerosols and warm the earth. With an incredibly primitive model (1975 - what was your computer?), he still managed to predict the temperature for 2010 with remarkable accuracy. Again, the point is this is the seminal paper on modern AGW and written when aerosols were dominant not "added to the theory". He correctly predicted GHG would dominate.

"I would not agree with you that a model can differ on how to compute anything."

Well I write the code for physical models (oil/gas generation) and so I respectfully disagree. Tell me again what the difference in model assumptions are?

You claim you are not a troll, fair enough, but so far you have made numerous incorrect assertions about climate science and use them as the basis of your skepticism. Someone relying on unsupported assertions is hard to take seriously. Please quote science papers or sections of AR4 when making assertions in future.
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29. ELSA If someone provides proper logical answers to my detailed criticisms I will be happy to shut up and go away.

Nobody wants you to shut up and go away, what we want is for you to have a rational discussion of the science of climate change. At the moment you are failing to do so because you repeatedly fail to answer questions that would make your position unambiguous, for instance

Elsa, just what observations do you think AGW theory is based on. Note that the core of the theory was fully fleshed out by Gilbert Plass in the 1950s. Please tell me which observations he used that are non-repeatable.

and

Now, what is your evidence that AGW theory has been modified to explain the 40s-70s cool period? Point to a paper where this modification was published.

If you carry on making assertions and not being able and/or willing to state the evidence for your beliefs, your posts will come accross as trolling and/or a bad case of Dunning-Kruger. This does neither side of the discussion any good, so please, answer these two questions explicitly and unambiguously and without equivocation.
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30. 1. Non repeatability (if that's a word)
We cannot rerun the climate. By this I mean that we cannot experiment with the climate. We cannot try what the temperature would be with a given CO2 concentration because (a) we cannot fix the concentration and (b) even if we could the other things that affect climate will have changed too.

2. Modification
In its crudest form the AGW theory (and I grant you this is a simplification) postulates that with rising CO2 the climate will warm. In the period 40s to 70s this not only failed to happen but probably the temperature actually declined. The usual escape route for the AGW theory is to attribute this to aerosols. Thus the theory needs to be modified. In its crudest form it has been falsified.
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31. elsa#80: "In its crudest form..."

So? We are not here to discuss 'crudest forms.' It is clearly a part of the overall understanding of climate that aerosols can cause significant cooling. Hence your claim of falsification of a cherry-picked part of valid science is false.

You need to stop coming up these silly, pedantic objections and move on to improving your own understanding the science. Otherwise, your just wasting everyone's time.
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32. elsa - You continue to (incorrectly) assign all of climate science on forcings to CO2, then claim to have 'falsified' that science. Again, and I stress again, I suggest you read the CO2 is not the only driver of climate thread. You are building a strawman, engaging in the Fallacy of the single cause.

In addition, I would point you at Lean and Rind 2008, where they explore this very question - solar, volcanic, ENSO, and anthropogenic forcings and their attributions to temperature change. Current warming would simply not be occurring without the anthropogenic influence.

As to repeatability - we can repeat all of the related science. Spectroscopy of various gases, sampling of atmospheric contents, satellite observations of spectral changes in IR to space, atmospheric water content, oceanic heat content, isotopic attribution of CO2, O2 depletion, and all of the various fingerprints of warming - ongoing changes, currently measurable, observable data, which support the science.

Your continued rejection of the data represents (IMO) nothing more than denial - repeatedly making unsupportable assertions while (essentially) sticking your fingers in your ears regarding the science.

And all that, while presenting zero evidence (references would be nice) for any alternative hypotheses.
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33. " Non repeatability (if that's a word)"

This is an old one. By same logic, most geological theory is unscientific and this one is also leveled at evolutionary biology.

However, nature and man deliver different forcings all the time and models, based on first-principle physics, manage to predict how climate will behave (which is not to be confused with weather forecasting).
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34. ELSA I gave you two challenges:

"just what observations do you think AGW theory is based on. Note that the core of the theory was fully fleshed out by Gilbert Plass in the 1950s. Please tell me which observations he used that are non-repeatable.

and

Now, what is your evidence that AGW theory has been modified to explain the 40s-70s cool period? Point to a paper where this modification was published.

You didn't answer either question. For the first question, I note the lack of a list of observations used by Plass (I rather doubt you even bothered to look up the paper). For the second question, I note the lack of a reference to a paper where the theory was modified, just a repetition of your previous unsupported assertions.

Your write "In its crudest form the AGW theory (and I grant you this is a simplification) postulates that with rising CO2 the climate will warm.". That simply isn't true, as I pointed out here where I wrote "CO2 radiative forcing is only one of the forcings that govern long term climate, as it says, for instance in the IPCC WG1 report. Does AGW theory say that temperatures cannot fall while CO2 levels rise? No, it doesn't." In other words, CO2 will only cause climate to warm, all things being otherwise equal. Now I know you are not ignorant of this as you wrote "even if we could the other things that affect climate will have changed too.". Which means that your arguments are clearly disingenuous.

So, you make assertions that you are unable or unwilling to substantiate, you are unable or unwilling to give direct answers to direct questions, you ignore responses to points that you have raised, you use the fact that there are other forcings when it suits you and ignore it when it doesn't. If you are going to behave like that, why on Earth do you think you should be taken seriously.

I think it is time for DNFTT.
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35. IMO, elsa is simply incorrect to say that the addition of aerosol cooling "falsifies" the statement 'with rising CO2 the climate will warm'.

In the historical period she notes, CO2 radiative forcing was still causing warming, even while solar and aerosol forcings were causing cooling.

Even accepting elsa's simplification on its own terms for the sake of argument, I conclude it does not stand up to scrutiny.
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36. Dikran
You asked me "Please tell me which observations he used that are non-repeatable."
I repeat the answer is all of them because the world does not stand still. We cannot try to test eg the temperature with a given level of CO2 and all other factors being equal over and over again. Each of them will have moved on and be different so the circumstances that we need to test the theory in a meaningful way cannot exist.

You then say "CO2 radiative forcing is only one of the forcings that govern long term climate, as it says, for instance in the IPCC WG1 report. Does AGW theory say that temperatures cannot fall while CO2 levels rise? No, it doesn't."

I completely accept that. But the problem for your side in this is that it results in a theory that cannot be falsified. Whatever happens the theory can be made to fit the facts. That is not to say that your theory is wrong (although I think that quite likely) but it not a scientific one for the simple reason that we cannot test it in any meaningful way. How can we disentangle the various effects of CO2, other greenhouse gases, water vapour,aerosols, sunspots just to name some that we know of? How about the ones that we do not know of?
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37. elsa@86
"But the problem for your side in this is that it results in a theory that cannot be falsified. Whatever happens the theory can be made to fit the facts."

I would certainly hope that the theory fits the facts otherwise it is worthless. If we followed your model of science then it would be impossible to expand knowledge when new information was learned. All old ideas and theories would have to be completely discarded when anything new was learned that was not explained entirely by the old.
Rubbish
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38. And with this most recent comment, elsa stands revealed as full-blown troll.

DNFTT.
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39. pbjamm
(-Snip-)
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Response:

[DB] The topic of this thread is Fritz Vahrenholt - Duped on Climate Change; please stay on-topic.

Off-topic portion snipped.

40. Elsa, Do you actually know which observations Plass used? Have you read the paper?

Elsa wrote "But the problem for your side in this is that it results in a theory that cannot be falsified."

This is not true, as I have already pointed out here where I wrote "If we have data or projections for the other forcings, then we can use the theory to determine/project the plausible range of the response to the combined forcings. If the observations lie outside that range then the theory is falsified. It really isn't rocket science."

How do we disentangle the various effects of different forcings? Using something called an attribution study. There is a wide body of literature on this subject, start with the relevant chapter of the IPCC WG1 report.

Thus it seems to me that not only are you unwilling to answer questions, you are also ignoring the responses to your assertions. As DB suggests, DNFTT seems the appropriate response. You had your chance to demonstrate that you were interested in the science by looking at the work of Plass; sadly it is clear that you are not interested in the answers to your questions.
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41. Elsa you are repeating "But the problem for your side in this is that it results in a theory that cannot be falsified." Repeating this does not make it true.

Climate theory makes predictions all the time. For a given set of forcing, you will get a given climate. (ie a 30 year average). Even the primitive model that was basis for Broekner paper got climate for 2010 right within the constraints. Your comment on this was to complain that the paper didnt predict decade of only slowly rising temperatures. Well of course it didnt because even the most advanced climate model today has no skill at decadal predictions.

I would note a recent comment from Gavin Schmidt.
"Obviously people have thought of this and there are a number of ideas that are being tested - but none of them really give what it wanted (i.e. predictions that will reproduce the interannual ups-and-downs that you could compare directly to the obs). For instance, a lot of work is being done on initialised predictions where you take the ocean state for the last few years, attempt to synchronise the various 'oscillations' and then run it forward. This shows some skill for a few years in something like the AMO, but can't give realistic ENSO forecasts longer than the specialised ENSO forecasting systems (i.e. 6 months or so). So the interannual short-term variability doesn't seem to be predictable. There are also big issues with drift in these runs, which makes even the multi-year trends someowhat difficult to interpret. Another idea is run multiple ensembles for short periods, pick the one that is closest to reality and continue the next set of ensembles from that one and so on. But this only produces a plausible hindcast that is attuned to the actual interannual variations, not a prediction. The fundamental issue is that it is likely to be very hard (if not impossible) to predict ENSO phase 5 or 10 years ahead of time and that puts a real limit on how good any short term predictions can be.- gavin"

You seem to be claiming that because you cant falsify a model with tomorrow's temperature, then its not falsifiable. This is wrong. Look at how well climate models predicted climate instead. Your "repeat but with one variable changed" approach does not work in many of the natural sciences. Fortunately we have developed the tools (contrary to your earlier false assertion) for dealing with multivariate hypotheses. It is possible to imagine all sorts of futures which would invalidate models.
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42. We cannot try to test eg the temperature with a given level of CO2 and all other factors being equal over and over again. Each of them will have moved on and be different so the circumstances that we need to test the theory in a meaningful way cannot exist.

Either deliberately or mendaciously Elsa is confusing the difficulty of repeatability, with repeatability itself. Further, there comes a point where it is possible to account - both empirically and with repetition - for a certain number of parameters, and begging for more complexity adds no appreciable understanding to the system.

In addition, having a repetition of a particular moment of the planet's climate is not a prerequisite for falsifiability, which seems to be Elsa's hook to try to claim that human-caused global warming is not testable science.

As scaddenp notes, it seems that Elsa is not as familiar with the meaning of Popper's concept as she pretends. Falsifiability is eminently possibly with the physics of human-caused global warming, although once again it might not be simple to do so. However just because a scientific verification is difficult, it does not mean that it is non-scientific.

And frankly, it would not difficult to falsify the physics of human-caused planetary warming... if it were indeed false. That it hasn't been falsified indicates the strength of the science, rather than the weakness. That denialists do not understand this fact indicates the weakness of their understanding of the science.

On a related matter, 'simplifying' a description of a system by implying that a single dependent variable (global temperature) should always show direct and consistent correlation with a single independent variable (in this case atmospheric CO2 concentration) is not scientific, and it most certainly does not constitute falsification. Scaddenp has explained this already, but is warrants repeating. That Vahrenholt sees fit to use this gambit is a sign of either his ignorance, or of his politics.
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43. Dikran@28, and all who followed on, may I respectfully suggest a slight change?

As I recall, the step of 'formulating a *theory*" is ~not~ the first step of a scientific investigation; rather, it is to formulate a *hypothesis*, then gather data, run tests, interpret data/tests, which ~then~ leads to a theory.

At least, that's what they taught me way back in the 90s...;) Then again, dammit, I'm just a geologist, Jim, not a English major!
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44. I find it is best not to get too hung up on terminology - sometimes the theory comes first, for example the hypothesised existence of the Higgs boson that CERN et al are trying to confirm comes from a theory that attempts to explain subatomic physics. IIRC we only think that the Higgs boson exists becase theory predicts that it should. Likewise there are some that would regard AGW as a hypothesis rather than a theory.
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