This point is THE critical one. It was the first point raised in the Skeptics Handbook, developed in the Second Handbook; the point that Dr Glikson had no reply to; the point that tripped up Will Steffen, Deltoid, and John Cook. As a modeler there was the moment in August 2007 when David saw the graphs below and said, emphatically: This is it. It’s over for the climate models. –JN
The public might not understand the science, but they do understand cheating
Dr. David Evans
19 October 2010
[A series of articles reviewing the western climate establishment and the media. The first and second discussed air temperatures, the third was on ocean temperatures, and fourth discussed past temperatures, the fifth compared the alleged cause (human CO2 emissions) with the alleged effect (temperatures), the sixth canvassed the infamous attempt to “fix” that disconnect, the hockey stick, and the seventh pointed out that the Chinese, Russian, and Indian climate establishments (which are financially independent of the western climate establishment) disagree with the western climate establishment about the cause of recent global warming and the eighth argued that hiring and firing policies and other government incentives created the consensus among western climate scientist that global warming is man-made.]
Click to download a pdf file containing the whole series
They Neglect To Mention That Evidence For One Link of their Theory Is Missing
The argument for man-made global warming consists of three links :
- We humans are raising the levels of CO2 in the atmosphere by our emissions.
- Increasing CO2 levels causes the temperature at the surface of the earth to rise, because CO2 is a greenhouse gas. This is the “direct” warming effect of the extra CO2.
- The earth responds to the direct warming in many ways, called “feedbacks”. The feedbacks warm the earth further, amplifying the direct warming about threefold.
All three links must be true for the theory to be valid; a chain is only as strong as its weakest link.
There is ample evidence for the first two links, and they are rarely disputed. The third link is where the dispute lies. In the establishment’s climate models, this amplifying feedback provides about two-thirds of the projected warming—without it there is only mild warming due to human emissions and no cause for climate alarm. There is no evidence for this amplifying feedback, but it is built into the climate models. When skeptic scientists say “there is no evidence” for man-made global warming, they are generally referring to the lack of evidence for these amplifying feedbacks.
[Some in the establishment would say there is evidence: They assume that all the warming since 1700 is due to rising CO2 levels (except for a small increase in the sun’s light output). We know the amount of extra CO2 over that period (link 1), how much extra direct warming that causes (link 2), and how much extra warming actually occurred (Figure 17)—so we can calculate the required effect of the feedbacks (link 3) to make that happen, which turns out to be threefold amplification. But this just replaces the threefold amplification assumption with the assumption that only rising CO2 levels caused the warming. It’s still, at base, just an assumption without evidence—because there is (and can be) no evidence that there were no other forces that could have caused the global warming.
The climate establishment also argues, in other contexts, that there are no other forces that could have caused the warming by saying their climate models can only explain the observed warming if CO2 is the only cause of the warming. This logic is circular, because the climate models are only calibrated with threefold amplification based on the assumption that there were no other causes for the recent global warming trend. Talk about having your cake and eating it too. The press apparently isn’t inquisitive enough to notice this trick. When critics outside the climate establishment point it out, the climate establishment just denigrates them and then announces in their most reassuring voice that they are the authorities and it’s all ok. What a bunch of charlatans! Finally, notice from Figure 21 that human CO2 emissions could not have caused the half of the global warming before 1850, so their assumption about no other causes is obviously wrong. So no evidence—just a logical trick that is sufficient to fool most of the audience.
They also on occasion offer up other historical instances as evidence for the threefold feedbacks amplification, but they are all very flimsy. The threefold amplification is really just based on the warming starting around 1700, which is the only instance for which we have decent numbers.]
If there was evidence for the threefold amplification by the feedbacks, surely we would have heard all about it, just like we hear about the evidence for the first two links? Instead we are just referred to climate models and told how terrific they are. But models are just computerized calculations; they are not evidence.
The climate establishment and media only talk about the first two links. Hardly anyone knows about the third link, which is responsible for most of the projected warming. If the case for man-made global warming is strong, why this obfuscation?
The effect of the feedbacks is the crucial question in climate science.
Empirical Test for the Link In Question
To appreciate the desperation and sheer chutzpah of the establishment’s shenanigans, you need to know a tiny bit about the feedbacks.
The dominant feedback involves the extra water vapor that evaporates, mainly off the oceans, due to the direct warming due to the extra CO2. (Water vapor is water in its gaseous form. When water vapor becomes liquid water again it forms droplets of water in the air, that is, clouds.)
There are basically two possible alternatives for this extra water vapor:
- It can tend to accumulate in the atmosphere, increasing the depth of humid air in the atmosphere. Because water vapor is itself a greenhouse gas, this further increases the amount of greenhouse gases in the air. This in turn causes more warming, thereby amplifying the direct warming. (Amplifying feedback increases the effect of an initial cause. Also called “positive” feedback.)
- It can forms clouds, without increasing the depth of humid air in the atmosphere. Extra clouds reflect more sunlight back out to space, causing cooling which counteracts the direct warming of the extra CO2, thereby moderating the direct warming. (Moderating or dampening feedback decreases the effect of an initial cause. Also called “negative” feedback. Note that negative feedback does not reverse the initial effect; it just reduces it to less than it would have been in the absence of the negative feedback.)
The threefold amplification assumed by the climate establishment can only occur if the first alternative is correct. To confirm that the feedback is amplifying, we need to see the depth of humid air increase during a period of global warming. The humid air is also warmer than the dry air above it, so we need to see it become warmer at heights initially just above the humid air. The climate models all specifically say that this happens.
Here is a “prediction” by the climate establishment that the feedbacks are amplifying, expressed as a pattern of warming in the atmosphere. This prediction is empirically testable.
This is the pattern of atmospheric warming that the climate establishment say occurred, according to their climate models. Each of the six diagrams shows temperature changes by latitude (x-axis) and by height in the atmosphere (y-axis, height in kilometers on the right).
Diagram A is the warming pattern due to an increase in greenhouse gases other than water vapor—that is, essentially from CO2 emissions. Diagram F is the warming pattern expected from the sum of all the five patterns A – E in the proportions the establishment believe those causes contributed to global warming; it is dominated by signature A because the establishment’s theory is that the warming was mainly due to CO2 emissions.
Notice the large prominent red “hotspot”, about 12 km high in the tropics, in F. The detection of this theoretical hotspot would go a long way to confirming that the feedbacks are amplifying; its absence would prove that the feedbacks are not amplifying.
The outcome of the climate debate hinges on this issue: a hotspot confirms their theory, its absence falsifies their theory.
The Theory of Man-Made Global Warming Failed an Empirical Test
The last period of global warming was about 1975 to 2001 (Figures 14 and 20). Fortunately, during the whole of this period there was a worldwide program of measuring the temperature at all altitudes using radiosondes—weather balloons with thermometers that radio back the temperature as they ascend through the atmosphere.
During the early and middle 1990s the climate establishment were expecting the radiosondes to find the hotspot, confirm the presence of amplifying feedbacks, and thus prove the last link in their theory of man-made global warming. But then their world fell apart.
By 1999 the results were in, but there was no hotspot. Not even a small hotspot.
Why didn’t the climate establishment rush out to the world with the good news, that they had overestimated the projected temperature increases, that there was now little cause for alarm over the climate?
They finally published the radiosonde observations in 2006, buried among four other diagrams from climate models at the back of a report. Here is that diagram:
This is all the data we will ever have about that warming period, because we cannot go back in time and take more or better measurements. We are only interested in the atmospheric pattern when there is warming, so this is all the data we have about hotspots until there is another period of warming (see Figure 20).
The observed pattern is nothing like the “predicted” pattern, so the climate models are wrong. There was no hotspot in reality, so the theory of man-made global warming is greatly exaggerated (because there are no amplifying feedbacks).
[The non-observation of the hotspot was later supported and extended by two independent observations, one on clouds (Spencer, 2008 and 2010) and the other on radiation leaving the earth (Lindzen and Choi, 2009 and 2010). In both cases the total feedbacks were observed to moderate the direct warming by roughly halving it, which suggests that the climate establishment are exaggerating future temperature changes by a factor of about six—that is, if they say 3°C hotter by the end of the century it will be about 0.5°C warmer.]
The Response of the Climate Establishment
First they ignored it, for several years. (It wasn’t like the media or politicians were asking them hard questions about the discrepancy in Figure 27. And it’s not like they wanted to jeopardize their new-found popularity and funding.)
Then, in 2008, they denied the data. Ben Santer emphasized the uncertainties in the data from the radiosonde thermometers. On the basis of a complex statistical argument he argued that it was possible that the observed data (Figure 26) was so error-ridden that the predicted hotspot (Figure 25) might in fact be present in the observed data. However radiosondes reliably detect temperature differences of 0.1°C when correctly calibrated and operated, and the hotspot is at least 0.6°C of warming. Some radiosondes may have been faulty, but hundreds of them could not all have failed to detect any hotspot.
Then, also in 2008, after nine years and with no new data, they claimed to have found the hotspot! Steven Sherwood adjusted the data in accordance with various theories and wind data from the radiosondes, and processed it on his computer to arrive at a new view of the data in Figure 26:
Looks like the predicted hotspot, right? But look closely at the color scale and note the color of zero change—it’s red! So if the atmosphere stayed at exactly the same temperature everywhere, Sherwood’s interpretation would be an all-red graph! The reds in his diagram blend together and it is impossible to see where his “hotspot” might be—but his “hotspot” is too faint anyway, because the hotspot in the climate models is at least 0.6°C over two decades.
If Sherwood used the same color scale as in Figures 25 or 26, it would be obvious that he had not found the hotspot. Why would a leading climate scientist play a “trick” like choosing the color scale such that no change or even slight cooling was in red?
What purpose could there be, except to mislead?
Even if you don’t understand the significance of the hotspot, isn’t a tricky color scale like this a sign of deception, a solid hint that they are trying to hide something?
Sherwood’s paper appeared in the Journal of Climate. Professor Sherwood was at Yale from 2001 to 2008, and is now at the Climate Change Research Centre at the University of NSW in Sydney.
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