Arguments
Climate Skeptic Fool's Gold
Posted on 19 August 2011 by dana1981
Over the past 40 years, global climate models have become dramatically more advanced and complex in their representations of the Earth's climate system. In the 1970s, when our understanding of the global climate (and our computing power) were still relatively rudimentary, some simple climate models nevertheless yielded global warming predictions which have turned out to be very accurate. In the 1980s, climate models and computing technology improved, and so did climate scientists' predictions using those models. Today's climate models are so advanced in their representation of the Earth's complex climate, that they run on some of the world's fastest supercomputers. As climate models are able to represent the climate more and more accurately, their predictions will continue to improve as well.
Some climate "skeptics" tell us that climate model predictions are worthless because they're just that - models. It's true that like all models, climate models will never be perfect, but that doesn't mean they can't be useful. Climate models have already proven that they can make accurate predictions.
The reason that even simple climate models nearly four decades ago were able to accurately predict the ensuing global warming was that they're based on physics. For example, we've known since British physicist John Tyndall's laboratory experiments in 1859 that greenhouse gases like carbon dioxide trap heat. In 1896, Swedish scientist Svante Arrhenius calculated how much the planet would warm in response to a doubling of the amount of carbon dioxide in the atmosphere, and his estimates were not far off from climate scientists' today. Because it's based on solid fundamental physics, climate science has aged like a fine wine.
Nevertheless, some scientists distrust the conclusions drawn from modern climate models, and have taken to creating simple models of their own. The most well-known of these climate model "skeptics" is Roy Spencer from the University of Alabama at Huntsville. Dr. Spencer has become notorious for frequently using variations of a simple climate model - not too dissimilar from those climate scientists were using in the 1980s - to make wild claims that mainstream climate science is wrong, and man-made global warming is nothing to worry about.
The real problem is that while most climate modelers constrain the possible values of their variables based on physical reality, Dr. Spencer does not. One example of these variables is the ocean mixed layer (the upper part of the ocean where, due to the wind blowing at the surface and stirring the upper layers, the ocean has about the same temperature and salinity). Measurements have shown that the ocean mixed layer ranges from about 25 to 200 meters below the ocean surface, and for a model as simple as Dr. Spencer's, the value should be around 100 meters.
However, intead of constraining his variables using physical measurements and then running his model to see if it fits observations, Dr. Spencer just runs his model without limits and tweaks the parameters until it matches the data. This is a practice known as "curve fitting" or "cooking a graph". In one instance where he concluded the climate is not sensitive to changes in greenhouse gases, Dr. Spencer's results used a mixed layer depth of 700 meters. In a recent study in which he concluded that more heat is lost to space than climate models show, amongst numerous other problems, Dr. Spencer's model used a mixed layer depth of 25 meters. In other cases, Dr. Spencer has used models with as many as 30 fully adjustable, unconstrained parameters. With so many variables and apparently no desire to match physical reality, Dr. Spencer's model could spit out literally any answer. As the famous mathematician, John von Neumann said,
"With four parameters I can fit an elephant, and with five I can make him wiggle his trunk."
And as Dr. Barry Bickmore added,
"give me more than 30 parameters, and I can fit a trans-dimensional lizard-goat and make rainbow monkeys shoot out its rear end."
Dr. Spencer is not the only scientist to conduct this sort of curve fitting exercise in recent months. Two other climate "skeptic" scientists, Craig Loehle and Nicola Scafetta, published a paper arguing that the majority of the global warming over the past 40 years has been caused by the 60-year astronomical cycles of Jupiter and Saturn. These scientists failed to explain physically how Jupiter and Saturn's orbital cycles could have such a large influence on the Earth's temperature. Instead, they just tried to see how well they could fit global temperature measurements over the past 150 years using a very simple model with 60-year cycles.
Loehle and Scafetta's model was so simple, in fact, that it only consisted of one short formula that I was able to plug into a spreadsheet and run in about five minutes. I ran the model backwards in time to see how it would compare to past temperature reconstructions, including one that Loehle himself created in a previous paper. The 60-year cycle was nowhere to be seen, even in Loehle's own temperature reconstruction, and after a few hundred years, the model diverged dramatically from the data.
Their model is just too simple to accurately re-create global temperature changes, and unlike real climate models (even the simple versions in the 1970s), Loehle and Scafetta's model is not based on physical reality.
Nevertheless, these curve fitting exercises have drawn a lot of attention. Forbes magazine ran a story on Spencer's study, written by James Taylor of the right-wing think tank Heartland Institute. The article exaggerated Dr. Spencer's findings, and managed to cram the words "alarmist" and "alarmism" into his eight-paragraph article fifteen times. Despite Forbes' long history of misrepresenting climate science resesarch, the popular search engine website Yahoo decided to re-publish the biased Forbes article. Many other media outlets ran stories on Spencer's study.
The other problem is the media's exaggeration of these studies' impacts. The man-made global warming theory is based on many, many lines of evidence. It seems as though every "skeptic" paper is touted as the silver bullet which is going to disprove the entire theory. It's actually very rare for a single study to overturn a scientific theory. In most cases, when a paper arrives at the opposite conclusion of all other studies in the field, it's because there are fundamental flaws in the paper. This is quite clearly the case for the Spencer and Loehle & Scafetta papers, and yet predictably, they're being touted as silver bullets by those who don't know any better, but want to believe the man-made global warming theory is wrong.
This is why an independent inquiry found that even the BBC has been giving climate "skeptics" too much air time. We should certainly pay attention to any good scientific research, but we shouldn't assume that a study's results overturn the body of scientific evidence just because we want it to be true. How many times must "skeptic" silver bullets turn out to be fool's gold before we stop assuming that they've disproven the robust man-made global warming theory?
"There is absolutely no doubt, none whatsoever, that the actual trend is not only upward, it’s at exactly the same rate throughout, it didn’t stop or slow down or level off. We can be quite certain, because the data were made that way."
The point: even in data we know 100% has a positive trend, there will be fluctuations given noise. So: fluctuations in real data doesn't mean there isn't a trend, any more than a chilly April after a warm March means it's winter. Not rocket science.
I'm not saying that a short term flattening means that the long term upward trend isn't correct. It seems to me that because of this flattening, it's just too early to claim model compliance, as they are still relatively new, and coincided with the flattening.
I see in comment 4 that there is a thread "Models are unreliable", so it's probably best if I try to transfer to that thread to find these answers. Thanks.
Refering to
Trenberth's Energy Balance
The heat retention estimate due to not reaching steady state for the level of greenhouse gases is 0.9 w/M2. Since the overall flux is ~341, this seems pretty small vs the naive expectactions of % accuracy on an energy balance this complex...and such eyeballing can lead people astray.
Of course the CO2 effect on flux isn't being measured by difference...but rather by the outgoing radiation from TOA and its spectral distribution....if I've got this right.
And as dana very clearly showed in this post hindcasting is not employed by Loehle and Scafetta.
Your assumptions about models are just that, and they are very, very, very wrong. You are so far off it's laughable. I encourage you to research things in substantially more depth before making such unsubstantiated claims, while insisting that others prove to you that they are false.
You might want to read this: Introduction to Climate Dynamics and Climate Modeling
The section that pertains directly to your ridiculous reference to latent heat is here in the chapter/section on heat transport.
Want a basic, simple model you can use yourself, that includes latent heat? Try STELLA:
Modeling Earth's Climate System with STELLA
STELLA II for Mac and PC
But really, it took me 75 seconds to find this stuff by googling "latent heat transport climate model". Was it really that hard for a "skeptic" to do the same?
As far as a citation... how about Effects of Dynamic Heat Fluxes on Model Climate Sensitivity: Meridional Sensible and Latent Heat Fluxes
I just have to say, I am so tired of "skeptics" who "know" everything because they don't bother to actually look for just a couple of minutes.
16.Scaddenp. I guess you are right--thanks.
Enlighten me. What do you know about models and their inadequacies, that I don't? Explain yourself more clearly.
It's strange how this (emphasis mine):which is a clear question and evidence of ignorance on the matter, supplemented by a skeptical but utterly foundation-less doubt. This later turned into this confident declaration:So where did this conclusion come from? What is the evidence for it? Why the sudden change from question to confident knowledge?
His response to a response to his vague request for evidence (and isn't it odd how he needs evidence to prove his assumption wrong, but not to make it in the first place?):As if no one can understand the mystical complexities of latent heat but someone who posts four very vaguely worded and utterly unsupported comments on a blog comment thread... comments which do nothing more than utterly without supporting foundation question the validity of the models.
And yet, from the original post above:
Hmmm. So whom should we trust here?
I chanced upon a delightful wee monograph stipulating that Tyndall was beaten to the punch by three years, by a certain Eunice Foote at "the 1856 AAAS annual meeting in Albany, New York." Though her work wasn't published, it was noted down by a journalist, thus:
http://www.searchanddiscovery.com/documents/2011/70092sorenson/ndx_sorenson.pdf
May be familiar to some contributors here, but a new one to me. Marvelous bit of history.
That is so cool! If it's not a hoax it should be brought into the mainstream, with Tyndall and Arrhenius, at ever mention of past climate science.
If accurate it seems like a fairly simple way to demonstrate the greenhouse effect to 'skeptics'. I wouldn't have thought that the extra warming within a glass cylinder would be significant enough to be measured by a thermometer... let alone 20 degrees warmer. Granted, this was apparently a 100% CO2 demonstration, but still an easy way to blow numerous 'skeptic' arguments (e.g. 'the CO2 effect is saturated') completely out of the water.
I'd be curious to know if other people find the article close to the top, as I did. Suggests it's a popular link, doesn't it?
Good news - you HAVE to love google and diligent librarians. I think this is confirmed. Check this link:
http://www.archive.org/stream/annualscientifi02crosgoog#page/n169/mode/2up
If you want to backtrace, I got that link from here, which I got from here. First search term was the title of the David Welles digest, "Annual of Scientific Discovery", and it was dead easy to do the rest.
I think that has to be legitimate. Agreed?
Ray Sorenson has replied to an email from me laying out a little detail as to how he came across the entry in Annual of Scientific Discovery, and another interesting item regarding a near-simultaneous discovery of the heat absorbing properties of CO2 by another researcher (1863). I've asked for permission to reproduce portions of the email and provided him a link to this thread. I'll update here if he has any issues with this.