I decided to look into global warming while teaching an Astronomy course in 2010. Venus, Earth, and Mars have differences in temperature that cannot be simply explained by their relative distances from the Sun. Venus has a “runaway” greenhouse effect, while Mars has very little greenhouse warming because it has very little atmosphere. Then I had to tell them the “inconvenient truth”: I am as clueless as anyone regarding the highly politicized debate about global warming.
Footnote: Physics majors might want to see my actual calculation of the Martian greenhouse effect (smallfiles01\Stefan.pdf). It was my intention to perform such simple calculations to get a handle on the various claims made about global warming. (And, I later found that such simple calculations have already been performed – see Section 7 below.)
Note to the Reader: I would greatly appreciate your comments. Send them to firstname.lastname@example.org and let the subject be skeptical.
1-Skepticism is a choice, not a judgement
I choose to remain skeptical on global warming, regardless of what the evidence says. I once spent over a decade in complete frustration, trying to be an “expert” in the teaching of math and science. Many of my colleagues had gone beyond the investigation of teaching methods, and on to implementation of reform. The sad part is that I am still intrigued by some of these ideas, and fear that important aspects of education reform will never be implemented because insufficient or unconvincing evidence was presented. Carefully constructed and repeatable experiments are possible in the field of math/science pedagogy, but my efforts to encourage such research were not appreciated by colleagues or supervisors. I noticed the skepticism and resistance to change among teachers – at both the college and precollege levels – and reasoned that we needed a simple way to convince the skeptics. I found the published papers in the field hopelessly unconvincing, full of subjective observations and carefully selected diagnostic “pre-tests” and “post-tests”.
2-Is Global Warming a house of cards?
One critic of global warming asserted that global warming is a “like a religion”, but I prefer words like “groupthink” or “confirmation bias”. The scientific house of cards typically starts with a seminal paper. Like ALL papers, this seminal paper is slightly flawed. Other papers follow that lean on this and other papers. It is only when the house of cards is built to some height can it be tested in an interesting way. Such testing of a theory requires time, and some could argue that global warming is too urgent for the “test of time”. Unfortunately the political fact is that massive large-scale efforts to deal with global warming are unlikely until the theory is fully tested, confirmed, and believed by almost everybody.
I tend not to believe in large-scale and outrageous conspiracies. If somebody helped Oswald kill Kennedy, then it was a tiny group that remarkably managed to keep a big secret. Organizations like the FBI, CIA, KGB, or even the Mafia would be unable to keep such an event under wraps. If thousands, or even just hundreds, of scientists are deliberately hiding something, two things would happen: First, there would be a number of disgruntled whistle-blowers. Second, the leaders of this infamous group would begin to feud with each other. Scoundrels are notoriously poor at cooperating. Therefore, my skepticism is more focused on unintentional biases than cynical fraud.
I have found Wikipedia to be a reliable source of information about science and therefore used it to look up “Global Warming” (smallfiles01/100216wiki.pdf). Wikipedia’s article on “Climate Sensitivity” (smallfiles01/100216wiki_sensitivity.pdf) was helpful, as well as link from Wikipedia to lengthy article by Stefan Rahmstorf that strongly supports the consensus view. (see smallfiles01/Rahmstorf_Zedillo_2008.pdf) It is nearly impossible to read a technical report and judge its merits, though an experienced person can often skim an article to ascertain that it written by a “quack” who only pretends to be a scientist. Both the quality of scientific writing and inspection of his publication record indicate that Rahmstorf is no “quack”. But as I already stated, we should not immediately eliminate the possibility of “groupthink”.
Wikipedia does not present a strong case against global warming, but this is appropriate, since an encyclopedia is expected to favor the consensus opinion. Wikipedia does describe the controversy in some detail, and even includes a list of prominent skeptics (smallfiles01/100216wikiskeptics.pdf) along with brief summaries of their objections. One complication in this debate is that neither the “skeptical” nor “consensus” views are well defined. Before exploring any alternative view put forth by “skeptics”, I need to learn more about the “consensus” and attempt to educate myself as to why this view exists. 2/18/2010. (later edited)
Since there is no unique “consensus” view, I should look for one appropriate to an investigation that is committed to neutrality. In other words, I seek a “consensus” view that can be tested. A website on global warming that ranks high on Google is sponsored by the American Institute of Physics (smallfiles01/100218aip_history.pdf). The Summary link at (http://www.aip.org/history/climate/summary.htm) on this contains the following graph, taken from a 2009 article by Lean and Rind (see smallfiles01/100218LeanRind.pdf):
click to enlarge smallfiles01/100218aipRindLeanTemp.jpg
As illustrated, Lean and Rind predict a temperature rise of 0.17 plus or minus 0.03 degrees centigrade per decade, provided we ignore the influences of:
· The El Ninos and La Ninas that almost randomly change the temperature by about 0.1C to 0.2C each year.
· Volcanoes that can drop the temperature by up to 0.2C for a couple of years (If it’s is super-volcano, then all bets are off!)
· The solar radiation variation (associated with Sunspots) that can add or subtract about 0.05C.
I looked at the references to this article and they seem OK. What I like best about this quasi-prediction is that we should be able to test it in just a few decades. It is worth noting that Rind and Lean do not claim to actually “predict” the weather over the next few decades, but instead make a precise and testable prediction as to how average temperatures will be correlated with unpredictable events (El Ninos and volcanoes) The temperature rise claimed by Lean and Rind is consistent with statements made by the IPCC.
On the day I went to Google, the top skeptical website was globalwarming.org ( s03\googleGlobWarmOrg.pdf ). Looking for skeptics who were also highly regarded scientists, I was intrigued by a statement that nearly half of seven Nobel Prize laureates in a panel discussion at Lindau were skeptics (see the top of page 2 of s03\halfnobelmyth.pdf and the first line of s03/cryptoskpetic.pdf). I copied an audio file (stored as Lindau_AUDIO.m4a but often removed due to its large size). An honest summary of the discussion was written by Christina Reed (s03\nobelsummary.pdf). The only true “global warming skeptic” was Giaever. There was a general consensus among the others that the real problem is not CO2 per se, but rather that we need to find a sustainable source of energy. I believe it was the same website (globalwarming.org) that led me to a claim that someone had published “proof” in a refereed journal that global warming was false (s03\FalseReference.pdf). I looked at actual the paper and saw at the top of the page that the article was unrefereed (s03\notreviewedAps.pdf). These blatant factual errors should be a warning to anybody who gets their information from the internet.
Even FOX news can’t seem to get it right. When I saw a something on FOX news about Al Gore, I found the transcripts on (s04\foxGoreWhopper.pdf), which claimed Al Gore had told a “whopper”. The links on that page went nowhere, but I finally traced the “evidence” that Al Gore misrepresented a statement by NOAA, by googling the words that the website had attributed to NOAA. The actual NOAA website tells a completely different story, as the reader can verify be reading s04\noaaprecipitationreport.pdf. This graph makes it clear that NOAA has reported extra moisture in the American northeast:
click to enlarge s04\noaa.gif.
I do not like it when Al Gore or anybody else tries to link this year’s weather to climate change. Such talk is highly misleading. But when Al Gore says something silly, it should be reported as “silly” and not as a “whopper” (defined in Wikipedia as s04\wikiwhoper.pdf). Where I come from, you don’t call somebody a liar when they repeat a statement made by the National Oceanic and Atmospheric Administration.
Even when FOX news reports the truth, something is fishy. Page one of Bret Baier’s transcript s04\baierflower.pdf documents that he suddenly reported that a “scientist” has raised concerns that global warming will cause flowers to lose their smell. No climate scientist in his or her right mind would raise such an issue. If anything, global warming will allow flowers to bloom everywhere! I managed to trace all this to comments made by people in Malaysia s04\malaysiaflower.pdf. Of all the science stories to slip into the daily news broadcast, why did FOX pick this one?
But the other side is also capable of misleading the public:
For example, one so-called “warmist” website illustrates the importance fossil fuel combustion with the following figure:
click to enlarge s03\checkbook.png
This fails to inform the unwary reader that nature plays a far greater role than humans do in the carbon cycle and balance of atmospheric CO2:
click to enlarge s03\Carboncycle.gif (3/24/2010)
My wild goose chase for Nobel Prize winning skeptics was not motivated by hero worship for those who have won such prizes. I searched for this elusive (and ultimately nonexistent) panel of skeptics because I was seeking small population of scientists from which an unbiased sample might be collected. Senator Inhofe and other have produced lists of scientists who are skeptical about global warming. While some of the names on that list don’t belong there, it is a mostly valid list. The problem with such lists is that there are even more scientists who take the consensus view that anthropogenic effects are the primary cause of global warming. Peter Doran performed a survey (s06\012009_Doran.pdf) that suggests that most scientists at affiliated with universities and/or federal laboratories hold the consensus view. Unfortunately, Doran’s database did not include scientists working for oil companies – that would have been interesting, but Doran apparently had no easy access to such a data base. I did a bit of a background check on Doran and discovered that he had provided evidence that much of Antarctica was warming, and therefore is one of many people who have “blown a whistle”, yet continue to hold to some form of the consensus view. (Other people who seem to have “blown a whistle” yet remained in the “club” include Cogley and Briffa, as discussed below.)
click to enlarge s07\survey.jpg
The fact that the scientific consensus supports the anthropogenic theory global warming cannot be disputed. Consider, for example, the simple but powerful claim made in Wikipedia: The finding that the climate has warmed in recent decades and that human activities are already contributing adversely to global climate change has been endorsed by every national science academy that has issued a statement on climate change, including the science academies of all of the major industrialized countries.
I explored the list of skeptics found in Wikipedia, and many of them have impressive track records as scientists. Some, such as Fred Singer and Richard Lindzen, have views on other subjects that strike me as “odd”. But nobody can dispute their scientific accomplishments or expertise. The arguments involved in the “hockey-stick” debate between Mann, McIntyre and McKitrick have become so technical that virtually nobody can master the intricate mathematics. So while McIntyre and McKitrick appear be “credible” skeptics, they are not “understandable” skeptics.
I think it is significant that many of the “whistleblowers” in this field are “insiders” who maintain largely consensus views on global warming, even after “blowing a whistle”. A good example of this is the question of whether the Himalayan glaciers are melting. These three websites, s05\HimGlacLal.pdf , s05\himmalaySciMaglet.pdf , s05\himalayusnews.pdf , document that the “whistleblower” Cogley also affirms that most glaciers are probably in the process of melting. Another example concerns the tree-ring divergence that played a central role in the “climategate” email story which erupted in November 2009. This controversy was no secret within the scientific community, as can be seen from the long list of publications that investigated this problem prior to 2009:
click to enlarge s06\treering.jpg
My investigation into two news “scandles” (i.e. the climategate emails on tree ring divergence, and the falsely reported melting rates of Himalayan glaciers) has me convinced that the scientific process is more or less self-correcting. In both cases, members of the scientific establishment played pivotal roles in investigating or uncovering embarrassing facts, without “leaving the club”.
On the other hand, I do fault IPCC for not highlighting a problem with tree-ring proxies when reporting the “spaghetti” version of the hockey-stick graph, which is shown at the beginning of the next section:
The climategate “scandal” was largely centered on the black curve, which shows actual thermometer measurements. The colored lines show various efforts to measure past temperatures by analyzing tree-ring thicknesses.
click to enlarge s06\spagetti.jpg
What is not shown in the figure above are any recent tree-ring estimates. Had they been shown, they would not have captured the rise in temperature indicated by the black line. In other words, the tree-ring data and the thermometer data “diverge” sometime between 1960 and 1980. This divergence calls into question whether we can use tree ring proxy data to estimate temperatures between the years 1000 and 1850 AD. This divergence is discussed in a paper by Wilson, et al, in (s08\Wilson_2007.pdf) and is depicted below:
click to enlarge s08\divergencesmall.jpg
I find this subject nearly impossible to analyze because much of it is about the character and motives of individuals. I can judge the skills of a scientist by looking at his or her publication record. But you can’t glean much about a people’s scientific integrity by reading what is written by or about them.
The diagram shown above suggests that the divergence between modern tree-ring proxy temperatures and actual thermometer measurements is about half a degree. Briffa is one of those who appeared to have “blown a whistle”, yet remained loyal to the “global warming cause”. His original (1998) graph shows a much larger divergence of perhaps 1.5 degrees:
click to enlarge s08\briffa.jpg
The title of Briffa’s paper (see s08\Briffa_et_al.pdf) is also interesting in that great pains seem to have been taken so as not to offend those who believe that tree rings make good temperature proxies. For two different assessments of the scientific integrity of using tree-rings as proxies, see s08\Oxburgh.pdf and s08\Wegma.pdf. (The latter analyzes the social issues involved when scientists collaborate to achieve a “consensus”.) I find it plausible that both assessments are correct.
8-Two credible skeptics
One of my favorite “credible skeptics” is Syun-Ichi Akasofu, who actually prefers not to be called a “skeptic”, but a “critic” of IPCC. (see s06\Why_has.pdf) Debates between “consensus” and“skeptical” scientists are asymmetrical. The “consensus” writes complicated papers, and the “skeptics” look for flaws by posing simple plausibility arguments, and claiming that we know less than we think we know. For example, Akasofu offers a simple sketch of global temperature graphs that include variations associated with ocean currents:
click to enlarge s06/littleiceagesmall.jpg
Akasofu suggests that present temperature rises might be a continuation of a poorly understood trend that goes back to the Little Ice Age. (See also his more detailed article s06\akasofu.LIAge.pdf). Akasofu’s graph (shown above) also contains a feature that is essential to understanding this debate. Notice that the computer models (labeled IPCC predictions) show a change in slope in the future that is more severe than has been seen in the past. This almost exponential growth in future temperature predictions is attributed to feedback mechanisms. The most important and least understood is probably water vapor and clouds: As the temperature rises, computer models predict a more humid Earth, which will cause a sharper rise in temperature because water vapor is a greenhouse gas.
If Akasofu uses simple graphs, then Garth Paltridge uses a simple formula based on the fact that our computer models rely on feedback (such as water vapor). (See s06\PALTRIDGE.pdf for an excerpt of his article) A well known example of feedback occurs when a spokesperson is using a microphone while standing too close to the loudspeaker. Ambient noise in the system gets amplified and then re-amplified as the signal again travels from the mike to the loudspeaker. As anybody who has experienced this knows, it is not easy to predict when that loud ringing noise will interrupt the person who is speaking. It is even more difficult to predict an unstable global climate. Paltridge argues that regardless of what the computer simulators believe, we cannot trust the computers.
This difficulty in making long-range predictions with unstable systems either is or should be understood by everybody who is studying our climate. The aforementioned article by Lean and Rind acknowledges this by focusing on short term predictions. It is interesting that I was immediately led to this article by the website sponsored by American Institute of Physics (http://www.aip.org). Both the AIP and the authors of that paper (Lean and Rind) have a healthy understanding of the role of skepticism in science. It is OK to be a skeptic about global warming, and with the help of people like Lean and Rind, we probably don’t need to wait much more than a decade to greatly clarify this aspect of the debate.
I am irritated by way IPCC emphasizes “confidence interval” in their reports, not because the phrase is being misused, but because it is apt to be misunderstood. Whenever a number is reported in the scientific literature, the uncertainty should also be reported. Consider, for example, the “hockey-stick” controversy. The gray regions in the figure below indicate a 95% confidence interval.
I maintain that no credible person would claim that they are 95% certain that the actual globally averaged temperatures fell within this range (of about ˝ degree!) almost a thousand years ago. I presume that this confidence interval indicates that the examination of more tree samples would not likely extend the estimate outside the grey shaded area. Such a statement can be established using probability and statistics. But no amount of statistical analysis can tell us whether or not it is possible to estimate past temperatures from tree rings, because that is a question not of mathematics, but of biology. It would be nice if scientists could report the actual odds of a given paper being valid, but how could one possibly perform such a calculation?
This is the conundrum of scientific uncertainty: Common sense demands that the procedure for declaring uncertainty be made in a completely objective way. Only mathematical formulas can yield such objectivity. Such formulas rely on a mathematical model, and the only available mathematical model is the one proposed by the author(s). Almost by its very nature, the calculation of a Confidence Interval requires circular reasoning.
For one more example of what I don’t like about IPCC, recall that the Lean and Rind paper was written to address the fact that the decade ending in 2010 was not particularly warm. In the previous decade, IPCC published the following graph:
click to enlarge s06\linearfit.jpg
It is hard to believe that people with the mathematical sophistication to analyze tree-rings using principle component analysis, would resort to a series of linear fits to suggest exponential growth in temperature. What is especially embarrassing about this graph is that data from the subsequent decade (2000-2010) shows a nearly flat temperature profile:
click to enlarge s07/SatTem.JPG
I am always looking for research that students can do. It must be useful and have unknown outcome, or else I don’t call it research. Since the hypotheses of confirmation-bias and conspiracy-to-get-funding can never be ruled out, they must always be investigated – but certainly not by professional climatologists! Two simple studies come to mind:
1. The Heat Island Effect can be investigated by measuring temperatures in the vicinity of a medium sized town (s06\heatisland1.pdf , s06\heatisland2.pdf). Some have claimed that this effect has biased estimates of global temperatures, since we tend to measure temperatures in cities, not in the countryside. I am convinced that a few studies by independent high schools could allow us to estimate the magnitude of this error.
2. An even easier study for the amateur scientist would be to use the fact that temperature data is also available on the internet for thousands of cities. Nowadays it would be very easy to repeat a study such as this one: s06\bowlinggreenpaper.pdf. This study suggests that there has not been significant warming in Ohio. I causally investigated this and concluded that this inability to detect a warming trend in Ohio might be due to the fact that Ohio is situated in a region of the United States that has not warmed significantly. Note the following chart:
click to enlarge s07\usmap.jpg (I neglected to document the source of this picture – perhaps NOAA?)
It has been about a year since I worked on this, but nothing has changed significantly. It will take another 5-10 years before 2009 article by Lean and Rind can be checked out (smallfiles01/100218LeanRind.pdf). But I thought about the asymmetric nature of distortions when I looked at how Fox news covered a news conference by Obama today, on July 15, 2011.