Anthropogenic Global Warming and the Scientific Method

• Guest post •

Anthropogenic Global Warming (AGW) alarm has been with us for a good while now. The matter seems to become more contentious rather than less. Unhappily, as a result of the mediocre quality of science education, many people do not know how to evaluate either a scientific hypothesis in general or AGW in particular — and irrespective of whatever anyone might think, because of how it is framed and evaluated, AGW is no more than a hypothesis.

Science is about ruling things out. Any good scientific hypothesis will make predictions about the natural world — ideally, it will predict at least one natural effect whose existence cannot be caused by anything other than the hypothesis being tested. Observations are then made to acquire evidence, and the evidence is evaluated against the hypothesis’s predictions. Evidence can either rule the hypothesis out or not; if the evidence differs from the hypothesis’s predicted effects, then the hypothesis is wrong and is considered to be ruled out, or falsified. That which has not been ruled out by evidence remains possible. If enough confirmatory evidence is accumulated, the hypothesis is elevated to the status of a theory. Scientific Method is, conceptually, no more complicated than that.

Popper’s philosophy

Karl Popper, the great philosopher of science, used a simple observational experiment to illustrate the scientific method’s requirement of falsifiability — the requirement that a hypothesis be stated in such a way as to allow its testing against evidence with a view towards ruling it out. He noted that most people had once assumed that all swans are white. This assumption was based on the observation, over time, of uncounted numbers of white swans — and each such observation was taken as evidence supporting the assumption. However, there came a time when a black swan was found in Australia, and its discovery served to disprove the assumption that all swans are white. In generalizing from this discovery, Popper understood that you would not test the hypothesis that all swans are white by undertaking a search for white swans — because no matter how many white swans you found, you would have neither proven, nor even properly tested, the hypothesis. Instead, you must mount an intensive search for a single non-white swan. If you found even one of those, you would have ruled the hypothesis out. Alternatively, and without finding a non-white swan, it remained viable — but because there remained the possibility of a single undetected non-white swan, it could not be regarded as proven.

Einstein’s relativity

Einstein’s Theory of Special Relativity provides an excellent real-world scientific example of evaluation by falsifiability. The Special Theory makes unique predictions about gravity’s effect on light’s behavior in a vacuum that, as far as anyone knows, could be accounted for by no phenomenon other than that assumed in the theory. When specifically tested for during a total eclipse of the sun in 1919, the gravitational effect Einstein’s theory predicted was both detected and measured to equal precisely his theory’s prediction. Special Relativity was hence verified — although, again, it is not regarded as proven. Instead, it remains possible in the absence of having been falsified by evidence. Now, it is true that Special Relativity is, like other theories, commonly accepted, and spoken of, as having been proven. However, that is merely a shorthand way of saying that it currently has no credible competition as an explanation of the phenomenon it addresses.

AGW hypothesis

The AGW hypothesis that so many people claim accounts for what is essentially pretend global warming has never been treated this way. Initially, its proponents engaged in a search for supporting evidence: Elevated average annual temperatures, local glacial retreats, elevated-temperature indicators in proxy systems such as tree-ring records, measurable coincident increases in atmospheric CO2 concentration, and so on — a search for white swans. But these efforts ignored, and failed even to seek, either any alternative explanations or evidence that would have ruled the hypothesis out. AGW has failed the predictions test again and again; any true scientific hypothesis with so poor an evidence-based evaluation record would have been scrapped by now. Instead, its proponents elevated it to the status of a theory and, ignoring the fact that climate changes continually, renamed it “climate change.”

No other potential causes of AGW have ever been investigated and ruled out. There must be at least one, because evidence shows that there have been times in the pre-human geological past when conditions were warmer and there was no glaciation at all anywhere on Earth. We also know, as a result of ice-core studies, that CO2 has generally been a lagging indicator — that is, atmospheric CO2 concentrations are documented to have increased after, rather than before, atmospheric temperature increases.

Nevertheless, its believers treat AGW as verified, and simply alter its components and predictions to conform to evidence. When the predicted warming did not occur and snows continued to fall during London winters even though it was predicted that they would fail, for example, or when polar ice sheets expanded even though the theory has predicted that they would melt away, the hypothesis should be considered to have been ruled out by evidence.

Rely on a failed model and you know not what you do

However, its proponents still treat AGW as though it were true. Otherwise-reputable scientists employ variations on several approaches to their falsification conundrum. The first of these approaches, the use of models, is a legitimate tool in particular scientific applications. Others amount to attempting to fudge the hypothesis to make it match evidence in an unscientific rearguard action.

Models are essentially used as predictive tools, so they are only as good as the information upon which they are constructed. If there are any unknown components in the modeled system, then the model’s predictions will, almost by definition, be unreliable. In the case of a system both as complex and incompletely understood as Earth’s atmosphere, the model’s construction will essentially be required to include untested, incomplete, and/or unproven function assumptions and data. In such a case, the problems and pitfalls of using these models to construct governing policies quickly become self-evident: People trying to rely on the models essentially cannot know what they are doing. When, for example, their model does not predict their real-world observations, they tweak it until it does — which introduces errors-by-expectation into both output and the policies based upon it. These errors increase in magnitude, and therefore in effect, in a non-linear fashion directly proportional both to the size of the system and to the modeled outputs.

AGW’s predictions are not being reliably confirmed by observations. When stasis or cooling occur rather than warming—as has been the case over the last decade and a half—atmospheric scientists fudge interpretations by saying that if it is cool, that is just weather; but if it is warm, that is climate. Alternatively, they claim AGW predicts the cooling—as, for example, with the recent polar-vortex outbreaks. However, a theory that predicts everything predicts nothing—because a theory that predicts everything cannot be falsified through testing; nothing will serve to rule it out.

AGW ruled out by evidence

Scientists have also approached the unaccountable stasis or cooling by going around and searching for “the missing heat” that their theory assumes exists and claims has already built up. But this is not a search that would test the theory. It is a search that assumes the theory to be true—it begs the question. Further, if the search detects the sought evidence, no one tries to rule out any possible causes other than AGW, assuming instead that if the evidence exists, there are no other possible causes.

In short, the AGW-cum-climate change debate is not about a hypothesis-cum-theory. Even though no one has investigated it with a view towards falsifying it, evidence has ruled it out repeatedly. It has no useful scientific applications because it has been broadened to predict all possible observations—thereby predicting nothing at all.


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9 Thoughts on “Anthropogenic Global Warming and the Scientific Method

  1. Richard C (NZ) on 02/12/2014 at 11:12 am said:

    >”However, a theory that predicts everything predicts nothing”

    Thomas November 30, 2014 at 7:28 pm [Hot Topic]

    “One cause of dropping SL around the Northern regions is rebound of the crust due to reduction of glacial ice cover.
    Some scientists believe that the AGW induced rapid (in geological time scales) redistribution of mass on the Earth surface may induce a spike in earthquake activity.
    and the paper here:

    >”Some scientists believe,,,,” That would be one Bill McGuire in particular but Kevin Trenberth subscribes to this too (private communication – climate drives seismicity):

    ‘Potential for a hazardous geospheric response to projected future climate changes’

    “In relation to anthropogenic climate change, modelling studies and
    projection of current trends point towards increased risk in relation to a spectrum of
    geological and geomorphological hazards in a warmer world, while observations suggest
    that the ongoing rise in global average temperatures may already be eliciting a hazardous
    response from the geosphere.”

    So AGW is a catch-all for everything imaginable, including air flight:

    “Airplanes of the future will have to carry lighter loads more often thanks to global warming, according to two scientists at Columbia University, New York. They reached their conclusion by creating models which predicted that by 2060 there will be more warm days but no commensurate technological advances in the aviation industry. The two scientists, Coffel and Horton, looked at a phenomenon known amongst pilots as ‘density altitude’, which affects a plane’s ability to take off. Essentially, on hotter days the air is less dense, making it harder to get a plane airborne. It is a particular problem at airports with short runways, as the planes will take longer to lift off. ”


    ‘–52C in Siberia: Over 70 passengers ‘push’ frozen plane to runway ‘

    “Freezing temperatures didn’t stop intrepid passengers from “helping out” a Russian plane that couldn’t move, because its wheels were frozen to the ground.”

    # # #

    The more bizarre and untestable (except for a 35+ year wait-and-see) the scope of predicted effects, the less credible the original (undocumented) theory becomes. AGW proponants think they have time on their side but they don’t:

    “In science, Occam’s Razor is used as a heuristic (discovery tool) to guide scientists in the development of theoretical models rather than as an arbiter between published models.[8][9] In the scientific method, Occam’s Razor is not considered an irrefutable principle of logic or a scientific result; the preference for simplicity in the scientific method is based on the falsifiability criterion. For each accepted explanation of a phenomenon, there is always an infinite number of possible and more complex alternatives, because one can always burden failing explanations with ad hoc hypothesis to prevent them from being falsified; therefore, simpler theories are preferable to more complex ones because they are better testable and falsifiable

    As Betsy Gorisch states, AGW is already ruled out by the evidence against it, let alone in 35+ years time.

  2. Peter+Yates on 02/12/2014 at 4:15 pm said:

    The ‘alarmist’ side of the debate shows signs of cult-like influences. These influences appear to be when the scientific method, and the scientific need for extraordinary evidence, are often largely ignored. The technical term for this is ‘cognitive dissonance’. The alarmists feel uncomfortable when they discover that their beliefs don’t match up with reality.

    One of the ways they reduce the cognitive dissonance is by ignoring or denying any information that conflicts with their existing beliefs. Also, they may justify the behavior by changing the conflicting cognition (eg. the warming has just paused and is sure to return at a later date, or the missing warmth is hiding in the deep oceans – where we can’t measure it).

    A parallel with this in the dark world of apocalyptic religious cults is when the world does not end on a certain date, and it is assumed that the calculations were wrong, or the deity has decided not to punish mankind after all.

  3. Excellent essay.

  4. HemiMck on 08/12/2014 at 10:10 am said:

    Saw a comment but lost the thread of John Key saying we were going to work on our agricultural emissions which (supposedly) make up 50% of our totals. Treasury estimate the cost at $53 billion

    As readers of this site know the multiple of 23 applying to methane was hypothesised over 15 years ago and has never been revisited. It is clearly wrong and overstates the number at least threefold. Methane has a half life of 8 years in the atmosphere and becomes CO2.

    Our problem is essentially political as it is only Argentina and ourselves who are significantly effected by the calculation. Years ago Argentina did attempt to have the number reviewed with no success. NIWA and the New Zealand green brigade have no incentive to address the issue, rather the reverse. Perceived as a rich country arguing a case to change the rules which mainly benefit us would not be to their liking.

    There is clearly nothing farmers can do about the level of emissions. There has been no significant scientific advance in the area and all they can do is pay – based on a double lie about the effects of methane.

    Unfortunately the only way to get a better outcome for the productive sector of the economy is for the whole castle to come down.

    • Andy on 08/12/2014 at 11:58 am said:

      Agreed, the methane issue is basically a scam.

    • Richard C (NZ) on 08/12/2014 at 12:56 pm said:

      >”Treasury estimate the cost at $53 billion”

      Eye watering – what does that pay for?

      NZ’s entire GDP (economic activity – not cash) was $185.8 billion in 2013 i.e. it’s not as if there’s $53 bln lying around. And I can think of better uses.

      Same with the Green Climate fund. Apparently Sub-Saharan African countries alone will need US$62 billion per year to invest in climate adaptation. They’re already hot, what will $62 bln per year pay for – sun umbrellas?

      More on that here:

    • Richard C (NZ) on 08/12/2014 at 1:22 pm said:

      That’s $13,250 from each of us.

    • Richard C (NZ) on 08/12/2014 at 5:40 pm said:

      >”……the multiple of 23 applying to methane was hypothesised over 15 years ago and has never been revisited”

      Before that, methane and CO2 were discarded from standard atmosphere calculations:

      ‘US Standard Atmosphere Model & Observations Prove Maxwell’s Mass/Gravity/Pressure Theory of the ‘Greenhouse Effect’ is Correct & Falsifies CAGW’

      The Hockey Schtick

      “The tiny 0.03-0.04% of CO2 in the atmosphere does not contribute in any significant way to atmospheric molecular mass, molecular density, partial pressures, heat capacity (Cp), etc., thus in the multiple versions of the US Standard Atmosphere models, the calculated CO2 effect on the atmospheric temperature was so negligible that the atmospheric scientists thereafter completely discarded CO2 from their model calculations of the atmosphere. The same potential effects were calculated for what is called today the “20 times stronger greenhouse gas than CO2″ methane; these atmospheric scientists found the mass contribution and heat capacity to the atmosphere from methane was far too negligible to consider, thus, it was also discarded from the model along with CO2.”

    • Richard C (NZ) on 08/12/2014 at 7:44 pm said:

      Methane is a “super pollutant” apparently:

      ‘Super Pollutants Act of 2014’- by Judith Curry

      The Senate held an interesting and potentially important hearing on super pollutants.

      The Super Pollutants Act of 2014 is legislation that has been introduced by Senators Murphy (D-Conn) and Collins (R-Maine), which is bipartisan legislation to address short-lived energy climate pollutants. The text of the bill is found [here], and Senator Murphy has a June press release [here]. Excerpts from the press release:

      U.S. Senators Chris Murphy (D-Conn.) and Susan Collins (R-Maine) today announced their plans to introduce legislation aimed at reducing emissions of short-lived climate pollutants (SLCPs). SLCPs, referred to as “super pollutants,” are non-carbon dioxide greenhouse pollutants that cause 40 percent of global warming. SLCPs range from methane that is leaked by landfills and oil and gas exploration, to refrigerants leaking from refrigerators and air conditioners, to soot from diesel engines and millions of traditional cookstoves all over the developing world. Studies show that fast action to reduce SLCPs in the atmosphere could cut the rate of sea level rise by 25 percent, almost halve the rate of temperature rise, prevent two million premature deaths each year, and avoid crop losses of over 30 million tons annually.


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