Climate warming: the debate continues

Alan Carlin believes that rising greenhouse gases are not the cause of warming, on scientific grounds.

Yesterday we published a long guest Post from Patrice Ayme who argued that climate warming is a very serious risk to this planet, as we know it.

Alan Carlin has gracefully given Learning from Dogs permission to reproduce his article that argues, on a scientific basis, that man-made greenhouse gases are not the cause of warming.

Again, this is an article that needs to be read.  Alan’s Blog is here.

Why the UN GHG Hypothesis Should Be Rejected on Scientific Grounds

Alan Carlin | August 9, 2009

In a previous post I explained why I believe that the United Nations GHG hypothesis that significant global warming will occur as a result of increasing greenhouse gas (such as CO2) levels is implausible.  In this post I will explain why I believe that the best available evidence indicates that the hypothesis is not just implausible but rather should and can be rejected on scientific grounds.

For a broader view of how science progresses see here. Clearly I am in the Popper camp in this regard. Kuhn’s view may more accurately describe how science has unfortunately sometimes been historically conducted, but certainly not how it should be.

Before going further, it is important to explain that the important word in the definition of the UN GHG hypothesis is “significant.” There is little doubt that higher levels of greenhouse gases are likely to lead to slightly higher global temperatures since that is why they are called greenhouse gases. The United Nations, however, claims that increases in the levels of these gases in the atmosphere are the predominant influence on global temperatures. Hence the qualification “significant” in order to include the UN claims while excluding the minor warming that has probably been caused by increasing levels of greenhouse gases in the atmosphere.

As explained in my Comments, the models relied on so heavily by the UN do not prove anything scientifically one way or the other.  They simply show what the model builders believe would happen if the hypothesis and all their other assumptions were correct. The model results are interesting, perhaps even useful, but irrelevant in deciding whether their AGW hypothesis should be accepted or rejected. This is because they do not compare the implications of the hypothesis with real world data other than past temperature data which the models have been modified to emulate.

The Critical Role Played by the Scientific Method

According to the scientific method, a scientific hypothesis must be tested by comparing real world data with the implications of the hypothesis.  This is how Albert Einstein was able to persuade the world that his ideas on relativity had merit.  Scientists kept proposing real world tests of his hypothesis but each test confirmed its validity. After a number of these tests, the opposition conceded that his hypothesis was valid. (For a description of this extended process see, for example, Jeffrey Crelinsten’s Einstein’s Jury: The Race to Test Relativity). A similar process resulted in the acceptance of Newtonian mechanics and other hypotheses which gradually assumed the status of theories.

If the comparison with real world data does not confirm the hypothesis, the hypothesis should be rejected. There are only two alternatives from a scientific viewpoint when this happens: Discard or at least modify the hypothesis or discover an error in the data used to reject it.  From a scientific viewpoint, it is totally irrelevant how many public officials or scientific organizations–or how prominent they may be–support a particular hypothesis.  A hypothesis has scientific validity only by comparison with real world data. Joanne Nova has expressed this very well in her Handbook downloaded here.

There are numerous inconsistencies between the UN CO2 hypothesis and observed data.  Gregory explicitly compares the explanatory power of the UN hypothesis with the competing Svensmark hypothesis and finds the UN hypothesis wanting.  Idso and Singer provide extensive scientific evidence against the UN hypothesis.

But perhaps the most fundamental comparisons are between the major physical effects of the UN hypothesis and available real world data.  There are four particularly telling physically-based basic comparisons in this regard.  According to the scientific method an inconsistency even in one of these comparisons means that the hypothesis should be rejected from a scientific viewpoint.  It is important to deal with the uncertainty introduced by the word “significant,” however. This uncertainty increases the likelihood that a few of the comparisons may prove positive. Hence it increases the strength of any negative finding. In fact, if a number of tests should prove negative it makes the tests very powerful evidence against the hypothesis.

Four Critical Comparisons with Real World Data

Acceptance of the hypothesis requires that each of the following four observations are present:

  1. There is a hot spot in the upper troposphere in the tropics as predicted by the UN. If greenhouse gases are significantly warming the Earth the first signs of it are supposed to appear about 10 kilometers above the tropics. The lack of such a hotspot is discussed in my Comments in Section 2.9 as well as by Joanne Nova downloaded here. She discusses the major objections that have been raised to this comparison and why she believes they are not credible.
  2. There is heating of the oceans.  The added heat generated by increasing greenhouse gas levels in the atmosphere must be stored somewhere. It has not been showing up in the atmosphere in the last decade, so if the hypothesis is valid it must be going into the oceans. But in the last few years this has not been the case. An extensive discussion of the evidence can be found here. The bottom line is that the AGW hypothesis fails this test as well.
  3. The observed outgoing radiation fluxes from the Earth decrease with increases in sea surface temperatures. Satellite data, however, shows an increase, which is inconsistent with the high climate sensitivities to increases in CO2 and positive feedback so crucial to the UN’s case. A new peer reviewed paper accepted for publication on this subject can be found here.
  4. The atmospheric response times for volcanic sequences would be longer than they would be without the UN hypothesis. If climate sensitivity is as high as the UN claims, it should show up in the atmosphere’s response time from volcanic eruptions. The reason for this is that climate sensitivity is also a measure of how tightly air and sea temperatures are coupled. High sensitivity is associated with weak coupling, allowing the establishment of significant disequilibration of the sea surface temperature. A discussion of this can be found in a 1997 report from the National Academy of Sciences here.  The discussion may be a little technical, but the conclusion that the data “is consistent with low [climate] sensitivity,” which is inconsistent with one of the UN’s crucial conclusions, is clear.

The conclusions are the same in each of these four cases: The UN hypothesis is not supported or even partially supported by these comparisons with real world data. As Professor Richard Lindzen of MIT has recently observed with regard to his findings on comparison 3 above, “In a normal field, these results would pretty much wrap things up, but global warming/climate change has developed so much momentum that it has a life of its own – quite removed from science.”

The data are far from perfect, of course, perhaps in part because of a lack of effort to gather it.  But they all tell the same story.  This means that the hypothesis should be rejected scientifically based on current information. Future testing could lead to other conclusions, of course, but for now rejection is the rational course of action.


Accordingly, using this hypothesis has no scientific basis based on current knowledge concerning these four comparisons.  Attempts to argue that it is anything more than a religious or superstitious belief must show that the data used in each and every one of these tests (as well as others that may be proposed in the future) is wrong.

Accordingly, using the UN hypothesis as a basis for formulating policy is not useful or relevant from a scientific viewpoint.  Attempts to do so are likely to lead to scientifically unsound policy. Given that the current proposed “solution”–radically reducing CO2 emissions–would cost many tens of trillions of dollars, it is particularly incumbent on those advocating this very large expenditure (for which there are many other uses if it should actually become available) to show that their solution should not also be rejected since it is based on a hypothesis that should be rejected.

The UN reports issued to date do not show that the data used in these four important comparisons is incorrect, and therefore the reports should not be used as a basis for policy in my view. Reports substantially based on the UN reports, such as the draft EPA Endangerment Technical Support Document reviewed in my Comments, should also not be used for policy purposes for the same reason in my view.

By Paul Handover

2 thoughts on “Climate warming: the debate continues

  1. The preceding essay of Mr. Carlin sounds scientific, but is not. It is just a piece of sheer propaganda, as the insistence that this is all about the “UN” shows readily.

    More than 98% of scientific papers support the fact that greenhouse gases cause warming, it has nothing to do with the “UN”, a political organization. Many conservative Americans do not like the “UN”, so, by painting the greenhouse with the “UN”, Mr. Carlin apparently hopes both will disappear. Mr. Carlin ought to be told that the “UN” is not a scientific organization.

    There is world scientific organization made of all the countries individually, which came with scientific evidence on “Climate Change” gathered UNANIMOUSLY, but that’s not the “UN”. That’s called the IPCC (International Panel on Climate Change). Once again, unanimous. Saudi Arabia or the USA or Cuba or Kuwait can block the entire set of conclusions. They did not. Unanimous.

    That the atmosphere should be warming at 10 kilometers is an absurdity, exhibiting a complete misunderstanding of the nature of the greenhouse: the greenhouse causes the exact opposite effect (infrared light blocked next to the ground cannot go and warm up the upper atmosphere, so the greenhouse causes a COOLING of the upper atmosphere!!!!!!!!!!!!!). Mr. Carlin knows too little physics to pass the first exam. (I used to teach physics at Stanford and Berkeley, and graded hundreds of students; in particular I taught the basic thermodynamics course for physics major, obviously differently from Mr. Carlin, who obviously has no notion of how a greenhouse works).

    After a student got an F, what to do? Talk to them kindly?

    The talk about volcanoes sounds scientific, but is nothing relevant. OK, volcanoes have a huge impact on climate, and probably killed the dinosaurs (lava of the Deccan Traps, more than a mile thick, 400 feet of which deposited in less than 10 years). But it’s neither here, nor there in the present debate.

    Fact is greenhouses gases augmented by more than 50% in a little more than a century (from 280 ppm to 450 ppm). Only complete fools would think that will have no impact. Half of the CO2 went into making CARBONIC ACID in the ocean. wait until it comes out (which it started to do in the Antarctic).

    The greenhouse has nothing to do with the UN, it has everything to do with the fossil fuels.



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