Sunday, May 06, 2007

Michael Mann vs Alexander Cockburn

Michael Mann didn't like Alexander Cockburn's essay in which Cockburn correctly compares carbon permits and indulgences - well, your humble correspondent might have been the first person who called the permits "indulgences". At least, it was an independent invention :-) because I had to find the word "indulgence" in a Czech-English dictionary. What is the real reason why Michael Mann considers Cockburn's text illogical? Well, here it is:
  • As if to drive the point home further, pundit Alexander Cockburn, known generally for his progressive views, has perplexingly disputed the existence of any link between CO2 emissions and rising CO2 concentrations...

Michael Mann tells us that it is completely unexpected from a progressive pundit to write something wrong about the global warming orthodoxy. It may be expected from conservative contrarians but if a progressive pundit writes something like that, that's a real sin! Well, such a comment reveals what are the primary ideas that drive Michael Mann's thinking and "science": it's pure politics. Everything else is adjusted to agree with his politics.

The infamous hockey stick graph, the only well-known result he has, is unfortunately another example.

Incidentally, global warming alarmism and leftism are correlated but they're not identical. I find it pretty reasonable if a progressive pundit is afraid of similar policies that existed under the Catholic Church - because progressive pundits are generally expected to dislike these religious policies, aren't they? There are many left-wing skeptics, for example Philip Stott. Many such people dislike the efforts to keep the third world poor. But good scientists must be able to separate science from politics.

In order to assure us that it wasn't just a typo, Mann makes this political analysis even more detailed. We learn that Cockburn is not allowed to write these things because they sound more skeptical even than the opinions of Patrick Michaels. Well, Patrick Michaels is probably considered to be the ultimate upper bound on the amount of skepticism that a human being can possibly have. ;-)

Well, I hope it is not a complete secret what I will tell you: I was sitting next to Patrick Michaels during a lunch in D.C. two months ago and he was the greenest person in the room. Even his shoes (combined with his suit) were green :-) and he has raised some arguably legitimate criticism of some of the scientific opinions about the climate held by the organizer of that lunch. ;-)

But let's get to the actual questions:

Cockburn claims that there is zero empirical evidence showing the CO2 impact on temperatures...

...and Mann doesn't like it, saying that even Patrick Michaels thinks that there is such a connection. But Patrick Michaels says something slightly different: he says that there is a convincing theory that shows that such an influence should exist. This influence is pretty close to the overall warming in the 20th century and the effect from every new CO2 molecule is smaller than the effect of the previous molecule which implies that even if the emissions of CO2 were accelerating, the temperature would only increase linearly or so.

Patrick Michaels, just like any sane person, realizes that CO2 is just one of many factors influencing the climate. In the Swindle documentary, it was him who explained that the people who think that CO2 drove most of the climate change in the 20th century haven't looked at the basic numbers.

I think that Cockburn is right when he says that there is no empirical observation that proves the relationship and the attribution. If such a paper existed, we would constantly hear its title - instead of vacuous and false comments about consensus. It would also mean that the value of the climate sensitivity would be known. It's not. How can we have empirical evidence for this effect if we don't know what its strength, after all feedbacks are included, is? It's like saying that we can observe a cat but we can't say whether it's bigger than an elephant or not.

Who has added CO2

Mann criticizes Cockburn for questioning whether the increase of CO2 is due to human activities. Well, I happen to think that if there were no industry but everything else were kept untouched, the CO2 increase wouldn't exist or it would be much smaller. But one can't say that the extra CO2 in the atmosphere is exactly the CO2 that was added by our civilization. There are many other sources of CO2 that are stronger, by orders of magnitude, than our production. But they're a part of the natural carbon cycle and this cycle would be close to equilibrium without our contributions.

But anyway, it's not correct to say that the extra CO2 "is" ours. You could equally well say that it came from some portion of dying vegetation.

Millions years ago, the concentrations could have been much higher. Note that the whole transportation produces less CO2 than farm animals, even today, and there could have been more animals around in the past. 450 million years ago the concentration of CO2 was probably around 3000 ppm, eight times higher than today - we can deduce it from the small number of stomata on the fossils of leaves.

Water vapor

The concentration of water vapor in the atmosphere is changing quickly and it arguably approaches some equilibrium value dictated by other quantities but it is a very rough approximation to say that water vapor is "a feedback not a forcing". In the real world, there is no strict separation to feedbacks and forcings. Every effect is influenced by others and it also affects others.

Water vapor in the atmosphere has a huge impact. Water is the #1 greenhouse gas and, more importantly, it is the material that creates clouds. Incidentally, in April, NASA has published a new finding that there exist "semi-clouds" (my term), a huge "twilight zone" (GRL) around clouds that covers about 60% of the sunny skies. In the existing climate models, these 60% of the sunny skies were described uniformly. The NASA finding makes it pretty clear that the existing climate models don't describe 60% of the clear skies quite adequately.

At any rate, the dynamics of water vapor is influenced by many quantities and water vapor also has a huge impact on many other things, and if you neglect one of the two groups of influences in this sentence, you are bound to end up with misleading results.

CO2 is a product, not a cause

Michael Mann also mentions the "tiny" problem that the Vostok ice core data show that the primary detectable influence was the influence of temperature on the concentration of many gases - CO2, CH4, and others. The 800-year lag is one of many ways to show the anti-Gore direction of the causal relationship. Everyone who still fails to understand that the ice core data don't contain any empirical evidence for the greenhouse effect reveals his or her inadequate thinking skills.

We have discussed this issue in detail, including some analysis of the hypothesis of a strong amplification of the initial temperature variations. Such an amplification is not only invisible in the data but it is very unlikely to be significant because it it were larger than the influence of temperature on the concentrations during the 800 years where a change of the trend could be seen, the climate would be a positive-feedback system that would have already exponentially grown out of the control in the past. The data make it much more likely that there are many negative, self-regulating feedbacks in the system.

In fact, I am sure that even most of the part of the public that has been exposed to arguments about this question from both sides has understood that the ice core data don't provide Al Gore with the argument he needed.

CNN viewers invited to make a Google search

Michael Mann also mentions that the viewers of Glenn Beck's special were encouraged to make a single, most important Google search. They were told to find about the

You can replace co.jp by com: I am just afraid that Google penalizes such links to their search queries and a smaller version of Google could be better.

Mann thanks CNN because the first hit is their blog. Well, my mouse can be defunct but when I click at his link (search for "Google that" at RealClimate.ORG), the first link shown on my screen is The Reference Frame. ;-) The pages of course depend on the details of the query but you can check that The Reference Frame is ahead of them in most similar queries you can write down, e.g. for the following queries:

  • inconvenient truth ice core graph (#1)
  • carbon dioxide correlation temperature (#1)
  • al gore ice core correlation (#1)
  • 800-year-lag (#1)
  • ice core cause effect (#1)
  • ice core co2 follows temperature (#1)
  • warming or co2 first (#1)
  • ice co2 concentration graphs (#1)
  • or even: al gore's comments about global warming

and many others. Mann's statement that RealClimate.ORG is the #1 in "that" query is just another example of his manifestly biased treatment of any data and his cherry-picking.

Entertaining update: When Michael Mann noticed that the Google hit #1 was The Reference Frame, he changed the search query from carbon dioxide to carbon monoxide. According to "experts" at RealClimate.ORG, the global warming was caused by CO not CO2. ;-) The readers probably didn't like CO much so they returned "carbon dioxide lags temperature ice core" without quotes and The Reference Frame returned to #1. Later, Michael Mann finally figured out the easy solution: "co2 lags temperature" without quotes gives them #1. However, when you replace "co2" by "carbon dioxide" or add "ice core" or virtually any other relevant words, The Reference Frame returns to the top. ;-)

Nature's new blog

Finally, Mann has to mention a new climate change blog of Nature. I guess that this entry drives him up the wall much more intensely than Alexander Cockburn and Glenn Beck because one of the first postings on that blog is about the decay of his "hockey stick". But he can't quite say it openly because that would damage the illusion of consensus - so he just says that "first reviews [of the new Nature blog] are decidedly mixed."

It can't be too easy for a person like Mann to be entangled into an ever more complex web of untrue assertions.

And that's the memo.



Other popular climate change articles on The Reference Frame

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