The perils of self-reinforcing arguments.

Professor Mark Cochrane’s perspective on ‘certainty’!

I’m an avid follower of Mike Stasse’s blog Damn the Matrix.  So it was rather fortuitous that two days ago there was a guest post on Mike’s blog from Mark Cochrane. Dr. Mark Cochrane is a Senior Scientist and Professor at South Dakota State University where one can read:

Dr. Mark Cochrane conducts interdisciplinary work combining ecology , remote sensing, and other fields of study to provide a landscape perspective of the dynamic processes involved in land-cover change. He is an expert on wildfire, documenting the characteristics, behavior and severe effects of fire in tropical and temperate forests that are inherent to current systems of human land-use and management. His research focuses on understanding spatial patterns, interactions and synergisms between the multiple physical and biological factors that affect ecosystems. Recently published work has emphasized the climate change, human dimensions of land-cover change and the potential for sustainable development.

The guest post was called Doom and Denial two sides of the same coin; I’m extremely grateful to Mike Stasse for granting me permission to republish the essay.


Doom and Denial two sides of the same coin.

19th June 2013

Another guest post by Mark Cochrane……  and I hope Guy reads this, I’d like his feedback, no pun intended!

Mark CochraneMark Cochrane

I’ve been asked by several people to address the take of climate ‘doomists’ like McPherson and indicate how my views on what the science indicates differ. First, let me just say that my differences with the doomist views are similar to my differences with the ‘denialist’ views, namely one of actually examining the scientific findings and concluding what they signify versus beginning with a conclusion and looking for evidence to support a pre-concluded viewpoint.

Appropriate use of science (or any information), requires weighing anything being newly reported against the rest of the accumulated evidence on a subject (e.g. climate change) that we have amassed, to date, and using this knowledge to infer the most probable meaning and significance. How credible is the source, how relevant are the results to the larger question, do the new results substantially change our previous understanding? If someone is presenting new ideas that claim to massively shift what we think we know about the world, have they been vetted (e.g. peer-reviewed), do they adequately explain how their new claims better explain observed phenomena than previous studies did and also detail why previous explanations were somehow erroneous? If the results are truly stunning, can they be replicated by others? Although some may find it hard to believe, there is a lot of space between climate denial and climate doom.

I’ve only seen the one talk now by McPherson but where the ‘we are doomed and soon’ meme falls apart is on general logic. You cannot say, there are positive feedbacks A, B and C, therefore life on Earth is suddenly going to end without considering:

  1. what are the current rates of those feedbacks,
  2. what is the rate of change for the feedback,
  3. what is the area affected by the feedback,
  4. what natural limits exist for the feedback,
  5. what negative feedbacks might occur in response?

If you listen to McPherson’s talk, what you get is a litany of disturbing findings, especially feedbacks, and then an expectation that you must reach the same conclusion that we are doomed, and soon. If someone would like to outline the chain of logic used, I’d be happy to discuss it. Even if you accept the chain of logic though, where, in any of it, is there evidence for the timeline being suggested?

Guy McPherson

There is considerable amount of concern about the feedbacks in the Arctic, with good reason, but people do things like linking the large amount of carbon stocks in the Arctic with rapid warming, with increased rates of release, with increased rates of warming……with the obvious end of all life on Earth – near-term extinction!

As anyone who has followed this thread knows, I am usually the one pointing out feedbacks and how most are not even included in current climate projections, in contradiction to those who claim such dire projections are all because of such feedbacks (which ‘skeptics’ claim don’t exist). This does not mean though that the existence of feedbacks means that we can then make the leap to a runaway greenhouse that will soon lead us to having the climate of Venus (atmospheric acid bath at temperatures that would melt lead). Perhaps providing some perspective on the recent material posted about the NASA CARVE project and what it means for all of that carbon in the (not so) permafrost will help.

As NASA recently reported (site),

“Over hundreds of millennia, Arctic permafrost soils have accumulated vast stores of organic carbon – an estimated 1,400 to 1,850 petagrams of it (a petagram is 2.2 trillion pounds, or 1 billion metric tons). That’s about half of all the estimated organic carbon stored in Earth’s soils. In comparison, about 350 petagrams of carbon have been emitted from all fossil-fuel combustion and human activities since 1850. Most of this carbon is located in thaw-vulnerable topsoils within 10 feet (3 meters) of the surface.”

“Permafrost soils are warming even faster than Arctic air temperatures – as much as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30 years,” Miller said. “As heat from Earth’s surface penetrates into permafrost, it threatens to mobilize these organic carbon reservoirs and release them into the atmosphere as carbon dioxide and methane, upsetting the Arctic’s carbon balance and greatly exacerbating global warming.”

In other words, there is 4-5 times as much carbon sitting around in those frozen soils as we have already emitted that are becoming increasingly vulnerable to being thawed out for a portion of each year.

Once those soils thaw they become accessible to microorganisms that feed on the incompletely decomposed plant materials that they contain. If there is sufficient oxygen (warm relatively dry Arctic) the process is faster and the product is CO2, if the process is anaerobic (warm relatively wet Arctic), then the product is methane.

So warming leads to thawing, thawing leads to microbial decomposition, and microbial activity leads to carbon emissions. These emissions are a positive feedback that makes the current process of greenhouse gas warming worse since each degree of warming yields more greenhouse gases that speed up the warming process further. This is where the message of doom goes off the tracks and extrapolates erroneously that this somehow means that all of that carbon is going to suddenly find itself in the atmosphere.

Three meters (10ft) of soil carbon doesn’t just suddenly evaporate into the atmosphere in the next few years. Thawing permafrost is not synonymous with melting carbon.  Even once permafrost melts, it is still very cold. However, bacteria can start digesting it – until it freezes again. Melted permafrost does not mean permanently melted. The surface layer of the Arctic lands are already in the active layer that temporarily thaws each year and then refreezes. Now, we are making more of the Arctic soil active to greater depths and at higher latitudes. This means that there will be more emissions from those soils.

Taken out of context snippets like this (below) from that NASA press piece can be made to sound catastrophic.

“Some of the methane and carbon dioxide concentrations we’ve measured have been large, and we’re seeing very different patterns from what models suggest,” Miller said. “We saw large, regional-scale episodic bursts of higher-than-normal carbon dioxide and methane in interior Alaska and across the North Slope during the spring thaw, and they lasted until after the fall refreeze. To cite another example, in July 2012 we saw methane levels over swamps in the Innoko Wilderness that were 650 parts per billion higher than normal background levels. That’s similar to what you might find in a large city.”

Parsing the quote, please note that “episodic bursts of higher-than-normal carbon dioxide and methane” in two locations (regions) does not mean the end is nigh. Higher-than-normal is just that, but how much higher and how long did it last? The scientists are saying that the observations do not match existing ‘models’ (models are wrong, a favorite meme), it doesn’t mean that such events haven’t been happening up until now (only that we didn’t know about them). As for the 650ppb increase over a swamp, that equates to being 1/3 higher than the background level. Methane and swamps go together so some higher level is to be expected. The question is if and by how much 650ppb is higher than it would have been back around 1980 or so? If it used to be 10ppb higher than background then you have a big change (640ppb), however, if it used to be 640ppb, then not so much (10ppb difference). Even if that is all new carbon being emitted, the local change becomes very small when diluted globally. The point here is not to poo-poo the findings or the scientist’s work, they are doing very important stuff (!), it is to provide context.

Just how bad could things be? I do not work in the high Arctic but I do work in similar organic soils in the tropics (peat swamps) where, because of intentional draining, the several meter thick peat layer that is ‘active’ is increased in an analogous manner to the effects of melting permafrost. Microbial degradation is occurring, with the difference that the temperature is very warm instead of being very cold. Think of how fast fruit spoils in your refrigerator versus on a hot window sill. In these tropical peat soils we see large amounts of CO2 coming off into the atmosphere each year now, but even with such large rates of loss, this equates to taking about 20-25 years to lose 1 meter of organic soil. In the Arctic the microbial degradation will be much slower due to the relatively low temperatures. This doesn’t mean that it is not important. Slow rates of emissions over a large area is still a lot of extra carbon going into atmosphere but this is a problem that is going to take centuries to play out, not less than a decade. It makes things worse but it doesn’t suddenly end life on Earth.

Incidentally, all of that soil carbon in the Arctic isn’t a uniform petri dish either. Some of that carbon is easier to access by bacteria than other portions. Emissions will rise quickly as the bacteria chew through the cellulose, for example, but things like lignin get left behind. The point being that even for a given mass of carbon in the ‘active’ layer, there will be a dampening of the emissions growth rate as the quality of the bacteria buffet goes down when it gets picked over.

I do not pretend to know what the motivations of ‘doomists’ are, whether it be honest despair or simple misunderstanding but they are conveying the same message of do nothing as those who deny the existence or importance of climate change. Denial = don’t worry be happy, while Doom = don’t worry, you can’t do anything about it anyway. Both viewpoints are wrong in trying to turn climate change into a false dichotomy of either fantasy or inevitability. Both the science and our choices are much more complicated. It’s uncomfortable but your choices do matter now and for generations to come. There is no ‘fixing’ things at this point but you still have the ability to choose how you react to the predicament we have created. Doom and denial are respectively trying to tell you that you either have no choice or no need to choose. But, as Philip K. Dick wrote:

“Reality is that which, when you stop believing in it, doesn’t go away.”


17 thoughts on “The perils of self-reinforcing arguments.

  1. Yes, I agree that both ‘doomists’ and ‘deniers’ are in danger of being seen as “two sides of the same coin”. However, having once spent 45 minutes talking to Guy McPherson on Skype, I do not see how anyone can accuse him of having reached a conclusion and then gone looking for evidence to support it.

    Furthermore, I am very surprised by the way in which Mark Cochrane dismisses the near-term importance of methane releases in polar regions on the basis that they will be much slower than processes he has observed in warmer climates: The main problem that I see with this theoretical deduction is that it is in direct conflict with the observational evidence that methane release from the seabed and permafrost is already accelerating..!


    1. Martin, thanks for your comment. I don’t read in Prof. Cochrane’s post the conclusions you mention. That is that the stances of no choice or inevitability are equally and crudely wrong.


      1. The conclusion I mention in my first paragraph is that seen in the title of Cochrane’s article and re-stated in his final paragraph. In between, however, Cochrane spends most of his time trying to argue that we don’t need to worry about things that are already happening faster than predicted even 5 years ago (i.e. sea ice melting, permafrost thawing, and methane release. However, I am not arguing for the ‘doomsters’ (i.e. that it is too late to do anything), I am just questioning why Cochrane spend so much time arguing, in effect, that ‘black’ is ‘white’?


  2. Really nice article but I would like to make one correction. In the article the author says: “because of such feedbacks (which ‘skeptics’ claim don’t exist).” It’s not that most skeptics claim the feedbacks don’t exist it is more along the lines of what you mentioned earlier in the article about the values related to the feedbacks.

    In modeling a bridge and how it withstands various forcings I know these force values through experimentation and real world observations. Therefore my model is extremely accurate in how the bridge will stand up to heavy traffic in a wind storm. But my issue with climate models is they use values that are (if being honest) educated guesses at best. There are no real world experiments, nor can there be any, that tell us with precision what the forcing values need to be, counter forcing, etc. Just take clouds as an example to prove my point.

    Now if all of this was purely an academic debate it would get as much press as the debate going on in the world of physics concerinng the multi-verse and string theory (fascinating by the way). But politicians have staked careers on it and there are trillions of dollars resting on this debate. That, as much as anything, forces the two sides to proclaim doom or scam.


    1. Hi John. Whilst I like your analogy from the field of civil engineering, I feel I must defend climate models. This is because their main problem is not uncertainty; it is their complexity. However, today’s super computers eat complexity for breakfast; and the uncertainties in any input parameters are dealt with using the Monte Carlo method. Therefore, when you suggest that input parameters are just “educated guesses”, you are in danger of appearing not to know how these computer models actually work; or running the risk of being grouped with others who don’t want you to understand how they work.

      I would like to invite you to read the brief quotation from The Hockey Stick and the Climate Wars, which I included at the end of this recent post on my blog. In these 4 paragraphs, Professor Michael Mann explains why we can consider climate models to be reliable. For reference, here is the final paragraph:

      The conclusion was clear: Natural [climate forcing] factors could explain the temperature changes of the past millennium through [to] the dawn of the Industrial Revolution, but only human influences could explain the unusual recent warming.

      The Skeptical Science website contains much more detailed rebuttals of all the currently popular arguments – including “computer models are not reliable” and “water vapour is the most powerful greenhouse gas”If any of these arguments had any merit, their originators would have won a Nobel Prize for Physics!.


      1. Mr. Lack, thank you for the comment. My comment about ‘educated guesses’ wasn’t meant as a snide type of comment. It is due to the complexity that they must be an educated guess. I have experience in modeling engineering and in helping to create some models for black hole entropy.

        Where I see the issue is in the unknown. I think even you would agree that clouds are extremely complex and all the modesl do not handle them with as fine a precision as they would like. And therein lies the issue. Monte Carlo optimization is really just going to come up with a probability curve of various outputs. But even then they rely on input ranges. But what if the ranges are off to begin with?

        See I have a major issue with the following statement “but only human influences could explain the unusual recent warming.” The cause is unknown and since there is no known cause it therefore must be human based. This is not based on finding the equations and math but instead based on a process of exclusion. The only problem is that there might exist unknown processes involved. This happens in string theory quite often but as I said trillions of dollars are not at stake. I will wait 5 more years or so. If the models are still way off then even you will have to admit that something is admiss.


      2. John, thank you for your reply. Have to say the science and the math of modelling are way over my head but the points you make are important; well to me they are!


      3. Dear John. If you are familiar with computer models, you should be familiar with the concepts of calibration and validation. Calibration is the process of determining the sensitivity of any set of model results to minor changes to input parameter values. Validation is the process whereby a model and its parameter values are shown to be reliable by their ability to recreate historical results (i.e. retrodiction)

        As the Michael Mann quote to which I have referred you demonstrates, climate models have been carefully calibrated and validated. They have also been demonstrated capable of correctly modelling the consequences of major volcanic eruptions (i.e. temporary cooling).

        The warming of the last 200 years is, very clearly, at odds with the 12k years of relative climate and sea level stability since the last Ice Age. This sudden change cannot be explained naturally, but climate models have replicated it by modelling the effects of super-exponential growth in CO2 emissions in the last 200 years. I therefore do not understand how you can say the [main] cause is unknown. However, with regard to your assertion (as it appears to me) that the few things we do not yet understand should be a reason for doing nothing, I would like to recommend that your read the comments posted by RobertScribbler in response to the most recent post on my blog.

        I think the reason String Theory is not questioned is that it does not demand that humans wake up to the reality that the Earth has a finite capacity to assimilate and/or recycle our pollution and that we have now exceeded it. Sadly, our politicians seem determined to ignore this fact, even though the people telling them to ‘wake up’ now include the International Monetary Fund and the International Energy Agency.


    2. I tend to agree with John (surprised?). Martin is under the misapprehension that the Monte Carlo method makes models more accurate. No. It’s a way of using highly powerful modern computers to run a model many thousands of times to test the impact of uncertainties in the input parameters, instead of just a handful of runs in the early days. The accuracy of the model is still dependent on the validity of the code and the input parameters – which might still be educated guesses. The other point is that calibrating models with hindsight is relatively easy. The real test is whether they accurately predict the future. There are big arguments over this, but certainly none of the major climate models predicted the current hiatus in temperature rise.

      Its interesting to see that, while Martin routinely attacks those who don’t agree with the ‘consensus’, he’s happy to divert from it himself when it suits.

      For example, the consensus is that CO2 emissions are only needed to explain the warming from 1979 onwards, not the past 200 years. It is a consensus that there was a Little Ice Age (during which Alpine villages feared being over-run by the then growing glaciers), and that early 20th C warming was mostly a recovery from that period. It is also the consensus that the Earth was warmer 6000 to 8000 years ago, and when there were much fewer glaciers than today.

      If in his statement: “the warming of the last 200 years is, very clearly, at odds with the 12k years of relative climate and sea level stability since the last Ice Age” he’s referring to the recent Marcott el paper, he is wrong again ( ). This includes a data point showing 1950 warmer than most of the past 11,500 years. And if you splice on the rest of the instrumental data, then now is warmer than the past 11,500 years. Wow! But in the paper itself, it states explicitly: “our reconstruction exhibits 0.6°C greater warming over the past ~60 yr B.P. (1890 to 1950 CE). However, considering the temporal resolution of our data set and the small number of records that cover this interval this difference is probably not robust.”

      “Not robust” is scientific terminology meaning ‘not to be relied upon for accuracy’. The average resolution of their data is 120 years. Therefore, it simply does not show temperature variations in less than a century. There may well have been changes of 1 degC or more within a single century, but this is not shown or known. Therefore, Marcott et al in no way demonstrates current warming is unprecedented, and the paper states that itself. To claim that it does, is at best mischievous.

      A particular amusing (and sad) aspect of the pro-AGW case is to claim, like Martin that: ‘it must be CO2 because we can’t think of anything else’. As John says, this is not a meaningful argument. Noting the consensus that early 20th C warming is not explained by CO2, we are told that during the 20-yr correlation of temperature and CO2 from (about) 1979 to 2000, ‘it must be CO2 because there is no known natural cause. Meanwhile, as we now go through a hiatus of ‘no warming’, we’re told its explained by unknown natural causes.

      This is called climate science.


      1. Oakwood, thank you for your long and comprehensive reply. I’m in no position to comment, not being a climate scientist. I was rather hoping Martin would, and will.


  3. As far as policy is concerned the question is NOT “climate change”. Nor is it about feedbacks. It’s about GREENHOUSE GAS CHANGE. We went in a bit more than a century from 280 ppm to above 450 ppm. Considering that enormity, everything else is red herring, there is no doubt.


    1. A wonderfully concise observation, Patrice. Sadly, it has taken me several days to appreciate it fully. 🙂


  4. For me this sentence spoke out to me..!

    “There is no ‘fixing’ things at this point but you still have the ability to choose how you react to the predicament we have created”

    A very informative posting Paul. I dare say the arguments will long go on … We are all in uncharted waters… and it appears that what ever opinion we have what will be will be regardless… For Nature is Nature and we are but one component within its make up

    Regards to both you and Jean…


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