Alex Cockburn, who has long been a low-key denier of the human contribution to climate chaos, has decided to take his contrarianism on this issue loud and proud. Because Alex is a bit too prominent to simply ignore, George Monbiot takes a few minutes from his busy schedule to tear the piece into little tiny shreds.
It takes Monbiot only a few sentences to point out that all the arguments Cockburn makes are well known and widely discredited, and that Alex uses zero references. Cockburn's sole source seems to be a guy he met on a Nation cruise. Alex is not only taking a highly destructive position, he is doing so without bothering to do his homework. Monbiot goes on to quote Cockburn himself on the nature of crank arguments. I recommend reading Monbiot's refutation, even if you are familiar enough with the debate to spot all Cockburn's scientific mistakes unaided. Because Monbiot illustrates here how, if circumstances force you, to deal with an opponent who makes an argument totally unworthy of any respect.
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randino Posted 11:29 pm
03 May 2007
But no one should lose any sleep over him doubting global warming. He is a classic loose cannon. He loves trashing the left and other progressive causes, just a little more than he does the conservatives and reactionaires.
There are plenty of other people who you should worry about much more than Alex. Alex is Alex; love him and hate him. However if there is a smack down between him and Monbiot let me know. I will get on my old World Wrestling Federation t shirt, and be in front row. THAT would be a show.
Randy Cunningham
Randy Cunningham
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chogan Posted 10:41 am
04 May 2007
I read Counterpunch for the mideast coverage and (until now) made a small annual donation to keep it going. I exchanged email about this article with Cockburn and (oddly, the wife of) his "expert". For my trouble I was literally called ignorant, arrogant, closed-minded, and foolish.
Since it is not at all clear from the article what their argument actually is, I thought I might let you know what I found out. It's pretty daft.
Putting aside the simple errors of fact (ie, models ignore water vapor), the article opens up like this.
At the pit of the Great Depression, they estimated that manmade carbon emissions fell by roughly 0.3 gigatons per year below pre-depression levels, or roughly 30% of 1929 levels. So far so good. The decline they posit there is right in line with economic statistics of the period. But the next part baffled me: their assertion was that because the level (and I mean, the level) of C02 did not decline significantly, that proved that the buildup of carbon in the atmosphere must be caused by natural sources, and man plays no role in it.
At first, I thought the were simply confused about the difference between levels and rates of change, and said that for a 30% decline, you ought to have seen a slowdown in the growth rate of C02 PPM, but not a large decline. Surely that's what they meant to say -- a measureable slowdown in growth was not apparent to them. (And I also said that you probably wouldn't be able to distinguish that from background variation in the growth rate.)
Now, I said what I said based on a quick back-of-the-envelope calculation, which I believe was correct. That 0.3 gt reduction in carbon emissions was not going to generate a more-than-2-ppm change in atmospheric C02, as they posited it must. I didn't have anything like an estimate of net carbon sequestration rates during the Great Depression in front of me. Does that exist, and if so, can anybody point me toward it?
At any rate, I got back a response that left me stunned. No, they meant that the C02 level should have fallen, and should have fallen quite a bit. Their reasoning appeared to be a simple analogy: well, if you can see the C02 level drop by 5 ppm every year due to annual cycle of photosynthesis, then of course a whopping 30% drop in manmade C02 should be clearly visible. In other words, if you can see worldwide photosynthesis in the data, you must be able to see this 0.3 gt drop in manmade C02 release.
So I (reasonably) politely noted that the basic process for photosynthesis involves something on the order of 100 gigatons (gt) of carbon to start with (not that the net effect is that, and only a part of that is Northern Hemisphere, but that that's the scale of the underlying process) versus the 0.3 gt drop in manmade carbon, a reduction in a carbon source. So my response to them was that if you believe this ought to scale like the impact of norther hemisphere photosynthesis, then basically you've just said that you're unlikely to see any impact. The basic processes are three orders of magnitude different in scale. If that really is your thinking, then the process is just too small to make a big dip in the C02 level.
I mean, that's now how I'd go about reckoning it, but if that's the argument, then that's the argument.
OK, well, that didn't phase them.
The next answer was this: carbon only stays in the atmosphere five years, not the long lifetime that you posit, so of course we'll see an effect. As for where they got that 5 year figure and what they meant by it, I was given a reference to an obscure on-line journal of combustion engineering. The paper was an intense, math-filled, jargon-filled piece of mixed analytical modelling and numerical analysis, to create a model of atmospheric heating. I don't do this for a living, but hey, I was a math major, I got through it. But the punch line is, the five year figure was based on two numbers pulled out of two references: one said total atmospheric carbon is about 750 gt, the other said total earth/sea annual uptake was about 150 gt (both roughly true, I believe), so, like, divide one by the other and get 5, which is how long carbon lasts in the atmosphere.
No kidding. Putting aside the fact that the whole concept is not right as any measure of how long a pulse of extra carbon is likely to persist in the atmosphere, I pointed out that the 150 gt was the GROSS carbon uptake, which is offset by (roughly) 145 gt of carbon that goes back into the atmosphere from land/sea sources. Leaving a net of, these days, about 5 gt. I've heard other, smarter people say that yes, the "mean residence time" can be measured at (say) 3 years, but at lot of that is for very transient carbon capture, like diffusing into and out of the ocean's surface. That small number has no bearing on trying to figure out the lag between a change in manmade carbon emission and a change in C02 levels.
Anyway, I never could put all the pieces of their story together into any logical whole. Apparently, another critical piece is that the oceans are rapidly offgassing C02, and that's where the rise in atmospheric C02 comes from. At any rate, as near as I could figure, a) they thought the 0.3 gt decline in manmade output was on the same scale as photosynthesis in North America, b) somehow (I'm not sure I got this right) they thought that carbon releases into the atmosphere disappear completely after five years - no half-life, no long tail, just phht and it's gone, and c) (I'm not sure where this fits) oceans are large net carbon sources ("like the fizz in soda water") that are rapidly offgassing large amounts of C02, and that's whats driving the rise in atmospheric C02. (I did mention that direct measure seems to indicate that oceans are actually absoring carbon, but that was immediately dismissed, and I don't know the level of uncertainty there anyways.)
So, dummy that I was, I actually put in the time to understand what they were trying to say, thinking there might be something there that I just didn't get. Once I figured out what they were positing, he only thing that required hard work was the mean residence time of carbon in the atmosphere (in the sense of half-life of pulse of additional carbon), because it seems that a) it's a fundamentally slippery concept because observed data reflect an amalgam of a large variety of processes, b) people use the same terminology to describe wildly different things (do you mean half-life of additional carbon injected into the atmosphere, do you mean time until the average C02 molecule leaves the air, no matter how temporarily, etc,) and also c) it looks like there is legitimate variation in the estimates of that, even once you've pinned down what "that" is.
Being an amateur at this, I looked at the information available, and decided that the decline of the '62-'63 H-bomb test C14 looked to give me the cleanest simple estimate of how rapidly excess carbon is cleared from the atmosphere. At least I understood it: just one pulse, and then a nice smooth decay. That event gives a roughly 11 year halflife for a pulse of carbon into the atmosphere. I'm sure there could reasonably be disagreement about that's the number to use, but it worked for me. When I took the annual percent reduction implied by that (around 3%/year), and multiplied that by the current excess carbon in the atmosphere (current amount less amount present prior to the industrial revolution, which I assmed represented the total size of the disequilibrium amount of carbon in the atmosphere), the result was about 5 gt of carbon -- which matches the net amount that is estimated to be absorbed by land/sea sinks each year. I'm sure those of you who know this subject well will laugh, but it worked for me. At that point, I had reconciled everything I needed to and gave up trying to talk sense to them.
So, be assured that you don't have to dismiss them just because the ignore the data, compare to none of the experts, rely soley on the work of one engineer who (as far as I could tell, though his wife insists otherwise) has never published anything on this topic. Rest assured that in addition, their underlying model, such as it was, makes no sense whatsoever, and that they did not appear to be aware of even the most basic data and concepts in this area.
So of course, the article has been picked up by lots and lots of junk news sources. But that's the way it is. After the initial insults, I never heard back from Cockburn. (I must confess that my first email was a tad abrasive.) I ended as civilly as a could with (the wife of) his expert.
What I really learned is that I'll never never do that again. What a waste of time. Even when the (wife of) the expert said things that directly contridicted the article (she knew full well that current climate models include the effect of water vapor), I never got any acknowledgement that any aspect of the article was incorrect. To the contrary, she was pleased that her husband's work had finally gotten the publication that it deserved, obvious errors and all. An on that happy note, I let it drop.
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