# The CO2 concentration graph: Guesses solicited for its future shape and consequences **URL:** \ **Category:** Great Debates\ **Created:** [August 14, 2009, 11:27am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391 "2009-08-14T11:27:28Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [August 21, 2009, 2:18am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/61 "2009-08-21T02:18:57Z")
> [@SentientMeat](#): > > (Of course, AGW skeptics are the _first_ to jump on local phenomena when they are used to demonstrate global trends!) As a relatively disinterested observer (well, until I got sucked into this placard thing…) I don’t observe this. I’m interested in human nature and why we believe things, and it is for this reason I am skeptical of AGW. What I’ve noticed as a fairly dispassionate observer of both camps is that it’s human nature to “jump on local phenomena,” and I find it equally frequent in both camps. Universal, actually. I’ll watch some special on TV that has a passing reference to AGW, for example, and the associated imagery will be some sort of tumbleweed blowing across a godforsaken desert landscape or something. I’ll see imagery of a drought but not imagery of a flood–on and on. It’s just how we are wired to think. We see confirmations and we dismiss “anomalies.” Confirmation bias is not limited to AGW deniers or supporters. I see it every day in folks from a dozen religions all confident that their God has just obviously manifested himself. I see it in the history of science, where the thinking masses clung to paradigms and gave them up only when there were too many epicycles to handle anymore. It’s obvious why we were wrong after our paradigms change, but until they do, it’s obvious to us why we are right and why our positions are obviously scientific, even with AGW. The most laughable reason I see commonly touted for believing in AGW, for instance, is an argument that most reputable scientists also believe it (or something to that effect). But it’s in our nature–even as scientists–to believe what others in our peer group believe, and if I had a nickel for every time scientists were collectively wrong, I’d get my 401k back where it belongs. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 3:13am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/62 "2009-08-21T03:13:02Z")
> [@Chief\_Pedant](#): > > Confirmation bias is not limited to AGW deniers or supporters. I see it every day in folks from a dozen religions all confident that their God has just obviously manifested himself. I see it in the history of science, where the thinking masses clung to paradigms and gave them up only when there were too many epicycles to handle anymore. It’s obvious why we were wrong after our paradigms change, but until they do, it’s obvious to us why we are right and why our positions are obviously scientific, even with AGW. You see that in the history of science? Well, you see, I have experience with history. And the history shows that it is true, but not as you expect regarding AGW. Most scientists were wrong at the beginning and in the middle of the past century. AFAICR scientists assumed that many of the objections against AGW were valid. It took years of research to demonstrate to the many that CO2 concentrations were rising, that it was mostly Human CO2; and research also showed that no, the absorption of CO2 by nature was not enough to stop the issue. Then evidence of the greenhouse effect and the water vapor feedback with CO2 convinced most scientists that we have a problem. [http://www.aip.org/history/climate/co2.htm](http://www.aip.org/history/climate/co2.htm) > [@Chief\_Pedant](#): > > The most laughable reason I see commonly touted for believing in AGW, for instance, is an argument that most reputable scientists also believe it (or something to that effect). But it’s in our nature–even as scientists–to believe what others in our peer group believe, and if I had a nickel for every time scientists were collectively wrong, I’d get my 401k back where it belongs. As mentioned, you are ignoring that history shows that indeed they were wrong, but it was when many dismissed AGW. They got better. However, just to be clear, I still think the predicted \*\*results \*\*of AGW and what to do about them still deserve discussion. ---
**Author:** ![Deeg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/deeg/32/2955_2.png) [@Deeg](https://boards.straightdope.com/u/Deeg)\ **Post date:** [August 21, 2009, 3:37am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/63 "2009-08-21T03:37:51Z")
> [@Chief\_Pedant](#): > > …if I had a nickel for every time scientists were collectively wrong, I’d get my 401k back where it belongs. It is the scientists who cling to out-dated theories (or those who refuse to believe the new ones) that are usually wrong. Has there ever been a new theory so widely accepted by scientists as AGW that was not the best theory at the time? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 4:07am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/64 "2009-08-21T04:07:19Z")
> [@SentientMeat](#): > > And you wouldn’t call this _roughly_ constant at _around_ 280ppmv? Christ … Christ. To read for comprehension you have to read in context. In the last 50, 000 years CO2 levels have fluctuated regularly and rapidly from ~250ppm to some unknown upper level. Temperature levels have also fluctuated rapidly though unpredictably. We have no idea what those upper levels are. Because of the well known smoothing effect ice core data lead a lot of people, yourself included, came to believe that CO2 levels and temperatures were comparably stable for millennia. Now that we have started to look at other proxy data, such as speleotherms, global dendrochronology and stomatal data we find that CO2 levels and temperatures were not stable, as you claim based on ice core reconstructions. Rather what we find is that temperatures varied by as much at least a factor of 2 larger than indicated by empirical reconstructions and that they do not support the widely accepted concept of comparably stable CO2 concentrations in recent past millenia. CO2 spikes \>300ppm may have been common in the past but not able to be resolved by ice core data. > [@](#): > > Just to clarify, are you suggesting that the \>300ppm concentrations of the last decades have nothing to do with humans digging up _vast_ quantities of carbon stores and burning them? I doubt that it has absolutely no effect. What I have yet to see is convincing evidence that it is significantly caused by humans. It has been well established that rises in global temperatures are always followed by a rise in CO2 levels. How close those correlations are temporally remains uncertain. However we do know that global temperatures have been rising for the past ~200 years. We would expect simply based on past performance that CO2 levels would have risen concomitant with the temperature rise. And that is precisely what we do see. And this remains one of the chief causes of uncertainty of the whole AGW hypothesis. We have a theoretical basis by which increases in CO2 levels may cause an increase in temperature, but no observational evidence that it is so. And we also have sound observational evidence that rises in temperature lead to an increase in CO2 levels, but no solid theory as to why this occurs. So we can’t say with any real certainty whether the rise in temperature is due to the increase in CO2 levels, or whether the rise in CO2 levels is due to the rise in temperature. I suspect that we both agree that it’s a little from column A and a little from column B. Most AGW patsies acknowledge that the increase in temperature must have lead to an increase in CO2 levels, as it has for every previous warming event. The only point where we really disagree is that you believe that the majority of the CO2 increase can not be attributed to temperature rise, and I remain unconvinced of that. And yes, I’m familiar with the carbon isotope work that implicates human carbon, and I’m familiar with the carbon discrimination abilities of plants and various other problems that cast doubt on such conclusions. Once again, I remain unconvinced of the level of human contribution, and once again nobody can come up with an actual falsification test for the claim. > [@](#): > > Whatever the “true” levels in the past million years, the system was clearly in _equilibrium_ in the longer term. No, it wasn’t. I already quoted several recent publications which say precisely the opposite. The more analyses that are done using proxies that don’t produce a smoothing effect the more publications we are seeing stating clearly that, far from being in _equilibrium_ in the longer term, simply do not support the concept of stable CO2 concentrations throughout the past 11,500 years. The only way I could possibly agree it was in equilibrium is if you meant that CO2 concentrations fluctuated wildly between unknown upper and lower limits that may have been much higher or lower than anything seen in the last 200 years but ultimately constrained by the pure physics of the system. If that’s; what you mean by “in equilibrium” then sure, I agree, but I don’t think that’s what you mean, is it? > [@](#): > > How are the demonstrably vast human emissions _not_ a clear departure from this natural equilibrium? Now I really don’t understand the question. What equilibrium are you actually referring to here, and in what system? If you simply mean that for along time fossil fuels were a stable carbon pool, and humans turned that into a net source, then maybe you could describe that as a form of equilibrium. But in that case I’m not sure where you are going with it. Carbon cycles, it doesn’t matter what the sources are. And in most cycles an increase in sources is counterbalanced by an increase in sinks. For example as CO2 levels in the atmosphere, more becomes dissolved in the oceans. That means that a departure from a “natural equilibrium” in the form of one stable pool becoming a flux doesn’t automatically mean that the entire system loses equilibrium. There is an unquantified amount of buffering within the system. Simplisitic arguments that “we’ve added carbon from a stable pool, so the whole system must be out of equilibrium” are simply not justifiable, and in fact provably incorrect. > [@](#): > > Well, _this_ patsy won’t - how’s that? Fancy taking the bet? What bet? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 4:18am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/65 "2009-08-21T04:18:21Z")
> [@Deeg](#): > > It is the scientists who cling to out-dated theories (or those who refuse to believe the new ones) that are usually wrong. Really? How does that work? Did the erroneous old ideas get handed down on stone tablets direct from God? Surely every single old idea had to once have been a new idea, didn’t it? For example, the idea that black people are genetically inferior could only have been postulated by scientists \*after \*the discovery of heriditary, right? So that was a new idea that was wrong. The same with the orbiting electron or “plum pudding” models of atoms, the existence of the aether and so forth. The idea that most new ideas are right and most old ideas are wrong makes absolutely no sense logically. I cant even see how such a situation could even arise. Every erroneous old idea had to have been adopted as an erroneous new idea at some point in time. > [@](#): > > Has there ever been a new theory so widely accepted by scientists as AGW that was not the best theory at the time? Sure, the idea that blacks are genetically inferior, the idea that disease was caused by humours and could be cured by bleeding, the idea that light was a wave propagated in an ether, the idea that stress caused ulcers. I could go on all day with examples of widely accepted theories that were opposed by small numbers of scientists. But frankly I’m having a hard time seeing what “best theory at the time” has to do with anything. Science is supposed to be about eliminating erroneous theories, not accepting them just because it’s the “best theory we’ve got”. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 4:38am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/66 "2009-08-21T04:38:22Z")
> [@SentientMeat](#): > > (Of course, AGW skeptics are the _first_ to jump on local phenomena when they are used to demonstrate global trends!) :rolleyes: Yeah, 'coz AGW patsies wouldn’t use a single photograph of a [”drowning” polar bear on an iceberg](http://newsbusters.org/node/11879) in summer to demonstrate global trends over century timescales? Right? And they would never use say, a [single hurricane](http://www.usatoday.com/tech/science/2005-09-01-katrina-global-warming_x.htm) as evidence of global warming trends. Right? SentientMeat this claim is just ridiculous. Lots of people on both sides make unjustifiable use of local data, but by far the worst offenders are the AGW patsies. It’s almost impossible to find a news article that reports a localised environmental event that _doesn’t_ invoke it as evidence of AGW. To claim that AGW skeptics are the _first_ to jump on local phenomena when they are used to demonstrate global trends is simply ludicrous to anybody who actually watches TV news or reads newspapers. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 4:50am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/67 "2009-08-21T04:50:37Z")
> [@SentientMeat](#): > > And **Blake** , might I enjoin you to share your vague guess as to what will happen to the CO2 graph over the next, say, two centuries, and the consequences thereof? We simply lack the data to make such predictions with enough accuracy to make it worthwhile. This is what separates actual science from psuedo-science. Scientific predictions are based on actual data and they are zble to be assigned probability levels based on solid mathemetics. Contrast that to the IPCCs “predictions” > [@](#): > > It seems like you’re willing to accept a level-off of 600+ ppmv, but unwilling to lay such a level at the door of humanity’s predeliction for burning I’m a scientist. It’s not a case of being unwilling or willing. It’s case of lacking sufficient data to attribute causation to anything. Science is dependent on having the necessary data to distinguish between competing explanations, and we don’t have it. That’s why the IPCC “predictions’” confidence levels are not based on any statistical test, but rather pulled out of the air. Science doesn’t pull confidence levels for hypotheses out of the air. If you lack the data to test your hypothesis you don’t go around stating that it’s 90% likely based on a whim. > [@](#): > > Even if, for argument’s sake, a significant proportion of the extra 1.7 ppmv of CO2 we’re measuring every year comes from natural sources (and I frankly don’t really see how that’s the case) That’s the problem. Nobody knows what causes that increase in CO2levels that always follows global warming events. Nonetheless we know that it must come from somewhere. Unfortunately this is the standard global warming patsy argument from ignorance. Just because nobody can prove it wrong you accept that it must be right. > [@](#): > > …surely it would be wise to, you know, stop _adding_ to it so much? Science can’t comment on what is wise. It can only comment on what is real. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 4:57am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/68 "2009-08-21T04:57:34Z")
> [@Blake](#): > > And yes, I’m familiar with the carbon isotope work that implicates human carbon, and I’m familiar with the carbon discrimination abilities of plants and various other problems that cast doubt on such conclusions. Once again, I remain unconvinced of the level of human contribution, and once again nobody can come up with an actual falsification test for the claim. [http://volcanoes.usgs.gov/hazards/gas/index.php](http://volcanoes.usgs.gov/hazards/gas/index.php) > [@](#): > > Comparison of CO2 emissions from volcanoes vs. human activities. > Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1999, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [( Marland, et al., 2006) - The reference gives the amount of released carbon (C), rather than CO2, through 2003.]. Human activities release more than 130 times the amount of CO2 emitted by volcanoes–the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002) [Sense from Deniers on CO2? Don’t hold your breath…](http://www.youtube.com/watch?v=WPA-8A4zf2c) ---
**Author:** ![Deeg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/deeg/32/2955_2.png) [@Deeg](https://boards.straightdope.com/u/Deeg)\ **Post date:** [August 21, 2009, 5:25am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/69 "2009-08-21T05:25:31Z")
> [@Blake](#): > > But frankly I’m having a hard time seeing what “best theory at the time” has to do with anything. Science is supposed to be about eliminating erroneous theories, not accepting them just because it’s the “best theory we’ve got”. The long arc of science is creating more accurate theories. Newtonian (i.e. “classical”) physics is the easy example; we know that Newtonian is wrong in many situations. Does that mean that classical physicists were wrong to accept it? Obviously the answer is no; at the time, once it was roundly accepted, Newtonian physics was the most accurate theory until the advent of Relativity and QM. It’s not a question of whether AGW is absolutely right or wrong–there are surely aspects of AGW that _are_ wrong that will be corrected in the future. To me the question is this: are the theories behind AGW currently the best explanation for the recent warming trend? Most scientists certainly think so. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 5:57am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/70 "2009-08-21T05:57:17Z")
> [@Deeg](#): > > The long arc of science is creating more accurate theories. Only where one theory is adopted _over_ a previous one. Clearly this does not apply to AGW which is the first theory adopted. In cases where science creates a theory to explain something previously totally unexplained its track record is very poor, especially where basic falsifiability is not or can not be applied, Freudian psychology being the textbook example, but the ether theory, Black inferiority and similar other examples are also numerous. Where an existing entrenched theory is replaced by a later theory the latter is usually correct. Where a theory becomes entrenched simply because it’s “the best we’ve got and explains what we think we see” it is usually wrong. > [@](#): > > To me the question is this: are the theories behind AGW currently the best explanation for the recent warming trend? Most scientists certainly think so. Most scientists thought that the continents were fixed, that stress caused ulcers and that disease was caused by miasma and could be cured by bleeding. That’s why science doesn’t work by consensus. An dthtais why in real science the question is _never_ “how many agree with me”. The real questions are “How can I falsify this” and “What is the probability that the results of that falsification attempt have another explanation that I’m not seeing?” Unfortunately for AGW the answer to those questions are “I can’t” and “I can never know”. I have no idea why GIGObuster quoted me and then posted non sequitur links to some apparently random web pages from AGW patsies. Totally mystifying. But not worth pursuing. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 6:04am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/71 "2009-08-21T06:04:40Z")
> [@Blake](#): > > Only where one theory is adopted _over_ a previous one. Clearly this does not apply to AGW which is the first theory adopted. No, history clearly shows the theory was not adopted early. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 6:13am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/72 "2009-08-21T06:13:57Z")
> [@Blake](#): > > Only where one theory is adopted _over_ a previous one. Clearly this does not apply to AGW which is the first theory adopted. No, history clearly shows that the theory was not adopted early. [http://www.aip.org/history/climate/co2.htm](http://www.aip.org/history/climate/co2.htm) > [@](#): > > Even if people had recognized this was untrue, there were other well-known reasons to deny any greenhouse effect in the foreseeable future. These reasons reflected a nearly universal conviction that the Earth automatically regulated itself in a “balance of nature.” Getting to specifics, scientists repeated the plausible argument that the oceans would absorb any excess gases that came into the atmosphere. Fifty times more carbon is dissolved in sea water than in the wispy atmosphere. Thus the oceans would determine the equilibrium concentration of CO2, and it would not easily stray from the present numbers. > > If somehow the oceans failed to stabilize the system, organic matter was another good candidate for providing what one scientist called “homeostatic regulation.”(12) The amount of carbon in the atmosphere is only a small fraction of what is bound up not only in the oceans but also in trees, peat bogs, and so forth. Just as sea water would absorb more gas if the concentration increased, so would plants grow more lushly in air that was “fertilized” with extra carbon dioxide. Rough calculations seemed to confirm the comfortable belief that biological systems would stabilize the atmosphere by absorbing any surplus. One way or another, then, whatever gases humanity added to the atmosphere would be absorbed — if not at once, then within a century or so — and the equilibrium would automatically restore itself. As one respected expert put it baldly in 1948, “The self-regulating mechanisms of the carbon cycle can cope with the present influx of carbon of fossil origin.”(13) > Yet the theory that atmospheric CO2 variations could change the climate was never altogether forgotten. An idea so simple on the face of it, an idea advanced (however briefly) by outstanding figures like Arrhenius and Chamberlin, had to be mentioned in textbooks and review articles if only to refute it. Arrhenius’s outmoded hypothesis persisted in a ghostly afterlife. > It found a lone advocate. Around 1938 an English engineer, Guy Stewart Callendar, took up the old idea. An expert on steam technology, Callendar apparently took up meteorology as a hobby to fill his spare time.(14) Many people, looking at weather stories from the past, had been saying that a warming trend was underway. When Callendar compiled measurements of temperatures from the 19th century on, he found they were right. He went on to dig up and evaluate old measurements of atmospheric CO2 concentrations. He concluded that over the past hundred years the concentration of the gas had increased by about 10%. This rise, Callendar asserted , could explain the observed warming. For he understood (perhaps from Hulburt’s calculation) that even if the CO2 in the atmosphere did already absorb all the heat radiation passing through, adding more gas would change the height in the atmosphere where the absorption took place. That, he calculated, would make for warming. > > As for the future, Callendar estimated, on flimsy grounds, that a doubling of CO2 could gradually bring a 2°C rise in future centuries. He hinted that it might even trigger a shift to a self-sustaining warmer climate (which did not strike him as a bad prospect).(15) But future warming was a side issue for Callendar. Like all his predecessors, he was mainly interested in solving the mystery of the ice ages. > > Callendar’s publications attracted some attention, and climatology textbooks of the 1940s and 1950s routinely included a brief reference to his studies. But most meteorologists gave Callendar’s idea scant credence. In the first place, they doubted that CO2 had increased at all in the atmosphere. The old data were untrustworthy, for measurements could vary with every change of wind that brought emissions from some factory or forest.Already in the nineteenth century scientists had observed that the level of the gas rose, for example, near a flock of sheep busy exhaling the gas, and dropped in London during the inactivity of a bank holiday.(16) If in fact CO2 was rising, that could only be detected by a meticulous program stretching decades into the future.(17\*) The objections that had been raised against Arrhenius also had to be faced. Wouldn’t the immense volume of the oceans absorb all the extra CO2? Callendar countered that the thin layer of ocean surface waters would quickly saturate, and it would take thousands of years for the rest of the oceans to turn over and be fully exposed to the air.(18) But nobody knew the actual turnover rate, and it seemed that the oceans would have time to handle any extra gases. According to a well-known estimate published in 1924, even without ocean absorption it would take 500 years for fuel combustion to double the amount of CO2 in the atmosphere.(19) > > G.S. Callendar, little-known pioneer. > There was also the old objection, which most scientists continued to find decisive, that the overlapping absorption bands of CO2 and water vapor already blocked all the radiation that those molecules were capable of blocking. Callendar tried to explain that the laboratory spectral measurements were woefully incomplete.(20) Gathering scattered observational data, he argued that there were parts of the spectrum where the CO2 bands did not overlap others. Some scientists found this convincing, or at least kept an open mind on the question. But it remained the standard view that, as an official U.S. Weather Bureau publication put it, the masking of CO2 absorption by water vapor was a “fatal blow” to the CO2 theory. Therefore, said this authority, “no probable increase in atmospheric CO2 could materially affect” the balance of radiation.(21) > > Most damaging of all, Callendar’s calculations of the greenhouse effect temperature rise ignored much of the real world’s physics. For example, as one critic pointed out immediately, he only calculated how heat would be shuttled through the atmosphere by radiation, ignoring the crucial energy transport by convection as heated air rose from the surface (this deficiency would haunt greenhouse calculations through the next quarter-century). Worse, any rise in temperature would allow the air to hold more moisture, which would probably mean more clouds. Callendar admitted that the actual climate change would depend on interactions involving changes of cloud cover and other processes that no scientist of the time could reliably calculate. Few thought it worthwhile to speculate about such dubious questions, where data were rudimentary and theory was no more than hand-waving. Better to rest with the widespread conviction that the atmosphere was a stable, automatically self-regulated system. The notion that humanity could permanently change global climate was implausible on the face of it, hardly worth a scientist’s attention.(22) > > The scientists who brushed aside Callendar’s claims were reasoning well enough. (Subsequent work has shown that the temperature rise up to 1940 was, as his critics thought, mainly caused by some kind of natural cyclical effect, not by the still relatively low CO2 emissions. And the physics of radiation and climate was indeed too poorly known at that time to show whether adding more gas could make much difference.) Yet if Callendar was mistaken when he insisted he could prove global warming had arrived, it was a fortunate mistake. > Research by definition is done at the frontier of ignorance. Like nearly everyone described in these essays, Callendar had to use intuition as well as logic to draw any conclusions at all from the murky data and theories at his disposal. Like nearly everyone, he argued for conclusions that mingled the true with the false, leaving it to later workers to peel away the bad parts. While he could not prove that global warming was underway, he had given reasons to reconsider the question. We owe much to Callendar’s courage. His claims rescued the idea of global warming from obscurity and thrust it into the marketplace of scientific ideas. Not everyone dismissed his claims. Their very uncertainty attracted scientific curiosity. > > The Speculations Vindicated (1950-1960) TOP OF PAGE > The complacent view that CO2 from human activity could never become a problem was overturned during the 1950s by a series of costly observations. This was a consequence of the Second World War and the Cold War, which brought a new urgency to many fields of research. American scientists enjoyed massively increased government funding, notably from military agencies. The officials were not aiming to answer academic questions about future climates, but to provide for pressing military needs. Almost anything that happened in the atmosphere and oceans could be important for national security. Among the first products were new data for the absorption of infrared radiation, a topic of more interest to weapons engineers than meteorologists.(23) > > The early experiments that sent radiation through gases in a tube, measuring bands of the spectrum at sea-level pressure and temperature, had been misleading. The bands seen at sea level were actually made up of overlapping spectral lines, which in the primitive early instruments had been smeared out into broad bands. Improved physics theory and precise laboratory measurements in the 1940s and after encouraged a new way of looking at the absorption. Scientists were especially struck to find that at low pressure and temperature, each band resolved into a cluster of sharply defined lines, like a picket fence, with gaps between the lines where radiation would get through.(24) The most important CO2 absorption lines did not lie exactly on top of water vapor lines. Instead of two overlapping bands, there were two sets of narrow lines with spaces for radiation to slip through. So even if water vapor in the lower layers of the atmosphere did entirely block any radiation that could have been absorbed by CO2, that would not keep the gas from making a difference in the rarified and frigid upper layers. Those layers held very little water vapor anyway. And scientists were coming to see that you couldn’t just calculate absorption for radiation passing through the atmosphere as a whole, you had to understand what happened in each layer — which was far harder to calculate. > > Digital computers were now at hand for such calculations. The theoretical physicist Lewis D. Kaplan decided it was worth taking somhttp://boards.straightdope.com/sdmb/showthread.php?p=11468361&posted=1#e time away from what seemed like more important matters to grind through extensive numerical computations. In 1952, he showed that in the upper atmosphere, adding more CO2 must change the balance of radiation significantly.(25) And really, just there one can see several examples (Yep, the theory was tested) were evidence would had buried the theory if it was a false one. People like Callendar would had remained in obscurity. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 6:20am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/73 "2009-08-21T06:20:06Z")
> [@Blake](#): > > I have no idea why GIGObuster quoted me and then posted non sequitur links to some apparently random web pages from AGW patsies. > Totally mystifying. But not worth pursuing. It was your: “I remain unconvinced of the level of human contribution” The quote shows that the USGS and their scientists are convinced. Of course if you insist that they are “patsies” then I think that anyone reading the thread would conclude that you are not being serious at all. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 7:53am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/74 "2009-08-21T07:53:14Z")
Yawn, lots of non-sequitur links to patsy websites. No actual argument. When come back, bring debate. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 7:57am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/75 "2009-08-21T07:57:04Z")
> [@Blake](#): > > Yawn, lots of non-sequitur links to patsy websites. No actual argument. > > When come back, bring debate. Translation: I do not want to deal with cites from scientists. I guess you think everybody else will ignore that you claim to be a scientist. And it seems that you are not taking back the howler of calling the USGS scientists “patsies”. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [August 21, 2009, 8:17am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/76 "2009-08-21T08:17:37Z")
BTW, the author of The Discovery of Global Warming, Spencer Weart > [@](#): > > originally trained as a physicist, is a noted historian specializing in the history of modern physics and geophysics. Until his retirement in 2009 he was Director of the Center for History of Physics of the American Institute of Physics (AIP) in College Park, Maryland, USA, and he continues to be affiliated with the Center. A patsy is a person who is easily manipulated or victimized. History shows that many scientists had good evidence (for the day) that showed that AGW was not going to be an issue. They really had no patience (that tough crowd is not easy to manipulate!) for the early AGW proponents that had little evidence. But thanks to the cold war evidence was found that \*\*started \*\*to convince most scientists about the problem. Nowadays even more evidence to support and confirm AWG is here. ---
**Author:** ![SentientMeat](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@SentientMeat](https://boards.straightdope.com/u/SentientMeat)\ **Post date:** [August 21, 2009, 9:35am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/77 "2009-08-21T09:35:44Z")
> [@intention](#): > > if we were able to magically freeze the level of added CO2 to the current level (we currently add about 7 gigatonnes of C to the atmosphere annually), the atmospheric level would not continue to rise indefinitely. As more is added, more is sequestered annually, and at some point they become equal. At that point, airborne CO2 levels out. If that is true, why is the CO2 concentration _rising_? If more was sequestered as more was added, the concentration would remain _constant_. We are, surely, _depleting the sequestered stores_ at a much faster rate than new stores can form? > [@](#): > > The problem is predicting emissions, and I know of no way to do that. It is surely common sense that until we replace high-emission power stations, transport, construction methods and whatnot with low-emission counterparts, the emissions will either remain the same or increase, given China & India’s emission growth? (Of course, if high CO2 concentrations won’t have any significant consequences anyway, we needn’t bother.) > [@](#): > > if we maintain emissions at the current levels we’d eventually burn all the carbon stores … but the level would never come close to 800 ppmv. Even if we depleted sequestered stores at a much faster rate than was being sequestered? I simply don’t see what _mechanism_ causes a level-off below 800 ppmv if carry on as we are, since all the natural sequestration mechanisms I know of simply don’t work _fast enough_: the number of trees is _shrinking_, not growing, for example. That leaves only phytoplankton - are you suggesting that they will start to convert massively more CO2 to make their coccoliths or something? (This would presumably require you to deny increased ocean acidity as well, yes?) > [@](#): > > My guess of the consequences, regardless of the level of probable change, is that they will be minimal. Just to be clear here - you believe that the Greenhouse Effect _itself_ is largely nonexistent? That if we magically removed pretty much all the CO2 from the atmosphere, the temperature still wouldn’t change? (You _do_ accept that CO2 absorbs infra-red wavelengths, right?) > [@Blake](#): > > I doubt that it has absolutely no effect. What I have yet to see is convincing evidence that it is significantly caused by humans. Where do you think the Gigatons of hydrocarbons we burn every year _go_, exactly? Think - in the Carboniferous period, vast amounts of CO2 became locked into safely buried solid or liquid stores. Do you think we’ve only dug up and burned an insignificantly tiny percentage of these stores so far? > [@](#): > > If that’s; what you mean by “in equilibrium” then sure, I agree, but I don’t think that’s what you mean, is it? I mean that there was no natural mechanism whereby safely sequestered stores of carbon were released at a rate of Gigatons per year, for decades or centuries. > [@](#): > > If you simply mean that for along time fossil fuels were a stable carbon pool, and humans turned that into a net source, then maybe you could describe that as a form of equilibrium. But in that case I’m not sure where you are going with it. Carbon cycles, it doesn’t matter what the sources are. And in most cycles an increase in sources is counterbalanced by an increase in sinks. Then why is the CO2 concentration _increasing_ at 1.7+ ppmv per year? When will these increased sinks kick in and level the graph out? > [@](#): > > For example as CO2 levels in the atmosphere, more becomes dissolved in the oceans. Thus making the ocean more acidic, and phytoplankton _less_ efficient at converting CO2 into coccoliths, yes? > [@](#): > > What bet? See OP, bottom line. > [@](#): > > To claim that AGW skeptics are the first to jump on local phenomena when they are used to demonstrate global trends is simply ludicrous to anybody who actually watches TV news or reads newspapers. Well, tomato, tomahto. **billfish** asked about a local measurement, I said careful - deliberately misdirecting a debate away from global trends is a common Denier tactic. But yes, silly arguments based on local phenomena are forwarded by _both_ sides. > [@](#): > > We simply lack the data to make such [CO2 graph] predictions with enough accuracy to make it worthwhile…Unfortunately this is the standard global warming patsy argument from ignorance. Just because nobody can prove it wrong you accept that it must be right. But what I’m asking you, and **intention** to do, is convince me that it’s entirely possible that the graph _won’t_ continue it’s upward trend until it reaches 600, 700, 800 ppmv or more, because I just _cannot_ see what natural mechanism will deliver us from this given the Gigatons we demonstably add each year. Because you know what? I **want you to be right**. I truly _want_ to believe that either [ul]the CO2 concentration is rising almost entirely naturally, or [li]some natural carbon-sequestering mechanism will kick in cause a level off of 500 ppmv or less, or [/li][li] 500+ ppmv concentrations won’t have significant consequences any old how.[/ul][/li]My current beliefs are that: [ul] [li]CO2 absorbs infra-red wavelengths, such that a world without it would be much colder. [/li][li]We are currently releasing Gigatons of the stuff per year from stores that took millions of years to form in the first place. [/li][li]If the graph keeps its line, the concentration will have _doubled_ in less than two centuries. [/ul][/li]I simply don’t understand how there can be no _cause for concern_, given the uncertainties. I wonder how I’ll ever explain myself to my grandchildren if hindsight shows that _was_ something we could have done, but didn’t, because we wanted to believe everything would be OK. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 21, 2009, 11:03am UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/78 "2009-08-21T11:03:21Z")
> [@SentientMeat](#): > > Where do you think the Gigatons of hydrocarbons we burn every year _go_, exactly? We don’t know, but you’re starting to ask the important questions, and that’s good. There’s a lot we don’t know about the global climate and global carbon cycling. We don’t know where the gigatonnes of carbon that produced the CO2 peaks following every previous warming event came from. And we don’t know where those gigatonnes of carbon went to. And we don’t know where the gigatonnes of carbon that produce the several \>300ppm CO2 peaks in the last millennium came from. And we don’t know where those gigatonnes of carbon went to. Past atmospheric carbon fluxes have been comparable to the current one insofar as they involved short duration CO2 increases of 60ppm. This means there must have been comparable amounts of carbon added to the atmosphere, and comparable amounts removed within those short (century scale) durations. Yet at the same time you want to deny that any mechanism can exist that can remove gigatonnes of carbon from the atmosphere. And that, my friend, makes no sense. We know the atmosphere can and does shuffle gigatonnes of carbon in century timescales. We don’t have a clue what the fluxes and pools actually are, but we know they must exist. To say that I should know where these fluxes are occurring now is simply shifting the burden of proof. > [@](#): > > Do you think we’ve only dug up and burned an insignificantly tiny percentage of these stores so far? This seems like a red herring If your hypothesis is correct then we have dug up precisely enough to raise CO2 levels ~50ppm within a century. This can’t be more than the amount needed to produce the ~60ppm changes seen in the past millennium. And we know that this amount of carbon can be removed from the atmosphere on a century timescale. Whether this amount is 99% or 1% of geological carbon reserves irrelevant. A total red herring. > [@](#): > > I mean that there was no natural mechanism whereby safely sequestered stores of carbon were released at a rate of Gigatons per year, for decades or centuries. How do you know this. We know that gigatons per year were added to the atmosphere for decades or centuries because the atmospheric CO2 concentrations changed at rates of 60ppm per century. And we know that those concentrations were returned to ~300ppm within a century. We have no idea where all that carbon came from, but it’s a pretty safe bet that it involved safely sequestered stores of carbon. > [@](#): > > Then why is the CO2 concentration _increasing_ at 1.7+ ppmv per year? When will these increased sinks kick in and level the graph out? Why has the same thing happen numerous times in recent geological history, including several shifts, up to 60ppm, in the past millenium? “All available records indicate a significant variability of atmospheric CO2 levels throughout the Holocene, showing repeated short-lived CO2 shifts of 20–40 ppmv, independently reproduced in the different studies… Moreover, available CO2 reconstructions covering the past millennium reveal a CO2 shift of approximately 30 ppmv …. The most recent reconstruction of a shift as high as 60 ppmv, shows a highly comparable temporal pattern” van HOOF et al 2005 “Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis” Tellus (2005), 57B “Alternating CO2 maxima of 300–320 ppmv are present at A.D. 1000, A.D. 1300, and ca. A.D. 1700.” Kouwenberg et al “Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis of Tsuga heterophylla needles” Geology 2005, 33 We simply don’t know what drove these rapid shifts in atmospheric CO2 levels, except that they seem to be caused by an increase in temperature, or at least they followed increase sin temperature. We don’t know why increased sinks kicked in and levelled the graphs out, we don’t; even know what the sources and sinks were. But that’s good science for you. We admit that there’s a lot we don’t know. We don’t; just go out and declare that something is doesn’t happen because we can’t explain it. > [@](#): > > Thus making the ocean more acidic, and phytoplankton _less_ efficient at converting CO2 into coccoliths, yes? Are you denying that the oceans act as a buffer against atmospheric CO2 changes? Because that was the only contention I made, and I think I can declare that 100% of geologists agree with me. > [@](#): > > See OP, bottom line. Oh is that all. My position, like most skeptics, is that we lack sufficient information to know what is going to happen because we have no working hypothesis that makes sensible predictions. So no, of course I won’t take the bet. It’s like asking me to bet on a horse race where I know nothing of the entrants or the track. It’s just a random chance bet. I’d be better off betting on a con toss. > [@](#): > > I said careful - deliberately misdirecting a debate away from global trends is a common Denier tactic. No, you didn’t. You said that use of local phenomena to demonstrate global trends was used by skeptics. Nothing about careful or misdirection of debate. And you said it was it was used “jumped” on “first” (ie more eagerly) by skeptics. But since you seem to conclude that is clearly not true, and that it is AGW patsies that jump on such tactics first we can leave it there. > [@](#): > > But what I’m asking you, and **intention** to do, is convince me that it’s entirely possible that the graph _won’t_ continue it’s upward trend until it reaches 600, 700, 800 ppmv or more, because I just _cannot_ see what natural mechanism will deliver us from this given the Gigatons we demonstably add each year. Can you explain what natural mechanism delivered us from the Gigatons that were demonstrably added add each year to produce the century scale 30-60 ppm shifts seen in past centuries? If not then I’m really not sure what I can do to convince you. Contrary to your claims in the OP that CO2 levels “stayed roughly constant at 280 ppmv for millennia, we know that isn’t true. It’s entirely an artifact of ice core smoothing. We know that in fact CO2 levels have always varied by \>30ppm on century timescales. How much they varied we really don’t know because even the stomatal data start to flatten out at really high levels. Certainly higher than 320ppm I’ve seen spelotherm data suggesting peaks higher than 400ppm. So what I’m asking you is what evidence I could collect that would convince you that this isn’t just another one of those short term CO2 increases? IOW what evidence could I show you to convince you it is entirely natural, just another CO2 spike caused by rapidly rising temperatures since the little ice age, the same as occurred after every other rapid temperature spike? This is really the heart of the problem. You are already convinced that the event is totally unprecendented and caused by humanity, and thus will need some unprecendented mechanism to turn it around. I’m not convinced it isn’t as natural as the dozens of similar events in the last half million years. And because of that I’m assuming the same natural events will turn it around. > [@](#): > > Because you know what? I want you to be right. And I want me to be wrong. Because if I’m right we will have the gravest difficulties using science to guide public policy for the next generation, at least. And that will be a true disaster. > [@](#): > > I simply don’t understand how there can be no _cause for concern_, given the uncertainties. I don’t think anyone saying there’s no cause for concern. It’s a case of proportionality. There’s cause for concern when someone walks down your street. He could be a homicidal axe wielding maniac. The probability is non zero. That doesn’t justify running out and blowing his head off. Our response has to be proportional to the level of concern, and that level of concern should be based upon the evidence of risk, not on the level of alarm. If the risk is low you watch him to see if his future behaviour invokes more concern. And that’s what I’m advocating here. Watch and collect evidence until we can quantify the risk to something better then “highly likely” based upon board consensus. I’m not dismissing the potential threat of AGW. It’s just that I’m reaching an age where I’ve seen these threats come and go so many times before in the form of overpopulation and male sterility and pesticide poisoning and new ice ages that I’m cautious. > [@](#): > > I wonder how I’ll ever explain myself to my grandchildren if hindsight shows that _was_ something we could have done, but didn’t, because we wanted to believe everything would be OK. How will you explain it to your grandchildren if hindsight shows that that man in the street _was_ a homicidal axe wielding maniac and there _was_ something you could have done, but didn’t, because we wanted to believe everything would be OK. D he then murders there mother. Better run out and blow his head off right now, just to be sure, huh? Needless to say you can’t live your life that way, and the “won’t somebody think of the children” trope is so lame that I can’t believe you invoked it. Being cautious sometimes leads us to miss an opportunity to act. An impulsive rush to commit irreversible acts without all the facts almost always leads to disaster. And if your children don’t understand that then you will have trouble explaining a lot of things to them. ---
**Author:** ![SentientMeat](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@SentientMeat](https://boards.straightdope.com/u/SentientMeat)\ **Post date:** [August 21, 2009, 12:13pm UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/79 "2009-08-21T12:13:27Z")
> [@Blake](#): > > We don’t know, but you’re starting to ask the important questions, and that’s good. But we _do_ know where the Gigatons of carbon we burn every year go. _Into the atmosphere_. > [@](#): > > Whether this amount is 99% or 1% of geological carbon reserves irrelevant. But if it _is_ a significant proportion of the carbon stores that had been sitting there for millions of years, and there is no quick way to recreate _those_ stores, that _would_ constitute a strong force _off_ natural equilibrium, yes? > [@](#): > > How do you know this? Because those self same stores were _sitting there for us to find_, and had been for hundreds of millions of years. > [@](#): > > We simply don’t know what drove these rapid shifts in atmospheric CO2 levels, except that they seem to be caused by an increase in temperature, or at least they followed increase sin temperature. But the CO2 increase is _leading_ not _lagging_ now, is it not? > [@](#): > > No, you didn’t. [Did too](http://boards.straightdope.com/sdmb/showpost.php?p=11464509&postcount=42) > [@](#): > > Can you explain what natural mechanism delivered us from the Gigatons that were demonstrably added add each year to produce the century scale 30-60 ppm shifts seen in past centuries? I would guess forest growth and phytoplankton shell-formation, for the most part. So henceforth, if huge new forests _didn’t_ grow, or phytoplankton _didn’t_ dramatically ramp up their performance in this respect, I would wonder where this other mysterious saviour you speak of was going to come from, and pray for it to hurry up since I do not share your confidence/faith in its Coming. > [@](#): > > So what I’m asking you is what evidence I could collect that would convince you that this isn’t just another one of those short term CO2 increases? Rapid planet-wide fossil fuel-store formation would set my mind at rest nicely, thanks. > [@](#): > > And I want me to be wrong. _What??_ You _want_ the negative impacts predicted by AGW-accepters? That is quite despicable misanthropy, is it not? > [@](#): > > And that’s what I’m advocating here. Watch and collect evidence until we can quantify the risk to something better then “highly likely” based upon [broad] consensus. But your fence-sitting position seems to be immoveable by evidence, since you can always explain record temperatures and CO2 concentrations by shrugging your shoulders and saying “Ah, but it might all be _natural_”. “Highly likely” is often as good as it gets in science, as you well know. I simply don’t see how you can’t consider it _highly likely_ that human activities have contributed significantly, if not overwhelmingly, to the CO2 increase since the Industrial Revolution. Same Facts, Different Views? > [@](#): > > Better run out and blow his head off right now, just to be sure, huh? If he’s made of straw, that’s probably a good idea. > [@](#): > > An impulsive rush to commit irreversible acts without all the facts almost always leads to disaster. And the _irreversible_ acts AGW-accepters propose are … ? Surely, if temperatures and/or CO2 drop due to some natural Saviour, we can just return to belching out the Gigatons? ---
**Author:** ![SentientMeat](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@SentientMeat](https://boards.straightdope.com/u/SentientMeat)\ **Post date:** [August 21, 2009, 12:40pm UTC](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391/80 "2009-08-21T12:40:15Z")
And an interesting claim is found [here](http://www.realclimate.org/index.php/archives/2004/12/how-do-we-know-that-recent-cosub2sub-increases-are-due-to-human-activities-updated/): \*Careful accounting of the amount of fossil fuel that has been extracted and combusted, and how much land clearing has occurred, shows that we have produced far more CO2 than now remains in the atmosphere. The roughly 500 billion metric tons of carbon we have produced is **enough to have raised the atmospheric concentration of CO2 to nearly 500 ppm**. \* Unless the accountants are so grossly mistaken as to be outight liars, the probability that human activities contribute little to the current CO2 concentration would appear to be nil. [Previous page](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391.md?page=3) [Next page](https://boards.straightdope.com/t/the-co2-concentration-graph-guesses-solicited-for-its-future-shape-and-consequences/506391.md?page=5)