While the official number for June 2008 global temperature anomaly from UAH is not out yet, Steve McIntyre at Climate Audit reports it to be -0.114 for the global number.
Click for a larger image
A number of commenters there are puzzled as to how Steve might have this “inside information” when it has not yet been published. Normally you’d find that data here
Steve left a clue in comments at CA when Lucia asked:
Did you get Roy Spencer to email you the data? I cleared cache and I don’t see June.
Steve: No.
Knowing Steve, I’m guessing he wrote a script to scrape data from this page http://discover.itsc.uah.edu/amsutemps/ (or a page like it) and then calculated the June global UAH numbers from it. Steve McIntyre is careful and cautious about such things, so I would trust his number even though UAH has not officially released it yet.
Congratulations to Steve on getting the “scoop”!
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Ophiuchus (14:46:13) :
“The anthropogenic increment in CO2 prior to 1950 was small, so we would back-project that its contribution was small — but then, the temperature increase was also small. So I don’t see a lot of useful information prior to 1950 for evaluating the AGW hypothesis. My statement is based on back-projection.”
Now we’re getting to the crux of the problem. I refer you again to the temperature data for the 20th century.
http://www.metoffice.gov.uk/research/hadleycentre/obsdata/HadCRUT3.html
What we have is sharp warming early in the century (pre-1950), a leveling off in mid-century (perhaps even a drop), and warming again late in the century. As you say, the CO2 increase happened mostly late in the century, but the rate of warming early in the century is not appreciably different from late in the century (compare the slopes from ~1920 to ~1945 and from ~1975 to ~2000). Again, I am focusing on trying to quantitatively evaluate the effect of CO2 and whether warming due to it can reasonably be called “catastrophic”.
I believe that modeling is an experiment as this phase of the theory game for climate change. Therefore any science worth his or her degree should have several experiments going at once. Seed plots are a lot like this. One can hypothesis (always in the null) that a certain mix of air, water, fertilizer, light, etc is optimal, but to test this, several plots are run at the same time with a control group. These plots are subjected to varying amounts of the “mix” to determine which one best promotes and therefore predicts optimal growth. The one tune AGW scientists seem to be violating this most basic principle of research. Unless I am wrong about that. Does anyone know of a group of scientists that are testing several models (some with CO2 as the forcer, some with solar as the forcer, some with oceanic processes as the forcer, some a combination of these, etc, versus a simple chaotic random model)?
Dav, I won’t bother explaining what I’m calling the “natural relaxation” hypothesis’ flaws because you have declared that you’re interested in this only if it is the same as the “no explanation” that you prefer. You’re saying that you have no alternate hypothesis to offer, but that AGW has to have something behind it to be taken seriously. OK, that’s fair. Here’s what it has behind it:
Physics predicts that, if you increase CO2 concentrations in the atmosphere, the earth’s temperature will increase. In the 20th century, CO2 concentrations in the atmosphere increased, and global temperatures also increased.
There you have it. You can argue the details, and there’s lots of interesting matters related to feedback to argue over, but the basic AGW hypothesis has both theoretical and observational support. So it passes whatever fundamental test we might apply to an hypothesis. In the absence of any other hypothesis, it’s the best we’ve got. That doesn’t mean that it’s absolutely, positively right. We can still have plenty of uncertainty regarding the details of the hypothesis and its predictions. But we don’t have any better hypothesis.
“If you have a better hypothesis, present it and your evidence” is precisely the circumvention I mean. I ask you to prove your belief in AGW and all you can come up with is “I can’t think of anything better how about you?” Sheesh, I rest my case,
I’ll say it as simply as I can: AGW has theoretical and observational support. Are you saying that anything less than this statement:
“AGW is a mathematically perfect concept that has been proven as a fundamental law of the universe” ?
is circumventing the question?
John M. presents the argument that variations in temperatures in the 20th century somehow disprove the AGW hypothesis. The flaw in this reasoning is the belief that temperature increase must be coupled to CO2 increase on a time scale of about a decade. That’s not part of the AGW hypothesis as I understand it. If you can find somebody who argues that temperature and CO2 should be coupled on a time scale of a decade, go argue with them. But I prefer the claim that the coupling expresses itself over a time scale of about a century. Which means that we can’t use AGW to make any useful predictions for the short term. However, we can make a general prediction for the next century that temperatures should show an underlying secular increase.
Again, I am focusing on trying to quantitatively evaluate the effect of CO2 and whether warming due to it can reasonably be called “catastrophic”.
Quantitative evaluation need not assume tight coupling. And the catastrophic scenario is not fundamental to the AGW hypothesis; it is only a worst-case scenario, not a central prediction.
Ophiuchus (16:28:30) :
If you refuse to be quantitative, then AGW is simply an interesting point of discussion, sort of like time travel.
I won’t bother explaining what I’m calling the “natural relaxation” hypothesis’ flaws because you have declared that you’re interested in this only if it is the same as the “no explanation”
Odd way to word what I said isn’t it? Why would “naturally occurring” equate to “no explanation”? What I said was: “natural relaxation” sounds like one of many natural explanations. As such, defeating it is pointless. Why? I repeat: defeating one doesn’t defeat them all.
Physics predicts that, if you increase CO2 concentrations in the atmosphere, the earth’s temperature will increase. … In the 20th century, CO2 concentrations in the atmosphere increased, and global temperatures also increased.
So, we come full circle in your presentation. Note this is where we started. Your argument is that AGW must have occurred because, well, because it can. Was all of that talk about differing feedback strengths just empty chatter?
Simply listing a possible cause and not being able to think of any other is very tenuous proof indeed. This all you’ve got? You really have nothing better?
But yet: the record clearly shows past variations of CO2 and temperature that preceded human technology, ergo, humans didn’t cause the fluctuation. For whatever reason you dismiss the possibility the same is happening in the present (unless I can provide some mechanism you understand). Get real. All I need to do is point to contradicting evidence. I’m not required to explain it. It’s YOUR job to explain why it isn’t the case.
I should think you could list specific tests to be made and show how those tests were successful by pointing to the literature. Why do you find this so difficult that you must dance around it?
I’ll say it as simply as I can: AGW has theoretical and observational support.
Forgive my exasperation with you but you have been repeatedly asked to present those very things and you have not. I started with the assumption that CO2 can cause a temperature rise, remember? Others have as well I believe.
Are you really saying your entire argument rests on CO2–>Higher temps alone? I mean coupled with an observed rise in CO2 and temp? If so, how is your argument dissimilar to the following? Matches can cause fires. This has been demonstrated. Starting a fire without matches or lighter is difficult. The house down the street has caught fire. Obviously, the house fire was the result of playing with matches. Note the correlation between matches and fires and the observation of a fire.
If your AGW theory rides on a similar argument then it’s on very shaky ground. Hardly compelling.
“AGW is a mathematically perfect concept that has been proven as a fundamental law of the universe ?” is circumventing the question?
Yes, very much. How does a bald statement answer the question: where’s the proof? — specifically show us something other than vague prediction.
Here’s one of your vaguer ones: Quantitative evaluation need not assume tight coupling.
Without quantification that’s about as weasel-ish as one can get. It amounts to: CO2 causes climate/temperature change but we can’t say how much. Not to mention that without quantification testing becomes very problematic. But then, maybe you don’t really want the AGW hypothesis tested.
You are wasting not only our time but yours as well. Do you truly believe that your talking around the subject and avoiding specifics is actually producing anything more useful than growing this thread? Do you really think you are expertly demolishing our questions?
The global temperature this month is exactly where it was in 1989…….yet CO2 continued to rise precipitously since that time. No cause and effect demonstrated.
The Artic is still frozen and sea levels are where they always have been.
The Anthropomorphic Global Warming theory is false.
All of this global warming nonsense for NOTHING.
Yes, it is that simple.
Correction: 1979
Ophiuchus (16:28:30) :
“Quantitative evaluation need not assume tight coupling. ”
So, are you saying that the sensitivity/positive feedback numbers in your
model are all over the place, or are you saying that the sensitivity/positive feedback number is constant and other conditions are masking the CO2 effect?
By the way, how do you account for the climate change from the MWP to the LIA?
Ophiuchus,
You wrote:
“Physics predicts that, if you increase CO2 concentrations in the atmosphere, the earth’s temperature will increase. In the 20th century, CO2 concentrations in the atmosphere increased, and global temperatures also increased.”
That hasn’t happened; see the graph at the top of the page. The Glo-Bull Warming theory is dead.
If you’d like to push your agenda using some other myth, now’s the time.
OK, I’m going to make a good-faith effort to sort this out, but I fear that tempers have already risen to the point where good-faith efforts are useless. Nevertheless, somebody’s gotta take the first step in sorting it out, and I’m willing to try.
It’s obvious that you and I, Dav, are talking past each other. So I’m going to go back to basics and walk through the logic to see where we diverge.
1. We both agree (I think) that the observational data is clear that we have seen a general rise in global temperatures since the 18th century.
2. Our main point of divergence, I suspect, is in the framing of question that we seek to answer regarding this general rise in global temperatures.
2a. My framing is, “What caused this general rise in global temperatures?”
2b. Your framing (I believe) is, “Did AGW cause this general rise in global temperatures?”
So our main dispute is, which framing is the proper framing? I argue that your framing is not answerable by the scientific method. Science cannot give absolute answers to any questions; it can only evaluate the relative merits of competing hypotheses. The trick here is probabilistic thinking as opposed to boolean thinking. Most people think that science is boolean, producing absolute black and white answers to questions. In fact, science is probabilistic; it yields only probabilistic answers. Even something so fundamental as Newton’s Laws cannot be said to be absolutely true; and indeed both Special Relativity and Quantum Mechanics showed that Newton’s Laws are only approximations.
Your framing asks for a boolean result: does or does not AGW explain the rise in global temperatures? A yes or no answer is not something that the scientific method can produce. What it can produce is a non-quantitative assessment of the likelihood that AGW explains the rise in global temperatures. The assessment is non-quantitative because ultimately it rests on non-quantitative judgements about the reliability of component factors of the overall hypothesis.
The people who demand proof about AGW or find flaws in various component factors are wrong to conclude that the existence of flaws discredits the hypothesis. Such flaws weaken but do not eliminate the hypothesis. And if the alternatives available to us are even weaker, then we stick with the best hypothesis we’ve got, even if it has flaws.
Now, you seem to be arguing in favor of an “unknown force” hypothesis. Correct me if I’m wrong, but your thinking seems to be that the rise in global temperatures could have been caused by some unknown force, and unless the AGW hypothesis can be proven, we have to accept this unknown force hypothesis. That’s not the way the scientific method works. There has never been any case in the history of science in which a hypothesis was rejected in favor of anything like an unknown force hypothesis. Consider, for example, the battle between the Steady State theory and the Big Bang theory in the 1950s, before the discovery of the 3ºK background radiation. There was scanty evidence for either hypothesis, but cosmologists did not decide that, because the evidence was scanty, they would reject both the Big Bang and the Steady State in favor of an unknown force explanation for the apparent expansion of the universe. Instead, they considered Big Bang and Steady State as the two primary hypotheses, but did not believe that either one had established itself with enough certainty to decide the issue.
This, I think is the central problem that divides us. If I have misapprehended your position, please clarify it for me.
Now, it may be that you are claiming that there exists zero support for the AGW hypothesis. If so, I can readily dismiss that. The first element of support is theoretical: we know that the greenhouse effect is real and it predicts that we should see a rise in global temperatures if we increase CO2 concentrations. So there exists theoretical support for the AGW hypothesis.
But now we come to a point that seems to generate a lot of confusion. I point to the rise in global temperatures as observational evidence in support of AGW — and you seem to think that this is somehow circular reasoning. If so, then I suggest that the problem here is confusion on your part as to the sequence of steps used in the scientific method to answer questions.
The starting point in the scientific method is observation, not hypothesis. First you observe some phenomenon. Then you ask, “What mechanism explains this phenomenon?” Then you formulate various hypotheses to explain the phenomenon. Then you compare those hypotheses with observation. By the way, none of this has to be quantitative — but quantitative information is usually more useful than non-quantitative information. Often you will need to extend your observations by gathering more data to discriminate between competing hypotheses.
I can’t recall a single case in the history of science in which any hypothesis was absolutely blown out of the water by observation. For example, the dramatic case of the 3ºK radiation provided powerful evidence in favor of the Big Bang theory — but some scientists argued that differing interpretations of the data removed the support from Big Bang. There was a lot of interpretation going on here. At no point was Big Bang ever proven, nor was Steady State ever disproven. What happened was that most of the scientists interpreted the data to favor Big Bang, and over the course of the next decade or so, the skeptics gave up or came around. (Side note for AGW skeptics: the existence of a handful of scientists who reject a conclusion drawn by a supermajority does not indicate that the conclusion is unreliable. There were diehards supporting Steady State well into the 1970s).
I’d like to wrap up this explanation with a point about skepticism. You folks have asserted that you want to be known as skeptics, not deniers. OK, that’s fine — but if you want to be called skeptics, then you should be honestly skeptical. Honest skepticism is catholic — it is applied with equal force to ALL competing hypotheses. Yet I have seen a woeful lack of skepticism in a number of points in our discussions. Consider, for example, the claims that scientists were all fired up over global cooling in the 1970s. A true skeptic would be skeptical of those claims, and would demand evidence. And indeed it takes but a few moments of searching the Internet to turn up plenty of evidence discrediting that pack of lies. But skepticism was nowhere in evidence in regard to that issue. People here seem to have bought that line lock, stock, and barrel without any questioning. That’s not skepticism and people who behave that way are lying when they call themselves skeptics.
Lastly, I’ll attempt to answer old construction worker’s questions. His first question seems garbled to me. He asks about “my model”. I don’t have a model, but I do support the broad AGW hypothesis. You are inquiring into the details of the science involved in the AGW hypothesis. I request that you frame your question with greater specificity.
Your second question is how do you account for the climate change from the MWP to the LIA?
I don’t have a hypothesis for that. I’m sure that there are some interesting competing hypotheses, but I have not studied the question and so I have no opinion on the matter. Do you have a preferred hypothesis?
OK, I’m getting lost in all this meta-discussion, and I’m not even sure you’re that far apart. Can I simply ask the following question of any parties still interested?
What do you estimate the climate sensitivity (‘C change) for doubling of CO2 to be? The options seem to be:
0: No effect at all
0.1-1.0: Some effect, as predicted by basic physics
1.0-3.0: Effect with positive feedback, as proposed by IPCC
3.0-6.0: Effect with tipping point, as proposed by Hansen et al.
Personally, I’d go for 0.1-1.0 from existing evidence, with a hunch that negative feedbacks (homeostasis) will keep it to the low end of that range in the longer term, but a concern that other non-CO2 factors (deforestation; soot) may at least cause major local issues, and possibly push it globally higher.
Paul Clark,
Good idea. I’m in for 0.1 – 1.0.
Put Ophiuchus in for a thousand word essay that says “it doesn’t matter.”
What do you estimate the climate sensitivity (’C change) for doubling of CO2 to be?
I’ll go with the IPCC value because I found their analysis reasonable.
Paul, from what I’ve read, a doubling of C02 from its current level would have very little effect, since most of the absorption bands that can capture C02 are already saturated, so I’d say in the range of 0 – 0.1. This is what makes the AGW alarmists’ cries of “climate catastrophe” so laughably pathetic – not only will any additional C02 have almost no effect on temperatures, but man’s contribution to C02 is only about 3%. You could spit in the ocean and have about the same effect on sea level as man can affect climate with his measly C02!
My Choice: Since past reconstructed records indicate that CO2 lags temperature increases, I will go with 0. It has no demonstrable cause and effect, only a lagging correlation. A large jump: makes me wonder if temperature increases cause a rise in atmospheric CO2. There is examined and tested theory to support that when looking at warm water.
The Reason: The short period we are studying is very noisy as are all periods of temperature. An overall first order trend line in the last 100 years that has predictive value is a weak proof, given the nature of past fluctuations, and I believe you must consider past fluctuations in your climate model, just in case those circumstances happen again. While modeling is far more complicated than linear fit, it too will have poor predictive value -and odds- that one would place bets on if it were a horse race. Its as if the AGW scientists have secret gnostic information that all causes in the past are over (even though they admit to not understanding the mechanisms), or are now somehow far less of a factor, so CO2 has to be it and our temperature will rise as CO2 rises.
The Thorn: There are other measures that show equal and even greater correlation to temperature than CO2, even though we don’t understand the exact mechanisms. The Sun’s output cyclically correlates very well with temperature fluctuation and gets even tighter with oceanic temperature swings.
My Main Complaint: Finally, the historical record demonstrates just as many correlations for solar forcing or oceanic forcing, or the combination, as it does CO2. So why aren’t these given equal modeling? And finally the standard experiment includes a control. It is relatively easy to build a random model to compare with all the other hypothesized models that should be getting equal treatment from the scientific community engaged in this model experiment.
Wanna Bet On It? The betting community is missing out on a great long term investment. They should convince the modelers to produce several competing models, including random, and then put it out there for the public to place bets on. I would spread my bet around all models that include solar forcing as the primary factor, with oceanic cycles as secondary.
@Ophiuchus (21:17:22) ,
OK. Maybe I understand where you’re coming from a little better but I think you’ve misinterpreted what I’ve been asking.
Yes, if there are two hypotheses, A and B, they can be compared. What is often forgotten, and I think this is true for you, is there is always a third possibility: something else. I believe you have forgotten this because you’ve more or less said that, lacking a better hypothesis, AGW wins. It is you who is more prone to binary thinking IMO.
The problem here may be more similar to drug testing where there is only one drug under consideration. In such a test, the question is: does the drug have a significant effect? The understood other is: administering nothing at all. The problem with testing AGW is the lack of a control group for comparison.
Still though, the question remains: is AGW a viable hypothesis? A better question is: “would the climate be the same if humans weren’t here?” Another phrasing: “do humans have a significant effect?”
(continued in a later post)
@Ophiuchus (21:17:22) ,
What would replace AGW if it doesn’t work? “Something else” aka “natural causes.” In drug testing, a control group is used to proxy the result of doing nothing at all, i.e., allowing nature to take its course. In climate hypothesis testing, there is no genuine control group. Instead the past is used as a proxy. Unfortunately, that adds other variables making it very difficult to determine what conditions would exist without the presence of humans.
So, how does one go about comparing hypotheses? I don’t know about you but I need to look at how well the hypothesis predicts (and/or “explains” i.e. predicts the past). If it can’t predict at all it’s totally worthless. What do we have? I might also point out that without being able to predict the future, any hypothesis is of questionable value.
Facts:
o adding CO2 causes temperature rise
o CO2 varied in the past in periods extending over centuries
o Temperature varied in the past
o CO2 and temperature were correlated
o this occurred before human technology
o CO2 rises lag temperature (implies: temperature rise causes CO2 rise)
o there was a warm period during medieval times that was likely warmer than today. (historic evidence, grapes grown in England, etc.)
present (and a bit before)
o there was a “Little Ice Age” bottoming around mid-1700’s
o temperatures have been rising since the mid 1700’s
o CO2 has been monotonically rising
o temperatures have risen and fallen with an apparent long term trend of rising
o majority of temperature rise has been in Northern Hemisphere
o added CO2 is assumed to mix evenly in the atmosphere thus it’s measured at only a few points on the Earth
o decreasing SH temperatures while increasing NH temperatures contradicts
o the majority of the anthropogenic CO2 was added post-1940
o 1940 marks the beginning of a 40 year cooling trend (one that even led James Hansen to a global cooling alarm)
Predictions by hypothesis:
Natural causes
there is no reason to assume that past causes no longer exist therefore
– temperatures will vary
o CO2 will vary
o temperatures will rise as CO2 rises
o CO2 will increase as temperatures rise
o temperatures and CO2 will be loosely correlated
AGW
o CO2 added from humans will cause temperatures to rise
o temperatures and CO2 will be loosely correlated
o unless humans change CO2 can only rise
As I see it, the only prediction by AGW is “it’s been shown that adding CO2 causes temperatures to rise.” IOW: humans affect temperatures by simply breathing. it “explains” at best one fact. And this fact is also predicted/explained by natural causes. Natural causes, OTOH, explain all facts. Neither hypothesis can accurately predict the future.
AGW has hardly been shown better than all other hypotheses. In fact, since it can’t be shown to accurately predict the future, it’s next to worthless.
Ophi, I specificly mentioned ENSO, Volcanoes and Solar as natural variations. They are the 3 majors, you can start with them.
Paul Clark (02:39:31)
OK, Dav, so you are offering as a hypothesis:
“Natural causes (something other than AGW) caused the increase in temperature since the mid-18th century.”
whereas my hypothesis is:
“AGW caused most of the increase in temperature since the mid-19th century.”
You list a bunch of facts. I’ll first point out that you’ve left out a few crucial facts (I’ll raise those later), but I’ll agree with all your facts except one: that temperatures in the Southern Hemisphere have been going down. I think you’ve gotten some bad data there. Fortunately, it’s not crucial to either of our cases.
The real problem with your analysis is that your framing of the hypothesis leads to useless predictions. Among the predictions that you attribute to your hypothesis are:
temperatures will vary
CO2 will vary
Well, yes, I agree, temperatures will vary — but that’s not much of a prediction. And it really isn’t saying anything to declare that CO2 concentrations will vary. So what?
The AGW hypothesis makes a prediction that temperatures will rise and right there in the middle of your facts list is the statement “temperatures have been rising since the mid 1700’s”
So you seem to be arguing that the AGW hypothesis correctly explains the observations and that a bland say-nothing hypothesis also correctly explains the observations.
But then you turn around and write this:
AGW has hardly been shown better than all other hypotheses. In fact, since it can’t be shown to accurately predict the future, it’s next to worthless.
The other hypothesis that you list makes only the non-prediction that temperatures will vary, whereas AGW predicts temperature rise. And yet you say that AGW has not been shown to be better than your hypothesis?!?!?
Look, if you’ve got some other hypothesis in your back pocket, let’s see it. But I’ll engage in some speculative anticipation. You seem to be blundering around the idea that there’s some magic “unknown explanation” that we should give credence to. As I have explained at length, that’s not how the scientific method works. If you have an idea for an explanation, write it up as a formal hypothesis and we can examine it. But if you truly are claiming that we should accept the “it’s a mystery” explanation, then all I can do is refer you back to my long description of the scientific method.
Mike C writes:
Ophi, I specificly mentioned ENSO, Volcanoes and Solar as natural variations. They are the 3 majors, you can start with them.
I cannot find any such reference in your postings. Could you give me a time index for the statement to which you refer? Even better, I’d appreciate it if you could gather together the bits and pieces and restate your question as a single unit.
Ophiuchus (14:19:45) :
Oh, stop already! I’m not offering that as an hypothesis — it’s already assumed in every hypothesis test!!!!
My point, that you’ve missed (deliberately?) is that natural causes explain more than AGW therefore, all the AGW-ers need to go back to the drawing board. In case, you don’t know (something I’m coming to believe more and more) “natural causes” is synonymous with “unknown.” Yes, indeed, UNKOWN CAUSES are a far better explanation for the present climate than AGW.
You really need to read what others are saying far more carefully than you are evidencing and avoid misquoting or representing what is said. Doing so is not going to be lost on the rest of us and will eventually relegate you to the dumb-dumb category. If you think you’re accomplishing anything else then you are wrong.
Of course, you may just be a bumbling troll that gets jollies out of being perverse. If so, you need to look up a guy posting as TCO on other sites. He’s a real pro and I’m sure he’ll be happy to give you pointers, maybe even OJT.
OK, Dav, you’re obviously angry at me and this has strongly affected your writing, so I’m going to walk away from this discussion in the interests of the public peace.
“0.1-1.0: Some effect, as predicted by basic physics”
This is actually incorrect. Basic radiative physics says that the equilibrium response to 2xCO2 will be a temperature increase of 1.1C. This is the baseline, the prediction from ‘basic physics,’ in the absence of any feedbacks.
“What Hansen and the IPCC seem to be saying is that there is positive feedback but currently damped by negative feedback. A “Tipping point” in his definition would be a point where the negative feedback is swamped (akin to walking off a cliff).”
No, this is not what Hansen and IPCC are saying. That is not how they claim positive and negative feedbacks work. A positive feedback with a gain of less than unity, is expected to cause an equilibrium temperature response of about 3C per 2xCO2. Less than unity gain is not a ‘negative feedback.’ A “tipping point” is not a point of runaway warming – it is a point at which we commit to a new temperature regime, perhaps a new warmer stable state, from which it will be very difficult or impossible to recover. Hansen is specifically referring to such things a permafrost melt and methane liberation, or arctic sea ice melt and its effect on Greenland ice melt, along with separate WAIS ice melt, and their effects on sea level and on increasing the speed of approach of the equilibirium warming, when he refers to a ‘tipping point.’
I also see several people above speculating that increasing temperatures right now are causing increased CO2. This is not possible. When in the past increased temp caused increased CO2, much of that increase in CO2 came via outgassing from warmer oceans. But we know that right now, CO2 in the oceans is increasing, not decreasing – net CO2 flow is from atmosphere to ocean, not out of ocean. This is causing ocean acidification, and it is another serious risk that comes with rapidly increased atmospheric CO2. We also see the signatures of CO2 coming from combustion of fossil fuels, in the isotope composition of atmospheric CO2, and in the decrease in atmospheric O2 .
Pamela Gray:
“My Main Complaint: Finally, the historical record demonstrates just as many correlations for solar forcing or oceanic forcing, or the combination, as it does CO2. So why aren’t these given equal modeling?
They are given ‘equal modeling.” All of those known effects are included in the models. Solar output, as TSI, is included – but TSI trend has been flat for 50 years now. Ocean effects such as El Nino adn La Nina come out of the models. Yes,many of the models produce El Nino and La Nina events, or something very like them. In any case, these are not forcings, they are redistributions of heat within the earth system.
And finally the standard experiment includes a control. It is relatively easy to build a random model to compare with all the other hypothesized models that should be getting equal treatment from the scientific community engaged in this model experiment.”
One control that is frequently done, is to run the models without an anthropogenic CO2 input. The models have parameterizations or ranges of inputs – places where our measurements constrain a range of physically rel values, not a precise value. Modelers have tried to play with these parameterizations and values in a no-anthropogenic-CO2 model, to get the rise in temps over the last century – and uniformly failed. The ONLY way to get model output for the coupled GCMs that matches the temperature increase of the last century, is to include anthropogenic CO2 as an input. The anthro CO2 then operates through basic radiative physics and feedbacks, such that it is very easy to use physically realistic values for all parameters adn settings, and reproduce the temperatures of the last cnetury.
I would just like to say, that while I disagree with Ophiuchus’ view, I have enjoyed the debate between him, Dav and others. One of the great things about this site is that the people who contribute are relatively open minded, if contrarian to the mainstream view. Long may this continue!
I think Paul Clark made the good point about there being several stances on this subject and by doing so, pointed out that there are levels of scepticism. I’d side with the 0.1-1 view that there is a limited affect, but nothing apocalyptic on the cards. I think the ‘end of the world’ scenario is the one the media hypes (it’s good story after all!) and is the one which many readers/posters here have the biggest disagreement with.