# Is Anthropogenic Global Warming Falsifiable? **URL:** \ **Category:** Great Debates\ **Created:** [June 16, 2009, 5:03am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911 "2009-06-16T05:03:51Z")\ **Posts on this page:** 20\ **Page:** 5
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 12:27am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/81 "2009-06-30T00:27:33Z")
> [@GIGObuster](#): > > I guess if you blink you will miss it (posted 2 times already): No, he didn’t miss it. You misunderstood it. That is not a falsifcation of AGW, it is a falsification of IPCC projections. Those are vastly different. In this thread we are working from the assumption that a prolonged rise in global temperatures is an observation, not a theory. IOW we both agree that CO2 levels and temperatures will continue to rise for the next 100 years. > [@](#): > > And \*\*wevets \*\*already mention several others. And has admitted that none of them actually falsify AGW, they just test alternate hypotheses. ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [June 30, 2009, 12:39am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/82 "2009-06-30T00:39:39Z")
> [@Blake](#): > > And has admitted that none of them actually falsify AGW, they just test alternate hypotheses. Of the **5** falsification tests in my post above, only #3 and #4 ( **two** out of the **five** ) test alternate hypotheses. ---
**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:** [June 30, 2009, 12:41am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/83 "2009-06-30T00:41:10Z")
> [@Blake](#): > > No, he didn’t miss it. You misunderstood it. That is not a falsifcation of AGW, it is a falsification of IPCC projections. Those are vastly different. In this thread we are working from the assumption that a prolonged rise in global temperatures is an observation, not a theory. IOW we both agree that CO2 levels and temperatures will continue to rise for the next 100 years. > > And has admitted that none of them actually falsify AGW, they just test alternate hypotheses. [http://boards.straightdope.com/sdmb/showpost.php?p=11248394&postcount=28](http://boards.straightdope.com/sdmb/showpost.php?p=11248394&postcount=28) [QUOTE=GIGObuster] That really sounds like grasping at straws. The fact is that the water vapor feedback was pointed as important for the Greenhouse gas theory to work, deniers on the Straight Dope even told us that the water vapor feedback was not demonstrated as it was mostly coming from the physical computer models. Had the new tests and satellite data (yes, a satellite was launched also to get data to confirm the results of the mostly theoretical experiments until then) had demonstrated that the water vapor feedback with CO2 was hooey then a huge component of the prediction models and the theory behind AGW would have gone up in smoke. [/QUOTE] > **[Water Vapor Feedback Loop Will Cause Accelerated Global Warming, Professor Warns](http://www.sciencedaily.com/releases/2009/02/090219152132.htm)** > > Here's yet another reason to hate humidity: it expands global warming, says a professor of Atmospheric Sciences writing in the journal Science. He says that warming due to increases in greenhouse gases will lead to higher humidity in the atmosphere.... > [@](#): > > “For years, there was a debate over this mechanism, with some even questioning if the water vapor feedback existed at all. But recent work on this feedback has moved its existence and strength beyond argument,” Dessler adds. > > **Predictions of significant global warming over the next 100 years by climate models require a strong water vapor feedback**. Recent estimates suggest the earth will warm from 2 to 4 degrees Celsius (4 to 8 degrees Fahrenheit) over the next century – a scenario that could have devastating long-term consequences. > > “Everything shows that the climate models are probably getting the water vapor feedback right, which means that unless we reduce emissions, it is going to get much, much warmer on our planet by the end of the century,” he adds. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 12:54am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/84 "2009-06-30T00:54:27Z")
> [@wevets](#): > > Of the **5** falsification tests in my post above, only #3 and #4 ( **two** out of the **five** ) test alternate hypotheses. The others either also test alternative hypotheses. For example “Can the human-produced carbon dioxide (and other gases) retain extra heat in the atmosphere?” doesn’t attempt to falsify AGW, it attempts to falsify whether carbon dioxide can retain heat. Indeed this fact was resolved long before the AGW hypothesis was ever proposed and could never have been used to falsify AGW short of some serious re-rewriting of the laws of physic. This is like exactly like saying that Christianity is falsifiable because it “predicts” that people in different parts of the world speak different languages. All you need to do to falsify Christianity is to demonstrate that the peoples of the world all speak the same language. Of course these examples are both nonsense. They aren’t examples of evidence that can be collected to falisfy the theory because they are both uncontroversial facts that were used in the _constructon_ of the theory. But I will ask you yet again: what evidence can I collect that I can collect that will cause you to reject AGW? ---
**Author:** ![elucidator](https://avatars.discourse-cdn.com/v4/letter/e/8edcca/32.png) [@elucidator](https://boards.straightdope.com/u/elucidator)\ **Post date:** [June 30, 2009, 12:58am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/85 "2009-06-30T00:58:16Z")
Given what we know about “greenhouse gases” and their effect in trapping heat, and given what we know about how much such gas we produce, couldn’t the shoe fit as easily on the other foot, might we not fairly ask why anyone would think that global warming \*wouldn’t \*result? And your elevation of the principle of falsifiability to an absolute is silly, reason and rationality occupy that spot, not any one principle of research, however valuable. Because our curiosity leads us to poke our intellectual noses in places where absolute certainty is probably not possible, that doesn’t mean that reasonable conclusions are useless. That’s Heisenberg. I think. Pretty sure. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 1:16am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/86 "2009-06-30T01:16:40Z")
> [@GIGObuster](#): > > Had the new tests and satellite data (yes, a satellite was launched also to get data to confirm the results of the mostly theoretical experiments until then) had demonstrated that the water vapor feedback with CO2 was hooey then a huge component of the prediction models and the theory behind AGW would have gone up in smoke. Well that would count, _if_ you could show me evidence of where you or someone else actually said that AGW would be rejected if the satellite data didn’t match the prediction. Of course if nobody ever said such a thing then this isn’t an example of falsifiability, it’s yet another example of confirmation. The AGW hypothesis is full of examples of where some data simply don’t match the theory. For example leaf stomatal data don’t support the 20th C warming event as being unprecendented in rate and contradict the assumptions of past stable CO2 levels that the theory hinges on. Dendrochronology and speleotherm data don’t; show any late 20th century warming trend at all. The temperature remained stable for ~1950 -~1980 and for ~1997-2009 despite increase sin CO2 levels. All those observations are either ignored completely or forced to fit in later models by adding more and more factors and forcing Unless you can provide quotes of where yourself or someone else actually said that AGW would be rejected if the satellite data didn’t match the prediction then we have no reason to believe that if the satellite data had proven to be antipathic to AGW it wouldn’t have been treated the same way.Your own quote gives us ahint of this when you note that “a huge _component_ of the… theory behind AGW would have gone up in smoke”, but stop short of saying that the theory itself would have gone up in smoke (ie been rejected). This is why falsifiability is so important in science. Finding confirmations such as the satellite data is easy, as Popper notes. You can find such confirmations for almost any theory. What defines science is not the confirmations. It is that it is predicted before hand what the data will be, and if the data don’t agree the whole theory is rejected. So I ask again: can you give me an example o some data that can be collected that will cause you to reject AGW? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 1:22am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/87 "2009-06-30T01:22:14Z")
> [@elucidator](#): > > Given what we know about “greenhouse gases” and their effect in trapping heat, and given what we know about how much such gas we produce, couldn’t the shoe fit as easily on the other foot, might we not fairly ask why anyone would think that global warming \*wouldn’t \*result? By all means do so, in another thread. > [@](#): > > And your elevation of the principle of falsifiability to an absolute is silly, reason and rationality occupy that spot, not any one principle of research, however valuable. Well I’m certainly convinced now that you’ve said it’s silly and supported your assertion with yet more assertions. > [@](#): > > Because our curiosity leads us to poke our intellectual noses in places where absolute certainty is probably not possible, that doesn’t mean that reasonable conclusions are useless. Absolute certainty has never been possible in science. That’s one of the defining principles of science science. If you are absolutely certain then you aren’t doing science. The fact that you think that this lack of certainty is recent or confined to AGW or wasn’t well known to Popper speaks volumes. And reasonable conclusions are always useful. The question is whether they are science. ---
**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:** [June 30, 2009, 1:28am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/88 "2009-06-30T01:28:43Z")
> [@Blake](#): > > So I ask again: can you give me an example o some data that can be collected that will cause you to reject AGW? Although you are trying your best to push it aside it was what the guy at Real climate said. If the global mean temperature from 2050 to 2070 would end up being lower than the 1950 to 1970 global mean temperature, that would that be enough to falsify the IPCC projections, and I would add that that also will falsify AGW as the projections are also based on what we see today regarding AGW. It would be clear then that something huge was missed in the calculation and the evidence gathered. ---
**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:** [June 30, 2009, 1:33am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/89 "2009-06-30T01:33:35Z")
> [@Blake](#): > > Well that would count, _if_ you could show me evidence of where you or someone else actually said that AGW would be rejected if the satellite data didn’t match the prediction. Of course if nobody ever said such a thing then this isn’t an example of falsifiability, it’s yet another example of confirmation. It is clear to me that the feedback was declared by many in the denial camp as a weak point in the AGW edifice. Finding evidence outside the lab is a problem for the skeptics, moving the goalposts is also a problem for them. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 1:44am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/90 "2009-06-30T01:44:11Z")
> [@GIGObuster](#): > > Although you are trying your best to push it aside it was what the guy at Real climate said. No, it isn’t, although you try to misprepsent it. > [@](#): > > If the global mean temperature from 2050 to 2070 would end up being lower than the 1950 to 1970 global mean temperature, that would that be enough to falsify the IPCC projections, and I would add that that also will falsify AGW as the projections are also based on what we see today regarding AGW. That’s a good answer. So in 40 years time AGW will have been through a falsification procedure and can be declared scientifically valid as per Popper’s definition. I accept that. > [@](#): > > It is clear to me that the feedback was declared by many in the denial camp as a weak point in the AGW edifice. Doubtless, though amongst many others such as the aerosol forcings, lack of correlation of ice core data with real measurements, lack,conflict with dendrochronology data and so forth. > [@](#): > > Finding evidence outside the lab is a problem for the skeptics, moving the goalposts is also a problem for them. What does that even mean? You haven’t actually answered my question: can you show me evidence of where you or someone else actually said that AGW would be rejected if the satellite data didn’t match the prediction. We both know that a lot of data doesn’t match the AGW theory. So how do we know that if the satellite data hadn’t matched it would actually have led to the theory being rejected, as you claim? Why can’t we assume it would have been either ignored or forced like all the rest of the data? Why assume that it would have counted as falsification when so much other data didn’t? ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [June 30, 2009, 1:50am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/91 "2009-06-30T01:50:03Z")
> [@Blake](#): > > We both know that a lot of data doesn’t match the AGW theory. What data doesn’t match AGW theory? ---
**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:** [June 30, 2009, 1:59am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/92 "2009-06-30T01:59:57Z")
> [@Blake](#): > > You haven’t actually answered my question: can you show me evidence of where you or someone else actually said that AGW would be rejected if the satellite data didn’t match the prediction. > > We both know that a lot of data doesn’t match the AGW theory. So how do we know that if the satellite data hadn’t matched it would actually have led to the theory being rejected, as you claim? Why can’t we assume it would have been either ignored or forced like all the rest of the data? Why assume that it would have counted as falsification when so much other data didn’t? Well you accepted already an answer, what is the problem now? 🙂 [QUOTE=New Scientist] “For years, there was a debate over this mechanism, with some even questioning if the water vapor feedback existed at all. But recent work on this feedback has moved its existence and strength beyond argument,” Dessler adds. Predictions of significant global warming over the next 100 years by climate models require a strong water vapor feedback. Recent estimates suggest the earth will warm from 2 to 4 degrees Celsius (4 to 8 degrees Fahrenheit) over the next century – a scenario that could have devastating long-term consequences. “Everything shows that the climate models are probably getting the water vapor feedback right, which means that unless we reduce emissions, it is going to get much, much warmer on our planet by the end of the century,” he adds. [/QUOTE] Again, it is clear that it would had been a serious problem for the theory, as it is clear to me that if the evidence had gone the other way skeptics would declare that the theory was dead, and the thing is, this time they would **had evidence to support their say so’s**. Many scientists would then get busy looking for the confirmation of this discovery and eventually the data would had killed the theory for good. ---
**Author:** ![elucidator](https://avatars.discourse-cdn.com/v4/letter/e/8edcca/32.png) [@elucidator](https://boards.straightdope.com/u/elucidator)\ **Post date:** [June 30, 2009, 2:10am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/93 "2009-06-30T02:10:00Z")
> [@Blake](#): > > By all means do so, in another thread… Thank you for your kind advice, but its rather late for that, isn’t it? I’ve already asked the question. And I have posed the question to someone, by his own assertion, very knowledgeable and well versed. So, I \*have \*asked, even if it were ill-advised: given what you know of science, gases, and their effects: wouldn’t you _expect_ a “greenhouse warming”? And if not, can you explain why not? And can you supply us with a means to falsify your explanation? > [@](#): > > …The fact that you think that this lack of certainty is recent or confined to AGW or wasn’t well known to Popper speaks volumes… I think no such thing. But that edge of certainty means that something can be real and yet not be falsifiable. Where we cannot be certain, we are left with the reasonable. What we know of gases and heat would lead us to expect a “greenhouse effect”, would it not? > [@](#): > > …And reasonable conclusions are always useful. The question is whether they are science. And if a reasonable conclusion is useful, even species-saving, will you refuse it because it doesn’t conform to the strict rules of formal science? Keep in mind, one can be rational to a point that becomes unreasonable. A preponderance of evidence compounded by the gravity of the situation makes it reasonable to act upon AGW, regardless of whether or not it is “falsifiable”, don’t you think? Or don’t you? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 2:38am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/94 "2009-06-30T02:38:12Z")
> [@WarmNPrickly](#): > > What data doesn’t match AGW theory? To give you a couple of examples that I picked up in a simple search: “The majority of the stomatal frequency-based estimates of CO 2 for the Holocene do not support the widely accepted concept of comparably stable CO2 concentrations throughout the past 11,500 years.” Wagner, F., Kouwenberg, L.L.R et al “Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency” Quaternary Science Reviews 23 (2004) 1947–1954 Without accounting for these opposite responses and temperature thresholds, climate reconstructions based on ring width will miscalibrate past climate, and biogeochemical and dynamic vegetation models will overestimate carbon uptake and treeline advance under future warming scenarios. Any assumption that white spruce growth at treeline will change uniformly in relation to climate appears unjustified, and this changing sensitivity to climate is an obvious contributor to the error term in ring-width-based reconstruction of past climate. Wilmking Juday et al Recent climate warming forces contrasting growth responses of white spruce at treeline in Alaska through temperature thresholds Global Change Biology (2004) 10, 1–13 Although we calibrated to the common 1856–1978 period, valid calibration using a reduced data set would be possible until the mid-1980s (Figure 5). After this period, however, the divergence between the tree-ring and instrumental data results in weakening of calibration results and failed verification statistics. there is significant divergence between reconstructed and actual temperatures since the mid-1980s, which, until valid reasons for this phenomenon have been found, can only question the ability of tree-ring data to robustly model earlier periods that could have been similarly warm (or warmer) than the present. D’Arrigo, Wilson 2006 On the long-term context for late twentieth century warming JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, None of this is controversial. The correlation between modelled temperatures and temperature proxies that weren’t used in constructing the models is weak. The correlation between proxies used used in the models and measured temperatures is weak for the late 20th century. This never falsifies AGW because it’s all circular: there’s so much evidence for AGW that the discrepancy must be explainable or able to be incoroprated into the models. And we know there is so much evidence because all the data can be explained or incorporated into the models. This particularly egregious in explaining why tree growth data don’t correspond to the last 30 years of warming, which is suppose dot b unprecedented based on the models. It’s explained by saying that the temperature change is so unprecedented that the trees can’t respond predictably. And we know it’s unprecedented because we don’t pick up the predictable signals of it in models based (at least in part) on tree rings. IOW we know that our models must work because they _don’t_ match the observations of the real world. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 2:56am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/95 "2009-06-30T02:56:41Z")
> [@GIGObuster](#): > > Well you accepted already an answer, what is the problem now? 🙂 That this unacceptable answer is totally unrelated to the other acceptable answer. I’ll accept that AGW is falsifiable and will become science3 in 50+ years time. I don’t accept your claims that the satellite data are an example of falsification rather than a search for confirmation. > [@](#): > > Again, it is clear that it would had been a serious problem for the theory, as it is clear to me that if the evidence had gone the other way skeptics would declare that the theory was dead, and the thing is, this time they would **had evidence to support their say so’s**. Many scientists would then get busy looking for the confirmation of this discovery and eventually the data would had killed the theory for good. I don’t see any reason to believe any of this. The ~70s cooling event didn’t kill the theory despite the skeptics saying that it should. All that happened was that a more elaborate model was created (incorporating aerosols) to incorporate the apparently contradictory observation. The cooling of the past 12 years will go exactly the same way, and we’ve already seen papers predicting 20 more years of cooling as a result of AGW, based on their preliminary models. The lack of correlation between proxies and the actual temperatures of the past 20 years hasn’t killed it despite the skeptics saying it should. Instead the proponents are looking for ways to incorporate the apparently contradictory theory into their models. And so on and on for every incident where the theory has failed some predictive test. I see absolutely no reason to believe that the same would not have been done for any contradictory satellite data. Can you provide some evidence that this would not be the case, to support your repeated assertions that it is would not? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 3:12am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/96 "2009-06-30T03:12:50Z")
> [@elucidator](#): > > But that edge of certainty means that something can be real and yet not be falsifiable. Where we cannot be certain, we are left with the reasonable. But it still isn’t science by Popper’s standard. > [@](#): > > What we know of gases and heat would lead us to expect a “greenhouse effect”, would it not? Not me, no. I understand that you can’t scale up from simple physics to complex systems with any accuracy whatsoever. To give you an example: cows eat plant biomass, right? So wouldn’t that lead you to expect that (absent major human interference) an increase in cows would lead to a decrease in plant biomass? And people eat food right, so wouldn’t that lead us to predict that more people would mean more hungry people? Certainly that’s what Malthus predicted. Yet both of those predictions are dead wrong. I know that you can’t predict complex systems by extrapolating from simple systems. You may wish to investigate that and see whether you still feel that you can do so. > [@](#): > > And if a reasonable conclusion is useful, even species-saving, will you refuse it because it doesn’t conform to the strict rules of formal science? I’m not refusing anything. I’m discussing whether something is science. There are all sorts of reasons to accept something": economic, military, prejudice, religion etc. However we are told we should accept AGW because it is science. I’m discussing whether it has met the most broadly accepted standard of science. > [@](#): > > Keep in mind, one can be rational to a point that becomes unreasonable. Sure, and one can garner so much wealth as to become impoverished. Oh hang on, no you can’t. > [@](#): > > A preponderance of evidence compounded by the gravity of the situation makes it reasonable to act upon AGW, regardless of whether or not it is “falsifiable”, don’t you think? Or don’t you? Beats me, I’m not here to discuss that topic, though again you can start another thread if yo wish. ---
**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:** [June 30, 2009, 3:19am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/97 "2009-06-30T03:19:10Z")
> [@Blake](#): > > I don’t see any reason to believe any of this. > > The ~70s cooling event didn’t kill the theory despite the skeptics saying that it should. All that happened was that a more elaborate model was created (incorporating aerosols) to incorporate the apparently contradictory observation. It was already explained that nature was still driving the changes. > [@](#): > > The cooling of the past 12 years will go exactly the same way, and we’ve already seen papers predicting 20 more years of cooling as a result of AGW, based on their preliminary models. I mentioned this already, it is apparent when looking at the whole picture, periods of 15 or more years of almost no change are normal, then it warms again. > [@](#): > > The lack of correlation between proxies and the actual temperatures of the past 20 years hasn’t killed it despite the skeptics saying it should. Instead the proponents are looking for ways to incorporate the apparently contradictory theory into their models. AFAIK this was already done. > [@](#): > > And so on and on for every incident where the theory has failed some predictive test. I see absolutely no reason to believe that the same would not have been done for any contradictory satellite data. What you are missing is that if evidence had not been found that then the theory would not be stopped immediately, but since we are assuming that the real world is set to discredit AGW then it is clear that confirmation would be found then and so we have a dead theory. > [@](#): > > Can you provide some evidence that this would not be the case, to support your repeated assertions that it is would not? As there was already and acknowledgment of one test you accept that should be enough. I see absolutely no problem on making tests that discredit all the items you are calling contradictory. The problem for the skeptics is that they are failing to do so. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 30, 2009, 3:35am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/98 "2009-06-30T03:35:01Z")
> [@GIGObuster](#): > > It was already explained that nature was still driving the changes. > I mentioned this already, it is apparent when looking at the whole picture, periods of 15 or more years of almost no change are normal, then it warms again. > AFAIK this was already done. Exactly. No mater what the data show it is either ignored or incorporated into the model. As a result no data at all contradict the theory. Even if we get 30 years of decreansig temperatures it will have been predicted by AGW theory. The theory can’t actually be validated within the lifetime of the poilcy makers. > [@](#): > > What you are missing is that if evidence had not been found that then the theory would not be stopped immediately, but since we are assuming that the real world is set to discredit AGW then it is clear that confirmation would be found then and so we have a dead theory. 😕 Sorry that’s not even English. > [@](#): > > As there was already and acknowledgment of one test you accept that should be enough. It’s completely different test, totally unrelated to the one we are discussing here. > [@](#): > > I see absolutely no problem on making tests that discredit all the items you are calling contradictory. I see no problem with that either. But see nobody doing so. Rather they are either ignored or else incorporated into the models. Just as any contradictor satellite data woudl have been. Which is the whole issue. AGW itself can’t be falsified with any evidence that anyone could actually collect. The best we can say is that we have a prediction that can be tested in 50 years time, and that until then AGW isn’t scientifically validated. > [@](#): > > The problem for the skeptics is that they are failing to do so. The skeptics don’t need to do test to discredit those things. Countless proponents have attempted to falsify those things and failed to do so. So they are either ignored or incorporate into the theory. And as a result the only way AGW can be falsified is if we wait 50 years. Until then it can’t be validated as science. ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [June 30, 2009, 5:05am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/99 "2009-06-30T05:05:58Z")
> [@Blake](#): > > To give you a couple of examples that I picked up in a simple search: > > “The majority of the stomatal frequency-based estimates of CO 2 for the Holocene do not support the widely accepted concept of comparably stable CO2 concentrations throughout the past 11,500 years.” > Wagner, F., Kouwenberg, L.L.R et al “Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency” Quaternary Science Reviews 23 (2004) 1947–1954 > > Without accounting for these opposite responses and temperature thresholds, climate reconstructions based on ring width will miscalibrate past climate, and biogeochemical and dynamic vegetation models will overestimate carbon uptake and treeline advance under future warming scenarios. > Any assumption that white spruce growth at treeline will change uniformly in relation to climate appears unjustified, and this changing sensitivity to climate is an obvious contributor to the error term in ring-width-based reconstruction of past climate. > Wilmking Juday et al Recent climate warming forces contrasting growth > responses of white spruce at treeline in Alaska through > temperature thresholds Global Change Biology (2004) 10, 1–13 > > Although we calibrated to the common 1856–1978 period, valid calibration using a reduced data set would be possible until the mid-1980s (Figure 5). After this period, however, the divergence between the tree-ring and instrumental data results in weakening of calibration results and failed verification statistics. there is significant divergence between reconstructed and actual temperatures since the mid-1980s, which, until valid reasons for this phenomenon have been found, can only question the ability of tree-ring data to robustly model earlier periods that could have been similarly warm (or warmer) than the present. > D’Arrigo, Wilson 2006 On the long-term context for late twentieth century warming > JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, > > None of this is controversial. The correlation between modelled temperatures and temperature proxies that weren’t used in constructing the models is weak. The correlation between proxies used used in the models and measured temperatures is weak for the late 20th century. This never falsifies AGW because it’s all circular: there’s so much evidence for AGW that the discrepancy must be explainable or able to be incoroprated into the models. And we know there is so much evidence because all the data can be explained or incorporated into the models. > > This particularly egregious in explaining why tree growth data don’t correspond to the last 30 years of warming, which is suppose dot b unprecedented based on the models. It’s explained by saying that the temperature change is so unprecedented that the trees can’t respond predictably. And we know it’s unprecedented because we don’t pick up the predictable signals of it in models based (at least in part) on tree rings. IOW we know that our models must work because they _don’t_ match the observations of the real world. Oh yea, I’ve read about this. It is certainly an interesting anamoly. IMO, the simplest explanation is that there is something wrong with our understanding of the complex process of tree growth rather than thermal absorption of gases. Then again, I’m more of a physical sciences guy. So maybe tree rings aren’t the best indicator of climate. That would be a bummer, but not because it has any say on AGW. It’s nice to have historic data that seems to corroborate AGW, but unless the data is shown to contradict AGW it really doesn’t mean anything one way or another. AGW comes down to the physical absorbtion of thermal radiation by CO2. You can debate figures on how much warming it will cause, but you can’t argue that it wont cause warming without violating physical laws. That is falsifiable. ---
**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:** [June 30, 2009, 5:16am UTC](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911/100 "2009-06-30T05:16:51Z")
> [@Blake](#): > > And as a result the only way AGW can be falsified is if we wait 50 years. Until then it can’t be validated as science. It \*\*is \*\*falsifiable in any any case. And I still agree with **wevets** that there are still other items that can falsify AGW. [Previous page](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911.md?page=4) [Next page](https://boards.straightdope.com/t/is-anthropogenic-global-warming-falsifiable/499911.md?page=6)