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Comments 96551 to 96600:
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apiratelooksat50 at 04:57 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
Dana @ 32 "you are neglecting physics. Previous Holocene temperature changes had physical mechanisms causing them - changes in solar, volcanic, etc. forcings. They were not caused by "magical natural cycles"." 1. Are the physical forces of solar, volcanic, etc... not natural? 2. Are you stating those forcings are not factors now? 3. Magical... Really? -
Daniel Bailey at 04:43 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
The disingenuity of the myth is made even more plain by looking at Arctic Sea Ice Extent even further back in time:
Science: Using all of the data to see the bigger picture.
The Yooper
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Daniel Bailey at 04:33 AM on 8 February 2011Crichton's 'Aliens Cause Global Warming'
Indeed. At one time, the "Consensus" was that Divine Happenstance determined rulership. As far as evidence for global warming, any lay person with Internet access can download empirical measurements of temperatures and see for themselves the warming of the world. Even if they eliminate up to 90% of the station data, the warming is still there, present even in the raw data itself. Nice post, Alden. The Yooper -
dana1981 at 04:19 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
The problem here is that there are two categories of "natural" forcing mechanisms which Spencer and pirate are incorrectly equating. 1) Natural physical mechanisms which we know can and have exerted a radiative forcing on the climate system, but which cannot explain the warming over the past century (solar, volcanic, orbital, etc.) 2) Spencer's mysterious "internal forcing" hypothesis which has almost no supporting evidence, no concrete physical mechanism, and is an entirely new concept. Putting Spencer's hypothesis on the same scientific footing as known natural radiative forcings is inappropriate. But that's basically what Spencer is arguing for. -
Steve L at 04:16 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
John, I've never seen Fig 2 before. There are a couple of things I find interesting there: there are a lot of missing data at the end of 1987; the annual average is higher than the midpoint of the range (even prior to 2007). I'm ignorant about why either of these things happened. -
michael sweet at 03:49 AM on 8 February 2011Global Warming and Cold Winters
Mozart: I provided you a link to prove my claim of record warmth in 2010. You have made an unsupported assertion that cold records exceed warm records in 2011. Provide a link to your wild, unsupported assertion of cold records exceeding warm records in 2011. The record warm temperatures at the start of January in Greenland, as much as 25C above normal for weeks, exceed anything you will be able to find for cold anywhere in the world. I had this discussion with another sqeptic last month, they cited record warm temperatures as evidence that it was getting colder because it was only 10C warmer than normal. Deniers love to make wild unsupported claims and waste our time chasing down the correct data. If you cannot provide data you must withdraw your wild claim. -
Mike Palin at 03:45 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
Please note that Harrison Schmitt's more recent, and in this context more relevant, credentials are as a politician in the Republican Party. That trumps his earlier training as a geologist or astronaut. -
dana1981 at 03:43 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
Joe Romm at Climate Progres just covered Articgate too. http://climateprogress.org/2011/02/07/harrison-schmitt-climate-science-denier-arctic-sea-ice/ -
Phila at 03:28 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
Pirate: (we could just as easily create a label called natural climate change deniers), Not without being hugely dishonest, you couldn't. The current understanding of AGW is partly the result of a long process of ruling out known mechanisms for natural climate change. An unwillingness to take vague, unsubstantiated guesswork about "unknown mechanisms" seriously is not "denial"; it's a demand for evidence. The fact that you can't provide that evidence is not our fault, or our problem. It's yours. it takes a leap of faith to abandon the repetitive, observed natural climate changes over the history of the Earth (both on the short and long scales) in favor of climate change wholly induced by the actions of humanity. No, it takes decades of observations and careful data-gathering by people who know much, much, much more about the science than you do. The fact that you refuse to accept those observations and that data because they make you ideologically uncomfortable is not our fault, or our problem. It's yours. -
Dikran Marsupial at 03:27 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
apiratelooksat50: Can you answer the question I posted in 27 directly? "With no measurable, testable, empirical difference between today’s temperature cycles and temperature cycles during the Holocene, the alternative AGW hypothesis necessarily fails." Not being able to disprove the null hypothesis does not disprove the alternative hypothesis. Nobody can prove that evolution didn't happen purely by random mutation rather than being driven by natural selection, but that doesn't mean that the theory of Darwinian evolution "necessarily fails". -
hengistmcstone at 03:26 AM on 8 February 2011Medieval Warm Period was warmer
Thanks to JMurphy who has provided me with some interesting reading which I accept. But I still see a problem with this. On the one hand SkS is saying the causes of the MWP are (largely) solar irradiance - the sun's output. On the other hand it is argued that the MWP may well have been a regional effect not global. How can these two arguments exist side by side? Greater solar irradiance would have an effect across the planet. In essence the intermediate answer to this Skeptic argument "To claim the Medieval Warm Period was warmer than today is to narrowly focus on a few regions... Globally, temperatures during the Medieval Period were less than today." negates the need for (and it could be argued unpicks) the basic argument -
dana1981 at 03:24 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
apiratelooksat50 #30 - you are neglecting physics. Previous Holocene temperature changes had physical mechanisms causing them - changes in solar, volcanic, etc. forcings. They were not caused by "magical natural cycles". Moreover, I don't think there have been any cases of 0.8°C warming in 100 years or 0.55°C warming in 35 years previously during the Holocene. Thus there is a difference between current and previous warming events. -
paulgrace at 03:24 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
I don't know about Schmitt these days, but many geologists work for or associate with other geologists that work for extractive industries, in the pursuit of fossil carbon to burn. I suspect this may expose them to significant pressure to view greenhouse gas issues from a particular slant. -
Same Ordinary Fool at 03:23 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
When you sit on top of a rocket, you must trust the science behind the engineering on which it was built. How would he have felt if the underlying science were a "skeptic science" that came from just 3% of the publishing scientists? And, in particular, that these scientists were the rump contingent, a predictable group in every scientific field, that resists the new research. And what would he have thought of the "heretic skeptics" campaigning for positions that the 3%'ers are unlikely to believe, and certainly couldn't profess in serious circles. And yet these "heretic skeptics" are the largest part of the movement. Did Harrison Schmitt ever think that he would become one? PS See geologist Richard Alley's video lecture, "The Biggest Control Knob, Carbon Dioxide in Earth's Climate History" http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtmlModerator Response: [Daniel Bailey] Converted URL to clickable link. -
Dan Moutal at 03:22 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
The comedian Marcus Brigstocke has a good analogy to this situation: saying that this is like standing at a train station and watching a 6 foot tall man walk through the gate. Then ignoring every single other person that also walked through the gate half an hour later seeing a midget walk through the gate and conclude that OH MY GOD PEOPLE ARE SHIRNKING!!! Or in other words, cherries are delicious. -
dana1981 at 03:20 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
A couple of points are worth noting. First, as discussed in the article and in more detail by Mark in #8, Spencer does sort of have an alternative hypothesis. It's that some unknown mechanism is causing cloud cover to change, perhaps through some unknown heat redistribution. It's not exactly just hand-waving "natural cycles", though I don't think it's far from it. I agree with Mark that it's the most plausible alternative to AGW put forth, but that's not saying much. Secondly, scientists can choose any null hypothesis they want for any given study. If they want to disprove "natural" causes, they can set the null hypothesis to "global warming is being caused by natural effects". Spencer's problem is that almost all climate scientists are convinced the warming is anthropogenic, so that's effectively their null hypothesis. Basically he wants them to continue trying to disprove "natural causes" when they're already convinced it's anthropogenic. My reaction to that is "tough sh*t". Like I said, any study can set any null hypothesis it wants. Spencer is free to attempt to disprove AGW, or attempt to prove his "internal radiative forcing" hypothesis. But the evidence is overwhelmingly on the side of AGW, so climate scientists are entirely justified in using it as their null hypothesis. apiratelooksat50 #25 - 50% is the minimum amount of warming over the past century that humans can be resposible for, unless climate sensitivity is below the consensus range of many different lines of evidence (2 to 4.5°C for 2xCO2). And physics is not a leap of faith. -
apiratelooksat50 at 03:12 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
The null hypothesis is the statistical hypothesis that states that there are no differences between observed and expected data. With no measurable, testable, empirical difference between today’s temperature cycles and temperature cycles during the Holocene, the alternative AGW hypothesis necessarily fails. -
MichaelM at 02:40 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
I would enjoy CSI: RSVP where corpses lie around with bullet wounds and axes sticking out of them and they are all deemed to have died of 'natural causes'.Moderator Response: [Dikran Marsupial] ;o) However, can we keep comments substantive (I am thinking here of RSVP's orignial post rather than your reply- the use of "natural" to mean "non-anthropogenic" is well established and causes no genuine misunderstanding). -
mozart at 02:38 AM on 8 February 2011Global Warming and Cold Winters
Really? We have something other than a model forecast? What would that be, a time machine? The fact is both the carbon and temperature projections require exponential responses. The most basic requirement of any model is that it duplicates known outcomes when fed with historical data. Something these models have always struggled to do. The veiled antagonism to any contrary view illustrates your problem. A strong bias hardly ensures good science in such an uncertain and complex field. Nor does the constant explaining away of contrary data with increasingly concepts. -
mozart at 02:16 AM on 8 February 2011Other planets are warming
The sun's output is still higher than any time in the entire century before 1950. Cirrus values may be consistent with rising tempsModerator Response: See the Argument "It's the Sun." -
RSVP at 02:11 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
Are humans now not part of nature? Even if global warming were wholely "anthropogenic", the idea that man is not a part of nature seems strange. -
Dikran Marsupial at 02:08 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
@apiratelooksat50 For a hypothesis to be a valid scientific theory it needs to be falsifiable. If you think the hypothesis is valid, give me an example of an observation that would falsify it (i.e. an observation that would be impossible if the hypothesis were true). -
Alden Griffith at 02:05 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
whoops - I didn't mean that to be an ad hominem remark. Sorry, if it reads that way.Moderator Response: [Daniel Bailey] Don't worry, it's pretty clear that it's not an A-H remark. -
Dikran Marsupial at 02:05 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
Icarus wrote: "All we need to know is whether, all other things being equal, elevated atmospheric CO2 causes elevated global temperature, and by how much." The fact that the rise in atmospheric CO2 is rising due to anthropogenic emissions is easily established*, hence if we know elevated atmospheric CO2 causes global temperatures to rise and by how much, we automatically know it is due to our activity. "So really the null hypothesis should be "atmospheric concentration of carbon dioxide has no effect on global climate"" Spencer can't use that as the null hypothesis as he says the warming (without feedback) from a doubling of CO2 is about 1 degree F, and that that statement is not contentious (see here). Very few skeptics think that CO2 is not a greenhouse gas, so they can't use a null hypothesis that they know from basic physics must be false. They generally argue that climate sensitivity is low and that negative feedback will prevent much warming (one wonders what happened to the negative feedback during the PETM event) Dr Spencer's null hypothesis is the right one, just inadequately specified; however the only way to specify what is plausible under "natural variability" is to build a model incorporating the known physics of the natural climate (given observed forcings other than anthropogenic emissions), and that has already been done and published in the IPCC WG1 scientific basis report. *If the natural environment were a net source of CO2 to the atmosphere, then (assuming conservation of mass) the annual rise in atmospheric CO2 would be greater than anthropogenic emissions, however the observations show this is not the case, the rise is only about 45% of anthropogenic emissions, so we know the natural environment is a strong net carbon sink, and hence is not the cause. -
apiratelooksat50 at 02:04 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
Dr. Spencer's challenge has validity. I do think it could have been worded better. It should be noted that his challenge does allow for the influence of anthropogenic CO2 on the current warming. What we know: 1. Climate has changed in the past due to external and internal forces. 2. Even with the higher CO2 levels, this interglacial period appears to have maxed out at more than 2 degrees on average below the previous 4 interglacials. 3. CO2 is a greenhouse gas and helps contribute to the vital warming of the planet. 4. Through the combustion of fossil fuels and landuse practices - man has contributed CO2 to the atmosphere and is partially responsible for the current rise in CO2 levels. Dr. Spencer is asking for a paper ruling out natural, internal climate cycles as the cause of "most" of the recent warming. That certainly leaves the door open for the contribution of CO2, and more specifically anthropogenic CO2, to the mix. According to one of your links above, in the past 150 years 50% of the 0.8 degree C rise in surface temperatures can be attributed to man. This isn't the place to squabble over those figures, but for the sake of discussion that is a contribution, not a cause. Most of us "deniers" (we could just as easily create a label called natural climate change deniers), agree that CO2 contributes to warming which contributes to climate change. We also think that man's land use practices contribute to weather and climate. However, it takes a leap of faith to abandon the repetitive, observed natural climate changes over the history of the Earth (both on the short and long scales) in favor of climate change wholly induced by the actions of humanity. -
Alden Griffith at 02:02 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
To me, this has nothing to do with area of expertise, but simply represents appalling analytical skills that are unacceptable in any discipline. Imagine a student in their graduate-level comprehensive exam trying to make a claim based on two data points that completely misrepresents the clear longterm trend. Fail. -
jonathansf13 at 01:20 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
A different way to state many of the comments here might be the following: For over 100 years there has been a developing theory that anthropogenic CO2 would warm the earth's climate. Then, in the past 30 or so years, evidence has been building that the climate is warming. The scientific process is then obligated to test the most prevalent theory, and it seems to me that is what has been happening in climate change literature. The theory of AGW via CO2 emissions consistently rises to meet all challenges, to date, while other hypotheses are either not sufficiently flushed out to have become "theories", or they are "flushed out" by the process. Spencer's complaint seems to miss these points entirely. He has every right to look for an alternative mechanism, but until he or someone else comes up with something that can be tested, it does not merit the time of the scientific community to test. It seems to me that there are some in the climate modeling community that could do a great service by taking a shot at parameterizing models with values provided by Spencer. If he cannot provide the parameters, then he has little to complain about. -
muoncounter at 00:42 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
#21: "Carbon dioxide is a perfectly natural substance and its atmospheric concentration varies due to natural causes," Perhaps you meant to say "concentration varies within limits due to natural causes." The A part of AGW is the excursion outside those natural limits. See Human CO2 is a small % or similar thread. -
Kevin C at 00:34 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
SNR: "Re null hypothesis: In the absence of identifiable factors, the null hypothesis must be that the temperature is constant. As soon as there is some change observed, "natural" factors can not have any priority in explanatory models, this is plain natural science." I'm not sure that's the case. Suppose (fictitiously) that we knew from multiple measurements that the sun was getting warmer, and that this was universally accepted. However there was a debate over whether this was the only factor affecting the climate, or whether there were other environmental factors causing more or less warming than the solar forcing, then the null hypothesis would be warming from the sun alone. So I think that the idea of a null hypothesis is actually often a social construct. In the type of simple cases you get in statistics and philosophy texts there is often a hypothesis that uncontroversially fills the 'null hypothesis' space. But I'm not sure that that is generally the case. But maybe the null hypothesis is determined by the question being asked? So if we ask 'is there warming', then the null will be no warming. If we ask, for our fictitious planet, 'is there non-solar warming', then the null will be solar-explained warming. But what happens if we reword the question? How about if we ask 'is there no warming?'. OK, that's an obvious trick . But if we have a different set of preconceptions from which the hypothesis of no warming looks surprising, then that becomes a sensible question. So I think I come back to the position that in non-trivial cases null hypotheses are socially constructed. In the case of a consensus, then the null hypothesis is primarily shaped by the consensus position. If that's correct, then the null hypothesis among scientists would be a climate sensitivity of ~3C, and the onus is again on Spencer to provide an alternative hypothesis. Of course we also exist in a social and media environment in which the consensus may be different. Which means you have to shift your null when talking to different groups. Messy! -
Icarus at 00:21 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
It seems to me that characterising the issue as one of natural vs. anthropogenic causes is missing the point. Carbon dioxide is a perfectly natural substance and its atmospheric concentration varies due to natural causes, so we only need to know whether and how that atmospheric concentration affects the global climate. In terms of the effect it has, it makes no difference at all whether a change in atmospheric concentration of CO2 is natural or anthropogenic. All we need to know is whether, all other things being equal, elevated atmospheric CO2 causes elevated global temperature, and by how much. Similarly for methane, albedo, aerosols and so on - all are naturally occurring factors which affect global climate, and in terms of the physics involved it makes no difference at all whether they are changing naturally or due to human activities. The effect on climate will be the same either way. So really the null hypothesis should be "atmospheric concentration of carbon dioxide has no effect on global climate" (and similarly for the other factors). Proving that these factors are changing because of human activities is a separate issue. Spencer is really just setting up a false dichotomy between 'natural' and 'anthropogenic' causes, when the real issue is "does increasing CO2, CH4 & N2O cause global warming?" and similar questions. He can't challenge AGW by citing imagined 'natural climate cycles', as if by discovering such cycles he could somehow change the laws of physics for the radiative properties of greenhouse gases. Science doesn't work that way. If there was some unknown natural cooling factor offsetting the warming from the proven effects of increasing greenhouse gases then there would have to be yet *another* unknown natural factor having an equal and opposite *warming* effect to offset the unknown natural *cooling* effect, thus leaving the known enhanced greenhouse effect intact... which is the same as saying that the known enhanced greenhouse effect is what is causing the current warming in the first place. -
SNRatio at 00:19 AM on 8 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
I wonder if it may have to do with failure to fully acknowledge the non-linearity of many effects. After all, 32 times as high CO2 as now is just five doublings, and it is not that much change in solar output needed to balance that. Feedbacks are mostly based on net forcing. As for this man, either he is making statements without having checked the underlying data, or he is consciously making an misleading presentation. I don't know what is worst. But I _really_ doubt he would say "temperatures have now returned to January levels" after a frosty night in April. -
RickG at 00:11 AM on 8 February 2011How We Know Recent Global Warming Is Not Natural
Dana1981. From the article: Dr. Spencer has proposed an alternative to the anthropogenic global warming theory. He suggests that some unknown mechanism has caused global cloud cover to decrease over the past century. Just wondering. If decreasing cloud cover lets more solar irradiation in, wouldn't ground based instrumental records show an increase in solar irradiation outside the solar cycle over the past 30 years? And since no increase over that period been shown, wouldn't that make Spencer's decreasing cloud cover hypothesis false? -
Dikran Marsupial at 23:55 PM on 7 February 2011CO2 lags temperature
Poptech@256 My opinion on E&E's reviewing standards has been formed by reading many of the papers published there that have been actively discussed. Many of them are badly flawed. If your opinion differs, that is fine, but if you want to change my mind on this, what is your evidence that the standards are as high as any other journal? As to Beck, the fact that refutations were published (with rejounder from Beck) is a confirmation that the peer-review failed. If a paper contains an error bad enough to warrant correspondance it should have been picked up by the reviewers and it shouldn't have been published (in that form) in the first place. Impact factor is not subjective in any way, it has an objective mathematical defintion. It may be discredited in the notes on your list, but gven that you have just demonstrated that you don't know what an impact factor actually is, it devalues your critique somewhat. -
SNRatio at 23:52 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
Re null hypothesis: In the absence of identifiable factors, the null hypothesis must be that the temperature is constant. As soon as there is some change observed, "natural" factors can not have any priority in explanatory models, this is plain natural science. On the other hand, natural factors can of course not be dismissed before they are checked out of the case. But they can not be assigned any importance on the basis of speculation or belief, even if they should later turn out to have importance. One basic problem with falsifying Spencer/Lindzen hypotheses about climate sensitivity, is that it is not a well-defined parameter that can be precisely estimated from a small set of observations. Rather, it is a "real" random variable, with a wide range of values possible - and observable. Therefore, it may be relatively easy for them to cherry-pick situations that seemingly support their assertions. As it is to pick examples supporting high sensitivity. The relevant issue here is not singular realizations, but long-term averages under the conditions that will prevail during the next several decades. And here, observations tend to support common consensus. Which is not strange, that consensus is established from a wish to get the best possible estimates, whether high or low, not from hypotheses about low sensitivity that seem to disregard much of the available evidence. -
littlerobbergirl at 23:41 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
would Bayesian analysis help? a very very low chance he is right, a very high chance everyone else is. (i had to look up the spelling, shouldnt use stuff i dont really understand lol) -
dorlomin at 23:38 PM on 7 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
Bern at 23:16 PM on 7 February, 2011 Schmitt is a geologist. What is it about some geologists that they get climate so completely wrong, to the point of making statements that are flatly contradicted by recent measurements? = = = = = = = = = = = = = Some of them do get quite foxed by CO2 levels in the early and mid Phanerozoic, they were notably higher. But then again that is more the solution to how we avoided freezing over with much lower solar energy. -
Kevin C at 23:27 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
Dikran: "Spencer has a hypothesis, but it is not yet a scientific hypothesis as it hasn't reached the point where it can make prohibitions on what we can observe so that it has the potenital of being falsified even if it is false. Until the null hypothesis is well-defined is meaningless to ask for papers where it has been rejected." Oh yes, you're right. I hadn't picked out the full nuance there. I think there is a rhetorical game going on too - labelling a particular hypothesis as 'null' in all but the most trivial cases has become a game of trying to grab the 'neutral' ground. -
Bern at 23:16 PM on 7 February 2011Articgate: perpetuating the myth that Arctic sea ice has recovered
Schmitt is a geologist. What is it about some geologists that they get climate so completely wrong, to the point of making statements that are flatly contradicted by recent measurements? -
Esop at 22:50 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
Seems like at least some of the "skeptics" are already abandoning the Global Cooling meme that they have been pushing for a number of years. I expected them to do that and replace it with "ok then, it is warming, but it is natural" sooner or later, but I had not expected it until 2012/13, as that will likely be the new record year. -
Eric (skeptic) at 22:47 PM on 7 February 2011The 2010 Amazon Drought
Rob Painting, I think that is an oversimplification. Reading through the Zeng paper (link in 20) I noticed that Zeng cannot separate the Atlantic warming from ENSO. It is certainly no coincidence that El Nino was present in 2005 and 2010. But it is true that ENSO is not the only factor involved. It is also true that El Nino does not always cause Amazon drought, but it is correlated along with La Nina and more rain in the Amazon. -
Dikran Marsupial at 22:30 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
Kevin C "Spencer has a hypothesis involving clouds, it's just not fleshed out to the same level of detail as the mainstream CO2 hypothesis." That is essentially my point, Spencer has a hypothesis, but it is not yet a scientific hypothesis as it hasn't reached the point where it can make prohibitions on what we can observe so that it has the potenital of being falsified even if it is false. Until the null hypothesis is well-defined is meaningless to ask for papers where it has been rejected. The funny thing is that climate modellers are perfectly happy to tell you what is consistent with climate variability, just look at the spread of the model runs (it is why model ensembles are useful). So we are in the funny situation where a challenge has been laid down where the challenger (apparently) won't say what is consistent with "natural variability" is, and won't accept the answers of climate modellers who will! -
Kevin C at 22:01 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
Actually, I think it is a little more subtle than a simple falsification question. If the 2nd-hand sources I'm reading are correct, Spencer has a hypothesis involving clouds, it's just not fleshed out to the same level of detail as the mainstream CO2 hypothesis. So the ideal here would be to develop a detail climate model based on Spencer's hypothesis and test its performance against existing climate models. It might perform better or worse, although I'd expect several iterations of peer review before drawing a fair conclusion. But here we run into a difference between 'the scientific method' and 'how science is done'. What I've described above is consistent with the scientific method (falsification, Bayes, etc), but falls down in practice because resources are finite. The system as described could be sabotaged by a flood of underdeveloped hypotheses which need to be tested and falsified. Indeed this may already be happening. 'How science is done' brings in extra factors - peer review, consensus. Things which have evolved as practical measures to make science work reasonably efficiently. Peer review as a junk filter, consensus as a mechanism to say 'stop - we've tested this hypothesis enough different ways, we haven't proven it (and never will), but it is good enough to be going on with'. Without these, science becomes bogged down (and thus Delingpole's peer-to-peer science can never work - under his model biology would do nothing but retest the theory of evolution over and over again to try and satisfy the IDers). So, I think on the basis of 'how science is done', the onus is on Spencer to demonstrate that his model can provide predictions which are both testable and as specific, and at least comparable to those provided by existing models. If he can do that, the 'the scientific method' will come into play to test them further. I may of course be giving him too much benefit of the doubt - after all I haven't read his papers and would not be qualified to judge them if I did. -
BillyJoe at 21:35 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
Post #1 is an "ad hominem" attack. I trust it will be removed by the censor. (Otherwise I want my comment about Monckton restored ;)) -
JMurphy at 21:16 PM on 7 February 2011CO2 lags temperature
Funny (but unsurprising, going by past form) to read Poptech 'correcting' others (this time Scopus) and telling them the 'truth' as he sees it - just like he did with Pielke Jr when he decided (against Pielke's wishes) to include his papers in his little list of what he believes confirms his own version of AGW 'alarm' - whatever that is. No matter. He will believe what he wants to believe and no-one else can tell him otherwise. And he does have to do his utmost to defend E&E, because so much of his little list rests on papers from that source, but we can look at some quotes to do with E&E, with links from the same WIKIPEDIA page that Poptech failed to acknowledge : "On our Energy and Environment paper from 1999, had we known then how that outlet would evolve beyond 1999 we certainly wouldn't have published there. The journal is not carried in the ISI and thus its papers rarely cited. (Then we thought it soon would be.) We were invited to submit a piece in 1997 or 1998 and we had this in prep and sent it in." Roger Pielke Jr again (Wait for Poptech to 'correct' Pielke Jr...) "Sonja Boehmer-Christiansen[Editor of E&E], a reader in geography at the University of Hull, in England, says she sometimes publishes scientific papers challenging the view that global warming is a problem, because that position is often stifled in other outlets. "I'm following my political agenda -- a bit, anyway," she says. "But isn't that the right of the editor?"" Chronicle of Higher Education, 4 September 2003 "Plimer repeatedly veers off to the climate sceptic's journal of choice, the bottom-tier Energy and Environment, to advance all manner of absurd theories: for example, that CO2 concentrations actually have fallen since 1942." Michael Ashley, Professor of Astrophysics at the University of NSW -
Paul D at 20:49 PM on 7 February 2011Monckton Myths - a one-stop-shop for Monckton misinformation
I think Monckton brings a new meaning to the term 'political science' :-) -
Rob Painting at 20:29 PM on 7 February 2011The 2010 Amazon Drought
Chris G @ 16 - There is evidence that they have become more intense over the last century (at least one coral study that I remember but can't cite at the moment There's a few, but this study illustrates what your're talking about: Teleconnection between tree growth in the Amazonian floodplains and the El Niño–Southern Oscillation effect - Schongart 2004 From the abstract: "El Niño causes anomalously low precipitation in the catchment that results in a significantly lower water discharge of the Amazon River and consequently in an extension of the vegetation period. In those years tree rings are significantly wider. Thus the tree-ring record can be considered as a robust indicator reflecting the mean climate conditions of the whole Western Amazon basin. We present a more than 200-year long chronology, which is the first ENSO-sensitive dendroclimatic proxy of the Amazon basin and permits the dating of preinstrumental El Niño events. Time series analyses of our data indicate that during the last two centuries the severity of El Niño increased significantly. -
Rob Painting at 20:21 PM on 7 February 2011The 2010 Amazon Drought
Eric (skeptic) - as far as 2005 & 2010 Amazonian drought are concerned, they are unrelated to ENSO (El Nino). They arise from the warm sea surface temperatures in the tropical Atlantic. From your comments thus far, it's not clear you have understood this. -
HumanityRules at 19:25 PM on 7 February 2011A Case Study of a Climate Scientist Skeptic
Glenn the difference between your analogy (#69) and mine (#68) seems to be that you are changing the flow rate between the two vessels while I alter the flow rate into the whole system. I would have thought the effect of CO2 is to alter the rate of in flow into the whole system rather than between the two vessels. Stabalizing CO2 would return the net infow to the whole system to zero and equilibria is restored by the natural flow of water into the ocean vessel. I accept that the ocean vessel should be much larger than the air vessel but shouldn't the value in your system be controlling flow into the system rather than between the two vessels? I also didn't mention in my example when the radiative forcing stops increasing and after equilibria is restored then both vessels will be fuller than before the increase of radiative imbalance. -
Dikran Marsupial at 19:14 PM on 7 February 2011How We Know Recent Global Warming Is Not Natural
The fundamental problem with Spencer's hypothesis is that it is unfalsifiable. As there is no specified mechanism or model that can be used to predict what observations are and are not consistent with the hypothesis, it is impossible to disprove. Karl Popper (very influential figure in the philosophy of science) wrote that the thing that distinguishes science from pseudo-science (e.g. astrology) is that there is always at least the possibility that a scientific hypothesis can be falsified. This means the hypothesis needs to make prohibitions on what can happen, the more prohibitions it makes, the better the theory. Clearly Spencer's hypothesis of "natural cycles" is not a scientific hypothesis, at least until he specifies the mechanism sufficiently that something is ruled out by it. Essentially, you can't prove any hypothesis by experiment or observation, all you can do is disprove, and to disprove a hypothesis it needs to be falsifiable (i.e. if the hypothesis is false, it must in principle be possible to show that it is wrong, and to do that there has to be some observation that would be impossible if the theory were true.). Note that mainstream climatologists do that all the time, that is exactly what climate models are for, making predictions that can be proven wrong by observation. Now where are the skeptics falsifiable predictions? I pointed out this objection on Dr Spencer's blog, last time I looked (Saturday), he hadn't answered it and my subsequent posts are in some sort of moderation limbo, make of that what you will. -
Dikran Marsupial at 18:55 PM on 7 February 2011CO2 lags temperature
Poptech@253 I agree, E&E *is* a peer reviewed journal; the problem is that the peer viewiew at E&E regularly fails and publishes papers with obvious gross errors (e.g. Beck). As a result, the journal is not very highly regarded, the papers it publishes are not widely cited and it has a low Impact Factor. That doesn't mean papers are wrong just becuase they are published in E&E, they stand and fall on their won merits.
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