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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 122601 to 122650:

  1. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Humanity rules touches on an important point about the petition that seems to have been missed by most critics. Apologies for anyone who has seen this comment before that I have posted elsewhere. "Re: the Oregon petition. I have been trying to spread my view on an aspect of the wording of the petition which seems barely to have been noticed. It is a misleading nature of the statement that even Jim Hansen could have legitimately agreed with. The wording in the petition is: There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gasses is causing or will, in the foreseeable future, cause catastrophic heating of the Earth’s atmosphere and disruption of the Earth’s climate. The weasel words are a)”is causing or will”, b)”catastrophic” and c)”disruption”. The first is an absolute statement. Even if the scientific evidence said there was a 99.99 % chance, then that is still not absolutely definite is it? A pernicketty type could not deny the very small possibility that the climate may not react as we think, so they would have been able to sign with a clear conscience. The second and third effectively put forward the straw man that climate science is saying that the worst scenarios will come to pass, warming will be at the very top of the scale and we will definitely be screwed. As the science and evidence does not state that categorically, again people can sign legitimately. The wording also seems to only restrict consideration to that warming likely to be caused by human emissions – it cleverly leaves out feedback emissions. The relatively small increases of temperature that human emissions alone are causing, and will cause, directly will, in turn cause feedback emissions (water vapour, melting permafrost, clathrates etc) that probably will cause the rises in temperature that are likely to be dangerous and lead to climate disruption. The petition implies that it only is concerned with direct human emissions. Just my interpretation, because I have really not seen any dissection of the actual wording – or if it’s been done it’s not widespread as a counter argument to the validity of the views of those who signed it. Nick Palmer "Sustainability and stuff according to Nick Palmer"
  2. HumanityRules at 21:06 PM on 11 March 2010
    Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    From the petitions home page. "There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gasses is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate." For me the important word in that sentance is catastrophic. It is difficult to actually lump all individuals who are critical of the state of climate science, the castostrophic predictions or the anti-human agenda it promotes as having one brain that denies all the science. For example assuming the Richard Lindzen on the petition is the same Richard Lindzen of Wikipedia's list of climate deniers then here is his position according to Wikipedia. "We are quite confident (1) that global mean temperature is about 0.5 °C higher than it was a century ago; (2) that atmospheric levels of CO2 have risen over the past two centuries; and (3) that CO2 is a greenhouse gas whose increase is likely to warm the earth (one of many, the most important being water vapor and clouds). But – and I cannot stress this enough – we are not in a position to confidently attribute past climate change to CO2 or to forecast what the climate will be in the future." I'm not even sure this form of analysis is valid. What percentage of any population would sign a contentious petition not matter what the subject. Especially one that would potentially expose them to co-workers, employers and funding bodies. In fact even those with little to hide aren't on there. I had a quick scan for some of the more infamous 'denier' names I know and couldn't find them. It's a dull and pointless exercise but feel free to give it a go. My experience of radical politics is that very few people are willing to put their head above the parapet when the nature of the politics goes against the prevailing current in society. Relatively small numbers of people in the 1950s, 1960s and even into the 1970s openly supported gay, black or womens rights, this did not make them unworthy fights.
  3. Arkadiusz Semczyszak at 21:00 PM on 11 March 2010
    Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    D. B. Klein, C. Stern The Independent Review, Spring 2009 "Generally speaking, we can observe that the scientists in any particular institutional and political setting move as a flock [!!!], reserving their controversies and particular originalities for matters that do not call into question the fundamental system of biases they share." —Gunnar Myrdal, Objectivity in Social Research "Perhaps we avoid studying our institutional lives because such work is not valued by our colleagues. The academy is, after all, a club, and members are expected to be discreet. Like any exclusive club, the academic world fears public scrutiny. Research is in the public domain. Outsiders [!] might use what the research reveals against the academy." —Richard Wisniewski, "The Averted Gaze" "The thousand profound scholars may have failed, first, because they were scholars, secondly, because they were profound, and thirdly, because they were a thousand. [...]" —Edgar Allan Poe, "The Rationale of Verse"
  4. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    So what we can conclude is that the OISM doesn't contradict the polls. With years to self select, we're on <1% of what they call 'scientists' (hey look, I'm now a 'scientist', thanks OISM!) they've collected 0.3% signatures. Polls seem to find over 80% support amongst Earth & atmospheric scientists, so it's no surprise they got 0.3% of them to sign a petition saying otherwise.
  5. Watts Up With That's ignorance regarding Antarctic sea ice
    CBDunkerson As far as feedback, I was talking about albedo. All you need is a thin covering of frost on the ground to make it white and increase reflectivity. You could have a km of ice melting below you, but that shouldnt affect this particular variable.
  6. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Perhaps the OISM should be as open in supplying the raw data on which their survey was based as they expect the UEA's CRU scientists to be with theirs?
  7. Watts Up With That's ignorance regarding Antarctic sea ice
    RSVP, thank you for perfectly demonstrating my point. Yes, sea ice coverage around Antarctica has increased slightly. Thus, that portion of the planet's ice is growing. Of course... it comprises less than 1% of the total. The LAND ice on Antarctica, which is 90% of the ice on the planet, is melting... as is the 9% of ice on Greenland and the remaining part of 1% found in the Arctic sea ice and total glacier mass on the other continents. So, as I said... the NET change is melting ice and a positive feedback. No matter how much 'skeptics' insist on seeing ONLY the minuscule fraction of ice which is growing.
  8. Watts Up With That's ignorance regarding Antarctic sea ice
    Tadzio, no most of us are amateurs too... we've just been at it a while now. I really can't tell you precisely what happens with deep water currents around Antarctica. Obviously they have to mix with the rest of the oceans, but how quickly that happens and/or exactly where I couldn't say. Sorry about the difficulty in getting answers. With so many debates going on a single post on a tangential issue tends to get lost. Best advice is to just keep reading. As you pick up more it gets easier to fit the pieces together.
  9. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Mike: 'I wonder how, say, neurosurgeons would react to a survey of particle physicists on their opinions of brain tumour treatment? Or what veterinarians think of the latest on loop quantum gravity?' As a psychiatrist, it happens to me all the time. I've learnt to live with it. Actually the added burden of accountability to the public at large while at times discomfiting has been a good thing for my profession.
  10. Every skeptic argument ever used
    This Nature article is interesting on Roman/Medieval/Little Ice age periods. The article describes research using clam shells instead of tree rings to look at the past climate.
  11. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    nerndt at 17:18 PM on 11 March, 2010 How well does near-vacuum conduct? You really ought to read Spencer Weart's history of climate research, here: The Discovery of Global Warming It's a fun read and once you've digested it you'll be much better prepared to deal with the finer points of the topic. Honestly, I don't want to sound supercilious but conduction is really not the issue here.
  12. Watts Up With That's ignorance regarding Antarctic sea ice
    CBDunkerson "The snow and ice cover of the planet is melting." My impression from the article was that ice cover was growing in Antartica, and please explain how it is melting at -17 C ?
  13. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    "I would be curious, RSVP, as to what you would answer to this question if given yes or no option in a survey." It is a meaningless trick question (for the reasons stated), but I would have to say "yes".
    Response: Thanks, I appreciate the response.
  14. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    It is ironic also that it is the experts who spend the most energy testing their own theories. The experts "require" empirical evidence to back their claims. If they are so sure of themselves, why do they continue to take measurements?
  15. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Unlike those that have commented that it is unnecessary to count heads I found this to be quite an interesting post and worthwhile. If statistics are being bandied about by the media over how many scientists agree/disagree with the concept of AGW then I think it is very important to know how these statistics are being obtained. The sad fact is that the vast majority of people will not do follow up research on these sort of statements, or about AGW at all and will get all their information from mainstream media sources. If these sources do not explain how the data has been obtained (and that would not make it nearly as sexy and controversial), then it must come from a post such as this. I also have a science degree, but I would definitely not consider myself a scientist, and I do know people who completed the same degree as me who would still rather believe quack theories on some subjects over proven scientific research. So while a science degree may teach scientific process, it can’t make all graduates apply it in all situations. Based on this I think it is valid knowing that the “scientists” in the OISM petition are no more qualified than myself. I have an opinion, but I would never pass myself off as an expert just because I have a degree, flattering though it would be to be considered a scientist!
  16. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Exactly what kind of people need to be convinced of AGW if it isnt precisely the educated class that appears in these lists? ...and as far as the question: "Do you think human activity is a significant contributing factor in changing mean global temperatures?". ...the wording is pretty loose and would be hard for anyone to deny. To say "significant contributing factor" isnt say much of anything. 4% could be considered "significant", for instance, we are talking about a pay cut, or increase in taxes. And anyone who lives in or near a city, (and that is about nearly anyone), knows very well that urban sprawl adds heat, which would necessarily "contribute" to an increase in mean "temperature". As I have said in earlier posts, a big problem with the marketing of AGW is that it doesnt restrict its claims nor provides precision in its definition of global warming. Why wasnt the question simply construed as: "Do you think human activity causes global warming?" ...since the letters AGW, afterall, say nothing more than this.
    Response: The wording of the question "Do you think human activity is a significant contributing factor in changing mean global temperatures?" was chosen in order to compare the results to a Pew survey that asked the same question.

    I would be curious, RSVP, as to what you would answer to this question if given yes or no option in a survey.
  17. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Geo Guy (#3): Do you feel that a housewife who has an undergraduate geology degree but taught middle school science as her career has equivalent expertise to a climatologist who has worked in the field for decades? I ask because, by your own statements, this hypothetical housewife is "qualified to reject any statement that they believe was reached at through a faulty process," even if she has never studied climate science. That's one of the main problems with the OISM petition - it produces a false equivalence between expertise in climate and expertise in other, totally unrelated fields, purely on the existence of a Bachelor of Science degree. The other point of my post is that, by the OISM's own criteria, their 31,000 signatories do not represent a "significant number of scientists who disagree...." Using the OISM's criteria, 31,000 people represents only 0.3% of all scientists. This is the difference between an absolute measurement and a normalized measurement - yes, 31,000 sounds like a lot of people, but in reality it's a tiny number when compared to the entire defined population.
  18. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    @4, chriscanaris makes an interesting comment with:
    "...a survey of what tertiary educated individuals with some background in the sciences might think is of some relevance so long as it is represented as no more than that".
    Yet unfortunately it is represented as more than that most of the time. The Petition Project is regularly trotted out as evidence that large proportions of real, qualified and practising scientists active in the field of climate studies have grave and serious doubts about what is published in the relevant literature. This is quite clearly not the case. Additionally, is a survey of people in other scientific disciplines any more or less valid than asking an intelligent layperson what their opinion is? I wonder how, say, neurosurgeons would react to a survey of particle physicists on their opinions of brain tumour treatment? Or what veterinarians think of the latest on loop quantum gravity?
  19. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    "I am curious as whether it is the younger scientists (who incidentally have more to lose) entering their careers as the oldies retire that will be the determinate of what improves the consensus in the statistics.' Peer review is a double edged sword. It may ensure quality or it may function as covert censorship in the setting of competing paradigms - a major problem when people have a huge emotional investment in an idea or a notion. Sometimes, peer review seems no more than a rubber stamp. Ultimately, there is no substitute for critical appraisal of the basic science (and climate science, while very complex, thankfully stays within the realms of Newtonian physics making it accessible to to the non-specialist).
  20. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    After subscribing to these posts for the past few months, it is clear that too much discussion is focused not on the true science of the problem. "What % of qualified scientists believe this or that?" Copernicus, Galileo, Einstein would all have been extreme minorities but with scientific insight and observation, the vast minority found reason and correct analysis. Much more research into measuring temperatures across both the atmosphere at low, medium and high levels, calculations showing energy gain/loss of solids versus liquis, versus gases must be made to determine where the true energy gains and losses are made. I am a lowly MS in AeroAstro from Stanford and I have strong misgivings about the true science that has been presented on the subject, yet I have little doubt about other scientific phenomena that have been discovered and modeled using engineering principles and equations. When will someone show more valid scientific data instead of roundabout opinions? Basic energy transfer ideals makes me think that most energy gain and loss by the earth is via heat conduction via the land and oceans, and virtually little by means of the atmosphere (i.e. gases). Once steady state occurs (energy coming in from the sun balances energy going out from the atmosphere), balance occurs. Heat retention in air is minimal compared to that of heat retention in liquids and solids. Can someone scientifically comapre those rates and relate them to the conditions of the earth with the energy it is constantly exposed to by the Sun? Mankind seems to always be so confident that they know the truth, until the lack of their knowledge shows them the folly of their ways. Please think about my post before denying keeping it.
  21. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    RE# 3 Geo Guy: I can assure you that over 80% of my colleagues have a serious doubt about the findings of the IPCC. That seems pretty significant, do you have any ideas of which parts or working group of the IPCC that is disagreed on? I too encounter people, although it is almost always the older 'grey'crowd at the office who are the more skeptical of climate science. My PhD student peers when we are not "busy" with our projects debate quite a lot about climate science but we accept the basic science (and some of us are in the Skeptics Society so we know what skeptic means) I would be very interested to see the average age of the scientists who are "climate skeptics". The most famous ones I can think of Plimer, Monkton, and Seitz are pretty old (by my standards at least :P) My old (now very much retired) physics lecturer used to tell us that when he was an undergraduate there was still quite a few of the older respected physicists out there who outrightly rejected Einstien's General Theory of Relativity. I am curious as whether it is the younger scientists (who incidentally have more to lose) entering their careers as the oldies retire that will be the determinate of what improves the consensus in the statistics.
  22. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    in my humble opinion, AGW proponents do not further their argument by trying to discredit those who question the science just because they do not have a 'climate science degree'. Human Caused Climate Change debate is not like proving F=ma. It is much more complex and the more I learn, the more I realize I don't know. When other science was debated in the past such as general/special relativity, Chandrasekhar limit, heisenberg uncertainty principle, etc. the average person had no real world comprehension of these topics and unless one was educated in quantum mechanics, astronomy or cosmology it was difficult to grasp. Few people, even with advanced science degrees, could understand the concepts enough to debate them. Notice that there are no websites dedicated to disproving Pauli's exclusion principle! And it is a sad commentary on our education system that we don't have better math/science education to allow more to understand these theories but it was Einstein who said (paraphrasing) that if you truly understand a topic on a fundamental level you can explain it in simple terms (i.e. E=mc^2). With Climate Science, the language is in temperature, ice, snow, water vapor, IR absorption, sea level, etc. so People have a real world understanding of that and hence anyone with a website and an idea can attempt to debunk it - though many are lacking the science to do that correctly. Climate Science is quite complex and as someone who is learned in the underlying physics of Astronomy/Cosmology with a dose of quantum mechanics and electrical engineering I can appreciate the complexities of this study. And i feel competant enough to read the peer reviewed papers, analyze measured data, compare AGW theories to observations, pose my own questions and draw conclusions. And anyone who understands the underlying physics can and should become educated in the field and seek their own answers through the peer reviewed literature and the observations. I think the Climate Science community should welcome the newfound interest in Climate Science and seek to understand this complex system through the scientific method. The fact that there are large numbers on both sides of this argument should tell us something. And not all can be explained away by politics and association with Coal/Energy sectors. Let's understand this complex system to the point where it can be explained in simple terms and understood by all - because the climate affects everyone.
  23. Antarctica is gaining ice
    Geo Guy at 16:23 PM on 11 March, 2010 Many references, but you won't cite any? Not even the one you quoted which I might add without a cite is not cricket, either; the authors I'm sure would appreciate attribution. From your further comment I take it that aggregated data is insufficient but a single year of data is? I don't find your approach persuasive.
  24. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    >>97.5% of climatologists who were actively publishing papers on climate change responded yes.(Doran 2009). >>What is most interesting about this study was that as the level of active research and specialization in climate science increases, so does agreement that humans are significantly changing global temperatures.<< This plays right into the hands of the "no funding without a cause" crowd of denialists. - Larry Weisenthal/Huntington Beach, CA
  25. Antarctica is gaining ice
    doug_bostrom at 07:12 AM on 10 March, 2010 There are many references to be found on the Internet, linked to valid scientific journals citing the rapid growth in the vast majority of the Antarctic landmass. I will leave it up to you to find them. In response to the author's response to mt comment: Being a geologist that has undertaken many gravity surveys, I am hesitant to make any interpretation based on aggregated data as you have done. It implies that the observed decrease is consistent throughout whereas that is likely not the case. You will get melting on the fringes and accumulation in the center - but the ice forming through the accumulation of the snow in the center is not the same as the ice that is melting on the fringes, which by the way shows a significant increase in ice mass from 2004.5 to 2005.5 suggests something else is happening or the data needs to be reviewed. The other point I will make is that a five year trend analysis, In addition,
  26. Watts Up With That's ignorance regarding Antarctic sea ice
    Hi ,Thank you CBDunkerson for being a bit more prescient about my question , yes I was wondering about the less saline water keeping the warmer heavier currents at the botttom and if there where any studies as to where these waters are forced to go ? . I guess iam a bit out of my league here most of you guys sound like actual scientist where as iam just nonscientist trying to understand a mutlidisipline problem . also iam scared cuase no one is listening !!! thanx daved
  27. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    I meant "sociology of science, history of science, and philosophy of science."
  28. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    gallopingcamel, consensus plays a huge and crucial role in science. It is different from simply voting, but it is consensus nonetheless. That fact rarely is emphasized in introductory classes on science. A short addressing of the role of consensus in science is a few slides in Naomi Oreskes's "Consensus in Science: How Do We Know We're Not Wrong?" More depth on the topic can be gotten from any number of books on sociology, history, and philosophy of science. To avoid duplicating my own comments (which would violate the Comments Policy), I'll just link to some relevant ones: 195, 196, and 197 on the thread There is no consensus. Probably that is the more appropriate thread if you want to discuss the role of consensus in science rather than the OISM petition specifically.
  29. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Folk with medical degrees (such as myself) are certainly not climate scientists. However, we do know something about scientific method, consistency and coherence of conclusions derived from data, validity, reliability, peer review, and the behaviour of complex systems. We also know a bit about lobbying by industrial groups (drug companies) and spend a great deal of time helping patients manage risk. We also know a fair bit about scientific fraud. We have also seen fashions come and go. Ultimately, folks such as myself become part of conversations which may influence the way someone votes (not that I would ever do that in my practice of medicine). My participation in this forum is one such conversation. I imagine a number of other participants on this forum are in a similar position, non climate -scientists, yet interested enough in a hot topic (pun intended) to engage with the issues. Consequently, a survey of what tertiary educated individuals with some background in the sciences might think is of some relevance so long as it is represented as no more than just that.
  30. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    I think that too much effort is being spent trying to disqualify or undermine the different sides to the argument and this post is a good example of this. Every scientist, no matter what background they come from, understand due scientific process and from that understanding alone, they are qualified to reject any statement that they believe was reached at through a faulty process. As for climate scientists themselves - what constitutes being one? Perhaps we can look at the World Meteorological Organization as starters - the UN organization established to facilitate the gathering of meteorological observations and promote the standardization and uniform publication of observation and statistics. It was through the WMO that weather forecasters switched from saying "a good possibility of rain" etc to assigning a probability (ie 60% chance of showers). I bring this point up because the purpose stated when the switch was made was simply that people did not understand phrases like slight chance, strong probability etc but felt a percentage assigned to a forecast was more meaningful. In other words when they say "60% chance of showers, there is no relation whatsoever to true probability from a statistical perspective, but rather they assign a percentage to allow people to better believe their forecast. In the end it has not resulted in better or more accurate forecasting. Instead of questioning the credentials of people on a list, even if 50% were found out to be incorrect, that still leaves a significant number of scientists who disagree with the findings of the IPCC. As a geologist with over 35 years of experience, I can assure you that over 80% of my colleagues have a serious doubt about the findings of the IPCC. In the end I guess we should look to the UN who recently agreed to appoint an independent commission to look into the activities of those scientists who were involved in the published findings of the IPCC reports, even though I have my doubts as I believe it was the way in which the UN established the IPCC in the first place that contributed to the poor scientific process used to generate the IPCC reports.
  31. Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    "Science is not a matter of counting heads......" So why do denialists continue to count them? I think as long this keeps happening, it is entirely fair play to continue to shoot this nonsense down in flames.
  32. gallopingcamel at 15:14 PM on 11 March 2010
    Guest post: scrutinising the 31,000 scientists in the OISM Petition Project
    Science is not a matter of counting heads so my advice to AGW Alarmists is to forget about it. The IPCC "scientists" may be heavily outnumbered by Noah Robinson's Myrmidons (>30,000 and counting) but it means nothing except to politicians who think in terms of "votes". The folks who wrote this post need to lighten up; this is something to laugh about.
  33. It's not bad
    Vinny Burgoo at 11:37 AM on 11 March, 2010 When assessing the importance of any single component of a population's water supply, it is important to remember that water needs to be available always, and the available quantity required at any given time is bounded by definite lower limits. I've seen a lot of criticism of water supply impacts based on the notion that "only" 20%, 10% or 5% of a given total regional water supply is sourced by glacial and snowpack meltwater. If during certain times of the year the component that is only 20% of an annual supply represents 50% of the instantaneous available flow, the perspective of persons depending on that supply will be rather different than for those of us sitting in our armchairs at safe remove, wondering what the problem is. Not to be repetitious, but tell an engineer that you're going to remove reservoirs supplying 20% of a water utility's capacity and he should not worry because the annual total amount of water passing by his system will remain the same and that engineer will think you crazy. As to the rather arbitrary separation of snow and ice meltwater sources, if as we can expect glacier disappearance is accompanied by more rapid melting of snow the current budgetary components of melt water sources are of less use in predicting future impacts of glacier loss. This hair-splitting about impacts of changes in regional water supplies resulting from warming is at the end of the day not very flattering to so-called skeptics. Rummaging around for minor flaws in citations is not a robust counter-argument.
  34. Trenberth can't account for the lack of warming
    Gianfranco: "Travesty" is one of those words a lot of English speakers commonly misuse. In fact, many people use it as a synonym for "pity", but with extreme emphasis. John: Terrific post and explanation, by the way. I think this is a nearly perfect example of the way such wholly accurate and innocent statements can be misconstrued by those looking for a good misconstruing.
  35. Scientists can't even predict weather
    Marcel Bokstedt, regarding chaos, please also see the Skeptical Science post Climate is chaotic and cannot be predicted.
  36. Scientists can't even predict weather
    Marcel Bökstedt at 09:54 AM on 11 March, 2010 Be sure to read Weart's retrospectives on the evolution of climate models. Getting the whole story will help clear up a lot of misunderstandings about how climate models function, what it is they're skilled at predicting, how skilled they are: Simple Models of Climate Change General Circulation Models of Climate Pretty fascinating just for the history if nothing else.
  37. It's not bad
    JC: 'I notice Kehrwald 2008 cites the IPCC AR4 as their source so until I track down the IPCC's peer-reviewed source (most likely Barnett 2005), I've removed Kehrwald.' Would that help? Kehrwald et al. offers several contradictory estimates of the number of people in South and East Asia who rely on water from melting glaciers. Would a peer-reviewed source for any of them really confer legitimacy on self-evident nonsense? Kehrwald's largest estimate: 'TP ice fields are a critical resource for one sixth of the world’s population'. 'TP' is 'Tibetan Plateau'. In Kehrwald, 'Tibetan Plateau' has at least three different meanings. Let's assume that this one was 'Himalayas plus Karakorams plus Hindu Kush plus Pamirs plus the Tibetan Plateau proper and the mountains on its western and northern rims'. Are the glaciers in this large region a 'critical resource for one sixth of the world’s population'? Er, no. Does any peer-reviewed literature say that they are? Probably. Does Kehrwald's cited source say that they are? No. The 'one-sixth' claim was attributed to AR4 WG2 Chapter 10, which says nothing of the kind. If not pure invention, it was probably a misattributed mangling of Barnett, which claimed (on very dodgy grounds) that 'more than one-sixth of the Earth’s population [relies] on glaciers and seasonal snow packs for their water supply'. Snow *and* glaciers. Worldwide, not just 'TP'. And note that Barnett's 'one-sixth' didn't include people living on the Gangetic plain. (He got something right.) The only other attributed claim in Kehrwald (750 million seriously affected) comes, it is said, from the Stern Review via WG2 Ch10. Stern did say something like that but its cited sources didn't support it. Things get complicated here, so I won't go further unless you insist. JC: 'I find it interesting that you'd 'remove the whole thing' - do you think the whole issue of threatened water resources for such a large proportion of the population is not worthy of concern?' I find it interesting that you are happy to accept that the water resources of such a large proportion are threatened. Peer-reviewed crap is still crap.
  38. Berényi Péter at 11:18 AM on 11 March 2010
    Watts Up With That's ignorance regarding Antarctic sea ice
    #84 Ned at 00:34 AM on 11 March, 2010 "Okay, for April I get a trend that is almost but not quite significant" I don't know what you did. Here are the data files for April and May. There are two separate columns in each at end of lines, one for sea ice extent, the other for area. Extent is defined as sea surface covered by at least 15% ice, area is actual ice cover. Trend slope (least square fit), mean & dispersion is calculated for each time series. Null hypothesis: Series is stationary, data points are realizations of independent random variables with normal distribution, mean & dispersion is same as calculated from data. Question: What is the probability (p-value) of slope being not less than calculated for actual data? Answer: April sea ice extent: 0.0295 April sea ice area: 0.009 May sea ice extent: 0.0212 May sea ice area: 0.0088 For sea ice extent null hypothesis is rejected at 95% (actually 97%) confidence level, for area it is 99%, both months. Looks pretty significant. Trend for April sea ice area is +26,060 km2 year-1 (+16% in 30 years). As extent is also increasing, ice covered area gets some (86 W m-2 average at TOA between 60-70S) sunshine in April, not much (24 W m-2) in May. Albedo increase is not negligible (up to 1020 J absorbed shortwave is lost compared to that of thirty years ago). "the Turner 2009 paper addresses your point about the seasonality of ozone depletion -- although the hole reaches a maximum in austral spring, models and observations show that its effect on circulation in the troposphere is greatest in summer and autumn" Funny. For some reason the ozone hole all but disappeared in 2002. And there is a dip in sea ice area for both April and May in the same year. Right? In this year ozone hole area is just 12 × 106 km2, half of last two decade's average, minimum ozone is 155 DU, 50% larger than average. But wait. Ozone hole occurs in Southern Hemisphere spring, so spring 2002 comes later than autumn, same year. One would not fancy precognition of ozone hole conditions by sea ice. Fall after this barely-hole is April-May 2003. Sea ice area is fourth largest on record. Of course it would be somewhat more correct to look at correlation between ozone hole extent & transparency and sea ice extent half a year later, but I would prefer not to re-digitize graphs. A pointer to ordinary data files, anyone?
  39. Scientists can't even predict weather
    Marcel Bökstedt, what you say is quite strange given that the physics behind climate models is very similar to that of weather predictions models.
  40. Peter Hogarth at 10:16 AM on 11 March 2010
    Visual depictions of Sea Level Rise
    Charlie A at 17:07 PM on 9 March, 2010 Concentrating on the gentle start of rise in sea level from about 1800, this is attributed to warming. A recent paper examines the causes: Anthropogenic forcing dominates sea level rise since 1850 Jevrejeva, Grinsted and Moore 2009 “We show that until 1800 the main drivers of sea level change are volcanic and solar radiative forcings. For the past 200 years sea level rise is mostly associated with anthropogenic factors. Only 4 ± 1.5 cm (25% of total sea level rise) during the 20th century is attributed to natural forcings, the remaining 14 ± 1.5 cm are due to a rapid increase in CO2 and other greenhouse gases”.
  41. Marcel Bökstedt at 09:54 AM on 11 March 2010
    Scientists can't even predict weather
    I'm not totally convinced about the accuracy of climate prediction, for the following reasons. Weather predictions are based on physics, which we understand reasonably well from a theoretical point of view. It seems to me that the main limiting factor when we predict the weather is not a question about limitations of the model used. The problem is that the model itself depends very sensitively on the initial conditions. My impression is that the limiting factor of climate prediction is different. They is not based on a theoretical understanding of the long term average of the models used to describe weather. It would probably be far too difficult to justify on theoretical grounds that the long term climate are NOT chaotic. That is, I don't believe that the statement above of what "the science says" can be justified by theoretical computations. Correct me if I'm wrong (but I don't think so). However, it might be possible to justify the statements by observations. My impression is that climate prediction is to a large extent based on observations. It is an attempt to systematize the data we have collected. That is of course an excellent method, but it makes the field more similar to biology or geology and less similar to physics. If we had a long series of observations of the global weather, we could inspect the data and check that up to some small uncertainty, climate shows no signs of being "chaotic". What makes me unsure is that we don't have that much assembled observational material. We don't have reliable global observational data for more than a century or so, and if we go back more than a thousand years, its almost all in the grey. The time scale is small compared to the time scale of climate changes. It is not at all clear to me that the series of observations is long enough to produce a reliable theory from available data, in particular to state that climate is "not chaotic". Also, the idea of systematizing a theory from observations must be based on some version of "all situations we encounter are similar to a situation we have seen before, so we can base our predictions on that similarity, and assume that history will repeat itself". We can predict climate change that is similar to climate change we have already seen. But we are (most likely) changing the climate into something we have not seen before, something that is not covered by previous observations - so how can we be sure that our model works in this new situation? If the model were based on theory, that would be an argument in itself, but if the model is based on observations, we should be less confident. The argument cuts two ways of course. If we are discussing the effects of human activities, uncertainties in current climate predictions could as easily underestimate them as overestimate.
  42. Watts Up With That's ignorance regarding Antarctic sea ice
    Peter @82, You did not specify the months either when you first mentioned the "significance" of the positive trend, nor when you asked me for the link (you are welcome by the way). Not knowing which months you were referring to, I then made a reasonable choice corresponding to the timing of the max. and min. extents, respectively. So they were not "the wrong months", as you claim. Then you provide unsubstantiated claim @82 that the positive trend is stat. sig. in the SH fall. Well, when Ned actually calc. some p-values he found that the positive trend was stat. sig. at 95% level of confidence in May only. Why did you not specify the months in question up front? Anyhow, I agree with what Ned said @84.
  43. Watts Up With That's ignorance regarding Antarctic sea ice
    WAG "Is anyone surprised at Watts? Just last week he claimed that an article from 1989 proved global warming was a hoax." No I'm not surprised. Especially after reading about he a D'Aleo concocting charts and making this claim. "NO WARMING TREND IN THE 351-YEAR CENTRAL ENGLAND TEMPERATURE RECORD" Long story short, they skipped the 19th century and only used summer temps. In the 18th century summers were indeed on the cool side. However winters were warmer than usual, so they didn't include them. http://tamino.wordpress.com/2010/02/15/summer-and-smoke/ How can anyone put their faith in Anthony Watts after that?
  44. Watts Up With That's ignorance regarding Antarctic sea ice
    For a truly detailed analysis of the years climate was in Antarctica and the implications look at the BAMS state of the climate 2008 report. Take a look at the full report link beginning on page 113. This is a big region and the story is not straight forward BAMS 2008
  45. HumanityRules at 01:57 AM on 11 March 2010
    Watts Up With That's ignorance regarding Antarctic sea ice
    This is a great review from 2009 which seems to sum up the present extent of our knowledge on the subject quite nicely. Here's a few points I took from it. 1) There is no warming trend over the continent except for the penninsular. 2) The cooling trend is probably caused by ozone changes but other explanations exist. 3) Apart from the penninsular all trends are very small. 4) There is no climate change signal in the antarctic historical temp data. That signal will only emerge later this century. 5) Climate models predict there should be a signal in the historical data as well as predicting reduced ice extent. The fact that models and observations differ remains unexplained. (I should add this review is very much with the consensus on the arctic data.)
  46. Have American Thinker disproven global warming?
    Yes, thanks, Steve, for that link! It explains clearly and thoroughly what I tried to explain in my comment 90 "Gary, you keep arguing that AGW theory requires OLR in the CO2 bands to decrease, while you refuse to allow any detailed qualifiers in that prediction.... [But] the actual prediction is not a short, obligatory phrase of introduction from a paper. The actual predictions are the models' outputs." Much more clearly, the author of ScienceOfDoom wrote
    For the authors of the paper to assess the spectral results against theory they needed to know the atmospheric profile of temperature and humidity, as well as changes in the well-studied trace gases like CO2 and methane. Why? Well, the only way to work out the “expected” results – or what the theory predicts – is to solve the radiative transfer equations (RTE) for that vertical profile through the atmosphere.... Now it is important to understand where the temperature profiles came from. They came from model results."
  47. Have American Thinker disproven global warming?
    Thanks, Steve. That looks like an interesting post. I only had time to skim it now, but I look forward to reading more carefully later.
  48. HumanityRules at 00:38 AM on 11 March 2010
    Watts Up With That's ignorance regarding Antarctic sea ice
    Response to #72 Apologies for the cynisism, I had written something longer but it got lost in the ether. I had alot more to say on the subject such as the whole body of work that links the arctic climate to the ENSO and AAO index variation. This explains many of the observations seen in the region without resorting to global warming. Or the real disagreements about whether the continent is warming up or actually cooling down. The AVHRR data seems to contradict land based measurements. Or the curious fact that the Zhang theory seems to rely on the fact that ice is melting at an increased and decreased rate simultaneously. I don't see in Zhang were he describes increased precipitation as a driving force. For him it's reduced salt rejection which is surely lost once ice extent begins to increase.
  49. Watts Up With That's ignorance regarding Antarctic sea ice
    Berényi Péter writes: "Check April and May." Okay, for April I get a trend that is almost but not quite significant at 95% (p-value 0.06). For May I get a trend that is barely significant (p-value 0.04). That's without any correction for temporal autocorrelation. My guess is that autocorrelation in sea ice extent over time scales >= 1 year is probably relatively slight, though such a correction would probably reduce the trend significance a little. It might be enough to make the May trend non-significant at 95%. If anyone cares, they can do the test. But here's the real point. BP continues: "The finding is robust, begs for an explanation. ... Ozone depletion is a spring phenomenon, most expressed in October, separated from sea ice by 180 degree phase shift. " "An explanation" is exactly what John's post at the top of this thread provides. And the Turner 2009 paper addresses your point about the seasonality of ozone depletion -- although the hole reaches a maximum in austral spring, models and observations show that its effect on circulation in the troposphere is greatest in summer and autumn. Have you actually read Turner 2009? I'm puzzled as to why you would say (paraphrased) "There's a slight increase in Antarctic autumn sea ice extent that needs to be explained" ... when the entire point of this thread and Turner 2009 is "There's a slight increase in Antarctic autumn sea ice extent and here's the explanation."
  50. Antarctica is gaining ice
    protestant also writes: Also i'd like to point out that "glacier melting" is no evidence to claim that global warming is still happening (NOR that its man made). You're right. If we had no other evidence that fossil fuel combustion produces CO2, and no other evidence that CO2 absorbs infrared radiation, then we wouldn't be able to conclude that anthropogenic greenhouse gases were warming the earth just from measuring glacier retreat alone. Fortunately, we have a great deal of evidence that already resolves these points. The loss of ice from glaciers and polar ice sheets is important for two reasons: (a) as an additional source of confirmation that demonstrates agreement with the many other lines of evidence of climate change, and (b) as an important consequence of climate change that will have large negative impacts on our economy and on social welfare in many countries by increasing sea levels.

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