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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 104601 to 104650:

  1. Climate is chaotic and cannot be predicted
    Norman, a "chaotic system" is characterized by non-linear dynamics (yep, lots of those in climate change) and by extreme sensitivity to initial conditions (nope, not the case with climate). The behavior of a chaotic system is very predictable - it will vary around it's attractor. Weather is chaotic, in that it varies hugely around the climate means due to the initial conditions - hence the ever changing state of sun, wind, rain, clouds, etc. The strange attractor for weather provides variability, and the extreme sensitivity to initial conditions (temps, humidity, clouds, etc., which we known only to a certain degree of accuracy) prevents accurate weather forecasts weeks in advance. But climate, as defined as long term averages, is not chaotic. If top of atmosphere IR decreases, there is an energy imbalance, the climate will warm. If the sun decreases it's output, there is an energy imbalance, and the climate will cool. The very nature of a running 20-30 average smooths the chaotic weather effects - and the "climate", although non-linear, is predictable to some degree of accuracy. It's not chaotic.
  2. Berényi Péter at 02:38 AM on 15 November 2010
    Solving Global Warming - Not Easy, But Not Too Hard
    #138 michael sweet at 12:21 PM on 14 November, 2010 I read some of your Nanotechnology Roadmap and I see no mention of fixing gigatons of carbon. They rely on fossil fuel for their carbon. Molecular nanotechnology simply needs carbon, whatever the source may be. As long as carbon based geo-fuels are abundant and cheap, they may be used for this purpose (as they are currently for plastics). However, it was your claim "in 200 years when all the oil, gas and coal have been used up" people would get in trouble. I doubt it, but if it happens, the next most obvious source of carbon is the atmosphere, isn't it? Molecular nanotechnology is the ability to build precise structures at the molecular level according to a pre-defined blueprint, where each atom has its specific place and is held there by strong covalent chemical bonds, resistant to thermal excitation under normal environmental conditions. It can be made cheap only by using molecularly precise self-replicating programmable constructors (called "assemblers" by enthusiasts) in molar quantities (102X of them). Each of these molecular machines would need some 1012 atoms, most of them carbon of course, at least for their structural backbone. Sounds familiar? Plants use ribosomes as self-replicating constructors and chloroplasts for photochemical carbon capture. And guess what? They do not use geo-fuels (that's done by underground bacteria), but atmospheric carbon dioxide, many hundreds of gigatons annually. The only trouble is plants (or bacteria or whatever) are not optimized to serve specific engineering purposes, but to produce more similar structures (according to a pre-defined blueprint stored in DNA). Ribosome, the programmable molecular constructor they rely on is not a universal one either. It can only put together arbitrary chains of 20 amino acids, fixed by peptide bonds, their folded 3D structure being often stabilized by secondary disulfide bridges between remote cysteine members of the chain. All the other large functional molecular machines (like tRNA molecules, ribosomal subunits or chlorophill) are constructed in ad-hoc reaction pathways driven by protein-based machines called enzymes. The same is true for most of the structural polymers like cellulose or chitin. We can obviously hack into these molecular machines. If it is done, it's called biotechnology. However, there is much more to carbon chemistry than the tiny segment covered by this God-given machinery. Some of the most powerful possibilities like diamondoid structures, nanotubes, graphene or Fullerenes are not accessible through this path at all. Carbon is pretty unique in its versatility. No doubt some structural diversity can be attained using silicone heteropolymers, but it does not even come close to carbon. Therefore industrial usage of carbon as the default structural material is expected to go up steeply in the future (meaning many gigatons of the stuff), replacing most other raw materials. At some point relative shortage of carbon is inevitable. On the other hand energy is not expected to be in short supply. Solar radiation is abundant, even at ground level (much more so in space, inner solar system). At the moment there is no economically viable way to use it, because cheap and efficient temporary storage is lacking, but with advanced molecular nanotech it should be easy to manufacture micron sized solar plants en masse (that could be applied to sunlit surfaces as paint), producing some nonflammable, not toxic energy-rich chemical (like sugar), storing it locally and later on turning it into electricity on demand by adjacent microscopic, molecularly precise fuel cell engines. As solar radiation at ground level on Earth is intermittent and has low power flux density, terrestrial land use requirements of solar power are high, even with the most advanced technology. Open surfaces that could be put to dual use without competing for sunlight with plant life, like roads or rooftops have limited extent. Therefore some more compact long term power source is also needed, presumably a nuclear one. The 3He-D fusion reaction is promising, as all the participants have electric charge (no free neutrons), therefore with appropriate arrangement no nuclear waste is produced. A molecularly precise design using smart materials with exotic electromagnetic properties and fast control should enable us to use very short acceleration paths to overcome the 3He-D potential barrier in an energy-efficient manner. 3He reserves in the lunar regolith are estimated to be about 2.5 million tons, enough for thousands of years. The same stuff in the atmosphere of gas giants is practically inexhaustible. With an abundant energy supply, we can forget about shortage of any raw material for a long time. Sorting atoms needs free energy, but from a thermodynamic point of view energy requirements are only proportional to the logarithmic rarity of the component to be extracted. With program-driven engines operating at the molecular level, we can get pretty close to the thermodynamic limit. Nuclear fissile material like uranium and thorium are also abundant in the crust. With molecular sorting capability these resources are inexhaustible, even in the long run (hundreds of million years). With closely controlled proper breeder technology all the long half-life reaction products can be eliminated or fed back to the reaction, making long term (hundreds of thousand years) nuclear waste storage unnecessary. Molecular machines, if their design is redundant enough and they have self-repairing capability can withstand quite high levels of radiation (as it is demonstrated by some bacteria). Therefore they can be used to sort nuclear waste as needed. Current new age Luddite trend of CAGW scare does not help to resolve real problems and implement knowledge extracted from long term basic research as engineering solutions. They are very successful in raising legal obstacles to R+D and investment, but fail to promote necessities, as worldwide compulsory industrial liability insurance for example. At the turn of 19th/20th century there was a horse manure scare. The stuff was supposed to flood cities by the end of 20th century and cover them in a several feet deep layer. What's happened in fact is quite the opposite. I have learnt from my grandpa that horse manure is best for nurturing cucumbers. But unfortunately it is in such a short supply by now, that it took me several weeks to get some. With advanced nanotechnology we can overcome all the present day pollution problems as well. Assemblers (the universal constructors mentioned above) can also be used backwards, as disassemblers (universal programmable deconstructors). They can be programmed to take things apart to their constituent atoms or small (and harmless) molecular compounds, making them accessible to re-assembly. That's what God's nanotech was doing for billions of years, successfully. Temperate forests grow on their own litter, year by year. Yet, they fail to turn into a refuse dump, because an intricate web of disassemblers are at work in the soil, all of them of the most precise design at the molecular level.
  3. forensicscience at 02:01 AM on 15 November 2010
    How significance tests are misused in climate science
    Climate sciencei is heavily reliant on proxy data and hence statistical methods, probably more than other empricial sciences are. Its not surprise that this part of the science comes under such heavy scrutiny. However, I would imagine that if climate scientists were in any doubt relative to natural variability they would not have published so many peer reviewed articles. So rather than bring up the subject we should be asking why so much literature on th subject if it has little or no merit?
  4. How significance tests are misused in climate science
    #23: "75% of climate science papers use statistical significance in a "misleading" way. Does that mean you think these are all written by "deniers"?" No, but it does mean that 75% of climate denier posts are misleading -- and that's significant.
  5. How significance tests are misused in climate science
    19.Eric L Erm this paper suggest 75% of climate science papers use statistical significance in a "misleading" way. Does that mean you think these are all written by "deniers"? Drop the rhetoric and stick to the science. 2.Daniel Bailey "Entirely scientific graph: Who worked out there were 17 pirates in 2000?
  6. Climate cherry pickers: cooling oceans
    BP #19 Note that I have used THEORETICAL 'observed' in parenthesis BP. I am well aware of the fact that the REAL observed number from CERES is 6.4W/sq.m. You should read more of my pieces on this blog. I got pilloried here making your point on MODELS: http://www.skepticalscience.com/Real-experts-dont-know-everything.html#30319 on "Real experts don't know everything" I was taking the 145E20 Joule number from Trenberth's Aug09 paper Table 1: http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/EnergyDiagnostics09final2.pdf Note that 'Observed' is used in Trenberth's Table 1 and the text pp23 notes that "The net imbalance is estimated to be 0.9W/sq.m" Trenberth reconciles the 0.9W/sq.m number in Figure 4 of the same paper which uses the IPCC AR4 Fig 2.4 Table of forcings PLUS climate responses - S-B radiative feedback of -2.8W/sq.m and WV + Ice Albedo feedbacks of +2.1W/sq.m He derives the S-B cooling from a 0.75degK increase in surface temperature since a AD1750. WV and Ice Albedo positive feedback +2.1W/sq.m is from Trenberth and Fasulo - an approximation. Perhaps you could turn your considerable (and oft referenced by me)talents to the history of this major climate response feedback (WV + Ice albedo) and whether it is real or theoretical too!!
  7. Climate is chaotic and cannot be predicted
    #18: "Here is a model of Earth's temp (simple model). It calculates Earth temp" There's nothing at all chaotic about this model; its just a demonstration of two straightforward equations. One of them just happens to have T4, which makes it sensitive -- not chaotic. Here's a definition of 'chaotic behavior'; note that it mentions 'weather,' not climate. You may be mistaking 'chaotic' with 'sensitive to change.' For example, in this image of a chaotic system, the position of the swinging pendulum (ie, the weather) depends on where it is when the machine starts. However, the envelope of possible positions (ie, the climate) is entirely predictable.
  8. Climate cherry pickers: cooling oceans
    And one final comment re : Daniel Bailey's comment, Which model do you choose? The ensembles are very course in their predictions and dont appear to have any particular specific skill over relatively short timescales.
  9. Climate cherry pickers: cooling oceans
    Bah, I should have kept reading. Re: Berényi Péter's comments ...Yeah, what he said :-)
  10. Climate change from 40 million years ago shows climate sensitivity to CO2
    Norman, a greenhouse effect greater than 70 F is entirely possible (after all, Earth's is currently about 60 F). Also, the 70% factor on sunlight was about 4.4 billion years ago while the timeframe Mars is believed to have had water is in the 4.1 to 3.5 billion years ago range... when the Sun was closer to 75% of current brightness. We know Earth had liquid water in this timeframe. There is strong evidence Mars did too. Yet sunlight alone clearly couldn't have caused that. Sunlight and more pronounced greenhouse effects (hardly surprising in the early volcanic history of the newly formed planets) could have.
  11. Climate cherry pickers: cooling oceans
    "Note that ocean heat measurements still find a positive energy imbalance - the planet is still accumulating heat - just not as much as the satellite data at the moment." Dont lose sight of the fact that it could be the satellite data that is wrong. Satellite data due to its complexity is far from a slam dunk its entirely possible the corrections need to be made to it and not the OHC data (or even some combination of the two but how would we know?) Its easy to put a stake in the ground and declare the satellite data as the "truth" in this, but that in itself is a significant assumption considering satellite data itself goes through processes of correction.
  12. The science isn't settled
    Eric #29: I reject the idea that good scientists would not look for counter-evidence that is not biased or tainted by their current theories Einstein: Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the "old one." I, at any rate, am convinced that He does not throw dice. Me: So Einstein questioned Quantum Mechanics by appealing to philosophy, an "inner voice" or religon, but not to any counter-evidence. Given that scientists are human beings, have belief systems and make their names by publishing it seems unlikely that any of them, which ever side of the debate they are on, would be completely unbiased, if only subconciously. What we should insist on is that the science as a whole be unbiased, not the individuals practising it.
  13. The science isn't settled
    Tom, I had to break my rule after adding "empirical" to your google search for "string theory". In the first link returned http://www.chowk.com/articles/8213 the author might suggest that I am a logical positivist, stuck in the early 1900's. The author says "Einstein, Dirac and many other scientists had intuitive kind of faith in the correctness of their theories without empirical evidence." He goes on to say they used subjective criteria to underlie that faith. I have that same faith in my theories of the world except I am not capable of venturing into relativity except where it is actually empirical. Given new evidence or new theories that conflict with mine, I will change to the combination of old and new theories that are completely consistent with the evidence. As for (objectively) statistical evidence, I am probably guilty of what Hoekstra http://pbr.psychonomic-journals.org/content/13/6/1033.full.pdf calls "probability as certainty" or "binary thinking". I take the view that most of those cases are avoidable, that direct evidence is available. While you again appeal to the concept of "theory-laden" observations, I reject the idea that good scientists would not look for counter-evidence that is not biased or tainted by their current theories. I think we will have to agree to disagree on that.
  14. Climate change from 40 million years ago shows climate sensitivity to CO2
    #69 RVSP Using this calcualtor tool: Calculates temp in absence of GHG. Is it possible Mars could have had water with a faint Sun? In the past, if the Sun was 70% as bright as today, Earth would receive 958 watts/m^2. Mars receives 2.5 less radiation than Earth so it would have only received 383 watts/m^2. The lowest the calcualtor goes is 800 watts/m^2 you have to interpolate the rest. Find a higher number on the solar scale and drop it by 417 watts/m^2. Watch how that lowers temp. Then look at the Earth's temp at 800 watts/m^2. Take that temp number and subract from it what you get with the difference of 417 to see what the temp would be at 383 watts/m^2. I was getting -100 F for a global temp (-59 F + -41 F). If you add a nice Greenhouse effect of 70F you are still -30 F. It would be like having a flowing river in Antartica in the Winter.
  15. Climate is chaotic and cannot be predicted
    #16 scaddenp ""Chaos" has a formal definition, and this doesnt meet it. Non-linear and sometimes highly sensitive to changes in forcing, but its not showing signs of developing in highly different directions for slight changes in conditions. You dont get an iceage because there is a volcano erupting." I guess that would depend on what you define as "slight". I am not the Master of Choao theory on the detailed definition. Here is a model of Earth's temp (simple model). It calculates Earth temp based on only solar energy and Albedo. This would be Earth without any GHG warming. But it is useful in demonstrating that Climate is indeed chaotic. Primarily with the Albedo (the Solar energy will not change much). They have lists of Albedo's to put into the calculator. I noticed that if the Earth were mostly forest the albedo would be much lower (oceans would be the same at there low albedo). Put in a lower albedo and see what happens to the Earth's temp even with no GHG effect. And you claim this is not a chaotic system? If the land is grass, desert, snow or forest it makes a huge difference in albedo and the overall temp. Try it and see and if I am wrong explain what is the flaw in my thinking. Thanks. Albedo Earth Temp calculator.
  16. Solving Global Warming - Not Easy, But Not Too Hard
    Re: RSVP. Another point RSVP is that the discussion was about the 'Free Market' which is a specific political view of economics.
  17. Solving Global Warming - Not Easy, But Not Too Hard
    RVSP: "Economics is the most honest measure of human motivation, which is in turn tied directly to natural chemical energy. If you havent seen this happening, you can be sure it is due to some unnatural political ideology." The fact that you stick to this inaccurate view actually implies that you have an ideology yourself. There is no intrinsic connection between economics and chemical energy. Like a religion, economics only exists in the human mind, chemical energy exists whether humans exist or not. In future stick to reality and not your beliefs.
  18. Solving Global Warming - Not Easy, But Not Too Hard
    RSVP, and you've somehow missed the fact that free market capitalism is itself an 'unnatural political ideology'?
  19. Climate is chaotic and cannot be predicted
    I dont have access to my paper lists (nor to my knowledgeable colleague) at home but if you look at Chp6 IPCC WG1 and look at section on "Abrupt climate changes in the glacial-interglacial record". Note that these are not necessarily global events - indeed some types are hemispherically anti- phased. Look at cites for main review papers. Note that this is very active field with interesting papers in the pipeline.
  20. Skeptical Science moving into solutions
    Berényi Péter @24 No BP, It's not a political agenda. Politics is the great irrelevency in the world. It is about recognising that human affairs and how we choose to run this planet have to fit within the constraints imposed by Mother Nature (to anthropomorphise a bit). And that the biggest problem in our attempt to do this is us. Human psychology thinks that we are the centre of existance and the world has to fit around us. This is what most people think of as the 'real world'. In reality the 'real world' is physics, physics, physics & physics. We are just an add-on. The disjunction between reality, and what people 'think' reality is, is at the very heart of the problem. And Old Ma Nature is a very unforgiving sort. 'You didn't realise I was serious dearie? Sorry, Your extinct?'. Her rules, her bat and ball. So to say we need to find strategies to connect people with reality (I won't say reconnect because we may never have been in the past) is not a political agenda. It is simply stating that we need to show people what a grown-up perspective on reality looks like. And politics isn't grown-up. Its just the sand-pit in the kindergarten.
  21. Solving Global Warming - Not Easy, But Not Too Hard
    archiesteel #136 "Discussions about the Free Market do not belong on this site, as they are political, not scientific, in nature" Tell that to a professor of economics. Economics is the most honest measure of human motivation, which is in turn tied directly to natural chemical energy. If you havent seen this happening, you can be sure it is due to some unnatural political ideology.
  22. Skeptical Science housekeeping: Comments Gluttony
    John, I agree with your comments policy. I recently spent some time posting comments on Newsbusters.org to preach to conservatives on man-made global warming, and I got ALOT of accusations of deception, disheartening insults, and character assination. I've already given up preaching to conservatives, I like it much better here were I can participate in intellegent discussions on climate change. Your comments policy really makes this website special.
  23. The science isn't settled
    But Eric, why do all scientists in all disciplines use the phrase "competing theories," since by your definitions such things cannot exist? According to you, in each domain there can be only "the" theory in which 100% of scientists have 100% certainty, plus competing "notions." So you call string theorists mere "string notionists"? But if 100% of scientists are 100% certain about the non-string physics theories, then those string notionists are not really scientists at all! They are poseurs! Another implication of your claims is that inferential statistics must never be used to analyze data, if those data are going to be used to verify a theory, since you claim that evidence less than 100% certain cannot be used to support a scientific theory, and inferential statistics yields probabilities between 0 and 1, exclusive. You also drastically restrict the ways in which a theory is replaced. If 100% of scientists are 100% certain in the correctness of "the" theory, then none of them would waste their time even entertaining alternate notions, let alone actively constructing alternate notions nor collecting data to support alternate notions. Nor would they waste their time gathering more evidence in attempts to further support the existing theory. The discovery of data that the current theory cannot handle must happen only accidentally, then. Clearly that is not how science really works. And then there is the problem of incomplete theories. Classical, Newtonian, theories of physics cannot explain the things that relativity theory and quantum theory can explain, and the latter two cannot explain everything, either. So by your definitions, none of those is a theory; all are mere notions. Which means there are no theories of physics right now!
  24. Climate is chaotic and cannot be predicted
    "Chaos" has a formal definition, and this doesnt meet it. Non-linear and sometimes highly sensitive to changes in forcing, but its not showing signs of developing in highly different directions for slight changes in conditions. You dont get an iceage because there is a volcano erupting. It is well worth reading Broecker - another one in works - but his work on the sudden hemispheric climate reversal's doesnt give you any reason for thinking the current warming is related to causes of these events. And no reason for thinking these events dont have specific causes. Catch up on some recent literature.
  25. What should we do about climate change?
    BP has posted some links describing the status of thorium reactors. Apparently these have not been built yet and are completely theoretical. Since a pilot plant will have to be built before any full scale reactors it will be at least 15-20 years before full scale reactors come on stream. I think that is too long to wait for a solution to be started and that other technologies are pursued while nuclear works out its problems.
  26. Solving Global Warming - Not Easy, But Not Too Hard
    BP, I read some of your Nanotechnology Roadmap and I see no mention of fixing gigatons of carbon. They rely on fossil fuel for their carbon. Your claim that this would remove the carbon from the atmosphere is false. Cite a page number that supports your wild claims. Then cite a peer reviewed paper, not an industry piece. Why do you ruin your reputation at this site with such absurd claims??? I see from your links that thorium reactors have not yet been built and are a completely theoretical proposal. I hope they work when they are finally built, at least ten years from now. The amount and type of radioactive waste from those reactors is unknown at this time. We need solutions now, not in 200 years. A two hundred year timescale is useless for my children, their children and me. I am astonished that you now claim your proposed solution is not useful for two hundred years.
  27. How significance tests are misused in climate science
    Tom Dayton, Eric L, Tony L and sout, Thank you for your comments and links. I understand this issue better than I did before.
  28. The science isn't settled
    Tom, thank you for that latest link which I have saved and will reread on occasion. Unfortunately I can't respond on this topic anymore.
  29. The science isn't settled
    Eric, it's frustrating that you merely repeat your assertion without responding to the evidence I have provided in links. Here is another link, this one about underdetermination of scientific theory, from the Stanford Encyclopedia of Philosophy.
  30. The science isn't settled
    Tom, most of your links suggest that science has been separated from, or progressed beyond what they call "Baconian inductivism". This appears to be a modern consequence of the need for theories of phenomena that are not directly observable. Your latest link gives examples of "atomic theory and the theory of gravity". The observations are thought to be "theory-laden" therefore unsuitable for inductive reasoning. The paper proposes using the principles of parsimony and "how well a theory ties in with other theories". But those are simply principles of concept formation. There is no difference between concept formation in all nonscientific realms and theory formation in science. The attempt to posit a difference leads to absurdities like the example in your paper: rejecting the theory that the moon is made of green cheese because of the "law" (no longer just a principle) of parsimony. In fact the moon is not made of green cheese because of a large number of theories and observations that conflict with that theory. No (falsely elevated) "law" of parsimony is necessary to reach that conclusion. Ultimately the real reason for such acceptance of subjectivism in science is revealed in your link: "Scientists (and regular human beings) are also affected by cultural, social, and personal beliefs.... Rather than the traditional view that science is to be protected from biases and other imperfections of people, it turns out that science is inescapably infected with humanness." That notion might be a good way to study past errors in science or science history, but it has not scientific purpose, is not required and must be rejected. This paper http://www.johnmccaskey.com/Induction%20and%20Concepts%20in%20Bacon%20and%20Whewell.pdf has a concise explanation of induction as used in modern science.
  31. The science isn't settled
    Tom, theories have one state, certain, otherwise they are not theories but notions.
  32. Solving Global Warming - Not Easy, But Not Too Hard
    @TOP: I'm not a botanist, or anything, but I'm pretty sure you can't plant a lot of trees per square meter in sand and rock.
  33. Solving Global Warming - Not Easy, But Not Too Hard
    @BP " Just a free market with no subsidies whatsoever and proper regulations (to ensure for example no high tech poison is left behind)." Discussions about the Free Market do not belong on this site, as they are political, not scientific, in nature. If we look at it from a scientific point of view, there is in fact no indication that Free Markets are self-correcting. The few historical examples we have of "true" free markets show they are unstable. Let me put it another way: there is a lot more empirical evidence supporting AGW theory than there is for the Invisible Hand of the market... Let's assume some degree of interventionism in the economy, because there will be - that's a pretty safe bet, whatever your own political ideology (death and taxes, and all that)...argue for Laissez-faire all you want, you can't scientifically prove its benefits, so don't bring it up in a scientific argument.
  34. Solving Global Warming - Not Easy, But Not Too Hard
    @clonmac The stuff coming out of Wiezman solves the problem. There is a finite amount of petroleum/coal. Planting the Sahara in trees would put a forest there that would pretty much outlive the lifetime of known coal and petroleum reserves and would remove all the current so called anthropogenic carbon from the atmosphere. It's not a wedge, it's the whole Gouda. I don't like the term sequestration for this because that term implies an activity that is solely for the purpose of removing carbon. Remember one of the forcings is reduction of forests and this is just changing the sign of the forcing with inherent benefits.
  35. Solving Global Warming - Not Easy, But Not Too Hard
    The "short-termers" here (i.e. those who say renewables are too expensive) are the same types of people who got us into this mess in the first place. You can't fix long-term problems with short-term solutions.
  36. Solving Global Warming - Not Easy, But Not Too Hard
    @62 BP: your post is highly misleading, bedcause it implies a beautiful grassland was spoiled by the buidling of the solar plant. However, Carrizo Plain is a huge area, and there is no evidence that significant loss of habitat occured. This is the same saying a photo of a polar bear swimming in water is evidence that global warming is true. It is illogical, irrational, and beneath you. You should retract yourself immediately.
  37. The science isn't settled
    No, Eric, you are very wrong that theories have only the two states of certain and uncertain. If somehow you did not get that point out of the links I provided earlier, try this page for an overview, and if you object to any of its claims, please do read the sources cited there for those claims: The Nature and Philosophy of Science. There is nothing special about that particular web page; you can find the same information easily in textbooks and in multiple places on the internet.
  38. Solving Global Warming - Not Easy, But Not Too Hard
    @45 RSVP: "Where all the natural gas is??" Solar and wind plants on the surface do not preclude natural gas mining below. In any case, not all of these desert environments have natural gas in substantial quantities.
  39. The science isn't settled
    Tom, thanks for the links. The proper role of probability and statistics in science is the evaluation of multiple samples of imprecise data (e.g. regression analysis of imprecise measurements, multiple model runs, sensitivity analysis, etc). That is basically what you would probably call "objective probability". See an explanation of that here: http://plato.stanford.edu/entries/science-theory-observation/ The "defense of IPCC's Bayesian methodology" claims that "Climatological analysis of the AR4 requires subjective assessment." I disagree. There is no requirement for subjective assessment in science. Science builds from a conceptual framework of theories based on observations. If the theories fit observations and each other, then they are certain. If the theories don't fit the observations or the theories conflict, then new theories are required. Those are the two states of science, there are no states in between.
  40. Miriam O'Brien (Sou) at 07:04 AM on 14 November 2010
    How significance tests are misused in climate science
    Thank you for this. I see problems more often (or more obviously) in popular articles about health-related research than climate-related research. Sometimes it's journos drawing invalid conclusions, on occasion it's been researchers apparently deliberately misrepresenting their own research (eg obesity). I'm not sure if some disciplines get better training in stats, or have access to professional statisticians. Tamino has posted a comment on this article that might be of interest to people: Tamino on Ambaum and stats
  41. How significance tests are misused in climate science
    I have not read Dr Ambaum's paper because it is not yet available in my bibliographic source but I look forward to it. I think that Eric L's comments are particularly insightful and it would be good if the Dr. would respond to them. More generally, I do experimental research in the social sciences and have always been aware, since my very statistics course of the difference between statistical significance and quantitative differences in effects. I cannot believe that climate scientists are not aware of this or do not understand the distinction. If you have taken advanced stat courses, you understood it or you failed the courses. In my studies, which are generally on very large samples of families (several thousand experimental and control members) it is relatively easy to show statistical significance when the quantitative differences in treatment effects are relatively small. And the first question that arises, especially from practitioners, is if this is real how much or how many cases should we expected to occur in which these changes will be observed? Statistical significance does indicate that an observed difference is real. There are other way of answering the question, is the size of the effect minor, moderate or large?
  42. The 2nd law of thermodynamics and the greenhouse effect
    Michele, back-radiation from cooler air to warmer earth is perfectly valid. Radiation from a cool object can be absorbed by a warmer one. Example, take a glow-in-the-dark haloween mask, put it in the fridge for a few minutes, then take it out. Can you see it glowing? If so, that means that your warm eyes are absorbing radiation emitted by a cooler object, which is exactly what back-radiation is about. So the idea of back-radiation does not contradict the second law of thermodynamics.
  43. Berényi Péter at 03:40 AM on 14 November 2010
    Solving Global Warming - Not Easy, But Not Too Hard
    #129 michael sweet at 10:38 AM on 13 November, 2010 Please also provide a link to a functional, full scale thorium reactor. We are talking about a two hundred year timescale, don't we? However, there is some aging background material, possibly more than one would wish for. International Atomic Energy Agency, November 2002 IAEA-TECDOC-1319 Thorium fuel utilization: Options and trends Proceedings of three IAEA meetings held in Vienna in 1997, 1998 and 1999 There are also private companies like DBI or Lightbridge going for a full thorium cycle. DBI is planning to build a small, modular, gas-cooled, carbon moderated thorium reactor demonstration plant in Chile. There may still be legal obstacles. The Thorium Energy Security Act of 2010 was introduced in the Senate of the United States on March 3, 2010, was read twice and referred to the Committee on Energy and Natural Resources.
  44. Keep those PJs on: a La Niña cannot erase decades of warming
    #65: "because nearly all of the warming in the last 30 years happened in a step in the end of 90's." OK, so here is a graph of HADCRuT global from the last 30 years. That positive trend of ~0.16C per decade must be what you mean when you say 'a step'. "Actually the step would have occurred in the end of 70's if El Chinchon and Mt Pinatubo didnt offset the warming followed from a huge stepwise warming induced by the PDO" So we'll go back to the beginning of the 70s: Pinatubo's 'offset' are those low spikes in the early 90s. Short duration. Transients. Here today, gone tomorrow (as opposed to that same positive trend). How Pinatubo 'offset' the warming supposedly 'caused' by a decades-long oscillation is beyond me. A google search of 'correlation pdo amo detrend warming' immediately shows watt the source of this illogic is. But then its easier to repeat than to think; do I hear a chorus of 'four legs good, two legs bad' coming from that direction?
  45. Climate cherry pickers: cooling oceans
    HumanityRules there's one point i think is missing/misinterpreted about Trenberth's remarks. Trenberth is talking about variability and I assume we all agree that we do not yet have the capability to follow the enregy flow over the short time period. Don't forget that we're talking about a time span of a few years, which does not have any particular meaning as far as the big picture is concerned. This is why we should like to have a better measurement system, not because it could in any way change/confirm what we already know but because we may learn a lot about some details of our climate system.
  46. Climate cherry pickers: cooling oceans
    Re: Berényi Péter (19) Nice comment. I must point out, however, that in the previous instances where a major disconnect was found between the models and measured data (such as with satellite data and Argo ocean data), there were found to be errors in the data collection. Once corrected, the data were then found to match the models. For serious flaws to exist in the models, which are based on the physics of our world, it is very likely that this would have been noted before now. Unless you have evidence to the contrary and a physics-based theory that explains why the models match reality the vast majority of the time for everything but OHC data? The jury is still out on how reflective of OHC the depth (sorry, no pun intended) and breadth of the Argo/XBT data is. While a great resource, it must be considered part of an incomplete picture of OHC and incapable of closing the global energy budget gap. The Yooper
  47. Berényi Péter at 23:54 PM on 13 November 2010
    The science isn't settled
    #18 Tom Dayton at 14:38 PM on 13 November, 2010 "Galileo was 100% certain that there are mountains on the moon." I am sure he was. He actually says it in his booklet Sidereus Nuncius: "I have been led to that opinion which I have expressed, namely, that I feel sure that the surface of the Moon is not perfectly smooth, free from inequalities and exactly spherical, as a large school of philosophers considers with regard to the Moon and the other heavenly bodies, but that, on the contrary, it is full of inequalities, uneven, full of hollows and protuberances, just like the surface of the Earth itself, which is varied everywhere by lofty mountains and deep valleys." However, you miss the point. Galileo's state of mind may be interesting from a historic point of view, but it is absolutely irrelevant to science. What matters is the evidence he gives in subsequent sections starting with "The appearances from which we may gather these conclusions are of the following nature: [etc. etc.]" (and also the detailed description of the instrument used for observation, given in previous sections). That's what makes his observations repeatable and his conclusions verifiable. This is what constitutes the scientific method and makes him a scientist. Without it he would be just another Moongazer disseminating vague Witchy Wisdom of Gaia’s Sacred Circle.
  48. How significance tests are misused in climate science
    The real abuse of statistical significance is among deniers who tout statistical insignificance as evidence of something. (See the misunderstanding of Phil Jones' statement on the statistical significance of warming.) No statistically significant result is no result; it is not evidence for the null hypothesis; it is not evidence for anything because statistical insignificance is always achievable with little enough data no matter what is going on. For real evidence that warming has stopped, you want statistically significant evidence that warming is not above a certain rate (let's say .05 degrees per decade). That would be something if that existed.
  49. How significance tests are misused in climate science
    I have to disagree with your application of Bayesian statistics; the scientists should not be bothering with them. When do Bayesian statistics matter? When the prior probability is extreme (very likely or very unlikely). So if the chance of a woman your age has breast cancer is 1 in 1000, and mammograms have a 1 in 100 false positive rate, and you had one done as part of a routine checkup and it came back positive, Bayesian statistics tells us that chances are you don't have cancer. But when your prior probability is something medium, it isn't likely to affect the significance of the result. What's more... just how do you establish the prior probability? By counting planets where the climate sensitivity is above 2 degrees per doubling of CO2 and those where it's below? And if you're already pretty certain that you know what the answer is, what are you adding by doing the experiment? Let's say the existing body of evidence leads you to be 99% certain, and your experiment doesn't cause that figure to budge, do you now show using Bayesian statistics that combining your result with the prior gives you 99% confidence and, presto! a statistically significant publishable result! Of course not. Another problem with this is that it's that prior (is Global Warming real?) which is precisely what we want to figure out, not the "real" posterior (is it really warming at the moment?) We want P(N), not P(N|M). Asking how to get P(N|M) from P(M|N) is getting a few steps ahead -- you also want to know P(M2|N) and P(M3|N) and P(M4|N) and all the other peices of evidence before you do that calculation. And if someone else finds further evidence and publishes a paper showing P(M5|N), well now that Bayesian analysis you did in your paper to get P(N|M1..M4) is out of date. But that calculation of P(M4|N) stands, and will forever be useful as a piece of the evidence used to assess P(N). Bayesian analysis provides a way of thinking about how to combine all the pieces of evidence to form your conclusion, but the proper role of research is to establish those individual pieces of evidence. Establish the symptoms if you will. One experiment is your family history, another the mammogram, another the biopsy. We don't calculate whether the mammogram is positive or negative by considering your family history, rather they stand as separate results which we then combine to make an inference. And in this analogy we can't perfectly do the Bayesian calculation because we don't really know what fraction of the population has cancer, except for what we infer through these tests. But you don't subject patients to tests that tell 1 in 5 healthy people they have cancer, and so likewise we demand statistical significance.
  50. Solving Global Warming - Not Easy, But Not Too Hard
    BP: "Your arguments are getting wilder and wilder." Indeed.

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