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dana1981 at 01:10 AM on 8 June 2012Fred Singer Promotes Fossil Fuels through Myths and Misinformation
chriskoz @1 - indeed, other than the Inhofe hoax comment the editorial did not touch on climate science at all. Singer entirely focused on telling Romney that he should focus on fossil fuels in order to win the 2012 presidential election. I have to say it was a little strange to read such a blatant political piece on a purported climate science blog, which claims to have won various science blog awards (those awards being based entirely on popularity, not quality, of course). BWTrainer @3 - I saw that post on WUWT. I didn't really like the way Hansen et al. had phrased the problem, because since CO2 is a long-lived greenhouse gas, we can't solve the problem without addressing CO2 emissions, and I think they focused too much on non-CO2 emissions. Watts exploited the somewhat poor phrasing in that 12-year-old paper. That being said, their point was simply that non-CO2 GHGs and black carbon have caused roughly as much warming as CO2 thus far, so we should also address those other anthropogenic forcings. I also found it rather amusing that Watts admitted that non-CO2 GHGs are "pollutants". I'm not sure why methane qualifies and CO2 doesn't. Bit of a slip of the tongue from Watts there. -
Composer99 at 01:08 AM on 8 June 2012The 5 characteristics of scientific denialism
Justin: Denialism is set squarely against the advancement of scientific knowledge and against innovation. Who are antivaccine denialists, AIDS/HIV denialists, germ theory denialists? They're homeopaths, chiropractors, holistic healers, reiki masters, and the like. They're the parents of autistic children asserting vaccines caused their childrens' autism and then resorting to bleach baths & enemas or industrial chelation to try to 'treat' it. They're the people claiming cancer is caused by liver flukes (Hulda Clark) or "acidity" (Robert Young). What they are not is furthering our understanding of immunology, virology, bacteriology, microbiology, and biochemistry. Likewise, young-earth creationists (engaged in denialism of geology & evolutionary biology) aren't the ones furthering our understanding of genetic evolutionary mechanisms or geological processes or paleontology. Suffice it to say, the suggestion that denialism is at all associated with scientific advancement is IMO unequivocally false. -
dana1981 at 00:55 AM on 8 June 2012Pal Review - the True Story and the Fairy Tale
gpwayne @6 - maybe I'm in a quasi-ivory tower here. I almost never see E&E papers cited, though I don't read the comments on The Guardian very often. John Russell @7 - thanks very much. The 3% figure is a ballpark, depending on what study is being referenced. I agree that technically the figure is probably lower, with 'undecideds' making up the difference. It would indeed be interesting to see the reviewers on E&E papers. -
BWTrainer at 23:40 PM on 7 June 2012Fred Singer Promotes Fossil Fuels through Myths and Misinformation
Let me apologize ahead of time, because what I'm about to say is only tangentially related to this column in that both are dealing with WUWT, but I didn't know where else to post. Having unfortunately clicked on the link to Singer's editorial, I stumbled across this brilliant Watts piece in which he basically claims that CO2 is nothing to worry about because James Hansen, in one paper from 12 years ago, said that focusing on non-CO2 GHG reduction would be a wise strategy. While the paper does say that, Watts (as usual) is horribly distorting the true message of it, which was that, at that point in time, the warming associated with CO2 was responsible for 50% of the increased energy, but was roughly cancelled out by the other cooling pollutants that were emitted along with CO2 when burning coal. In other words, the Earth would be twice as hot if not for air pollution. But that's apparently a positive in Watts' book. Great news! The pollution that is killing us is also acting to cool the planet, so we should keep on burning away! -
Composer99 at 21:08 PM on 7 June 2012Fred Singer Promotes Fossil Fuels through Myths and Misinformation
The evidence suggests that, with limited exceptions such as the Keystone decision, President Obama has been pretty pro-fossil fuel in deed. That said, given Singer's history on climate science and the policy imperatives it reveals I'm not surprised he has so baldly misrepresented the activity of the first-term Obama administration. -
Dikran Marsupial at 20:12 PM on 7 June 2012Pal Review - the True Story and the Fairy Tale
I'd be rather suprised if Energy & Environment didn't have a significant pal review issue. There simply are not very many skeptic climatologists competent to review the science based papers published there, so unless they regularly send papers out to mainstream climatologists to review (the E&E papers I have read suggest this is unlikely) they would have to settle for incompetent reviewers (i.e. people competent in their own field, but unqualified or inexperienced in climatology). Many journals publish the names of the reviewiers that they have used each year (obviously not mentioning which papers they reviewed). It would be interesting to see such a list for E&E. It would go a long way to addressing the pal review issue if more journals did this. -
chriskoz at 19:42 PM on 7 June 2012Fred Singer Promotes Fossil Fuels through Myths and Misinformation
Is the "'hoax' of climate catastrophes from rising CO2 levels" the only statement related to climate science Singer has uttered? As the atmospheric physicist, Singer should do much better, shouldn't he? At least try to justify that statement with some arguments (valid or not) but he didn't say any supporting word? Instead he's chosen to talk about the market of fossil fuels, where he is not an expert (I cannot find anything related in his CV), so no wonder the talk does not make sense. That's an indication how far from reality this man has departed. -
John Russell at 19:02 PM on 7 June 2012Pal Review - the True Story and the Fairy Tale
A few comments. 1) You write "the ~3% minority of experts who think humans aren't the dominant cause of the current climate change". Is this correct? As I remember it the figure is 1%, with 2% being in the 'don't know' category. 2) GPWayne is correct to call this 'projection'. Because the contrarians operate as a pals network themselves, experience tells them that this must be the way everyone works the system -- I mean, stands to reason doesn't it? 3) I was confused by the large 'Dana1981' at the start of the second paragraph of GPWayne's comment. I thought for a moment that that was Dana's response and had to read it twice before I realised it was a continuation of Graham's comment. Dana: I am astonished by the quality and quantity of your output. More power to your elbow. -
gpwayne at 15:37 PM on 7 June 2012Pal Review - the True Story and the Fairy Tale
While Michaels is indeed something of an expert on the subject, his expertise comes from himself being one of the individuals most guilty of engaging in climate research pal review.
Projection should be another category, making it 6 characteristics of denialism. From the constant references to blind belief unsupported by evidence (religion), to the conspiracy theories of 'pal' review, through the references to 'alarmist' science (what's more alarmist than a world conspiracy of scientists, or a global plot to control and tax us?), it is so often the case that those making the accusations are most guilty of that which they claim to abhor, as we can clearly see in Michaels' case. One thing is clear: the contrarians are entirely unconcerned with their own egregious hypocrisy. Dana1981: much though I admire your contributions, I think you misunderstand the nature of the debate in the same way as do so many with a science background. When you say 'Ineffective pal review though, since everybody knows the journal (E&E) isn't serious', you are really referring to those who are either scientists or informed lay people. The public can make no such distinction, which is why E&E papers are so frequently cited in Guardian debates, for example. They may be duff papers, but they are far from being ineffective. Underestimating the enemy is never a wise strategy, and we are engaged - like it or not - in a propaganda war, which is largely the sub-text of this article. -
JohnMashey at 15:26 PM on 7 June 2012Pal Review - the True Story and the Fairy Tale
Well-known PR techniques in climate anti-science include, in decreasing order of desirability: • Publish a paper refuting the existence of AGW in a good journal, such as Science or Nature. This basically does not happen, so next best is to publish one arguing for much higher uncertainty than the mainstream. • Find a otherwise-credible journal with process weaknesses. a) Either find a sympathetic editor (CR, deFreitas) or b) exploit the weaknesses, especially if the journal is unfamiliar with the context issues (Remote Sensing) • Publish a paper with reasonable, if unremarkable research that only experts follow, but with unrelated comments casting doubt on AGW, that can be quoted as appearing in a peer-reviewed journal. (many cases at CR) • Publish in a journal that will publish almost anything. (E&E, Journal of Scientific Exploration). -
calyptorhynchus at 10:31 AM on 7 June 2012Don Easterbrook's Heartland Distortion of Reality
Just a little quibble about Figure 1, the line up to 2000 is black with blue dots indicating each year. This gives the impression of blue and black lines superimposed and it looks as if Easterbrook B continues this line. Better to have a plain black line for the observed temperatures. -
dana1981 at 04:45 AM on 7 June 2012Don Easterbrook's Heartland Distortion of Reality
Yes as Dikran notes, Easterbrook's presentation of the IPCC projections was a gross distortion, but we should not comment about his motives. Let's just proceed under the assumption that simply made a number of errors and to this point nobody has corrected them. -
Don9000 at 02:54 AM on 7 June 2012Don Easterbrook's Heartland Distortion of Reality
Dana: Thank you for the excellent report [snip]Moderator Response: [Dikran Marsupial] Please can the discussion on this article be kept strictly to the science, without any inferences regarding motives or ad-hominems. -
Enginerd at 14:11 PM on 6 June 2012In Search Of: Himalayan Ice Loss
Thank you for this very thorough and informative post. Justin: The post from you (and Wikipedia) is correct. The time scale considered in the data is "ridiculously short" when compared to geological time scales. The problem I have with such arguments, however, is that they become convenient excuses for not acknowledging the effects of climate change. For instance, when climate-related records fall year after year after year, you can always state that the time frame covered by our data is "ridiculously short." Not a very scientific argument, I must say. To me, the information presented here is yet another in the growing list of converging lines of evidence showing that our climate is most definitely warming, and this warming is due largely to anthropogenic emissions of greenhouse gases. -
ranyl at 10:17 AM on 6 June 2012Modelling the Apocalypse
Please excuse my rushed post Tom, and I did not ascert that loss of the Arctic sea ice would entirely mimic the Laurentide Ice sheet loss in anyway, just pointing out it is a large area of sea that is changing colour in the summer when it does get a reasonable amount of insolation on average in the present day of ~180w/m2/pa compared to ~300w/m2/pa for the Laurentide Ice sheet and Laurentide Ice sheet was larger than the summer average summer extent of the sea ice at ~12million km2 compared to 7million km2 (before 2000), therefore clearly less than ice sheet. However the ice sheet would have taken eons to melt whereas the arctic sea ice seems to be melting very quickly especially in the important summer months and in the summer months the insolation in the arctic latitudes is higher than the lower latitudes of the Laurentide ice sheet, at ~500 w/m2/pmonth, compared to 480w/m2/pmonth...http://aom.giss.nasa.gov/cgi-bin/srmonlat.cgi, therefore my pint was not that the alebdo effect was the same as the Laurentide ice sheet more that it is quick and I suspect it is significant due to its size. In the Lowe paper the headline detail was that the rate of fall of PCO2 was 0.2ppm per yer, so a whole magnitude less than your ascertation of 2ppm, and this was mainly due to carbon modelling they used including a climate-CO2 positive feedback factor. The majority of this feedback is derived from tropical feedbacks as demonstrated by Roeckner et al(1), and is due to temperature change and water stresses in tropics, however these are very mild for low emissions scenarios and represent a fall in the size of the annual sink not a trnasformation of the sink to a source as has occured in the tropics already. These models by Roeckner also shows however that boreal continue to an ever increasing sink yet it is already been shown the Canadian boreal forest is source, due to forest fires and infestations both factors which are not included in these carbon models and not in Archers paper either. And neither models included permafrost release of CO2 as this has only occurred realistically since 2010. Also Note Lowe didn't include any other GHG for the graph above and they started the simulation from temperature and GHG records in 2000, and thus no heat stored in the ocean for the 2012 no emissions scenario yet both the 2050(so 50years of additional heating) and the 2100 run do and both scenarios continue to warm after the emissions stop. Now is it me or is the heating in the pipeline due to lagged the expression of the eenrgy imbalance to surface temeprature expression a myth, as far as I have read the earth is meant to warm to about 1.4C above pre-industrial according Hansen etc whatever we do, due the warming in the system yet these models are showing no additional heating at all. (1)Historical and future anthropogenic emission pathways derived from coupled climate–carbon cycle simulations Erich Roeckner · M. A. Giorgetta · T. Crueger · M. Esch · Julia Pongratz, Climatic Change (2011) 105:91–108 http://www.springerlink.com/content/q50mp5004654654k/ I would also suggest you reas the European Nitrogen Assessment on the Nitrogen fertilization effects and ozone interactions with methane, it all seems reasonable, well considered and well investigated. You say that the factors I mentioned as not being included in the carbon models are, yet this is not the case, for although they may include the effect of a warming ocean on its ability to absorb CO2 they don't account for the scale of changes being observed and nor do make the Southern ocean a source due ot increasing westerlis as has also been observed, and the changes in North Atlantic and never mimicked by the models, further more the FACE traisl show nutrient deprviation effects and water stress factors that are greater than predicted and they show a cessation of the CO2 fertilization effects after 5-10years whereas the modles keep on increaseing this unless water stress intervenes, and although the models do indeed mimc some eco-systems shifts due to changing climate none of them include eco-systems and biodiversity losses due to oceanic dead zones, pollution, waste, over exploitation, eco-system destabilisation, invasive alien species, and eco-system effects on CO2 sequestration may well be more profound than cliamtic effects,"At the study site, local disturbances appeared to exert an impact on the observed carbon sequestration, whereas climatic factors made moderate contributions." (2). 2. Detection and attribution of global change and disturbance impacts on a tower observed ecosystem carbon budget: a critical appraisal Akihiko Ito, Environ. Res. Lett. 7 (2012) 014013 (6pp) http://iopscience.iop.org/1748-9326/7/1/014013 Then you say that many of the papers I quoted previously were about climate sensitivity, and you say this is off topic, well I disagee aswe seem to be talking about whether we agree that a temprature flatline is realistic with a total cessation of CO2 emissions. I say this is not realistic and the main reason for the lack of warming is due to an overactive draw of CO2 casuing an exagerated cooling influence...and of course there will be further warming due to the other GHG's and sudden loss of aersols that would occur, the heating already in the pipeline and the continued albedo effects, so the assumption for me is incorrect and leads to a false hope. Also the CS is critical, and Hasen and Sato CS is for CO2 alone, they are very clear that the albedo effects during the alst several glacials is as strong and they only make the last glacial 4.5C coler and the early Pliocene 2C warmer, whereas many others make the last glacial 6C cooler and the Pliocene 3-5oC warmer, and remember again CO2 was 350ppm then...although Hansen does agree that the arctic sea ice melt shoudln't make a huge difference as it is small, despite its size and influence on th ewhole cliamtic system, which so seems to pumping heat into the arctic at faster rates than anticipated. Considering the ppm have risen from 280ppm to 393ppm for ~1/2 Trillion tonnes I presume that another 1/2 trillion tonnes (1 trillion in all) will get us to ~500ppm and you are sayign you feel safe with as all emissions will stop at that point and the overshoot scenario fuesl by carbon drawdown will keep us below 20C, yet all th recent models in the papers previously quoted make 2C inevitable and by 2050 for this size of scale of CO2 in the atmosphere. Now I could go on and mention the greater of effects of droughts on the carbon cycle than anticipated, the increases in soil respiration in Autumn, and the recent paper by Shakun (3), where the primary driver for temperature rise is CO2, and alebdo has a surprisingly mainly regional effect, and despite CO2 plateauing at 12000BP the temperature rises a further 1C, as a by the by they have a CO2 rise of 0.44 (180-260ppm) of a doubling and a temperature rise of 3.5C, or a CS for CO2 if the ice albedo is considered a feedback (and small as they suggest) of 7.9C, or a CS of ~4C if split 50/50 into CO2 and ice as Hansen and Sato do. Anyway bottom line for me is that 350ppm if the Pliocnee data is right means a shift in climate that is at best risky and means 1.8-3C warming by 2100 unless you use Hansens Pliocene values when we get 1.6C (but this level of warming in temr sof climatic shfits etc is the same as the 1.8-3C above in real terms), is only just safeish considering the events that are already occuring (Missippi Floods, French Floods, Pakistan, Amazon Drought, Queensland floods, Texas Drought, and so on and so on).. So for me we are already well over our carbon budget and our eco-systems are feelinjg the strain, so I call not only for 350ppm as a definitive target but also a realisation of what that actually means, I using the MagicC model to get to 350ppm will take a mircale of zero emissions by 2017 and large carbon sequestration after that to increase the 0.2ppm/pa to 0.5ppm/pa, counter the CO2 influxes from permafrost melt, wetland increase, etc. And finally in the study by Archer, they pulsed the CO2 into the atmosphere so 50% shoudl have been withdrawn almost immeadiately to keep with the reality we know and therefore to ascertain how slow CO2 will be drawndown once it is at a certain ppm, you have to go to the 50% point(1year) and then see the rate of decline and doing that it takes about 400year to fall to 50% so much slower than the graphic suggests. Therefore it is up to you if you feel reassured with putting another 1/2 Trillion tonnes of CO2 into the atmosphere at this point to have a 50/50 chance of missing 2C, like 1.9C is safe!, However I don't and there are many calling for 350ppm amd I agree with them. (3)http://sciences.blogs.liberation.fr/files/shakun-et-al.pdfModerator Response: [DB] Converted Google link string into actual URL. -
Philippe Chantreau at 09:13 AM on 6 June 2012Bob Carter's Financial Post Gish Gallop of Scientific Denial
Leto I disagree. It is important to point out Carter's statute as fake expert for numerous reasons. The first one is that his expertise is limited enough to border on the non-existent. There is no reason to sugar-coat it and use politically correct euphemisms to describe that, especially in view in the hateful rethoric spewed by deniers against real experts. The next one is that, even though his expertise is so limited, he portrays himself in the exact opposite fashion and he, and others, then attempt to use the impression thus created to ascertain ideas from authority, an authority that in fact does not exist. Many people comment here on climate. I have followed SkS since its very beginning and I was part of the original moderation team. I relinquished that privilege when I no longer had the time to keep up with the work and build my expertise to a level appropriate for the standards maintained here. I have closely followed the evolution of most of the moderators and I am pleased to say that their level of expertise on the subject has increased constantly, continues to do so, and is now quite impressive. Yet I do not recall a single one of them ever claiming to be an expert. They all defer to scientists who actively study the field and regularly publish their findings (the real experts). That is the basic premise of SkS' existence. Commenters on SkS are very rarely called upon to disclose their expertise. When someone makes sweeping statements (in any direction) going against well established science without the necessary substantiation, they're asked their sources for such statements. If nothing comes, there may be sometimes asked by other commenters what their expertise is. I can not at the moment recall an occurrence in which the moderation team asked a commenter to disclose their expertise. It is quite common that egregious mistakes be pointed out in no ambiguous terms, as they should be. That is another area where sugar-coating should be avoided. Even at that, if you peruse the 2nd law of thermodynamic thread, you'll gain new respect for the patience of SkS' moderators. -
SRJ at 08:19 AM on 6 June 2012Solar cycles cause global warming
A new paper by Kristoffer Rypdal demonstrates that the cycles in the temperature series found by Camp and Tung are caused by volcanic eruptions, not the solar cycle. Citing from the paper: "In particular, the cyclic GMST variations reported by Camp and Tung [2007] is naturally explained as a result of a succession of volcanic eruptions, ending with Mount Pinatubo in 1991." Reference: Rypdal, K. (2012), Global temperature response to radiative forcing: Solar cycle versus volcanic eruptions, J. Geophys. Res., 117, D06115, doi:10.1029/2011JD017283. -
dana1981 at 07:06 AM on 6 June 2012Pal Review - the True Story and the Fairy Tale
Alexandre @3 - I think a key difference is that Climate Research was considered a serious peer-reviewed climate science journal before the pal review incident. Energy&Environment has never been considered a legitimate peer-reviewed climate science journal. But I agree it could qualify as 'pal review'. Ineffective pal review though, since everybody knows the journal isn't serious. -
Alexandre at 06:48 AM on 6 June 2012Pal Review - the True Story and the Fairy Tale
What about the openly biased Energy&Environment, the ultimate refuge of climate inactivists? I wonder if that is good enough to qualify as pal review... Maybe editor-simpathy-review? -
Marco at 05:06 AM on 6 June 2012Pal Review - the True Story and the Fairy Tale
Allow me to make one objection, composer99: most journals do not make it clear who the Editor is that handled the paper. Climate Research did do this until about 2006 or so. That means that it will be difficult to do a similar analysis for "mainstream" climate scientists. -
dana1981 at 02:37 AM on 6 June 2012Bob Carter's Financial Post Gish Gallop of Scientific Denial
Leto @38, see my comment #16 which explains why we raised the issue of Carter as a fake expert here. Additionally, fake experts are one of the five characteristics of scientific denialism, as noted in the post, and we have been trying to highlight those characteristics when they are exhibited by denialists. Carter gave us a great example of the fake expert characteristic here. Good points on the subject from Tom Curtis @39 as well. -
Composer99 at 00:03 AM on 6 June 2012Pal Review - the True Story and the Fairy Tale
I'm sure that those accusing mainstream climate scientists of undertaking pal-review could surely come up with a similar network of connections to substantiate their accusations - if the accusations had merit, that is. -
Tom Curtis at 21:05 PM on 5 June 2012Bob Carter's Financial Post Gish Gallop of Scientific Denial
Leto @38: "An expert is someone who knows some of the worst mistakes that can be made in his subject and how to avoid them. WERNER HEISENBERG, Physics and Beyond" Heisenberg provides us with the best, succinct definition of expertise. In any field, somebody is expert if they don't make the bad mistakes. An expert batter (in baseball) will still make mistakes. But he will pop up a fly ball because he is trying to hit a home run against good pitching, not because it is pure chance for him to get a better hit. In science, the definition is particularly applicable. If you don't make mistakes in science, it just means you are not trying interesting hypotheses. But the mistakes of the expert are different from those of the non-expert. For a start, they are new mistakes. The expert knows his field well enough to know the mistakes others have made, and how to avoid them. Further, they are interesting mistakes. That is, they are mistakes which you need to learn something knew in order to discover that they where a mistake. Contrast that with Carter's performance above. Do we really learn something knew to discover that 29/360 is not 0.1 (10%) as Carter asserts (Cherry Sun)? Or that contrary to Carter, the radiosonde data shows a greater warming than the surface warming and does not follow a step function (Radios own goal)? Well, perhaps it is new to us, but to a climate expert? Or consider his only genuine scientific article in climate science. In it he took some temperature data, removed the trend, found a significant correlation with ENSO, and then concluded that ENSO explained the trend! Is it really a great discovery to find out that is a mistake? So, Carter claiming to be a climate expert is like somebody who falls prey to the Fool's mate claiming to be a Grand Master. The claim of expertise, given the types of mistakes he makes, is simply not credible. He is a fake expert. -
Harald Korneliussen at 20:58 PM on 5 June 2012New research from last week 22/2012
Those pictures of Greenland are pretty, and would be good for encouraging interest in climate science. Pity the full resolution versions of them are paywalled. -
skywatcher at 18:41 PM on 5 June 2012Models are unreliable
Hi JasonB, you provide a very interesting perspective there, and I think you make the most important point as well:It certainly wouldn't have less trustworthy just because it wasn't written by somebody with a CS degree.
This is the key issue - is the code any less trustworthy because somebody wrote it who wasn't at the core, a CS specialist< and I concur with your answer that it is not. I don't doubt that (for example) code I wrote was a lot more 'clunky', poorly commented, inefficient and all the rest than a CS specialist's code! (though clunky 3D graphics were quite fun to do). Equally I suspect the coders of big GCMs are much more skilled at efficient algorithm generation than I ever was, as they need to be, running large computationally expensive programs. The core algorithms that controlled the scientific part of my programs were as you describe them - transcriptions of mathematical expressions, and computationally relatively straightforward to implement. Some algorithms are harder than others, of course! Ensuring they are correctly implemented is where detailed testing and validation comes in, to make sure the mathematics and physics is as good as you can make it. These are then documented and described in relevant publications, as with all good science. All part of the scientific coder's life. Thanks for your perspective. -
Leto at 18:12 PM on 5 June 2012Bob Carter's Financial Post Gish Gallop of Scientific Denial
As a very occasional reader of climate science sites, including this one, I would like to add that I also find the tag 'fake expert' unhelpful in this case. I accept that Carter is less qualified than many others to comment on paleoclimatology. I also accept that his actual claims seem flawed, from which an inference can be drawn that his expertise is, indeed, minimal. I just don't see that tagging him as a 'fake expert' helps the argument. It would be different if he had never studied or published in a relevant field, and was unambiguously lying about his background, but that is not the case. If he wrote a sensible defence of AGW, with exactly the same credentials, would you think it necessary to call him a 'fake expert'? If not, then you are basically saying he is fake because he is wrong. If I have to accept the flaws in his position before deciding he is indeed a 'fake expert', then it is those flaws, rather than the tag, that do all the heavy lifting in the debate. Describing him as a 'fake expert' merely distracts from the otherwise interesting discussion of why he is wrong, and comes across to me (and possibly other readers) as an ad hominum argument. Readers who can already see why he is wrong will not be more convinced because you add the 'fake expert' tag. Worse, readers who are unconvinced of his errors will merely conclude that his errors are not sufficient in themselves, to carry the argument, and require propping up with attacks on his expertise. Cheers, Leto. -
JasonB at 17:36 PM on 5 June 2012Models are unreliable
Perhaps some personal experience may be illuminating. Lest this be perceived as "dogpiling", I'm happy to respond in the context of skywatcher's claim "It is much easier to begin with an understanding of climate and physics, and graduate onto writing computer code, which is fundamentally not that difficult to do, than the alternative." I am part of a team of three people that writes scientific software (not climate-related). It involves modelling, calibration, error estimation, and 3D graphics, and the consequences of mistakes can be extremely serious. Two of us -- myself included -- are computer science graduates. The third has a PhD in the field that the software is actually used in. My CS degree was very heavy in mathematics (an option I took because I love maths) and the software is very maths-intense, which is obviously an advantage. I understand how the software works, and can explain it to others. However, the scientific innovations in the software usually come from the guy with the PhD in the field. I normally take his working implementation and optimise the hell out of it, as well as do all the 3D graphics stuff, etc., but he usually comes up with the core algorithms. He had no formal computer science training, and learnt most of his coding "on the job". His implementation is still often far from perfect, especially performance-wise, and he isn't aware of a pretty large body-of-knowledge about how to implement things well, but it still works. If he didn't have us, I believe he could still have produced working software that would have done the job, although it would have been orders of magnitude slower, less "fancy" from a user's point of view, and probably much harder to maintain and difficult to understand. It certainly wouldn't have less trustworthy just because it wasn't written by somebody with a CS degree. OTOH, if we didn't have him, we could still have written some software (I know, because we had more primitive software 15 years ago when he joined) but it wouldn't have been as sophisticated and it certainly would have taken us a lot longer to think up the algorithms that he has developed over the years. Writing computer code can either be extremely easy or the most difficult thing a human being can attempt to do. It depends on the nature and complexity of the code. Scientific code is generally not that complex from a computer-science point of view -- the important parts are simply direct transcriptions of mathematical expressions -- and so speaking as a computer scientist, it doesn't bother me in the least if no computer scientists are involved in the writing of GCMs. What they are possibly missing out on is optimised, multi-threaded implementations with wizz-bang 3D GUIs and easy-to-maintain code, but that doesn't change the correctness or reliability of the models. I also have no problem categorising people with a few decades of experience of writing code without CS degrees as "computer modellers". My PhD supervisor, like virtually all CS academics of his generation, had degrees in other disciplines (physics, in his case). It would be pretty absurd to classify me as a computer modeller but not the people who taught me! -
Tom Curtis at 17:21 PM on 5 June 2012Modelling the Apocalypse
ranyl @19: 1) The list of scientific papers you appear to have copy and pasted from some bibliography includes many papers only tangentially related to this topic. The first two, for example, represent estimates of climate sensitivity rather than discussion of the carbon cycle. (I also note in passing that the list violates the intent of the comments policy stipulation that naked links not be provided. If you are going to cite papers, you should at least summarize them unless they are directly related to your comments, and it is clear from context how they are so related.) 2) Although you make a long list of factors not taken into account by the various models, in fact most of them do take most of those factors into account. Those which are not included (eg, nitrogen fertilization) are recently raised considerations, and it is not at all clear that they are well founded. 3) Suggesting that loss of the Arctic sea ice will have a similar albedo impact to the loss of the Laurentide Ice Sheet is just rubbish. Regardless of area and underlying surface, there is a vast difference in latitude and hence of effective insolation. Albedo effects from the loss of Arctic sea ice will be significant, but is not the game changer you imagine. Estimates of Equilibrium Climate Sensitivity based on the LGM, such as those by Hansen and Sato, already include the albedo effect of a larger loss of sea ice (a fast feedback) from lower latitudes. Therefore if that feedback is stronger than is thought, it must be because some other feedback is weaker than currently thought, for empirical estimates of climate sensitivity include all fast feedbacks by their nature. 4) The rate at which CO2 is carried to the deep ocean does not depend on CO2 "gradients". The pCO2 of atmosphere and surface ocean equilibriate in approx a year, with the ongoing removal of CO2 to the deep ocean being effected by the thermohaline circulation rather than by diffusion. As such, the rate of that removal is a function of pCO2 in the surface ocean and the pace of the thermo-haline circulation. Ergo, a pulse gives a reasonable estimate of the time to oceanic equilibrium. 5) I note, also, that even Lowe et al 2009 (your fourth reference)shows near flat temperatures in the first century after the complete cessation of emissions in all three scenarios she examines, even though she argues and models a very slow decline in CO2 levels:
She even shows a limited probability of exceeding 2 degrees C provided emissions are kept below the trillion tonne limit (equivalent to the cessation of all emissions in 2050):
It appears that my conclusion is fairly robust.
Finally, if your respond again with a gish gallop as in your last post, I will not bother responding again.
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Riccardo at 17:21 PM on 5 June 2012Lessons from Past Predictions: Hansen 1981
curiousd you can not use Beer's law to calculate the forcing; you can not even use it to calculate the infrared flux to space. You need to take into account the absorbed as well as the emitted fluxes, the vertical profiles and the wavelength dependence. This is what a radiative transfer code does. The simplified formula is just a empirical fit. Here's the paper. -
scaddenp at 14:47 PM on 5 June 2012IEA CO2 Emissions Update 2011 - the Good News and the Bad
Peter, (saw your post on RSS). Can I suggest you put comments on models in Models are unreliable and the LIA comments in We coming out of the LIA -
JasonB at 14:41 PM on 5 June 2012Lessons from Past Predictions: Hansen 1981
curiousd, the logarithmic expression for dF in terms of CO2 concentrations is empirically derived from observations and calculations using radiative transfer codes, not established from first principles, and in fact it's only a first-order approximation that is "accurate enough" (given other uncertainties) for the ranges of CO2 concentrations that are of concern to us. As you can see from the TAR, various approximations have been used at different times by different authors, although they're all pretty similar. Because it's logarithmic, an exponential increase in concentration will result in a linear increase in temperature (ignoring feedbacks). Unfortunately, CO2 concentration has been increasing at a rate greater than exponentially so the CO2 forcing is growing faster than linearly. -
curiousd at 14:04 PM on 5 June 2012Lessons from Past Predictions: Hansen 1981
Thanks CB.....short of it was that late at night I was misreading a stack of data on CO2. Sorry. One more tho.. Since it turns out that the dF = ln (C2/C1)x const leads to that exponential formula I got, this got me to thinking about where that logarithmic dependence on concentration comes from, since by standard Beer's law physics you would expect an exponential to a power with an effective absorption coefficient involved. I was digging all around the net and I guess maybe this ln dependence is empirical, and has to due with the fact that the CO2 only allows radiation to go through at the wings of the transmission window? If the derivation is really that hairy then for my purposes I don't need to go through it, but just checking here. -
Peter42 at 12:22 PM on 5 June 2012IEA CO2 Emissions Update 2011 - the Good News and the Bad
To Tristan @ 41 (01:34 AM on 4 June, 2012), JasonB @ #42 (11:42 AM on 4 June, 2012), scaddenp @43 (14:16 PM on 4 June, 2012), and adelady @44( 14:56 PM on 4 June, 2012): (-Snip-)Moderator Response:[DB] You have previously received moderation for being off-topic. The scope of this current comment far exceeds that of the OP of this thread. You are welcome to resubmit the applicable portions on applicable threads, separately. Note also that when engaging multiple participants at SkS it is considered good form to post separate comments to them. This prevents "dog piling".
Please take the time to review the Comments Policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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JasonB at 10:56 AM on 5 June 2012Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
Tom @7, reading their other press releases also shows them boasting about the use of geothermal energy to "significantly reduce our carbon emissions". I guess not enough. This article quotes the SCA Hygiene president saying that it will "impact profits", but it also mentions two other companies will receive 94.5% of their needed carbon permits for free. (That article also puts to bed the idea that the carbon tax won't have any effect on emissions -- it's full of steps that the companies will take to reduce their carbon footprint.) Like you, I couldn't find any mention from SCA Hygiene about the carbon tax causing layoffs -- not surprising, given it hasn't even started yet. They do state how they've been hurt by cheap Asian imports, and a high A$ will no doubt cause them pain. The only connection I could find between SCA Hygiene, layoffs, and the carbon tax was posts by another fellow called "Dale" who claimed "SCA Global announced due to rising costs in wages, electricity and the carbon taxes in AU and NZ made the Australasian business unfeasible" without any references -- but again failing to note that the carbon tax hasn't even started yet, and electricity prices have risen in the past few years by far more than the carbon tax will cause it to rise in many parts of Australia without the carbon tax in place. What about the rising wage costs? Perhaps Dale was laid off because he cost more than workers in Indonesia? If the announcement was accurately reported, then it seems taking on "and the carbon tax" to every announcement of layoffs or closures will become a cliche. But even if it's the straw that breaks the camel's back of a business that's been put through the ringer due to rising wage costs, rising electricity costs (apart from the carbon tax), and a high A$, it's disingenuous to blame that final straw for the outcome -- after all, a slight additional increase in the A$, or salaries, or coal price, or... could have just as easily been that final straw, and as we've seen in announcements before the carbon tax is even in place, companies seem happy to use it as an excuse regardless of whether it actually has an impact or not. -
ranyl at 09:16 AM on 5 June 2012Modelling the Apocalypse
16. Schneider B. “Global warmth with little extra CO2”, Nature Geoscience, VOL 3, pg. 6-7, 2010 17. Csank, A.Z., et al., “Estimates of Arctic land surface temperatures during the early Pliocene from two novel proxies”, Earth Planet. Sci. Lett. (2011) 18. Hansen, J. et al., “Climate simulations for 1880-2003 with GISS modelE.” Clim. Dynam., 29, 661-696, 2007 19. Lowe A. et al “How difficult is it to recover from dangerous levels of global warming?” Environ. Res. Lett. 4, (2009) 20. Solomon S. et al, Persistence of climate changes due to a range of greenhouse gases PNAS. October 26, 2010 21. Wang Y-P, et al, “Nitrogen constraints on terrestrial carbon uptake: Implications for the global carbon-climate feedbacks”, GEOPHYSICAL RESEARCH LETTERS, VOL. 36, 2009 22. Boer G.J et al, “Temperature and concentration feedbacks in the carbon cycle” GEOPHYSICAL RESEARCH LETTERS, VOL. 36, 2009 23. de Boera H. J. et al “Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2” PNAS, Jan 2011 24. C Yi et al “Climate control of terrestrial carbon exchange across biomes and continents” Environ. Res. Lett. 5 (2010) 25. Canadell J.C. “Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks” PNAS , November 2007 26. Harvey L.D.D. et al, Convention on Climate Change as a function of the climate sensitivity probability distribution function, Environ. Res. Lett. 2 (2007) 27. England M.H. et al. “Constraining future greenhouse gas emissions by a cumulative target” PNAS, September 2009 28. Azar C. et al, “The feasibility of low CO2 concentration targets and the role of bio-energy with carbon capture and storage (BECCS)”, Climatic Change (2010) 29. Anderson B et al, “Beyond ‘dangerous’ climate change: emission scenarios for a new world” Phil. Trans. R. Soc. A (2011) 30. Arora V.K. et al, “Carbon emission limits required to satisfy future representative concentration pathways of greenhouse gases”, Geophys. Res. Lett., 2011 31. Kurz et al, “Risk of natural disturbances makes future contribution of Canada’s forests to the global carbon cycle highly uncertain”, PNAS, 2008 32. Ramanathan et al, “Global and regional climate changes due to black carbon”, Nature Geoscience, 2008 33. Wild M., “Global dimming and brightening: A review” JOURNAL OF GEOPHYSICAL RESEARCH, 2010 34. Wild, M et al, “Global dimming and brightening: An update beyond 2000”, J. Geophys. Res, 2009 35. Sutton M.A. The European Nitrogen Assessment, 2011 36. Jan de Boer H. “Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2”, PNAS, Early Edition, Jan 2011 37. Arneth A et al, “Terrestrial biogeochemical feedbacks in the climate system” Nature Geoscience, VOL 3, AUGUST 2010 38. Cao L & Caldeira K. “Atmospheric carbon dioxide removal: long-term consequences and commitment.” Environ. Res. Lett. 2011 39. Lacis A.A. et al, Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature, Science 2010 40. Barbero, L et al, “Importance of water mass formation regions for the air-sea CO2 flux estimate in the Southern Ocean”, Global Biogeochem. Cycles, 25, 2011 41. Schuster, U. et al. “A variable and decreasing sink for atmospheric CO2 in the North Atlantic” J. Geophys. Res. 2007 42. Jackson J.B.C. “The future of the oceans past”, Phil. Trans. R. Soc. B , 2010 43. Cai W-J et al, “Decrease in the CO2 Uptake Capacity in an Ice-Free Arctic Ocean Basin”, Science, Vol.329, July 2010 44. Boyce D.G. “Global phytoplankton decline over the past century”, Nature, July 2010 45. Zhao M. et al, “Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009”, SCIENCE 2010 46. Kerr . R. “Global Warming Is Changing the World” SCIENCE 2007 47. McNamara J.P. , “Arctic Landscapes in Transition: Responses to Thawing Permafrost” Eos,June 2010 In the seriesof papers above it becomes quite clear the CO2 is not going fall rapdily after even a total stopping of Co2 emissions and th epaper by Archer is useful but hten not really, for it assumes continued CO2 fertilization to large degrees and as it puts th etotal pulse of CO2 upfront it creates large atmospheric CO2 to Oceanic CO2 gradients pushing CO2 into the ocean at far greater rates than be expected now. Also I woudl suggest that you consdier further the scale of nitrogen fertilization response w ehave had since the 50's, increaseing the land sink and the oceans sink as the nitrogen a spercolated throughout the whole environment, and then of coruse looking at the Archer data even more closely ~50-60% of the CO2 remian in the atmoshpere for ~200years, and the CO2 models used doesn't really account for nutrient deprivation that well, no accoun tof permafrost releases, no accoun tof the increasing SH westerlies upwelling, no accounting for the increasing wetlands were getting, no accounting for the severity of droughts we are having, no accounting for the facts that from the face trials the CO2 fertilizatione ffect is short lived, no accounting for the removal of nitrogen fertilization as an urgent neccessity, no accounti9ng for the reducing sinks in the S. Ocean, North Atlantic, Off Japan for some reason, the loss of Phytoplankton, the increasing forest fires, the fact the Canada has become a carbon source, as have the tropics,no accounting for the facts that as the CO2 falls the sinks will re-relase the carbon they have stored,no accounting for the rise in CO2 as the world warms from oceanic sources and no accounting for the large scale biodiversity losses that are being witnessed that simplify eco-system and reduce carbon storage. All the aside an dwhy I mentioned the albedo effect, it is now clear that when ther eis ice on this planet th eeffective CO2 forcing is doubled, and keep in mind the arctic summer ice was 7million km2 recently, tha tis larger than the laurentide ice sheet and the water is darm blue compare dthe lighter land beneath the ice, meanign the albedo effect of a melting sea at the pole is considerable and quick... Then back to PETM when CS is higher than 3oC with the latest CO2 proxies by some way, nearer 7C, and then consider that again that the Pliocene was 3-5C warmer at 350ppm. And I'm sorry but to suggest that a trillion tonnes of carbon is in anyway safe, especially considering the major weather events and ice melt we all already having seems intellectual denial to me of the real situation..we don't have any room to put more CO2 into the atmosphere indeed if we don't start taking it out, and somehow increase carbon uptake from into the sinks to get the 350ppm then times will be interesting, although the scale of the problem to get to 350ppm is daunting indeed, for using even a simple CO2 with sinks that say high, to get to 350ppm means a 400ppm peak by 2017 and carbon sequestration from that point. -
sidd at 07:51 AM on 5 June 2012New research from last week 22/2012
The Rignot paper is quite interesting. A result I had not expected is that basal sliding dominates. sidd -
Bernard J. at 23:48 PM on 4 June 2012Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
Regarding Dale's claim at #6 about being retrenched, I did the obvious thing and emailed SCA. I'll pass on any answer that I might receive. -
Tom Curtis at 22:47 PM on 4 June 2012Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
Dale @6, it's rather odd that I haven't heard about these retrenchments based on a tax that hasn't even been implemented yet. Even odder that there is no mention of them that can be found on a google search. Oddest of all is that while SCA Hygiene Australia did release a press release saying that a Federal Government decision could cost "thousands of jobs", the decision they were worried about was "the removal of dumping duties on rolls of toilet paper imported from Indonesia and China", with no mention of the Carbon Tax at all. Indeed, the terms "Carbon", "Tax", "global" and "warming" cannot be found by google search on the SCA site at all. In short, Dale, your story does not wash. -
Dale at 21:43 PM on 4 June 2012Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
Can someone please call my old boss and tell him he didn't need to retrench me and heaps of others due to the carbon tax? A calculated rise of $9.3 million due to the carbon tax had to be recouped somehow. Oh, I used to work for SCA Hygiene Australasia, heavy energy and transportation users. Thanks. -
CBDunkerson at 21:21 PM on 4 June 2012Lessons from Past Predictions: Hansen 1981
Curiousd, at 2 ppm per year, a 360 ppm starting point, and a 560 ppm target (two times the historical ~280 ppm amount) it would take (560 - 360) / 2 = 100 years (i.e. 2100) to reach double the historical CO2 level. To double again to 1120 ppm it would then take another 280 years if the 2 ppm increase per year held constant. I'm not sure how you are getting the 116 years figure (among other things it seems to assume annual increase remains a constant percentage of the accumulated total... which contradicts your own statement of a 2 ppm constant increase), but even if it were correct it could not then simply be extrapolated to another 116 years to forecast another doubling of CO2 levels as you indicate. If the rate of increase remains constant then the time required to double that atmospheric CO2 level also doubles. All that being said, the rate of atmospheric increase has not been constant. In the 1990s it was a bit below 2 ppm per year and it is now a bit above. However, this rate of acceleration is largely dependent on levels of human fossil fuel use and thus predictions of what it will be a century out are little more than guesswork. -
curiousd at 21:02 PM on 4 June 2012Lessons from Past Predictions: Hansen 1981
Hi again Tom Curtis, I should also say that we do teach - say in talking about multiplying bacteria - that N = N1 x 2^(t/d.t.), d.t. is doubling time (You cannot use the e base with these folks for obvious reasons). But now I can say that there is an analogous expression that applies to something climate scientists call the climate sensitivity and the expression is C= C1 x 2^( T increase eventual/ T climate sensitivity). However - T increase eventual is indeed eventual - there is a fast reacting and slow reacting component. All this gives me a handle to incorporate and connect the climate sensitivity concept into the lecture on exponential growth, population growth, demographic transition, and so on then ask problems like the one I put into post 25. -
curiousd at 17:49 PM on 4 June 2012Lessons from Past Predictions: Hansen 1981
Hi Tom Curtis, Say you are teaching this stuff to people who are paranoid of even simple algebra, and have been dragged kicking and screaming into a situation where they have to learn some math and physics to graduate. If they are to be tortured by math and physics anyway might as well give them problems like this: From Mona Loa data the annual growth of CO2 in the decade 2000 - 2010 is reasonably constant and averages about 2 ppm/year. The concentration of CO2 in the atmosphere in 2000 was about 360 ppm. (a) If present growth rates of CO2 continue, what is the "doubling time" in years for CO2? Standard rule of thumb for non scientists with math paranoia: D.T. = 70/ % increase. They would struggle to figure out what % increase 2 out of 360 was, but about half the class would do it correctly and get 116 years. (b) Climatologists have a parameter they call the "Climate Sensitivity" which is the temperature increase that is eventually guaranteed for a doubling of CO2. It could perhaps also be called the "doubling temperature." What would the eventual increase expected in world temperature that would result from 232 years of CO2 growth at the rate of the 2000 - 2019 decade? This is two doubling times of growth, which result in two doubling temperatures or an eventual guaranteed increase of 5.6 degrees C I would then ask them to compute the equivalent change in degrees F and here I would get really crazy answers from about half the class which I would need to adjust. -
Neven at 16:38 PM on 4 June 2012Toxic mercury, accumulating in the Arctic, springs from a hidden source
Another source of mercury in the Arctic is so-called bromine explosions (in this blog post on Arctic pollution): Drastic reductions in Arctic sea ice in the last decade may be intensifying the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, according to a new NASA-led study. The connection between changes in the Arctic Ocean's ice cover and bromine chemical processes is determined by the interaction between the salt in sea ice, frigid temperatures and sunlight. When these mix, the salty ice releases bromine into the air and starts a cascade of chemical reactions called a "bromine explosion." These reactions rapidly create more molecules of bromine monoxide in the atmosphere. Bromine then reacts with a gaseous form of mercury, turning it into a pollutant that falls to Earth's surface. Read more here. -
john byatt at 16:24 PM on 4 June 20122012 SkS Weekly Digest #22
The QLD minister for Climate Change Science&Policy confirmed today what had been obvious to most of us already, he is a sceptic. http://www.abc.net.au/worldtoday/content/2012/s3517410.htm -
adelady at 14:56 PM on 4 June 2012IEA CO2 Emissions Update 2011 - the Good News and the Bad
@40 "I’m simply not prepared to rely on models as much as others are so prepared. I’ve had a little to do with them over time, and recognise their value and risks. Does that address your question?" Recognising 'their value and risks' is what scientists themselves do. If you read journal papers or other commentaries and discussions by climate scientists, they're absolutely open about the specific purposes or limitations of various models and model components and the projects based on them. You really do need to be more specific. Do you mean that you think that the failure to predict the collapse of Arctic sea ice could be related to the limitations of the OHC modelling underlying the earlier projections of a slower decline? Or some other specific problem in lining up observed data and modelled projections? Or are you just nervous about models because they're models? -
scaddenp at 14:16 PM on 4 June 2012IEA CO2 Emissions Update 2011 - the Good News and the Bad
"Does that address your question?" It isnt a critical enough approach for my tastes. "Reasonable" can mean logically sound or it can mean say suggesting a middle ground on say sensitivity or simply, confirming my prejudices. A question like "are current temperatures consistent with the published science" has a yes/no unequivocal answer. The first step would be to check what the science actually says. (Eg one model result would be Keenlyside 2008 - so far not that cool). Wouldnt it be nice if the science was collated and evaluated in one place? That is what IPCC does - have you actually read the IPCC WG1. What are your ways of evaluating the trustworthiness of sources? The statements of all the science academies of the world doesnt convince you, so what matters? Do you prefer peer-reviewed papers or is fossil-fuel funded disinformation worthy of equal consideration? Oh and by the way, we depend on GCM models for constraining answers to questions like "what would 500ppm of CO2 do to the climate" in numerical terms but we dont need models to show the world is warming or that increasing GHG concentrations in the atmosphere causes warming. "Public statements" are not science. Worse they are often just sound bites selected by the media. Is it from a press-release accompanying a published paper or just someone's opinion. As with my point above - check with the source if you dont trust the speaker but its not science unless it is based on peer-reviewed publications. As to the response to Eric, my point was that you will have to adjust to high petroleum prices no matter what. You can do it now with bumping carbon tax and like, and help slow climate change; or you will do later when also facing climate problems. Its not primarily a climate issue. Hell, I would be happy if petroleum was untouched (my livelihood) so long as not another coal-powered station was built. I would be horrified if it was suggested that the plight of the "fuel poor" was a reason for delaying action on climate. Its a bit rich worrying about those who can even afford to buy fuel at relatively low prices when climate change will bite the truly poor through drought and salt-invasion. I understood Eric to mean that you have to put in measures additional to carbon tax to ensure fairness which the US is well able to afford. -
Chris G at 13:19 PM on 4 June 2012Modelling the Apocalypse
Tom, I think I should have digested your last paragraph a bit more before commenting. Surely not an entirely accurate depiction of what you wrote, but maybe not too far off: As the upwelling of the ocean is helping keep the surface cool, the downwelling is helping to extract/sequester CO2 from the atmosphere. The maximum temp reached is quite a bit lower than what would be expected only from the maximum CO2 level. Here's to hoping you are right. -
Tom Curtis at 12:50 PM on 4 June 2012Lessons from Past Predictions: Hansen 1981
curiousd @22, you can partially eliminate that problem, and conditions (b) and (c) in my 23 by calculating the Transient Climate Response, which is about 2/3rds of the ECR (with a large uncertainty). However, the remainder of my points from my 23 would still stand. -
Tom Curtis at 12:44 PM on 4 June 2012Lessons from Past Predictions: Hansen 1981
curiousd @21, I believe your mathematics is correct (though maths is not my strong suite). What is absent is an awareness of the physics. Your formula would be useful to predict the change in CO2 concentration if: a) We used the measured climatology (>29 year mean) of Global Mean Surface Temperature for two periods, commencing t1 and t2 to determine dT; b) t1 and t2 where sufficiently far apart in time for the Earth to reach an equilibrium response to a change in forcing; c) t2 was sufficiently long after the last change in CO2 concentration for the Earth to have reached the equilibrium climate response; and d) Change in CO2 levels where the only change in forcing between t1 and t2. For conditions (b) and (c), a sufficient period is certainly not less than a century, and may be considerably longer. Conditions (a) through (c) when we compare data from paleoclimatology with each other, or to present values. Condition (d) has probably never been satisfied on Earth, and is certainly not being currently satisfied. The standard formulas are useful because we can calculate the change in forcing for a variety of forcings, sum them and then calculate to a first approximation the expected Equilibrium Climate Response. Being more accurate, we would apply a weighting to each forcing separately to allow for the fact that different forcings have slightly different feedback responses due to differences in geographical, vertical and temporal distribution. By definition, the weighting of CO2 = 1. (We could of course, define any other forcing as having a weighting of 1 instead, simply by varying the constant in the second equation.) So, given the above, my question is, where are you going with your equation? -
curiousd at 12:25 PM on 4 June 2012Lessons from Past Predictions: Hansen 1981
OOPS! No my last sentence beginning "And" is wrong above. Because the dT contains rapid response components and long response components. I was forgetting about that important point.
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