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Rob Painting at 10:58 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Tom, cold water being able to absorb more CO2 is definitely part of the answer, but so too is eutrophication - where nutrient run-off from agriculture (mainly) ramps up phytoplankton growth (they're surface-dwelling marine plants). During phytoplankton blooms, large volumes of CO2 are utilized as phytoplankton absorb CO2 into organic tissue. When they die a week or so later, they fall to the ocean floor and are broken down by bacteria, thereby releasing the CO2 they stored in their tissue (remineralization). This makes the ocean floor seawater more acidified. The 'Biological Carbon Pump' was discussed in the SkS post Ocean Acidification: Corrosive waters arrive in the Bering Sea And another culprit is increased upwelling in some regions in response to ocean circulation changes brought on by global warming. These processes acting together are rapidly acidfying the subsurface ocean in cooler regions of the globe, and are also de-oxygenating these areas. Anyway, I have future ocean acidification posts covering these topics. -
muoncounter at 10:42 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
The linked paper under 'equivalent to atmospheric CO2 levels of 2300 ppm' in the post states: Peak pCO2 values of >230 Pa (>2300 μatm) and pH values of < 7.5 Those are pressures; I understand that 230 Pa is equivalent to 2300 x 10^-6 atmospheric pressure, but how does that produce an equivalent volumetric concentration of 2300 ppm? -
mancan18 at 10:19 AM on 22 December 2011Plimer vs Plimer: a one man contradiction
In describing Ian Plimner’s new book, How to Get Expelled From School: a guide to climate change for pupils, pundits and parents, John Howard referred to leftie science teachers as being the problem regarding proper debate in relation to climate change. The book is supported by the Institute for Public Affairs, and the comments were made at the book’s launch at a meeting of mining company executives. Ian Plimner, and his fellow IPA scientist mate Bob Carter, have attacked the scientific consensus related to climate change; that global warming is occurring and is causing climate change and is due to excess human emissions of greenhouse gases like carbon dioxide. In trying to debunk this hypothesis, they have also attacked the integrity of world’s climate scientists. They have attacked the integrity of the national science academies of the world’s leading nations. They have attacked the stance made by many of the world’s leading companies. They have attacked the integrity of the scientific process and now, in publishing this new book, he and John Howard have attacked the integrity of the nation’s science teachers. Is there nothing and no one that these climate deniers will besmirch in order to deny the basic scientific hypothesis: “That carbon dioxide is increasing, average global temperatures are increasing and that climate change is occurring at an unprecedented historical rate and it is due to human activities”? However, Plimner and his IPA and conservative political mates like Howard, do not attempt to disprove the hypothesis, they simply deny it. They have conducted no scientific research related to climate change and they have published no scientific papers related to climate change in the recognized scientific journals for peer review and scrutiny by recognized climate scientists. What have they done? Nothing. Instead they publish their politically motivated scientifically distorted views in the public media because what they are saying is so scientifically inconsistent that the mainstream scientific media won’t print it. And how do they do it? Make statements like Plimner’s “undersea volcanoes emit more CO2 than humans do”. Do we see the research? Have we seen the Plimner undersea volcano survey with its CO2 measurements from a representative sample of volcanoes? No, we see Plimner’s estimates of what he thinks are the number of volcanoes and how much CO2 he estimates is emitted. Now this type of pseudo scientific research might be enough to fool the popular media but it will not fool reputable climate scientists. Like any good propagandists, deniers of the likes of Plimner (and Carter, Monkton, Spencer, McIntyre, and Lindzen et. al.) will use their scientific credentials gained in other fields and use most of the truth to appear credible but in doing so confuse the scientifically uninformed. In reality, they fail or neglect to clearly explain scientifically; how greenhouse gases can be increasing, how temperatures are increasing, how climate change is occurring, and is having significant impact on the biosphere that we all rely on for life and how all this is natural. Plimner might be a good mining geologist and mining CEO but as a climate scientist, he is a dud. -
Tom Curtis at 10:16 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Rob Painting @7, I think it should be made clear that high levels of carbonate and bicarbonate in Norwegian seas relative to current atmospheric levels of CO2 is because of the cold water absorbs more CO2. Therefore colder waters will be more acid for a given CO2 concentration than will warmer waters, as can be seen below:
It is not because of unusually high CO2 concentrations in the atmosphere above Norway, or because of local water pollution.
At least, that is as I understand the situation.
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muoncounter at 10:05 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Rosco#6: "natural sources of atmospheric CO2 are far larger than manmade releases." Of course, you are aware that those 'natural sources' have been in place for a long, long time. So long that an equilibrium known as the Carbon Cycle is well-established and well-known. So those 'natural sources' aren't part of this problem; the folks that dumped a large mass of carbon into the atmosphere in under 200 years; more than half of that in the last 60 years - that's the problem. -
Tom Curtis at 10:02 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Westerwick @9, I believe Rosco is referring to the fact that CO2 at the Earth's surface is held in three large reservoirs, the upper ocean, the atmosphere and the biosphere. Exchanges between these reservoirs dwarf any additions to the total system by humans. Of course, all three systems are in effective equilibrium, so that net flux between any two reservoirs is close to zero. To increase the amount of CO2 in all three reservoirs requires CO2 from another source, and human emissions dwarf all natural emissions from other sources. Of course, the full facts of the matter have been carefully concealed from (or by) Rosco to create a misleading impression. -
Stevo at 10:01 AM on 22 December 2011The Media & Global Climate Science Communication
John Hartz @ 16 The quick and dirty answer to your question is that efforts were made in the 1990s to limit the amount of media ownership by another media moghul. While all attention was limiting the extent of the Packer empire, particularly in television, the newspaper market was slowly shrinking. Fifteen years ago most Australian cities had two competing newspapers for consumers to choose from. Now, all but Sydney and Melbourne have only one paper each. Murdoch papers now dominate because the smaller operators have died off. Attention was paid by government to limiting how much of the market a company could buy up but had no answer for how to stop a near monopoly growing by virtue of it's competition witherring on the vine. -
Westerwick at 09:46 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Rosco--You are correct about CO2 solubility as a function of temperature, but that effect will be totally overwhelmed by the other equilibria considerations. As with any gas-liquid interface with a soluble gas, the system will always attempt to reach equilibrium, and be concurrently losing gas out of solution from the water and absorbing gas from the air. Increased water temperature will shift that equilibrium point to lower net CO2 absorption. In the past century or so, the overall water temperature has increased overall roughly a degree or so. The concentration of CO2 in the atmosphere has increased by nearly 50%. All other things being equal, the net absorption into the water will increase because of the increased concentration and it will try to reach its new equilibrium point based on that, with a slight modification because of increased temperature. Your argument about all CO2 increases due to water temperature increases, well, doesn't hold water (sorry). There isn't enough CO2 in the ocean to "boil off" like that with a small temperature change, aside from the inconvenient increases in the CO2/carbonate/acidity concentrations. If the overall system was that sensitive to temperature, we would see very high CO2 concentrations in the tropics since the CO2 would leave, and very low levels in the northern oceans. In actuality we only see only a couple ppm difference, and most of that seems to be a result of delays in mixing from sources to lower concentration areas. As for "government agencies" and their claims, I think we need to see specific citations and contexts. The natural sources are huge, but when we put the system out of balance and have system response times measured in centuries, it will take time to get back to equilibrium. In the meantime, the climate changes and the oceans become more acidic. -
Paul D at 09:21 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
fydijkstra many fish are sensitive to even small changes in ph levels even if it doesn't kill them. The question then is whether species would adapt or would migrate. But why conduct a massive experiment with CO2 emissions just to find out what happens? -
Rob Painting at 09:18 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Yvan -"The only problem with this analysis is the CO2 level used are on the extreme high end of the possible" That's not correct. 2300ppm (equivalent) is already experienced over summer and autumn in Kiel Fjord, an area close to cod spawning grounds. This was pointed out in the post. If you look at figure 4 (medium =1800ppm scenario), you'll notice an increase in cod larvae tissue damage and, undoubtedly, a consequent increase in mortality. Also, many regions along the Atlantic coast of North America (home of the inland silverside studied in Baumann [2011]) are seeing acidification much worse than anticipated. In other words, ocean acidification is very likely affecting these fish egg/larvae today. -
Rosco at 08:57 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
A well established scientific fact - increasing water temperature results in lower solubility of CO2 in the oceans. The net result is less not more CO2 in the water - some well qualified scientists even say the increases in water temperatures observed are responsible for most of the atmospheric increases in CO2 levels. There are numerous references including US government agencies which claim natural sources of atmospheric CO2 are far larger than manmade releases. Either way, no matter what you believe the fact remains - CO2 is less soluble in warm water and rapidly escapes to the atmosphere.Moderator Response: [Rob P] Do yourself a favor and read the rather extensive SkS series OA is not OK which is written by actual experts on the topic. The warming oceans will make relatively little difference to CO2 uptake by the oceans. -
Eric (skeptic) at 08:56 AM on 22 December 2011Roy Spencer on Climate Sensitivity - Again
CBDunkerson, you should read Spencer and Christi's explanation of what that graphic is, http://www.drroyspencer.com/2011/12/addressing-criticisms-of-the-uah-temperature-dataset-at-13-century/ In a nutshell it is the increase of temperature trend over time (i.e. the world is warming). It is not a graphic showing biases in their estimates (although there were some). -
Brian Purdue at 08:45 AM on 22 December 2011The Media & Global Climate Science Communication
Yvan Dutil – You misread the tenor of the article. I am definitely not optimistic, but very pessimistic about the way the mass media communicate information. In the print media example cited there was an overwhelming “imbalance” in the media coverage. The statement was made in article “So what message should the mass media be communicating about climate change science?” The mass media is NOT getting the climate science message out – you have to go to specialised media sources for that. The decline of journalistic standards (not the fault of most journalists) is self-evident in the absence of “accurate and unbiased” communication of climate change science. Your example of the introduction of pseudoscience by the media is not an isolated case but typical of the way the industry operates. The article was about highlighting the mass media climate science communication problem - not fixing it! -
Yvan Dutil at 07:52 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
The only problem with this analysis is the CO2 level used are on the extreme high end of the possible. From the data they give, actual high CO2 concentration are not cause by the increase of atmospheric CO2. However, increase of organics matter in ocean due to fertilizer run-off my increase it. -
Utahn at 07:13 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
Interesting link Gerda, it would be even more interesting if they went back to 1900 or so ;) Like their acronym as well, apropos... -
littlerobbergirl at 07:00 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
thanks utahn, i was thinking that also. it's obviously a tool that can be used for both, as i found a nasa site specifically dealing with smoke http://www.ssd.noaa.gov/PS/FIRE/GASP/gasp.html presumably the natural and man made signals are distinct and easily separable... -
littlerobbergirl at 06:53 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
maybe something to do with the location on the sensors? e.g. wdca sites seem to be mostly in europe, n.america and africa, none in asia; http://wdca.jrc.it/data/parameters/data_AOD.html which would give good results for background (mostly natural) haze but not human emissions on the timescale and period we are dealing with here? -
Utahn at 06:53 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
skept.fr (and Gerda) I think the links to AOD are found embedded in Tamino's article . Plus you could ask him directly there...I'm not sure if human aerosols get to the stratosphere as easily as volcanic... -
littlerobbergirl at 06:42 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
fyd.. and where is that buffer coming from in shallow water where these fish babies are? oh yes, mainly the shells of reef forming organisms. slowly, and patchily. so it's quite possible to get extreme acidity locally, as mentioned in the article. the 'steady state' model just doesn't fit on less than geological time scales or smaller than ocean wide geographical scales. -
pbjamm at 06:26 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
fydijkstra@2 Do you have a link to your paper/study? -
John Hartz at 06:17 AM on 22 December 2011The Media & Global Climate Science Communication
Speaking as a Yank, why on earth did Australians let Murdoch's news empire gain control 70% of the country's print media? -
fydijkstra at 06:08 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
The oceans form a pH-buffered system. This means (check your lower grade chemistry lessons) that large changes in CO2-concentration will result in small changes in pH. The present pH-change is insignificant. Predictions of extreme pH-changes are incredible. Not much to worry about.Moderator Response: Your comment demonstrates you have not read our extensive OA not OK series. Please read this before commenting further. I consider your comment to be trolling and will delete further trolling without notice. [Doug] [muon] fixed link -
dana1981 at 05:42 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
Hi Gerda. I haven't researched exactly how AOD is developed, but I don't think so. Look at Figure 2b above - volcanic eruptions are clear, but there's no indication of human aerosol influences. -
littlerobbergirl at 05:42 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
oh bother! sorry, didnt read the second page of comments. -
dana1981 at 05:41 AM on 22 December 2011Roy Spencer on Climate Sensitivity - Again
Tristan - that's an interesting idea, though it seems a little mean :-) I wouldn't want to imply that because the UAH trend estimates have been trending upward at 'x' °C per decade, that trend will necessarily continue. The trend might be worth a brief mention though, with that caveat. -
littlerobbergirl at 05:38 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
hi dana, nice graphs! i get it, only too well. am i right in thinking the optical index will filter out effects not only from volcanic activity, but also from human produced black carbon etc? if so, why no mention? i'm thinking of changing my handle to 'einstein's barmaid' :D -
AussieinUSA at 05:37 AM on 22 December 2011The Media & Global Climate Science Communication
#6 - While I applaud Julia for what she is achieving, I do wonder if she would be implementing any Carbon Tax if she had a clear majority after the elections. IMO I don't think she would have. Thank goodness for a hung parliment! @14 - You have hit the nail on the head with one of your quotes about the person with the loudspeaker. I find this to be quite common even in basic dialogue with fellow workers. One denialist shouts or yells out loud that AGW is a hoax, so everyone likes to believe him and think he is an expert. Frankly it reminds me of one of my childrens temper tandrums. However as he shouts it out loud I think the average Joe see's this as confidence and therefore believe he must know what he is talking about. -
michael sweet at 05:22 AM on 22 December 2011Roy Spencer on Climate Sensitivity - Again
CBD: excellent graph. It should be added to every post about Spencer and Christy. The entire Post article was a good read. -
Tristan at 05:17 AM on 22 December 2011Roy Spencer on Climate Sensitivity - Again
Dana, I hope you fit a line to their predictions ;) -
Mikemcc at 04:59 AM on 22 December 2011Animals and plants can adapt
The link to Univ of Texas climate change impact article (marked by the text "timing of breeding, migration, flowering, and so on") is broken. It looks like they've moved the article. I think the link was to this article http://web5.cns.utexas.edu/news/2004/11/global-warming-2/ -
DrTsk at 04:41 AM on 22 December 2011The Media & Global Climate Science Communication
@JH Not off topic at all, when it is presented as a clear example of the problems that we are facing with respect to accurate and effective communication by the media. The guy with the loudspeaker trumps all voices. Especially, with all the social media noise. I like the saying "Death by data", where you generate so much irrelevant data for a project that in the end you don't have time to analyze or even find the relevant data. The same is true with information : "Death by information". That is the problem that social media have generated for people that do not have the time, the will, or event the tools (mental or otherwise) to collect, analyze, draw conclusions etc. I despair looking at the fact that politicians, forming the policy for the response or not to global warming, are IMO at a low point with respect to the quality and accuracy of information that are fed to them by their underlings.Moderator Response: [JH] With all due respect, you re-posted a statement made by a climate denier on a comment thread to an article. The original post is about how the mainstream media in Australia covered climate change policy-making in Australia. -
dana1981 at 04:10 AM on 22 December 2011Roy Spencer on Climate Sensitivity - Again
Yes, look for our response to the UAH 33rd anniversay release, probably on Monday. -
Albatross at 03:23 AM on 22 December 2011Roy Spencer on Climate Sensitivity - Again
CBDunkerson @27, Agreed. Spencer and Christy have way too much confidence in their product. Other satellite products such as STAR show much greater rates of warming in the mid-troposphere than do UAH and RSS. So to claim that the satellite data are the gold standard or the benchmark for global temperatures is just plain wrong. This was a pretty blatant PR exercise and misinformation campaign by Christy and Spencer-- and I suspect that we will keep hearing them repeating the same debunked myths each year. They seem to be under the impression that if they keep repeating falsehoods they will become true. That was a pretty good article by Freeman, good for him for calling Spencer and Christy on their misinformation. But no worries, SkS is on the case and will have something posted soon :) -
skept.fr at 03:19 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
#53 KR : I agree with your presentation of FR2011, the near-linearity of the signal suggest residual noise (if any) is probably weak. But the fact that there is no acceleration in the trend could also suggest that there is a residual natural cooling noise in the past decade (and/or warming in the previous). If so, the AGW rate would accelerate in reality. I don't know, but I'm pretty sure FR2011 cannot be interpreted firmly in a "reassuring" way (you know, interpretation like "don't worry, warming rate is steady, it proves that we will get 1,7 K in 2100 in BAU scenario"). #dana1981 : the anthropogenic sources of aerosols is supposed to have decreased in the 1980-1990s (works of Martin Wild and co-authors on "global brightening"), then increased in 2000s due to global increase of coal plant emissions (Chinese and emerging countries). (So again, one should note this a cooling trend in the 2000s decade.) Is there a reference web source explaining how the AOD is calculated (methods, sites, etc.)? For example, I don't know how the indirect effect (in cloudy sky) can be measured. -
dana1981 at 03:13 AM on 22 December 2011Ocean Acidification Is Fatal To Fish
Really good post Rob, but rather disturbing that we keep finding new unintended consequences of anthropogenic climate change. A lot of people rely heavily on fish for food - decreasing stocks due to acidification would be really bad news. -
Foster and Rahmstorf Measure the Global Warming Signal
dana1981 - I agree on the human aerosols. I suspect our data on the subject (given the regional nature and short lifespan of human aerosols) isn't terribly good, but I've suggested the same over at Tamino's blog. In the meantime, I don't think F&R have in any way claimed that these are the only exogenous influences on climate - simply that they are large ones, and that accounting for them improves our view of GHG influences. -
dana1981 at 02:57 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
Agreed with KR @53 - this paper certainly doesn't remove all exogeneous factors, just 3 big ones (3 of the biggest, in fact). The one criticism at WUWT that I'd like to see implemented is the influence of human aerosol emissions. That would make for an interesting addition to the analysis, if we could get good enough emissions data. -
muoncounter at 02:37 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
skept.fr#52: "The 2000s decade could well have been the definite proof that natural factors are henceforth unable to cool the Earth, even in the most favorable condtions for that." Fair point. I noted here that quiet solar conditions (a natural variation if ever there is one) were ideal for the onset of cooling; F&R's important result show no evidence of that happening. But surely the pseudo-skeptics will cry, 'wait 'til next year!' -
Foster and Rahmstorf Measure the Global Warming Signal
skept.fr - As I (personally) interpret F&R 2011, the purpose of the paper was to remove large, known sources of variability from the temperature signal, and see how they affected the statistical relevance of an underlying warming trend. Hence their regression against ENSO (known to affect temperatures, with at least a partially understood physical basis for those effects), volcanic/sulfur aerosols (simply on the basis of albedo), TSI (goes without saying), and the annual cycle. The results indicate a very strong agreement among the five temperature records, a clear linear trend, and greatly reduced variability in that identified trend. In addition the correlation strength and lag times are quite interesting, and match reasonable expectations of the physical basis for their effects on temperatures. Remaining variability may be (I would almost say "would have to be") due to other effects. But - given the statistically linear residuals of the data after these components, these other potential influences do not show a cyclic effect, or for that matter a dominant effect, on the data that we have so far. Perhaps after some time, with more data, we might have enough to tease out other cyclic or acyclic influences on temperature. Right now, with the data used in the F&R paper, limited by (among other things) the length of the satellite record - there's little evidence for it. -
skept.fr at 00:54 AM on 22 December 2011Foster and Rahmstorf Measure the Global Warming Signal
Tom : thank you. Bert : read my first message in #13, my point was clear about signal-noise disambiguation, and my conclusion was clear too : "I think FR get the broad picture with their choices, but I don't know if the decadal trends they obtain from their removals are very precise. Maybe lower, maybe higher." (My emphasis). In my opinion, if multidecadal unforced variability exists and is assessed, the real AGW signal may well be higher (not lower) that the conclusion of FR2011. For example, if you look at this recent Douglass guest post on Curry's blog, you see that the author suggests the internal variability modes could have known a very low shift at the beginning of the 2000s, the lowest of the past 70 yrs (figure 1 from Towsley et al 2011). If he is correct (that I don't know, and remind this is just a blog post without real scientific value), it would mean that instead of a slight warming, and the warmest T from instrumental records, past decade should have known a very sharp cooling. So, maybe we underestimate (even FR2011) the real signal of AGW in climate. That is why even people who refers to the sun or the natural variability, frequently in a perspective of denialism, doesn't understand the real implication of what they advance for climate. The 2000s decade could well have been the definite proof that natural factors are henceforth unable to cool the Earth, even in the most favorable condtions for that. And this would be quite a bad news for all us. You must really keep an open mind on all these questions. I'm skeptic, not denier. -
Yvan Dutil at 23:35 PM on 21 December 2011The Media & Global Climate Science Communication
I don't share your optimism about the effectiveness of a good communication strategy. I have a Ph.D. in astrophysics and have given a countless number of interview. Many time, an astrologer was invited in the same news report to give a "balanced" view. In addition, I dis some science journalism. I can confirm, there is ZERO time to check your sources. Even putting things in context is very hard due to the limited amount of space. -
CBDunkerson at 23:02 PM on 21 December 2011Roy Spencer on Climate Sensitivity - Again
Spencer and Christy are at it again, using the 33rd anniversary of the satellite record to repeat their claims that their satellite records 'disprove' climate model projections and that the observed warming is therefor mostly 'natural variability'. A Washington Post article on these claims included a great rebuttal in image form;
This was apparently created by John Abraham and sent to them by Andrew Dessler. In any case, I hadn't seen it before and it really brings home just how many serious problems there have been with Spencer & Christy's work and how they have consistently been biased in one direction.
The temperature trend Spencer & Christy show now is more than 0.2 C per decade higher than their original claims. If we apply that as a 'demonstrated uncertainty range' around their current claim then the possible spread on their current value includes warming much greater than any of the mainstream projections.
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Tom Curtis at 23:00 PM on 21 December 2011Foster and Rahmstorf Measure the Global Warming Signal
Bert @50, while I may be disappointed in the end, on evidence to date I do not think you have skept.fr's measure at all. He is not a carbon copy denier, and should not be treated as one. Further, suggestions that he has simply trying to distract us from the obvious are not helpful. -
Bert from Eltham at 21:10 PM on 21 December 2011Foster and Rahmstorf Measure the Global Warming Signal
skept.fr The core of your question is now differentiating signal from noise?! I will say this very simply that the eddies in the flow of heat have been subtracted from the measured signal by FR 2011. These are real perturbations of the GTA caused by both the drivers and mediators apart from our CO2 pollution. The resultant signal is our contribution to the temperature increase of SpaceShip Earth You are complicating what is a simple scenario by pointing to red herrings. I reckon I have your measure. Bert -
Tom Curtis at 20:31 PM on 21 December 2011Foster and Rahmstorf Measure the Global Warming Signal
skept.fr @48:"Tom : only one such "oscillation" has a proven effect on global climate - ENSO I think we disagree on this point, because I consider there is a debate in climate community."
You misunderstand me. There is debate about the effect of several of these oscillations on global temperatures, most particularly the AMO and the PDO. But for just one oscillation has the debate moved to the point where it is beyond reasonable dispute that that oscillation effects global temperatures, ie, for ENSO. For all other candidates, you will find evidence and scientists on both sides of the debate. -
skept.fr at 20:16 PM on 21 December 2011Foster and Rahmstorf Measure the Global Warming Signal
#45 Tom : "what we are finding puzzling about your concentration on the AMO is, as has been pointed out, it is just one of many posited oceanic quasi-periodic fluctuations" Agree with that, but note that my concentration on AMO comes from the fact that Tamino has written on it on his blog, so I took this as an example of what I called in my very first message "the other Os". Following the advice of muoncounter, I posted a question on Tamino's blog, so I'll let you know. My question had no mention of AMO, here it is for information: I miss a point. In IPCC AR4 3.3.6 (2007), several patterns of variability are described, Southern Oscillation being one among others. On long term, these oscillations are centered on a zero mean value (they don’t create heat). But for a shorter term as 1979-2010, why should we consider the sole ENSO as a multidecadal “noise”? Or more precisely, on a 32 yrs period, from which physical arguments must we choose one oscillation in particular, rather than zero oscillation or all oscillations? Thanks. Tom : only one such "oscillation" has a proven effect on global climate - ENSO I think we disagree on this point, because I consider there is a debate in climate community. That's why I quoted Swanson, Tsonis or Latif as examples of scientists having recently published on multidecadal effects on internal (or unforced) variability. Real Climate had published a guest blog of Swanson (link above), so I suppose it is not a scoop. And in fact, IPCC AR4 3.6.8 2007 already said : Decadal variations in teleconnections considerably complicate the interpretation of climate change. Since the TAR, it has become clear that a small number of teleconnection patterns account for much of the seasonal to interannual variability in the extratropics. On monthly time scales, the SAM, NAM and NAO are dominant in the extratropics. The NAM and NAO are closely related, and are mostly independent from the SAM, except perhaps on decadal time scales. Many other patterns can be explained through combinations of the NAM and PNA in the NH, and the SAM and PSA in the SH, plus ENSO-related global patterns. Both the NAM/NAO and the SAM have exhibited trends towards their positive phase (strengthened mid-latitude westerlies) over the last three to four decades, although both have returned to near their long-term mean state in the last five years. In the NH, this trend has been associated with the observed winter change in storm tracks, precipitation and temperature patterns. In the SH, SAM changes are related to contrasting trends of strong warming in the Antarctic Peninsula and a cooling over most of interior Antarctica. The increasing positive phase of the SAM has been linked to stratospheric ozone depletion and to greenhouse gas increases. Multi-decadal variability is also evident in the Atlantic, and appears to be related to the THC. (My emphasis) So as you can see, the IPCC 2007 acknowledges that there have been decadal change in some pattern inside the 1979-2011 period, for NAM/NAO, SAM, Atlantic MOC, not only ENSO.The fact that ENSO have the strongest signature on T does not imply that coupling / decoupling of other patterns of variability during there decades have no signature at all on regional T and so mean global T. #47 Bert : "You either do not really understand the physics or you are as is usual with the deniers of AGW, casting doubt on the basic premise by pointing out a meaningless anomaly that has no basis in reality. Or you are genuine and simply misguided. Which is it?" You've a lot of hypothesis about me, I'd prefer a lot of hypothesis about my questions! That is I prefer ad rem to ad hominem. Of course, oscillations do not create heat, but just change its pattern of distribution between ocean and atmosphere. The point of the discussion is not to say that oscillations produce GW — nonsensical as I've already said (so please read me more attentively), they oscillate around a zero mean —, but to understand how FR 2011 can separate signal and noise. That is the core of their approach, and the core of my questions. -
Bert from Eltham at 19:35 PM on 21 December 2011Foster and Rahmstorf Measure the Global Warming Signal
skept.fr When dealing with slightly turbulent flow it is useless to dwell on one of the vortices as a driver of the overall flow. It is a property of the flow rather than a cause. All the 'oscillations' are just this. You either do not really understand the physics or you are as is usual with the deniers of AGW, casting doubt on the basic premise by pointing out a meaningless anomaly that has no basis in reality. Or you are genuine and simply misguided. Which is it? Bert -
Tristan at 18:19 PM on 21 December 2011Foster and Rahmstorf Measure the Global Warming Signal
Tom It's not just somewhat arbitrary, it's entirely arbitrary. P-values, and more importantly, likelihood distributions give us information with which to make decisions. A p-value of 0.05 will result in some decision being made. A p-value of 0.07 will result in some decision being made. They might result in the same decision, they might not. Most decisions are more finely grained than simply 'do' or 'don't'. In the case of this study, the p-value is stacked against a pretty strong body of work that implies that the AMO isn't an actor in global temperatures. I think it'd take much more than p:0.05 to shed doubt on what we currently believe. -
Mond from Oz at 18:14 PM on 21 December 2011Correction to the True Cost of Coal Power - MMN11
(apologies if this is off topic) Today (21/12) SMH 'Business News' writes that some 32 billion AUD is to be spent on mergers and acquisitions in coal production in Australia. Question: On average rough estimate how much does it cost to get a ton of coal out of the ground? In other words, how much coal is this talking about? -
DSL at 15:29 PM on 21 December 2011The Media & Global Climate Science Communication
DrTsk, I wonder if Althouse is also a 9/11 Toother. He should be picking cherries out of his teeth for brushing aside all other atmospheric scientists in favor of the Happer stance.Moderator Response: [JH] Off topic.
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