Arguments
Recent Comments
Prev 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 Next
Comments 41551 to 41600:
-
sereniac at 11:19 AM on 5 October 2013IPCC model global warming projections have done much better than you think
KR #95 indicated:
"A La Nina, with higher wind-driven exchange of deep cooler water, moves a greater portion of that incoming solar energy into the oceans, cooling the atmosphere by ~0.1 C. An El Nino reduces the deep circulation, reducing energy flow into the oceans, causing that energy to remain in the atmosphere and warm it by ~0.1 C. It's really that simple."
Does the ocean data support these changes in energy distribution/location resulting from ENSO variation and when these data are incorporated into models does their output still support the warming trend?
I suspect this will lead to a link somewhere- which would be welcomed.
Thank you
-
sereniac at 11:12 AM on 5 October 2013IPCC model global warming projections have done much better than you think
I find this fascinating.
I'm hoping that I'm asking semi-intelligent questions that other forum readers will find beneficial, however if this is too basic, or covered elsewhere then please tell me to depart and I will happily comply.
I completely agree with KR that extended analogies quickly lose their fidelity and can be dangerous if projected backward onto the system itself as well as extended beyond their foundation. The two slit experiment has clearly shown the conceptual limits of regarding say an electron as just a localised chunk of matter like a ping pong ball.
Glenn Tamblyn's final point:
"Mr Jones' glucose problems become apparent when he can't engage in his training for the fun run because he is hobbling along with a cane."
This raises the question about how long Mr Jones' cane hobbling can be delayed if there is a long series of intense training for fun runs. i.e. how long can the warming signature be obscured by a long series of intense la nina.
I think Mark R #81suggested that this might be of the order of 1-2 decades should a kind of permanent la nina cut in.
My "belief" is that this would be very difficult for most people to accept which is why I constructed the analogy as a lay explanation to show how long term trends can be masked by factors that are periodic but still unpredictable in intensity and duration.
This is a major issue for the perception of AGW I think because many people have great difficulty reconciling the assurance that climate systems are predictable even when major components of it are not.
I hope this is not too off-topic and political.
Thank you
-
Rob Honeycutt at 11:03 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
In other words, Bob, you can't just post a comment from Lucia. She can come here and make the comment herself if she likes. If you want to have your comment not moderated you need to provide your own substantive points.
-
Tom Curtis at 10:45 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
The comments policy states:
"No link or picture only. Any link or picture should be accompanied by text summarizing both the content of the link or picture, and showing how it is relevant to the topic of discussion. Failure to do both of these things will result in the comment being considered off topic."
(My underlining)
My understanding is that the purpose of this section of the comments policy is to ensure posters actually engage in the discussion by showing the relevance of their linked material to the discussion. If they do not so engage, readers are left to guess as to whether the link is in fact worth following; and if followed, what part (if any) of the linked material is relevant to the discussion on SkS.
IMO, Bob does not follow the letter of this requirement, and blatantly fails to follow the spirit.
-
Leto at 08:49 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Re: OPatrick @19, quoting the draft report:
"Models do not generally reproduce the observed reduction in surface warming trend over the last 10–15 years."
You said: " the replacement wording is not different enough to justify her criticisms."
I think we are in broad agreement, but I would go further... It was appropriate to remove the bolded statement, because it was ambiguous, propping up a contrarian talking point that should not be an issue in the first place. Ensemble means do not reproduce the recent "hiatus" (and are not expected to), whereas as individual model runs do reproduce a pattern of randomly distributed hiatus decades (some individual runs would even - by chance - roughly put the "pause" in the historically correct place). The distinction is not well covered in the removed statement.
Curry should know this. She is engaged in a disinformation exercise, not science.
-
Bob Loblaw at 07:56 AM on 5 October 2013CO2 is just a trace gas
Tom:
My definition is the essential of the old reasoning that led to the (poorly-chosen) name "greenhouse effect". The idea was that the glass of a greenhouse let in visible light and block IR going back out. There is the old "re-radiation" line of thought that builds into that as well. So, like a greenhouse, the atmosphere lets in visible light and blocks IR.
Now, it turn out that greenhouses are not warm because of the blocking of IR - plastic ones transparent to IR work just as well - but rather due to the greenhouse confining heat close to the surface by reducing turbulent mixing of the air. So, the radiative effect of the atmosphere isn't at all like a greenhouse. [And I know you know that.]
But then, it turns out, thinking solely about the radiative effects of the atmosphere also doesn't really explain it all, either. If radiation were the only way of moving energy around, the atmospheric temperature profile would be a lot different from what it is - with a much warmer surface. But the atmosphere is mixed, and much energy is carried from the surface to the upper atmosphere by thermal mixing and by evaporation (at the surface) and condensation (at height). [And I know you know that, too.]
So, neither the greenhouse, nor the atmosphere, are explained by soley the IR radiation characteristics.
I disagree that a definition of "greenhouse effect" that only looks at IR radiation is "best". If the atmosphere was opaque to visible light, then the top of the atmosphere would be hottest, and IR wouldn't matter much at all. After all, look at the stratosphere: just the extra absorption of energy in the UV range is enough to reverse the temperature profile. The fact that much of the energy from the sun reaches the earth's surface is an essential part of the process.
Until I try to access a copy through work, I'll have to settle for the abstract of the paper you reference. Although I understand the need to correct distortions of the radiative effects of various constituents that are presented, the paper does just appear to focus on the IR radiation portion of the issue. That's enough to show the bogosity of "it's all water vapour" crowd, but it's still an incomplete picture.
-
funglestrumpet at 07:10 AM on 5 October 2013Residence Time and Prof Essenhigh
Jose_X @ 17, 18 & 19 Thanks for taking so much trouble and effort to answer the question I didn't ask, but should have. Now I understand it better, thanks to you, I rather think I might have won a few discussions in the past rather unfairly! Still, all's fair in love and war, isn't it?!
-
Jose_X at 07:00 AM on 5 October 2013IPCC model global warming projections have done much better than you think
To summarize an important point Leto made on the analogy:
The temperature of an el nino year is like finding the weight of a person right after they put a large meal into their stomach.
The temperature of a la nina year is like finding the weight of the person right before they eat.
It should be clear that a person who is gaining weight steadily (consuming higher calories than they expend) will still likely have a lower weight tomorrow right before their large meal than they will today right after their large meal. So while their weight trend is going up, it doesn't go up in a straight line. It oscillates as they consume a meal and later burn some of it off before the next meal is due. Because the net weight gain per day is relatively small compared to the weight of each meal, the main difference on whether they weight more or less tomorrow is based on when the weight measurement is taken relative to their meals. -
Jose_X at 06:47 AM on 5 October 2013Residence Time and Prof Essenhigh
funglestrumpet @14, here is the summary:
We can roughly liken CO2 going into and out of the atmosphere using 3 analogies.
1 -- We don't care about how long it takes for extra man-made air put into a ballon, or water put into a tank, or food put into a body, to exit.
2 -- We care instead about how long it will take to return to normal volume once we stop adding the man-made air, water, or food.
The argument described in this article crudely measures how long it takes a man-made molecule of air, water, or food, to exit, but that doesn't address what we care about: how long it takes for these systems to return to the normal levels after we stop adding the man-made air, water, or food. I don't care about the speed of travel in my body of my daily cheesecake (from entry to exit). I care about how long before I lose the weight I put on because of that cheesecake. -
Jose_X at 06:38 AM on 5 October 2013Residence Time and Prof Essenhigh
funglestrumpet @14, here is take two (using two different analogies than the earlier air in balloon analogy, water in tank and food in body).
The argument in this article (even if using a too crude model) is about how long it takes for a molecule of "man-made" CO2 to come into the atmosphere and leave.
Is that what you care about? If I have a large tank to which I am adding water but from which some water is leaving, do you want to know how long before the water molecule I add leaves at the bottom? Do you care if the addition is slow and the escape is slow so that the transit time is 1000000 years? Would it make a difference to you if instead the addition and escape were super fast and took 1 second?
I think the primary question (the question as goes global warming) is how fast that tank is being filled *after* we take into account the result of both the additions and the subtractions.
Do you want to know how fast it takes for the food you eat to exit OR do you want to know how much weight you are putting on after taking into account how much you eat and what leaves the body?
The latter is what is important. The argument above tries to make a claim about the latter based on (a crude) analysis of the former without taking into account net gains or losses.
If you care about the latter, then the answer you want is how long it would take for the CO2 to return to "normal" (ie, to some base reference level after factoring out natural factors that may change that reference level over time) after we remove the "man-made" components. Ie, you want to know how long before I return to my "normal" weight after I stop eating that extra dessert after every meal. How long it takes for the food to pass through your body (very fast or very slow) is irrelevant. -
dana1981 at 06:36 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Ugh, well I just wated 5 minutes of my life reading Tisdale's post. If Tisdale ever actually says anything intelligent, then let me know. Until then I prefer not to waste my time reading his drivel.
-
Jose_X at 06:21 AM on 5 October 2013Residence Time and Prof Essenhigh
funglestrumpet @14:
Man is adding CO2 and some of that is leaking back out. This we all seem to agree on. But..
The argument described at the top is a simplified model. Too simplified. It assumes that the atmosphere is a pipeline. It obviously is not. While an engine might have most of the air coming in at one location then move to exit elsewhere, perhaps crudely approximated as a single file queue, the atmosphere has lots of CO2 rise high to areas where there are few sinks. There is no physics that I know that suggests a model of a queue applies. The CO2 is *not* following a path single file that takes it way up high and then spins and comes down to leave at the ground level. That 5 year figure is the result of a simplified queue model. You can forget about it unless perhaps you want to believe the man-made CO2 entering and leaving the atmosphere is doing so in as a queue.
Another analogy is the difference between fast moving draft air in a narrow cooridoor that is open at each end. This is like a queue. The atmosphere instead is like a huge balloon with two openings near each other, where one opening slowly adds air and the other slowly removes it. In this balloon example, we have nothing resembling a queue.
Besides that the flow is not like a queue IMO, you are asking a different question than what is presented above. The five year is supposed to be the average time for CO2 to move into the atmosphere and back out, but the question you are asking is how long before we return to the same quantity of CO2 we had if we stop adding CO2. You care about how long before the air in the balloon gets back to the same quantity if we remove one of the several drivers adding air into the balloon.
If we stop adding, there will be a net loss of CO2 that will slowly work its way back towards a more natural condition. It will take many years to make it most of the way there, but like an exponetial decay curve (if that model were to resemble the effect) we would never really get back all the way. Of course, the earth is more complex. If we plant and manually sustain more trees (or add other CO2 sinks.. eg, consume CO2 via microorganisms that sequester the result in some chemical form), then we could not only get back to "normal" as defined by today's system but even go beyond it. And then there are planetary effects and basically a bunch of effects (feedbacks) that don't follow the exponential decay model either.
Sorry to not give you a precise answer. You asked in the right place and some studies address that concern. I just wanted to give an idea that what you are asking has nothing to do with this abstract 5 year calculation. -
funglestrumpet at 06:21 AM on 5 October 2013Residence Time and Prof Essenhigh
MA Rodger @ 15
Thanks, that is exactly what I was looking for!
-
MA Rodger at 05:39 AM on 5 October 2013Residence Time and Prof Essenhigh
funglestrumpet @14.
Archer 2005 concludes with the following line that may be what you are looking for. (I have edited a little it to make its meaning clearer.)
A better approximation of the lifetime of fossil fuel CO2 for public discussion might be ‘‘300 years, except for 25% of the CO2 that lasts forever." -
funglestrumpet at 04:59 AM on 5 October 2013Residence Time and Prof Essenhigh
HELP!!! Could someone please help a poor confused bloke like me who comes here to help them do battle at the street level on the climate change front (think Daily Mail readers and the like)?
For instance, when 'debating' with a typical denier on the "global warming has stopped" meme, I have tended to use the argument that it takes ages (plus or minus an age or two) for CO2 to fall out of the atmosphere (and sod what Newton might have to say on the topic because apples are a lot heavier than CO2 molecules and thus fall more readily).
It follows that global warming cannot have stopped because the excess CO2 we have pumped into the atmosphere over that last half century or so is still airborne and will be there for a long time yet warming the planet as it does so. Five years is not even near half an age, so what number of years should I use in presenting my case, 5, 50, 75 or what?
I imagine the answer lies in the article somewhere, but it is well hidden from a simpleton like me.
-
william5331 at 04:35 AM on 5 October 2013Residence Time and Prof Essenhigh
There is a grain of hope, losely related to Prof. Essenhigh's contentions. Carbon dioxide varies about 7ppm annually or more accurately, 8 up and 6 down. Natural processes remove far more CO2 than any silly system we could devise to sequester Carbon dioxide. Of course we must first stop pouring Carbon dioxide into the atmosphere but then we could give Gaia a chance and restore her systems for removing CO2 to their full potential.
http://mtkass.blogspot.co.nz/2013/03/removing-atmospheric-carbon-dioxide.html
-
raywey at 04:23 AM on 5 October 2013Residence Time and Prof Essenhigh
A useful analogy (and a bit closer to the actual situation than the queue) especially here in Caifornia where lots of people have spas and swimming pools:
My pump circulates water into and out of my spa at an input rate of **** (fill in your
favorite number) and removes it at the same rate. But I have taken my garden whose
and added water at a much smaller rate (&&&&). The residence time for any molecule of water in the spa is short compared to the time the hose fills an empty spa, but does anyone think that it is not the hose that is causing the water level in the spa to increase? -
Composer99 at 04:04 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
If that's what Tisdale comes up with as an "only imaginable reason", then I submit that he is admitting to having a very stunted imagination.
Which would be selling himself short: like most "pro/semi-pro" contrarians/deniers, Tisdale actually has a very fertile imagination. (Unfortunately, he has the bad habit of mistaking (or misrepresenting) the fruits thereof for reality.)
-
Rob Honeycutt at 03:55 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Let's look at Tisdales opening complaint where he states,
The models presented from the IPCC’s 1st, 2nd and 3rd Assessment Reports are considered obsolete, so the only imaginable reason the IPCC included them was to complicate the graph, redirecting the eye from the fact that the CMIP3/AR4 models performed poorly.
Really? The only imaginable reason? Do you start to wonder why Lewandowski is publishing on conspiracy ideation amoung climate denialists?
So, Tisdale starts off with the assumption that there are no other possible explanations for including FAR, SAR and TAR data. I can offer a simple explanation. How about the idea that they would be criticized if they didn't include them?
I have a hard time fathoming why any half way intelligent person would read beyond this one statement in Tisdale's post, other that just morbid curiosity.
-
Rob Honeycutt at 03:42 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Bob... Tisdale randomly dismisses Tamino's point, that was clearly accepted by the IPCC as being correct, that it is not proper to baseline on a single anomalous year.
This is exactly the problem with "leaked" versions of a draft paper. Those who are so mentally inclined, like Tisdale, McIntyre and others, are going to divine nafarious intent where there is none.
Tisdale also lacks the capacity to do actual statistical analysis to show his point, something that Tamino is capable of doing and, in fact, did.
-
Bob9499 at 03:16 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Dana, Bob Tisdale comments on your post:
http://wattsupwiththat.com/2013/10/04/no-matter-how-the-cmip5-ipcc-ar5-models-are-presented-they-still-look-bad/
-
Albatross at 02:36 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Hi OPatrick,
No worries, we seem to have had a miscommunication. I think that we are on the same page now :)
-
OPatrick at 02:29 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Albatross @23 - I never bought it as such in the first place, I just thought that Dana was mistaken to have said Curry had quoted the IPCC discussing the issue in the SPM, when she was actually quoting something which she felt (to be generous) had been left out of the Approved version. As we have both shown the replacement wording is not different enough to justify her criticisms.
-
Albatross at 02:20 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Opatrick @19,
The following claim by Curry is demonstrably false:
"Nowhere in the final WG1 Report do we see the honest statement that appeared...."
Please read AR5 WG1 that was released this past Monday. They say, and I quote:
"Most simulations of the historical period do not reproduce the observed reduction in global-mean surface warming trend over the last 10–15 years (see Box TS.3). There is medium confidence that the trend difference between models and observations during 1998–2012 is to a substantial degree caused by internal variability, with possible contributions from forcing inadequacies in models and some models overestimating the response to increasing greenhouse-gas forcing."
Now do you still buy Curry's claim as being correct? I hope not.
You also seem to be missing the point (I noted another problem with Curry's comment in my post @12 above).
-
OPatrick at 02:17 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Bob @16 - yes I read it, but having done so fairly quickly I am far from clear of the point she is making. Her ability to communicate her points clearly, other than her opinion of Tamino, is not fantastic.
However, she does say that Tamino is correct to have criticised the draft AR5 WG1 SPM report for incorrectly aligning projections to observations in a single year and then rants about Dana who is quoted having credited Tamino for pointing out what she has just said he was correct about.
-
kanspaugh at 02:15 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Could it be that Curry just wants publicity? Thinks the more she's in the news, the better for her consulting business? And, since she can't get much press attention as a climate scientist -- not bright enough -- she'll get it as a contrarian? Could it be, in short, that Judy is all about the Almighty Dollah?
-
Albatross at 02:09 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Bob @14,
Oh shame, the spinmeister fake skeptics are upset. Who is "Lucia"? Oh right, another contrarian who likes to argue and nit pick to distract while missing the bigger picture. I doubt very much that Tamio is wrong-- let me see, Tamino who is professional statistician (who has actually pubished peer-reviewed climate papers) versus a "skeptic" mechanical engineer.
Lucia is arguing semantics, white noise. Before you get too excited please also read my post @12, Curry et al. are wrong on sooo many levels ;)
-
OPatrick at 02:08 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
dana @10 - Curry's claim was:
Nowhere in the final WG1 Report do we see the honest statement that appeared in the Final Draft of the SPM:“Models do not generally reproduce the observed reduction in surface warming trend over the last 10 –15 years.”
It seems to be true that the wording has changed from the Final Draft to the Approved SPM. The first paragraph of the final draft section on Evaluation of Climate Models begins with:
There is very high confidence that models reproduce the more rapid warming in the second half of the 20th century, and the cooling immediately following large volcanic eruptions. Models do not generally reproduce the observed reduction in surface warming trend over the last 10–15 years.
Whilst the Approved version has
The long-term climate model simulations show a trend in global-mean surface temperature from 1951 to 2012 that agrees with the observed trend (very high confidence). There are, however, differences between simulated and observed trends over periods as short as 10 to 15 years (e.g., 1998 to 2012).
The highlighted sentences (my bold) do not seem far enough apart to justify her implication of a lack of honesty.
-
dana1981 at 02:08 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Nor, by the way, is Lucia's anal semantics nitpicking applicable to anything in the above post, by the way.
-
dana1981 at 02:07 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Bob @14 - I hope your comment was intended as a joke. If not, you either didn't read or didn't understand the above post. As I said, IPCC Figure 1.4 is baselined using the period 1961–1990. Lucia is just being anal (which is what she does best) about the language Tamino used in his post, and her criticisms are not remotely applicable to AR5 Figure 1.4.
-
Bob9499 at 02:02 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Opatrick, have you read Lucia's post, or was yours just a knee jerk reaction.
Moderator Response:[RH] Bob, please note that this is not WUWT or Lucia's place or Curry's blog. There are clear standards for posting here. Please read them before continuing on. Everyone here is willing to discuss the issue but you're going to have to conduct yourself in a professional manner.
-
OPatrick at 01:58 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Bob @14 - you appear to have a different understanding of the meanings of the words 'destroy' and 'clear' from me, at least.
-
Bob9499 at 01:48 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Lucia just destroyed your post and clearly demonstrated why Tamino is wrong.
http://rankexploits.com/musings/2013/taminos-take-on-figure-1-5/
-
Albatross at 01:14 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Hi Chris @11,
Well yes of course, but you seem to be missing couple of key points:
1) Generating thes complex graphics takes time and to get it right almost always requires several iterations. To expect otherwise is just not being reasonable.
2) Keeping #1 in mind, note that the draft figure was stolen/leaked (probably by fake skeptic) almost a year before the release of AR5. So it is not surpring that it had a glitch.
The lesson to be learned here Chris is that one simply cannot trust fake skeptics to act in good faith or with good intentions. They will mislead and misinform at every opportunity. As a case in point, ompare for example how statistician Tamino dealt with the situation when it was brought to his attention, compared to say how McKitrick and McIntyre and Curry dealt with the situation.
-
Albatross at 01:04 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Judith Curry exposed
Dana very nicely covered just how wrong Curry et al. are in their (biased) opinions. However, believe-it-or-not the reality is actually much worse for Curry.
Curry is of the opinion that climate models do not help her understand climate. A bizarre thing to claim for three reasons:
1) William Connolley calls out Curry on her double standard. He notes:
"...if you write a paper in which “the model simulations … were the main source of data used in the analysis” and yet you don’t think the models help, you’re not really going to write anything sane".
Exactly. Well, why does she bother using them for her research then? The truth, as we know, is that all models are wrong, but they are still incredibly useful tools. Curry is being disingenuous.
2) It gets worse though. Curry and her husband Peter Webster run a consulting company called "Climate Forecast Applications Network (CFAN)". Think about that name, what it indicates they do and then try and reconcile it with Curry's musings about climate models. From the CFAN web-site (my bolding):
"CFAN can transform future climate scenarios into meaningful information for your organization."
Those "future climate scnerious" are undoubtably based (at some level) on output from climate models developed and run by agencies that also provided their model output for inclusion in the IPCC assessment reports.
Curry also assures their clients that:
"CFAN's approach to developing future climate scenarios provides the basis for assessing future risk to your organization, as well as for identifying future opportunities."
So Curry is promising all kinds of deliverables based on the very climate models that she claims are "wrong". How bizarre.
3) Now for the pièce de résistance. This one is more subtle but every bit as egregious.
Again from the CFAN web site (my bolding):
"CFAN's weather and climate predictions, spanning time scales from days to decades, are based upon a sophisticated statistical/dynamical system that utilizes ensemble forecasts from multiple weather and climate modeling centers."
Producing decadal forecasts is notoriously difficult. As Dana mentioned above and as Curry also concedes, current climate models struggle on the decadal scale (for reasons that I won't go into here). But riddle me this. Curry is entrusting her business (and income) on the very models that she claims are wrong. What is more, she is trying to claim the models are wrong period by using data on a decadal time frame (full well knowing that they struggle on such time scales), but at the same time is informing CFAN clients that they can provide forecasts on a decadal time scale. Her duplicity is just astounding!
Curry wants to have it both ways. She wants to play rhetorical denier games in the public eye, and she also wants to derive income from the very models that she alledges are wrong.
CFAN clients and graduate students (present and prospective) should find these revelations more than a little disconcerting. She is misleading more than one group of people here.
-
ChrisRapley3131 at 01:02 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
On an issue so sensitive as this it would have been a whole lot better if the figure had been produced correctly in the first place. Mistakes get made and that's real life - but on this particular graph and in this particular way - there is a lesson to learn, surely?
-
dana1981 at 00:20 AM on 5 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
OPatrick @8 - that may have been what she meant, but it's not what she said. The fact that the folks working on the SPM went out of their way to address this relatively trivial issue just because so many contrarians were making noise about it, and she's still complaining that they didn't adequately address it, says a lot.
-
IPCC model global warming projections have done much better than you think
Sereniac - I am personally quite wary of extended analogies. A simple analogy between a portion of a complex system and a more commonly known system may be helpful in explaining how that part of the relationship acts, but the larger and more complex the analogy the more likely it is that the reader will mis-extrapolate from it, attempting to argue back from that analogy to the complex system.
Analogies are not the original, and commonly understood relationships in the analogy may or may not map back to the complex system.
In terms of the actual climate system: ENSO variations change the Pacific ocean circulation. Sunlight comes into the climate, warms the oceans and atmosphere, and is radiated away to space - input and output. ENSO variation affect how that energy behaves when it is in the climate system.
A La Nina, with higher wind-driven exchange of deep cooler water, moves a greater portion of that incoming solar energy into the oceans, cooling the atmosphere by ~0.1 C. An El Nino reduces the deep circulation, reducing energy flow into the oceans, causing that energy to remain in the atmosphere and warm it by ~0.1 C. It's really that simple.
-
Leto at 23:33 PM on 4 October 2013IPCC model global warming projections have done much better than you think
Sereniac,
The problem I have with that analogy is that the fitness training is not just a distractor that hides the true fitness signal, it leads to genuine improvements in fitness. The ENSO fluctuations do not lead to analagous true improvements in the global heat balance.
What if your Mr Jones is becoming morbidly obese, and this can be accurately projected using a metabolic model, but his measured weight flucutates in the short term by as much as a 2kg (eating 2kg donuts, as he does at random times, inflates his apparent weight by 2kg).
He visits the doctor immediately after a donut splurge, and posts a record weight (c.f. 1998 el nino). He then continues to eat excessively, but 15 days later, his next weight assessment happens to be just prior to his daily donut splurge. He has actually gained 1.5kg in weight, and is now posting a record empty weight (c.f. recent record la nina), but his measured weight is 0.5kg lower than the last measurement. He boasts that his weight trend is going down, and declares the doctor's metabolic model to be bogus. On the contrary, he is fatter than ever, and his next post-splurge weight is expected to break all records (c.f. next significant el nino).
A plot of his post-splurge measurements shows no overall change in the post-splurge trend, as does a plot of his pre-splurge weights (c.f the separate el nino and la nina trends in the Neilson-Gammon plot), but the short term fluctuations in apparent weight mean that he often has pseudo-pauses in his relentless weight gain. The existence of such pseudo-pauses is entirely expected in the metabolic model, though the timing of the pauses is outside the scope of the model, and an ensemble of model runs will average out the pauses so that they are not apparent. Nonetheless, he uses the pauses as an excuse to continue his unhealthy lifestyle.
-
bouke at 22:48 PM on 4 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Thanks for the replies @5-7. Inspired by Kevins remark, I googled around some and found a nice explanation at the American Chemical Society.
-
OPatrick at 22:27 PM on 4 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
This is an odd statement, given that Curry had earlier quoted the IPCC discussing this issue prominently in its Summary for Policymakers:
"Models do not generally reproduce the observed reduction in surface warming trend over the last 10 –15 years."
Wasn't her point that this quote did not appear in the WG1 report?
-
Glenn Tamblyn at 22:01 PM on 4 October 2013IPCC model global warming projections have done much better than you think
Interesting analogy Sereniac. One thing missing from it is the quantitave apart from words like 'dramatically'.
Lets epand the analogy by saying the Mr Jones health indicators tend to rise by X when he trains for a fun run and decline by Y when has allergies. And his glucose problems cause a decline of Z per year. So how easy is it to detect Z in amongst X and Y? That depends on the relative magnitude of X, Y & Z.
If X and Y are small, Z can be detected quickly. If they are larger, Z takes much longer to detect.
Back to the ENSO issue. El Nino (X) and La Nina (Y) produce effects that can change average temperatures by +/- 0.1 to 0.2 Deg. This can mask global warming (Z) on time scales of a decade or so. But on multiple decades to a century, where global warming might cause temperature changes of 2-4 DegC (depending on what we do with emissions) then Z becomes very clear.
Mr Jones' glucose problems become apparent when he can't engage in his training for the fun run because he is hobbling along with a cane.
-
Dikran Marsupial at 20:47 PM on 4 October 2013Residence Time and Prof Essenhigh
chriskoz Essenhigh's 5 year figure for residence time is correct, and indeed agrees with the figure given in the IPCC WG1 report. His error lies in not understanding the distinction between residence time and adjustment time.
We should not be too hard on Prof. Essenhigh, his research record in his own field (combustion) appears to be very good, and it is all too easy to make this kind of error in moving into a tangentially related field. The email correspondence I had with Prof. Essenhigh while writing my response published in Energy & Fuels was generally very cordial.
-
chriskoz at 19:56 PM on 4 October 2013Residence Time and Prof Essenhigh
Essenhigh's 5y residence time number is bogus not only because it fails to consider the natural inflow (emissions from ocean/biosphere back to atmosphere) but also because, due to limited capacities of the natural sink such as ocean, the flow rates (determined by Henry's law) change over time.
Only a part of CO2 molecules has a residence time of rougly 100y (a bit more than 75y calculated by vmin@8 but the same ballpark). In case of 1000GtC emissions, that part is some 50% - i.e. 500GtC of the original emissions being absorbed by the ocean surface results in OA reaching new equilibrium, therefore no more CO2 can be absorbed by Henry's law.
The rest (500GtC) must wait for the deep water mixing and the reaction with sediments which takes 1-10Ky. Only 300-400GtC is taken that way, again due to limited sediment capacity.
The rest (100-200GtC) must wait for the rock weathering processes which take sometime from 100Ky to 500ky (depending on current geological conditions).
So, the residence time is not a simple constant number when we are dealing with such big amounts comparable to the natural sink capacity. In case of the emission scenarios considered in Anthropocene, it means 10 to 20% of emissions will stay in A for up to half a million years.
Obviously, such science is well beyond Essenhigh, who makes very basic mistakes (i.e. ignores the inflow & Henry's law) that preclude any understanding of carbon cycle in geological sense.
-
Kevin C at 19:55 PM on 4 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
It's also worth noting that land-ocean surface temperature records work with anomalies rather than temperatures, and thus they don't provide an absolute temperature against which to compare the models.
BEST have addressed this, but their currently released data is land-only.
-
Dikran Marsupial at 19:29 PM on 4 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
bouke, it is because the models do a much better job of modelling changes in response to forcings than in terms of absolute temperature (i.e. there are more or less constant offsets in absolute temperature between model runs). For climate change research it is the response to a change in the forcings that is of interest, so the simplest thing to do is to apply the baselining procedure to eliminate these meaningless offsets. Note also that if you want to perform a comparison involving both surface and satelite observations you have to look at the anomalies anyway as there is a big difference between absolute temperature at the surface and in the trophosphere due to the lapse rate.
This is something well known to any climatologist that has worked with model output and is essentially uncontraversial, so it is somewhat surprsing that Curry and McIntyre are making a fuss about it.
-
Dikran Marsupial at 19:23 PM on 4 October 2013Residence Time and Prof Essenhigh
vmin Residence time is defined as the mean length of time a molecule of CO2 remains in the atmosphere before being taken up by the terrestrial or oceanic reservoirs, so Essenhigh is correct in using the term residence time. His error lies in not understanding the difference between residence time and adjustment time, which is the characteristic timescale with which the atmospheric concentration responds to a change in sources and sinks (which corresponds to your 75 year figure). The IPCC define these differing definitions of lifetime in the glossary of the WG1 report, but unfortunately do not clearly distinguish between them in the report itself (although the 1990 report that Essenhigh cites makes the distinction very clearly).
-
Marco at 19:12 PM on 4 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Bouke, it is not about the vertical scaling, but about what point you use as a reference. 1990 as a single point is a bad reference, as it would be above the trendline. 1991 would be a bad point, too, as it is below the trendline. You should use a baseline *period*, which will eliminate much of the short-term noise. Whether you put that baseline as an absolute value or assing it to zero and put the other data as anomalies does not change any conclusions.
-
bouke at 18:39 PM on 4 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
I am wondering, why are graphs always shown with temperature anomalies and not with the actual temperatures? That should remove any confusion with baselines.
-
PJKs_shirt at 16:15 PM on 4 October 2013Skeptical Science now an Android app
Any chance of porting the app to Sailfish?
Prev 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 Next
