Gavin Schmidt recently addressed Judith Curry’s 50:50 argument in a Realclimate post. In Judith’s response (which doesn’t really say much) she finishes with,
I do regard the emerging realization of the importance of natural variability to be an existential threat to the mainstream theory of climate variations on decadal to century time scales. The mainstream theory views climate change as externally forced, e.g. the CO2 control knob theory. My take is that external forcing explains general variations on very long time scales, and equilibrium differences in planetary climates of relevance to comparative planetology. But it does not explain the dominant variations of climate on decadal to century timescales, which are the time scales of relevance to policy makers and governments that are paying all this money for climate research.
So, unless I’m misunderstanding Judith she really is suggesting that natural variability could significantly influence warming on timescales as long as a century. Although Judith doesn’t specify, I’ll assume that the implication is that it could provide as much as half of the warming over the course of the instrumental temperature record – since 1880, so longer than a century but let’s just work from there.
So, I thought I’d try to put some numbers to this to see how plausible it is that natural variability could play a significant role in the warming since 1880. Let’s set down some basic numbers. We’ve warmed by 0.9oC since 1880. In the absence of any other changes, this would increase the outgoing flux by 3 Wm-2 (
So, when Judith suggests that a large part of the warming on century timescales could be natural, what does she really mean? There are two possibilities that I can think of and I’ll try to explain them below.
- Half of the change in radiative forcing is natural and half anthropogenic – i.e., about 1.75 Wm-2 each.
- This would suggest that the aerosol forcing has to be on the high side.
- If we assume that half the warming is natural and half anthropogenic, then it suggests that the feedback response to natural warming is significantly higher than that due to anthropogenic warming (since the anthropogenic forcing is unlikely to be less than 1 Wm-2).
- If half the warming is natural and half anthropogenic, then in fact the TCR would be between 1 and 2oC and the ECS would be between 1.25 and 2.5oC (since the anthropogenic forcing is between 1 and 1.75 Wm-2 and the planetary imbalance would be 0.25 Wm-2).
- In some sense, this possibility doesn’t really make much difference as it would simply imply that a large part of the anthropogenic warming has been masked by a potentially large negative aerosol forcing.
- The alternative is that Judith means that half the warming is natural and half anthropogenic and, consequently, that half the feedback response is natural and half anthropogenic [i.e.,
where
is the anthropogenic forcing]. Let’s consider 3 different possibilities, low, high, and medium anthropogenic forcing.
- The anthropogenic forcing is around 1 Wm-2 (very large aerosol effect), and the feedback to natural and anthropogenic warming is around 1.25 Wm-2 in each case.
- This would suggest that the feedback is quite high since the natural and anthropogenic warming contributions are around 0.5oC each.
- In this scenario the TCR would be around 1.9oC and the ECS would be around 2.5oC. Again, it would seem to be a scenario in which aerosol forcing is masking a lot of anthropogenic warming and the long-term warming would be in line with IPCC scenarios.
- The anthropogenic forcing is around 3 Wm-2 (very small aerosol effect), and the feedback to natural and anthropogenic warming is around 0.25 Wm-2 in each case.
- The feedback is very small. This would appear to make it difficult to explain long-term natural warming since this would seem to require that the feedback exceed the Planck response.
- The TCR would be around 0.6oC and the ECS would be around 0.7oC which would suggest that the equilibrium response to the doubling of CO2 would lead to less warming than CO2 alone (overall feedbacks would have to be negative).
- The anthropogenic forcing is around 2 Wm-2 (average aerosol effect), and the feedback response to natural and anthropogenic warming is around 0.75 Wm-2 in each case.
- The TCR would be just less than 1oC and the ECS just about 1oC, so suggests that a doubling of CO2 would, in equilibrium, be associated with no feedbacks. This seems odd, since the initial assumption results in the feedback response being positive.
- The feedback response to the natural warming is quite a bit smaller than the Planck response due to the natural warming. This would seem to make long-term natural warming quite difficult. Presumably natural warming can only be long-term if the feedback response exceeds the Planck response.
- The anthropogenic forcing is around 1 Wm-2 (very large aerosol effect), and the feedback to natural and anthropogenic warming is around 1.25 Wm-2 in each case.
So, I’ve thrown this together a little fast and when I was thinking of this there were other factors that I’d thought of, but have now forgotten. From what I can see, there isn’t an easy way to construct a plausible scenario in which natural variability can have played a significant role in the warming over the last century or so. Again, this isn’t me saying that it can never do so, just that given the information we have for the last 100 years or so, and the state we’re in today, there doesn’t seem to be an easy way to construct a plausible scenario. If others can think of one, or can add other reasons why it’s implausible, feel free to do so.
...and Then There's Physics 
Why don’t you just say the obvious which is Judy is serving denier koolaide to the denier crowd.
Why do you continue to extend her any possible scientific credibility?
TLE,
Because I’m trying to be skeptical and because I’d rather someone tried to provide an explanation for their view than simply get away with making claims that they never back up (of course, that is probably what will happen anyway, but it’s worth a shot).
TLE
The above post is why I read this blog. I would like to understand – to the best of my limited ability – why some claims are weak. ATTP’s willingness to scratchpad his thinking on this blog is, as he says, properly sceptical [sp!]. He is testing GS’s analysis, not parroting it or rejecting it unexamined. This is what he does. It would be nice if his more strident critics noticed that once in a while.
I believe Dr. Curry is referring more to ocean variability on longer time scales. The current “Cause of the Pause” if you will. There are quite a few papers that mention century scale and longer variations or pseudo cyclic oscillations that quite likely are “forced” at some time in the distant past but take quite a while to “settle” out. These “oscillations” tend to impact the distribution of energy between the hemispheres which you can “see” by simply taking the difference the Northern and Southern Hemisphere surface temperature anomalies.
A Paleo reconstruction you might want to check is the Oppo et al 2009 Indo-Pacific Warm Pool SST reconstruction which covers 2000 years and indicates the depths of the Little Ice Age in that region was about 1700 A.D and has an interesting recovery curve from that period.
captdallas,
Indeed, but I don’t think this matters. If you want long-term surface warming, you have to find some way to prevent the energy released from the oceans from simply radiating back into space. That’s what radiative forcings/feedbacks do. So, an ocean cycle by itself can certainly release energy and heat the surface. Without some kind of change in forcing/feedback, that energy will be lost quickly and the system will equilibrate in a matter of months. That’s what I’m trying to get at here.
I’ll have a look at that paper you suggest but the only paleo examples of unforced variability are the D-O events, but these are associated with an ice sheet instability and, hence, with a change in albedo.
BBD,
Thanks. I went for a run this evening and constructed this post in my head. The one I wrote down doesn’t seem nearly as clear as the one I imagined 🙂
ATTP/Cap’n
Cap and I have had this discussion before, and it never really resolved ;-). I argued exactly as you do.
One sticking point was that if the oceans are releasing long-sequestered energy to the atmosphere, the OHC profile should be cooling at depth and warming of the surface waters. Which isn’t what appears to be happening.
When you add that to the conservation of energy issue, well, I can’t see the physical argument holding up.
There is a difference between unforced variability and not knowing what forcing caused the variability. For example you assume 0.0 is the “normal” imbalance, but we are in a point in precessional cycle where the southern hemisphere with larger ocean area is getting peak insolation. So a quarter of the imbalance could be natural with very long term forcing impacts. The “cause” of the LIA is elusive, but some combination of solar and volcanic forcing is suspected. With the newer volcanic paleo reconstructions, a mega volcano circa 1225 followed by increased volcanic activity could have cause the slide in the the LIA taking nearly 500 years to hit the minimum. At the current rate of Ocean Heat uptake, it would take around 400 years to fully recover. A weakly damped recovery curve matches the Oppo 2009 nicely.
How can the oceans release long sequestered (below 2000 meters) energy from the depths to warm the atmosphere? The stuff that comes up from the depths is cold as an ice cream headache, and it seems to me it would cool the atmosphere.
Cap
So how do we square long-term deep ocean energy storage and current release with the observations? How to account for the wrong-way OHC depth profiles with increased warming at depth? If an upwelling of deep water is heating the atmosphere where is it? Which basin? Where do we see cooling at depth as the upper ocean warms?
Anders:
Seeing I’ve just awoken, and do not have my head in the game enough to consider later discussion, I’ll just note that she may simply mean that a period of 1.5 cycles of a substantial oscillation can still introduce a strong trend. She is committed to the trend from 1910-1940 being almost entirely due to an unforced variation. Therefore she is also committed to the trend for approximately 1910-2000 having approximately a third of the 1910-1940 trend as a unforced component, and from 1910-2060 having approximately one fifth of the 1910-1940 trend as an unforced component. Hence “century timescales”.
I should note that most pushers of large decadal natural variability do not commit to consistent periods or amplitudes for different repetitions of the cycle, and suspect Curry is no different. As such, she may allow the peak natural variability from 1910 to be any time between 2040-2090, and that the trend contribution to be from a quarter to double what we would expect from comparison to the 1910-1940 trend would lead us to expect (from her assumptions).
On top of this, Curry may argue that natural variability at greater with periods greater than 100 years exist, and be poorly constrained due to lack of sufficiently long reliable data.
While the energy released from the oceans from a putative long term cycle will radiate back to space, it need not do so rapidly. The decay time (τ) to reach equilibrium temperature in response to a radiative forcing is of the order of 60 years. That will also be the decay time to damp any temperature variations from natural fluctuations, as the processes involved are the same (I think). That is of little consequence for small temperature variations, which do not need to decay much to be swamped in the background of small temperature variations; but a sufficiently large fluctuation may take substantial time to be so swamped. Further, a fluctuation involving a transfer a retention of heat at the surface (by say a periodic slow down of the thermohaline circulation) need not end in months, or even a small number of years so that there may be a longer lasting impact.
> How can the oceans release long sequestered (below 2000 meters) energy from the depths to warm the atmosphere?
Sharknados.
JCH, if the ocean upwelling cools the atmosphere, a less cold ocean upwelling may well cool the atmosphere less leading to an overall warming.
(Or perhaps its little green men. Anything but sharknados ;))
Unless I misinterpret you, I’m not sure you’ve correctly estimated forcings and feedbacks. The forcing since 1880 is what it is, probably much less than 3 Wm-2. I don’t think you can add the Planck Response of 3 Wm-2 for a 0.9C warming to a residual 0.5 Wm-2 to arrive at 3.5 Wm-2, since positive feedbacks to the actual forcing would yield a 0.9C warming by nullifying a portion of the Planck Response such that the actual rate at which radiative restoration is approached declines below 3.1 Wm-2/K.
It seems to me we’ve already pretty much excluded a more than minor role for internal warming at least since 1950 in our previous discussions, but I’m not sure we have enough evidence about earlier intervals for a similar conclusions. We may be beating a dead horse at this point.
I do regard the emerging realization of the importance of natural variability to be an existential threat to the mainstream theory of climate variations on decadal to century time scales.
Sorry, I know enough about thermodynamics to not buy into this at all. It’s nonsense. Not worth my time. Any time you pump a reservoir their will be fluctuations. We are pumping several reservoirs here, the atmosphere, the terrestrial biosphere, the ice sheets and the oceans. Before we started pumping it with carbon dioxide, a variety of complex and toxic emissions, etc, nature was pumping it, just at a different level. We are just seeing predisposed pre-civilization natural fluctuations dynamicall adapting to accommodate our very robust newly created perturbative forcings. If Judy wants to or thinks she can disentangle this, she needs to do it from a position of neutrality, which she demonstrably is not.[Mod: One sentence removed – name calling]. If you want to disentangle it, ignore Judith Curry.
Well ATTP, you got me to click over to Curry’s blog again!
Her post has literally no substance. She could have whittled it down to 6 words: “I don’t believe Gavin proved me wrong.” Really revealing is this exchange in the comments:
Unpacking that response, we have a backhanded insult of Mann and Colose, a backhanded insult of Cook and Lewandowsky, immense confusion about their research (she’s probably talking about the 97% consensus paper, but Lewandowsky wasn’t involved with that), and then a commen that lots of people “on the other side” are RTing her.
So apparently Judith Curry views denier trolls re-tweeting her as positive affirmation, and doesn’t care about climate experts detailing her errors and confusion. On top of that, the comments on her blog read much like those on WUWT – little more than a denial echo chamber with the commenters stroking her ego because she insulted a mainstream climate scientist. If that’s where she’s spending her time, it’s no wonder she’s become so confused and misinformed about issues like global warming attribution.
What an utter load of baloney. Even during the ‘pause’ when atmospheric warming slowed down and ocean warming sped up, we were still warming at a rate 10 times faster than at the end of the last ice age. Judith is again spinning out utter carp, and living in a world that doesn’t exist, which is no surprise at all.
As for net forcing. We are at positive 2.35 watts per meter squared once you add in the masking effect of aerosols. Drop the aerosols out and you probably get close to 3.5.
Cold ocean water upwelling cools the atmosphere and warms the ocean. Warm ocean water down welling cools the atmosphere and warms the ocean. We’ve been in this ocean phase for some time. Has the atmosphere cooled? No. It warmed a bit more slowly. Has the ocean warmed? Yes, and quite a bit more rapidly.
Fred,
Hmmm, I thought you could. Of course, my 3.5 Wm-2 is forcings plus feedbacks, but I still think that a 0.9 degree rise in temperature and an energy imbalance of 0.5 Wm-2 implies an overall forcing plus feedback of 3.5 Wm-2. Could be wrong, though.
Isn’t there a difference between internal variability having played a role during some earlier period (say 1910 – 1940) which it could have done, and internal variability still essentially playing a big role over the entire interval (1880 – 2014, for example)?
Tom,
Yes, I can see that. However, then we get to the problem of trying to explain a significant natural oscillation that produces natural warming, while at the same time the OHC continues to rise.
I’m going to have think about that, but given the heat content of the atmosphere, I had always thought that any warming that isn’t associated with a change in radiative forcing (or a radiative feedback) would radiate away very quickly. On the other hand, if the entire system is below equilibrium by (for example) 1 degree, then it would take around 60 years to accrue all the energy required to return to equilibrium. Similarly, if we had excess energy of this amount then I can see how it might take 60 years to lose this energy. This seems distinct though from a scenario in which we’re roughly in equilibrium and in which some kind of internal variability operates.
capt,
This doesn’t really make sense to me. We’re in a position where the temperature has risen 0.9 degrees and we still have a planetary energy imbalance of 0.5 Wm-2. So, what I’ve done here is to try and work out if there is a way in which we can associate some of the radiative influences with natural variability so that natural variability plays a big role. The answer appears to be no.
Actually, I’ve just remember what else I was going to say about this. If you consider the scenarios where aerosol forcing is assumed to be large, then even if natural warming is significant, the climate sensitivity values are consistent with IPCC estimates. So, if this is plausible, natural warming is simply compensating – today – for a very large aerosol effect and long-term warming will still be in line with IPCC projections.
When one considers the scenarios where aerosol forcing is average or small, then the climate sensitivities are close to – or below – 1oC. This would appear inconsistent with paleoclimate. It would also suggest that we would have to have a very lengthy period of no warming if both TCR and ECS are going to be small.
The other issue with the latter case is that the feedback response then appears to be smaller than the Planck response due to the natural warming. If this is the case, it’s hard to see how natural warming could persist for many decades (i.e., in the absence of other forcings, this form of natural warming should produce a negative energy imbalance and the excess energy should be lost). So, this brings us back to a point Fred Moolten – I think – made on an earlier post. We need to distinguish between natural warming that can exist in its own right (i.e., in the absence of other forcings) and natural warming that simply acts to influence the rate of anthropogenic warming.
There are two real issues:
1) How well we can constrain natural variability?
2) What can we say about the warming from AGW over various periods?
Then we have the semantic issue related to the interpretation of the statement of the IPCC AR5 WG1 SPM. The semantic issue influences the way we relate the real issues to the actual statement of IPCC.
I disagree strongly with Judith on something that involves the the point (2) and the semantic issue. It’s more difficult to tell in detail, how I disagree, because I cannot follow her logic.
On point (1) I may be closer to Judith than to ATTP. I don’t think that we really can constrain natural variability particularly well, when all obvious mechanisms are included, and when we observe that this is really an issue, where we have rather weak reasons to believe the present climate models. (I have specific reasons for this belief, but I don’t go in them here.)
On (2) it’s essential that the inference must be Bayesian (it’s the only valid form of inference in my opinion). Therefore it’s essential that based on simple and solid theoretical grounds we do expect some amount of smoothly accelerating AGW contribution to warming over the latest century. On natural variability we do not expect as prior anything specific. Applying Bayesian reasoning in this setting leads to estimates of TCR that are essentially as presented by IPCC. The estimates exclude with high likelihood TCR values less than 1.0 C and with extreme likelihood values less than 0.5 C.
Judith doesn’t seem to accept the application of Bayesian reasoning along the lines I consider strongly supported.
Now to the semantic issue. What does IPCC mean? My interpretation is that it means simply that AGW calculated from TCR is more than 50% of the observed change in temperature from 1950 to 2010. I would apply some smoothing at both end points, but otherwise simply concern the two values, not what has gone on between the two points. Judith seems to argue for some other interpretation that I really cannot understand.
In my interpretation the claim that Judith presents is equivalent to claiming that a TCR of less than 0.5 C has an likelihood of 50%. That’s nonsense.
Pekka,
Technically, I agree with you and hence, I guess, with Judith. My point here is that when you try to construct a physically plausible scenario in which natural variability provides a significant fraction of the warming over the last century or so, it appears to be inconsistent with other evidence. So, this doesn’t mean that we suddenly understand natural variability, or can constrain it, simply that we can’t seem to find a plausible scenario for it providing significant warming on century timescales, given our knowledge of our current climate.
My understanding is simply that what they’re saying is that it is extremely likely (> 95% chance) that anthropogenic influences produced more than 50% of the warming since 1950. In fact, from Gavin’s post, the 95% confidence interval appears to be 80% to 130% of the warming over this period.
I agree and it seems that Judith is confusing the 50% of warming with a 50% chance of the warming being anthropogenic.
What Judith has written would make more sense to me, if we were discussing a change in temperature that’s highly unexpected, and for which we could list several potentially contributing factors which would, however, be so weak that getting the observed total would not allow for any of the factors to have a significant value of wrong sign,
That’s, however, not the case, as I have explained.
Pekka,
I agree and it would be interesting if Judith were to try and actually construct an actual scenario for what she thinks is happening.
As with several others here, I find it very hard to follow Judith’s logic.
However, I have had a reponse from her – you may find it of interest. Let’s see if she follows up.
Fred Moolten on RC delivers a very poweful point – that natural variation moving heat around the climate system is excluded as a cause as OHC has risen during the period. I guess that leaves natural changes in albedo (clouds?) causing a consistently rising radiative imbalance as the only explanation barring AGW.
http://www.realclimate.org/index.php/archives/2014/08/ipcc-attribution-statements-redux-a-response-to-judith-curry/comment-page-1/#comment-589438
I also note that Chris Colose makes the point that the existence of such large natural variations implies a high sensitivity (ie no negative feedbacks) – which in turn rules out a low AGW contribution. This seems a very convincing line of argument to me.
VTG,
Indeed, BBD’s made that point many times before.
Looking over Oppo et al. (2009), I’m not seeing support for the claims. Cap should perhaps step us through the analysis.
Dana,
BTW, did you notice that tweet from Roger Pielke Sr that claimed that your suggestion in your Guardian article that we were accruing energy at a remarkable rate was absurd?
Whether large natural variability implies high sensitivity depends on the mechanisms of the natural variability. If the mechanism works trough the TOA balance, natural variability is as strong as GHE, when the related influence on TOA balance is as large as the forcing from GHE. (Changes in cloud cover are probably the only final mechanism for that, but the state of the oceans may influence the cloud cover in a more persistent manner.)
If the natural variability is related to changes in the heat content of deep ocean (deep meaning in this case the opposite of near surface ocean, not necessarily really deep) the geographic distribution on the changes may differ from those due to OHC and therefore lead to significantly different feedbacks.
How strong the argument of Fred is for the recent warming assuming little natural variability in TOA balance depends on the accuracy of the OHC data.
I don’t see any reason to think that the conclusions of IPCC are wrong, but I do think that interpreting the evidence is more complicated than many seem to indicate.
I’m really trying again to approach this with an open mind, and I’ll admit a lot of this is going over my head. I have a poor grasp of a lot of the concepts that are being discussed, so I’ll focus on one aspect.
Prof Curry often seems to mention “AMO and PDO etc” in relation to multi-decadal variability, and that the IPCC haven’t taken AMO and PDO etc into account. I’m not sure what the “etc” refers to so I’ve looked at AMO and PDO. Looking at 5-yr moving averages of AMO data (back to 1856) and PDO data (back to 1900), both seem to have exhibited periodic peaks and troughs, with perhaps (very roughly) 30 to 80 years between each peak (there’s admittedly not many cycles in the data; I haven’t attempted Fourier analysis). My very basic expectation would be that over timescales of more than a few decades, changes in temperature due to AMO and PDO would balance out, owing to their cyclical or quasi-cyclical nature. It seems clear from surface temperature records that the Earth has warmed over the last century, with the global average surface temperature in the last decade being more than 0.5 degrees C higher than the peak of the 10-year average in the 1940s (looking at GIStemp). I realise that observational data is not as good the further back in time we go, but it doesn’t seem v feasible to me that AMO and PDO have had a large effect on global temperatures compared to forcings, given that the temperature seems to be so much higher now than it was in the first half of the 20th century.
I’m being very simplistic and I’ve missed out a lot of other factors here but.I would really like someone (perhaps someone who thinks there is strong evidence that natural variability is much more significant in terms of recent warming than the IPCC have stated) to explain what’s wrong with my reasoning. Also, is there strong evidence for longer time-scale cyclical natural variations (over a century or more, but shorter than the very long cycles associated with ice ages) that might be acting? I’m not aware of any but then I’m an amateur.
I would think that quite strong evidence would be needed to pose an “existential threat to the mainstream theory of climate variations on decadal to century time scales,” and I’d really like to know what that evidence is, if it exists.
Rob,
Yes, I think that is one of the arguments that people make. In general, though, many who do so assume that any variability around the linear trend is internal variability. The issue is, though, that the forced trend is not necessarily linear. In fact, you can produce quite a good fit to the instrumental temperature record by using a forcing dataset and a 6-month lagged correction for ENSO. So, if you really want to determine the pattern of the internal variability, you need to first remove the forced component. This is what a recent Mann paper tried to do and why they argue that the AMO has been producing cooling over the last decade or so, while others argue it’s been producing warming.
I notice that Andrew Dessler made a relevant comment in the DotEarth article that Pekka highlighted earlier. Even though there do appear to be 60ish year signals in the data. Finding a 60 year signal in a datatset that is only 100 years or so long, does not necessarily tell you that that it is some kind of cyclical process. You really need many periods to be confident of that. A lot of the variability could well be a consequence of variability in the forcings.
ttp, “This doesn’t really make sense to me. We’re in a position where the temperature has risen 0.9 degrees and we still have a planetary energy imbalance of 0.5 Wm-2. So, what I’ve done here is to try and work out if there is a way in which we can associate some of the radiative influences with natural variability so that natural variability plays a big role. The answer appears to be no.”
There is always enough solar energy available to drive the system warmer. Clouds mainly with aerosols and surface albedo combine to limit the amount that reaches the “surface”. To have an “equilibrium” condition that is accurate enough for a static radiant model to work is pretty unlikely. It can get you in the ball park, but the oceans are a Thermo/Fluid dynamics problem with much ;longer time scales and a constant dis-equilibrium condition. This is more the forte of the GFDL with its aqua and ridge world models that are still coming of age. You need to figure out the liquid 70% of the “surface” before you can use the simpler radiant model on the whole surface.
Another Paleo related paper, “On the relative importance of meridional and zonal SST gradients” Brierley and Fedorov 2010 gives an idea of the potential impact of SST gradients. Toggwieler et al with the GFDL have a number of papers on the shift in the westerlies related to hemispheric imbalances that can impact average “surface” temperature. Basically, if you have hemispheric imbalances a radiant model that requires equilibrium isn’t very accurate. So you have to back away from the anomaly simplification and look at actual absolute temperatures.
Now look at the actual SSTs by hemisphere. The SH with more ocean area and higher average insolation is about 3 C degrees cooler than the NH. The oceans transfer energy to the land areas mainly in the NH and there is no energy transfer that is 100% efficient. So even in “equilibrium” the ocean would need to absorb more energy than they transfer to remain in a steady state. An ocean imbalance of 0.25 Wm-2 while it provides 18 Wm-2 of mainly latent energy to the land areas is remarkable efficient.
Remember of course that if the observations and model ensemble mean agreed well we would not be having this discussion. So would you rather continue singing the praises of failing models or expand you perspective?
Thanks, Very Tall. My own contribution was to answer PaulS’ rhetorical question:
PaulS’ comments are worth reading. If they don’t work, I don’t know what could. I mean, they even succeeded in getting a concession from Carrick, although the latter should know that PaulS’ a regular at James’.
Cap
You did not answer my question.
Instead, you barge on, as you did during our previous exchanges. This isn’t helping. In order for you to recognise that your conceptions are flawed, you must answer relevant questions.
Argument from false assertion, or put in the vernacular, skeptikoid crap.
@willard:
Paul S’ comments are (always) excellent indeed. His technical understanding as well as his ability to unravel the big picture is on a par with that of the most prolific scientists in the field. This time, he is particularly spot on regarding volcanic forcing: judithcurry.com
@dana:
Wow, what a ridiculous second tweet from Judith. Thanks for sharing that gem. There is a reason not to follow (or even blick) some circles. I know, I know, shame on me … I’m hopelessly trapped in group-think …
I hadn’t but I just looked it up. As usual he only considers 0–700m OHC and ignores the deeper oceans.
https://twitter.com/RogerAPielkeSr/status/504330406729367552
That’s always been his tactic. He tries to pretend he’s considering a better metric than most climate scientists by looking at OHC rather than surface temps. That would be true if he would consider all OHC. Instead he just cherry picks the data that seem to support what he wants to believe (slowed warming). But when you consider all the data, it’s a very different story.
And now looking at the responses, I see you and Rob Painting and others already made that point 🙂
Let’s try the link again: judithcurry.com
In case it doesn’t work anymore this way, here the ugly looking version:
Nice, it is still working (some mistake during the 1st attempt obviously). But somehow I picked the link to your comment, willard. Here the one I was referring to: judithcurry.com
> here the ugly looking version
The expliciter the URL, the better. It removes the need to hover over the link to see where it goes. That’s one movement less for everyone, which translates into many men and women hours.
@willard: okay, ugly version from now on then 😉 (hope I remember it the next time)
ATTP – “Of course, my 3.5 Wm-2 is forcings plus feedbacks, but I still think that a 0.9 degree rise in temperature and an energy imbalance of 0.5 Wm-2 implies an overall forcing plus feedback of 3.5 Wm-2”
I don’t think that’s the way it works. A positive feedback doesn’t increase the TOA radiative imbalance but rather reduces the rate at which the imbalance declines as a function of temperature change. As an example, let’s suppose the current forcing is 2.4 Wm-2, which is probably about right, but that the forcing has just been imposed, with no temperature response yet – i.e., the radiative imbalance equals the forcing of 2.4 Wm-2. In the absence of feedbacks other than the Planck Response, that imbalance would decline toward zero at a “rate” of about 3.1 or 3.2 Wm-2/K warming. In the presence of positive feedbacks, the radiative imbalance woulds still decline toward zero rather than increase, but the decline would be slower. If, for example, the feedback mitigated the Planck Response from 3.2 Wm-2K down to 1.6 Wm-2/K, the temperature would have to rise twice as high to restore balance. For a CO2 doubling equivalent to 3.7 Wm-2, the result would be a warming of about 2.4 K rather than 1.2 K at equilibrium.
The 0.5 Wm-2 current imbalance in conjunction with the 0.9 C temperature rise reflects the fact that the imbalance created by current forcing has been declining more slowly than it would have if only the Planck Response had been operating.
Fred,
I’m not quite getting the difference. Without feedbacks a forcing of 3.7 Wm-2 would be balanced by a temperature rise of 1.2K. We can determine how that temperature rise would increase the outgoing flux in the absence of a change in forcing using
which for 
and 
K, you get around 3.7 Wm-2. (i.e., they balance, as expected).
On the other hand if a change of forcing is balanced by an increase in temperature of 2.4K, then that increase in temperature is associated with an increase in outgoing flux of 7.4 Wm-2. Therefore, it would seem that what we have is a change in forcing of 3.7Wm-2 and a feedback response of 3.7Wm-2 (i.e., a total of 7.4 Wm-2).
Yes, this may be correct, but I’m not sure it’s inconsistent with what I’m saying. You’re correct, I think, that a feeback won’t increase it, but I still don’t see why one can’t represent the forcings plus feedbacks as something with units of Wm-2 (which is all I was really trying to do).
Having said that, the paper we were discussing in the previous post was determining the TOA flux in the situation where all that was operating was internal variability. Presumably that has to be a situation where the TOA flux increases because of a feedback response to some warming (due to the natural variability)?
Since you seem to understand this quite well, you’ve got me worried than I’m missing something here 🙂
We might assume that the relevant climate response for the historical increases in CO2 concentration is 2 C / 3.7 W/m^2. Based on that 0.9 C corresponds to 1.7 W/m¨2.
An alternative approach is to assume an “equilibrium” climate sensitivity of 3 C/3.7 W/m^2. With that 0.9 C corresponds to 1.1 W/m^2, but now we must add the remaining imbalance and we get 1.6 W/m^2.
ATTP – “You’re correct, I think, that a feeback won’t increase it, but I still don’t see why one can’t represent the forcings plus feedbacks as something with units of Wm-2 (which is all I was really trying to do).”
You could do that, but it wouldn’t represent a real world event. In other words, if you start with a forcing of, say 2 Wm-2, sat at the TOA with an accurate flux meter registering 2 Wm-2, and then imposed some positive feedbacks,your flux meter would show the original 2 Wm-2 declining as the temperature rose – it just would decline less per degree warming than if the feedbacks weren’t there.
My favorite paper for illustrating how feedbacks operate is Soden and Held 2006, with particular reference to Table 1. It shows that overall feedback is negative due to the strong Planck Response. After positive feedbacks are applied, overall feedback remains net negative, but less so. It would take a climate destabilizing net positive feedback (one overwhelming the Planck Response), to amplify rather than reduce the TOA radiative imbalance created by a forcing.
It’s true that there is probably some value of Wm-2, which in a “Planck Response Only” world, would create the same warming as would occur in the real world with feedbacks operating. I’m not sure simply adding forcings and feedbacks would do that accurately, but in any case, it could create a misleading mental picture of what actually happens.
Fred,
I agree, but I still think one can cast the feedbacks as having units of Wm-2.
I think I’m reading Soden & Held differently to you. The Planck response is negative (between -3 and -3.5 Wm-2K-1) but if I look at Figure 1, the overall feedback response (All) is between 1 and 1.5 Wm-2K-1.
If I redo my calculation assuming that anthropogenic forcings are around 2 Wm-2 and assume that temperatures have rise 1K (rounding up), then the Planck response is just over 3Wm-2 and, by adding in the current energy imbalance, I get a total response of 3.5Wm-2. If I then remove the anthropogenic forcing, I get a feedback response of 1.5 Wm-2K-1 which seems consistent with Soden & Held.
I think I see what you’re doing. You’re including the Planck response in your feedback – I think. What I mean is all feedbacks other than the Planck response. If that is the case, then I should have made that clearer (I tend to ignore the Planck response when I think of feedbacks, but I shouldn’t as I’ve done this before and confused things somewhat in doing so).
So, when Judith suggests that a large part of the warming on century timescales could be natural, what does she really mean?
Of course, with most people one could just ask.
ATTP, thanks for your response to my comment. I’ve now read the dotearth article that Pekka pointed to in an earlier post on turbulent oceans and greenhouse heating and it is interesting. I take the point that “Finding a 60 year signal in a datatset that is only 100 years or so long, does not necessarily tell you that that it is some kind of cyclical process” – although I don’t know whether that gives any support to Prof Curry’s suggestion that “AMO and PDO etc” are likely to have caused a large proportion of the recent warming (?)
There are a couple of other related things which I’d like to ask about, which I think Curry has possibly mentioned a few times (although perhaps off-topic, apologies if this is the case, I’m happy to be moderated out…)
1) I’ve seen Curry suggest (I’m paraphrasing – apologies if I’m misinterpreting Curry’s words) that if natural variability has caused the recent “hiatus” then it could also have contributed to warming in the 1980s and 90s (and hidden a mismatch between modelled and observed surface warming) and that this has been overlooked or underplayed by the IPCC. I’d really like to know whether this argument is thought to have any mileage and if so what its significance is.
(When I first read this suggestion I thought that perhaps Curry might have a reasonable point (I think ENSO was predominantly towards El Nino in the 1980s and 1990s and more predominantly neutral in the 2000s, looking at averages of MEI). But I v much doubt that the IPCC’s contributors were not aware of this, particularly as quite a lot of attention in AR5 was given to the “hiatus”. And indeed in AR5 WG1, Box TS3 Figure 1 shows that observed surface warming for 1984 to 1998 was larger than most models predicted (suggesting that internal variability had played a role), while observed surface warming for 1998 to 2012 was smaller than most models predicted.)
2) I think Curry also suggests that climate models are “running hot” (i.e. the majority of models have predicted more warming than is actually the case). I’m aware there have been quite a lot of papers (some of which are referenced at http://www.realclimate.org/index.php/archives/2014/03/it-never-rains-but-it-pause/ ) which have perhaps suggested that the models aren’t really running hot after all. I wonder whether 1) this issue is pretty much settled or whether there is still quite a lot more work to be done on it and 2) if the models are “running hot”, what does this mean in terms of the accuracy of estimates of Equilibrium Climate Sensitivity and Transient Climate Response?
The significance of what Prof Curry says on these issues is impossible for me to judge (I don’t even know if observations of ocean warming are in line with climate model estimates).
ATTP,
If you wish to relate TOA imbalance (or forcing, which refers to TOA imbalance) to surface temperature change you can forget totally the Planck response. The only thing that you need is the relevant climate sensitivity / response with all feedbacks that contribute to the change being considered.
Of course you can get the same results based on no-feedback sensitivity and all feedbacks, but if you don’t get the same answer for the same assumed feedbacks then you have made an error in this more complex way of calculating.
Rob,
As far as point 1 is concerned, I think that what Judith suggests about the 80s and 90s is a fair point. It could well be that natural variability acted to increase how much we warmed in that era relative to the long-term anthropogenic trend. What I would say, though, is that there is a difference between natural variability influencing the rate at which we warm given an underlying anthropogenic trend and natural variability being able to warm in its own right (i.e., if the 80s and 90s were influenced by natural variability does this just mean that we warmed faster because of this, or does it mean that we would have warmed in the absence of any anthropogenic influence – I think the former is more likely than the latter).
2. I think the models running too hot is way too early to say. Even without any of the attempts to explain this, the observations still lie within the 95% confidence interval. The ensemble range is set so as to illustrate the possible range and we’d expect the observations to lie outside this range a few percent of the time. Additionally, when people have considered what might have caused the “hiatus” and corrected for this in the models, the models match the observations quite well.
On the other hand, the mean long-term trend in the models is higher than the long-term trend in the observations, so it is possible that they’re – on average – running hot, but I wouldn’t see that as significant yet and the models are still consistent, so they do present the possible range of future warming.
ATTP
Is it? Did you have a particular source in mind here?
BBD,
Grant McDermott has a post on this that I can’t see to find, but Tom Curtis has pointed this out before. I think the mean long-term observational trend is (1970-2014) is around 0.16oC per decade, while the long-term model trend is around 0.2oC per decade. The observational trend lies within the 95% confidence interval for the models though.
Thanks ATTP
Would I be right in thinking that were it not for the recent slowdown in the rate of surface warming, the modelled and observed trends would come into very good agreement?
Was this the Grant McDermott post you were looking for?
BBD,
Yes, that’s the one. I guess if the slowdown is indeed just some indication of variability, then I suspect the most you could say is that we don’t yet know if the mean model trend is likely to be close to the long-term anthropogenic trend, but we probably can’t yet claim that it isn’t.
Judith Curry has apparently written “I think both 0% and 100% are extremely unlikely.”, referring to the anthropogenic contribution to warming between 1950 and 2010. She had just previously said something about the 100% as an upper limit:
I can’t make any sense of this – it seems improbable that she could genuinely be arguing what she appears to be arguing. Is there anyone who is both willing and able to translate what Curry is saying here in simple terms?
OPatrick,
I guess this illustrates that Judith has a point when she quoted someone who said This article shows how you cannot ‘debunk’ someone if you have not understood their point.
I assume you’ve seen Paul S’s comments on that thread?
I try very hard not to go to Curry’s place, I find it ineffably depressing. I have just scanned through a number of his comments, which all seem clear and reasonable which in turn suggests there is something worth addressing.
BDD, your question has been answered a number of times but you refuse to think outside of your equilibrium box. ”Climate sensitivity” is classically defined as the change in surface temperature as a response to radiative forcing. It is an equilibrium concept that is almost completely divorced from the flux of heat into the deep ocean.” that is a second hand quote of Gavin Schmidt. If the ocean is not in “equilibrium”, the models don’t compensate. So you have to have a pseudo-equilibrium of sorts where heat uptake/loss by the oceans doesn’t impact the simplistic radiant models trying to estimate “climate sensitivity”. There is plenty of paleo evidence of longer term pseudo oscillations related to both precessional and obliquity cycles that appear to have periods ranging from decadal to millennial .time frames.Nielsen, S.H.H. et al 2009 for example and the more recent Chen and Tang indicates the ocean pseudo oscillations do have an impact on “Global mean surface temperature”. Wishing or smoothing away ocean heat transport variations doesn’t solve any problem.
captdallas,
I can see how ocean heat transport could influence the TCR, but not the ECS. Do you agree, or do you think it can influence both?
Also, if it does influence the TCR, but we control the change in anthropogenic forcing, then if we warm more slowly because of influences due to ocean heat transport, we’ll build up a larger planetary energy imbalance and warming will accelerate, so it would seem to me that if ocean heat transport can’t influence the ECS, there’s also a limit to how much it can influence the TCR-to-ECS ratio. Again. do you agree?
If you disagree with this, maybe you could explain why.
For ECS, isn’t that pretty much definitional? Unless, I suppose, one imagines internal variability operating on a scale exceeding the relaxation time of the fast feedbacks, although evidence for such would be hard to come by.
I know I’m repeating myself, but it’s actually kind of amazing to want to focus on such things at a time when we’re seeing slow feedbacks start to kick in, to the great surprise of the experts.
This issue of interpreting the SPM statement on mostly anthropogenic was brought up immediately after the SPM was made public. Judith expressed similar thoughts in her first post on the subject as he did again. I was probably the first to present arguments similar to those of Gavin, Paul S and Verytallguy at Climate Etc in the comments to that first post. I don’t think that there’s much originality in what I wrote, but for that reason I remember so well that the issue was brought up then, and has been brought up many times since by many people, JimD has perhaps done it most often.
Steve,
Focus? If you’re referring to my response to captdallas, I’m trying understand the significance of what’s being said. I can’t see it.
Pekka,
Yes, that’s what is most surprising – many appear to have clearly explained the issues with Judith’s position.
Cap still hasn’t answred my question, nor BBD’s. At this point I’m looking for evidence that cap understands this material at a level deeper then what would be allowed by a casual reading of the abstracts.
Cap
Oddly, I never saw those responses. Perhaps for the thread and readers here, you could summarise where observations indicate cooling at depth and an increase in OHC in the surface layer?
Before we get out of our boxes, we need to consider observations and evidence.
Anders, I was referring to cap’s assertion, not your questioning of it, although FWIW I think I have enough evidence to predict that all you’re going to get from beating your head against that particular wall is a painful flat spot.
But let him prove me wrong!
BBD,
Maybe in the same way that judith thinks that if she presents an argument that noone can understand that it can’t then be debunked, Cap thinks that by answering a question in a way that you can’t understand means that you can’t claim it hasn’t been answered?
Steve,
I have no doubt that that’s what will happen. I just have to start remembering to not band my head against the wall in the first place 🙂
Steve
Here’s a couple of dingers from back in the day:
And:
Actually I do have to thank cap for pointing to Oppo etal. (2009), which I linked above. More on that when I have time, at this point probably tomorrow.
Steve
Interesting… Citation?
vtg,
What about the WAIS?
There are a multitude of papers relating to ice sheet melt, permafrost loss and tropical rainforest die-back that I’m sure you haven’t missed, vtg. Deep ocean warming is another, notwithstanding that it acts to cool the surface in the short term. Don’t take this as a complete list.
ATTP,
ok, so ice sheet mass loss as a slow feedback. I’m notsure if increased discharge was expectedor not. I’m in interested to know what Steve was getting at. What are other slow feedbacks? Vegetation?
Steve, we crossed. I wasn’t aware any of those are at a rate not expected at current warming. Any links?
ATTP, I’m very grateful to you for your helpful response to my questions, which have been nagging at the back of my mind for some time.
Pekka – “I was probably the first to present arguments similar to those of Gavin, Paul S and Verytallguy at Climate Etc in the comments to that first post.” This is interesting. I think I’ve read posts by Curry on this before but I didn’t realise (or had forgotten) these particular arguments from Curry had been challenged in a similar way before. (I’ve not found the stamina to go through all the comments on climate etc). I suppose the repetition of these discussions benefits me as there’s a lot of things that I pick up second or third time around that I missed first time, but I would guess it’s infuriating for experts.
vtg,
Isn’t the issue more about how we define fast feedbacks. As I understand it, climate models can’t capture these slow feedbacks (ice sheet loss, for example) so any ECS estimate from a climate model is, by definition, due to fast feedbacks only. Similarly, if you consider the ECS from paleo estimates, they (from what I’ve seen) typically regard the external forcings as being due to CO2 and albedo changes due to reduction in ice, and hence only capture fast feedbacks. So, as I understand it, in that sense ice sheet mass loss would be regarded as a slow feedback.
Basically it is definitional, going back to the original assumption by the Charney committee that feedbacks not seen to be operating at the time and expected to not operate significantly during the time needed for relaxation of the fast feedbacks (oops on that latter) could be excluded from sensitivity calculations. Also, trying to incorporate slow feedbacks in GCMs would have been entirely impractical, and to a great extent still is (although an effort is made to compensate for this for some feedbacks by using specialist models to specify boundary conditions for the GCMs). Plus there are earth models (ESMs and EMICs) that are computationally simplified enough to try to track the slow feedbacks over time, although they and the aforesaid specialist models are sharply limited by a poor understanding of the underlying physics and biology — “poor” because observations of slow feedbacks are necessarily limited. Of course IANAS and probably am not describing this at all precisely.
So given all this, what we see is a pretty steady stream of obs and paleo papers pointing up deficiencies in the models relating to slow feedbacks. My favorite example is the inability of any model to manage the transition from current climate to a Pliocene-like one (i.e. one where ~400 pmm CO2 has been allowed enough time to drive the climate to an equilibrium state). I have all admiration for the modelers, but this shortfall has overwhelming significance for policy. Yet, we hardly ever hear about it. Go figure.
vtg, I’ve commented on particulars extensively on this blog. OTOH I can hardly blame others for not focusing on what amount to side discussions since I have that problem myself (my kingdom for an eidetic memory).
But as persistent windiness seems to have sent Anders into posting hiatus, maybe I could attempt a guest post on the subject. At the least I’ll point to a few example papers, but as I’m really running late now that will have to be tomorrow.
Steve,
Sure. I assume you’d include something on the significance of the PETM.
Do have a look at this paper (abstract only, unfortunately). GCMs can more or less handle Pliocene climate if Arctic sea ice is specified to be absent, but can’t capture the feedbacks needed to get rid of it to begin with (or to amplify Arctic temperatures more generally).
I shouldn’t neglect to mention the paper’s important finding that it’s the oh-so-ephemeral Arctic sea ice, not the ice sheets, that stands between us and a rapid transition to Pliocene-like conditions (although if we’re lucky it will turn out to be the case that the ice sheets will have to melt back substantially, and maybe permafrost too, before the sea ice can go).
TTP, “I can see how ocean heat transport could influence the TCR, but not the ECS. Do you agree, or do you think it can influence both?”
Since a ECS may not really exist because of the long over turning time of the oceans, ~1700 years, it could be an influence in that respect. TCR is about all we can hope to estimate right now IMO.
BBD, I have no doubt you likely miss “it” along with many other things.
Steve Bloom, Sorry I missed your question. The only “claim” I was making is the Oppo 2009 shows a decline in IPWP temperatures from roughly 1225 AD to a minimum ~1700 and a rise to the end of the reconstruction in 1955. The rise has a pattern that can be reasonably match with a weakly damped response curve. The IPWP is one region consider a good “teleconnection” to global temperatures because it has lower THC through flow Paleo has plenty of issues, but the reconstruction as binned by Oppo et al makes it fun to splice with instrumental data, which I did as a bit of a lark,
http://redneckphysics.blogspot.com/2013/12/2000-years-of-climate.html
No error bars included since was just a lark.
captdallas,
That’s a cop out (although maybe you don’t realise it). Rephrase ECS to an equilibrium temperature to which we will tend and and maybe try answering my question again.
Okay, you have over-stepped the line now. You are lying. You have never answered the question. You evaded it, just as you are doing here.
You can get away with this at Judith’s but not here.
ATTP, “That’s a cop out (although maybe you don’t realise it). Rephrase ECS to an equilibrium temperature to which we will tend and and maybe try answering my question again.”
It “may” be a cop out, but I doubt it. If you compare NH and SH SST reconstructions over the last ~7000 years the SH has be warming while the NH has been cooling most likely due to shift in precession. That changes the meridional heat flux. Based on NH SST and deep ocean temperature reconstructions, the DO lags SST by ~ 1700 years. If an equilibrium can be established in a period much less than 1700 years, then there can be a useful ECS. If not you have to bite the bullet and do the fluid dynamics. The lower TCR estimates become, the less likely ECS will be useful. It all depends on the required accuracy.
ATTP, as for the “equilibrium” temperature consider instead a reference temperature to monitor. Since the best estimate of the “average” ocean temperature is 4 C degrees (S-B equivalent of 334 Wm-2) and the best estimate of “average” DWLR is 334 Wm-2 (4 C effective temperature), the average temperature of the total ocean thermal reservoir would be a reasonable reference. That changes very slowly in the ocean case and now that the two are in somewhat of a steady state and there are indications that the imbalance has been decreasing, not a bad thing to watch.
captdallas,
I’m not following your reasoning. The point I’m trying to make is that the equilibrium is set by our albedo, the TSI, and the composition of the atmosphere. Ocean cycles cannot influence that, hence no amount of ocean dynamics can change the ECS (unless it changes our albedo, or the GHG composition of the atmosphere). Furthermore, if ocean cycles reduce that rate at which we warm (by sequestering more of the excess energy in the deep ocean) this will produce a larger planetary energy imbalance, increase the amount of energy that needs to be sequestered and, presumably, accelerate surface warming (i.e., the oceans can’t continue to accrue an ever increasing fraction of the energy).
I tried this. If you assume that a much larger fraction of the ocean is essentially instantly involved in sequestering the excess energy (i.e., rather than only the top 100m or so, you make it 1000m), this reduces the TCR, but only delays reaching 2 degrees by about 50 years and you reach equilibrium in around 500 years. You can look at this if you’re interested.
So, I’m interested in whether or not you can actually quantify how the oceans can delay the warming substantially. I don’t see it, but maybe you can convince me otherwise. As it stands, it just seems that you’re hand waving about oceans, without considering the role of radiative forcings and planetary energy imbalances.
Cap, you made a claim above for the relevance of Oppo etal. (2009) to Judy’s stadium wave claims. But it’s not an OHC paper, so I’m not seeing the connection. Explain please.
I had a look at your page, but it’s not clear to me what you mean by “scaling.” What exactly are you doing when you do that?
Steve bloom, not exactly, I claim that the Oppo etal 2009 supports longer term oscillatory behavior in climate. While it is not an “OHC” reconstruction, the 2000 years of climate lark of mine uses OHC, Global mean sea level, land surface temperature, SST and CET scaled to show similar oscillatory behavior and a related slope. The Stadium Wave paper did imply longer term, ~300 year influences which Oppo etal 2009 does somewhat support.
The reason the IPWP should have a fairly good correlation with “global surface temperature” is because it has less THC influence. My statistical prowess is very limited, but the India Ocean has a better correlation to “global” temperature than any other ocean basin based on my simple OpenOffice packages. I believe that would imply there is more than just an AMO/Stadium Wave influence to consider. There are large uncertainties of course, but the correlations with GMSL and OHC are interesting none the less. I have also scaled basin SST with basin OHC ( actually vertical temperature) and it appears it can provide a reasonable estimate of changes in OHC allowing for the progressively deteriorating accuracy of the SST data set of course.
I have looked at Oppo etal 2009 about every way I can think of and it appears to be a solid piece of work other than possibly a slight binning issue.
So if long-ago subducted warm waters are upwelling, we would see cooling at depth and warming SSTs and increased OHC at the surface layer.
Instead of mashup graphs which arguable demonstrate exactly nothing, were are the OHC depth profiles showing this happening now?
BBD,
Isn’t the issue with this that water is incompressible, so that even if there is a lot of energy at depth, the water is still much colder than the surface. Therefore if you replace a certain volume of surface water with the same volume of water from the deep ocean, you should see surface cooling, not warming?
ATTP, “I’m not following your reasoning. The point I’m trying to make is that the equilibrium is set by our albedo, the TSI, and the composition of the atmosphere. Ocean cycles cannot influence that, hence no amount of ocean dynamics can change the ECS (unless it changes our albedo, or the GHG composition of the atmosphere).”
The problem with “set by albedo” is that a large portion of albedo is a response to ocean cycles. It is kind of a chicken egg thing. One of the papers by Toggweiller, http://www.gfdl.noaa.gov/bibliography/related_files/jrt0901.pdf describes the impact of shifting westerly winds, basically migration of the ITCZ, Shifting wind patterns would also vary the efficiency of the Antarctic Circumpolar Current impacting the THC circulation. It is an absolutely marvelously complex fluid dynamics problem. If all of that averages out over some meaningful time frame, you can assume a “fixed” albedo, but the Oppo et al 2009 seems to indicate that isn’t the case.
“I tried this. If you assume that a much larger fraction of the ocean is essentially instantly involved in sequestering the excess energy (i.e., rather than only the top 100m or so, you make it 1000m), this reduces the TCR, but only delays reaching 2 degrees by about 50 years and you reach equilibrium in around 500 years. You can look at this if you’re interested.”
Schwartz estimated about an 8 year settling time for the bulk mixing layer which seems reasonable to me. The longer term deeper ocean heat gain would only have about a .2 to .3 C impact per century. That is significant for a lower “sensitivity” not so much for a high “sensitivity”. As I said, it depends on the accuracy you need.
“So, I’m interested in whether or not you can actually quantify how the oceans can delay the warming substantially. I don’t see it, but maybe you can convince me otherwise. As it stands, it just seems that you’re hand waving about oceans, without considering the role of radiative forcings and planetary energy imbalances.”
The problem really is the variation in the mixing efficiency of the ACC and North Atlantic, so I am somewhat arm waving because it is difficult to quantify. The ACC though is equivalent to about 5 Gulf Streams in flow so it shouldn’t take much to have a noticeable impact.
Captdallas,
I’m not sure I’m following this either. Are you suggesting that ocean cycles could produce some kind of negative feedback? The only one I can think of is clouds, but my understanding is that the current evidence suggests that they provide a small positive feedback.
That seems sensible, but that’s kind of the point, isn’t it? If CS is high (or even medium) ocean cycles are unlikely to influence it significantly.
Okay, fair enough.
ATTP
There are lots of issues 😉
You are of course correct, but as I understand it, the deep water formation by the THC can’t even happen unless the OHC at the point of downwelling is low enough for the water to sink. Deep water in the THC is just cold, full stop.
I have problems understanding how ocean circulation can store and release energy as Cap seems to believe.
“scaled to show similar oscillatory behavior and a related slope”
Is this to say that you flattened them to match? If so what’s the validity of the slope you got?
Re the similar behavior, generally these things should be expected to *approximately* track each other over an extended period of time (maybe not CET since it’s a single location that would need to be shown, not assumed, to be representative). Oppo et al. demonstrated that by overlaying their record on a then-recent Mann NH reconstruction. What do your comparisons show that theirs doesn’t?
But you still haven’t related any of this to OHC changes, or at least deeper ocean temperatures in that region, regarding which there ought to be some literature. Have you looked?
Oppo et al. also note the cause of the LIA dip in the IPWP. I have to say it doesn’t make me think first of an OHC connection. Volcanic aerosols with a primary impact on the surface, more like. Why do you think otherwise?
The Toggweiler article on shifting Westerlies that Cap linked above suggests that, under orbital forcing, meltwater-triggered AMOC shutdowns cause NH cooling and SH warming. This increased the ventilation of the Southern Ocean and net CO2 release to the atmosphere.
ATTP, “I’m not sure I’m following this either. Are you suggesting that ocean cycles could produce some kind of negative feedback? The only one I can think of is clouds, but my understanding is that the current evidence suggests that they provide a small positive feedback.”
If can swing negative or positive and while clouds would be the major factor you also have atmospheric circulation changes. There is a variation in the magnitude of Sudden Stratospheric Warming events and Arctic Winter warming related to the circulation patterns. Susan Solomon noted the changes in stratospheric water vapor related to Brewer-Dobson circulation for example and poleward flow of O3 and water vapor impact the ability of the polar atmosphere to retain energy. All that can lead to disruption of the polar vortex etc. etc. Quite a bit of dynamics beyond my pay grade.
Steven Bloom, “Is this to say that you flattened them to match? If so what’s the validity of the slope you got?” the slopes themselves are not particularly valid it is the relative variation that may have some validity. The BEST land temperature data scaling for example represents the land amplification that should be expected and was noted by BEST. Which is the answer to this, “What do your comparisons show that theirs doesn’t?”
“But you still haven’t related any of this to OHC changes, or at least deeper ocean temperatures in that region, regarding which there ought to be some literature. Have you looked?”
Since I was comparing the IO SST and Oppo SST reconstruction with IO ocean heat uptake, I did the other basins just as a gut check. The more recent Rosenthal et al 2013 had a few items that needed correction, but that could be compared if you like. The deepest part of the deep ocean though is elusive. My comparison was with the 0-700m data and there is reasonable agreement IMO, FWTIW, though I didn’t make an attempt at error bars. Most of this is going to require a serious ocean model to sort out which is where the GFDL seems to be in the lead.
captdallas,
WADR, it just seems that you’re essentially saying “maybe”.
BBD, “The Toggweiler article on shifting Westerlies that Cap linked above suggests that, under orbital forcing, meltwater-triggered AMOC shutdowns cause NH cooling and SH warming. This increased the ventilation of the Southern Ocean and net CO2 release to the atmosphere.”
Right and at the start of the Holocene we had one orbital forcing and now we are at the other extreme of the precessional. If you read more of Toggweiler, the shifts in westerlies would change the flow rate of the ACC and Antarctic sea ice extent and orientation shift the flow closer to (further from) the Antarctic convergence zone. You don’t have to have a full stop of the AMOC to have an impact. The object is to try and predict what is going to happen and paleo at this point could be the most valuable tool for that purpose. As it is, there is a decreasing Arctic sea ice trend and an increasing Antarctic sea ice trend which should be some what relevant.
ATTP, “captdallas,
WADR, it just seems that you’re essentially saying “maybe”.”
Unless I was 100% sure I would not say anything else. As I said before, the observations are at the lower end of the “projected” 95% confidence range. How far below that range does it have to be before it is called an over confidence range?
captdallas,
Fair enough, but I think I was looking for something a little more quantitative. I think I’ve provided some actual reasons why ocean cycles are unlikely to play a big role (on medium- to long-terms) in how we warm. I was hoping you might try and quantify what you seem to be suggesting, which – to be fair – I don’t really understand.
Cap
Net CO2 flux from ocean to atmosphere?
ATTP, “Fair enough, but I think I was looking for something a little more quantitative. I think I’ve provided some actual reasons why ocean cycles are unlikely to play a big role (on medium- to long-terms) in how we warm. I was hoping you might try and quantify what you seem to be suggesting, which – to be fair – I don’t really understand.”
I will look around to see if there are more current papers on the mixing issue other than the Chen and Tung, but the ARGO and other data near the poles really limit things.
BBD, “Net CO2 flux from ocean to atmosphere?”
Don’t have a clue. Lowell Stott is supposed to be working on a paper but that also involves mid to deep ocean temperatures that are limited. The big shift around 1970 didn’t seem to impact the trend so I doubt there is much there. There was a shift around 5000 years ago in the paleo data that might have been about it for precessional impact on CO2.
I see the Professor Irwin Corey of Climate Etc has started commenting here. Quite the schtick he has going there.
But Cappy is also effective as an OWN GOAL scoring machine. A recent link he gave me was to an ENSO Proxy dataset
which I have been analyzing here
http://contextearth.com/2014/08/26/soim-fit-to-unified-enso-proxy/
and at the Azimuth Forum
http://azimuth.mathforge.org/discussion/1451/enso-proxy-records
Remember Twain’s logic behind Tom Sawyer’s picket fence paint job?
Anders –
Is there any way that you can put “own goal” and “hand wave” into the moderation algorithm? I think it’s high time that both expressions get retired.
There is nothing wrong with the phrase “own goal”.
The problem with deniers is that they are desperate to come up with a counter theory to AGW. Yet, science is resistant to being malformed into something it can’t be — further evidence can only lead one closer to some objective truth.
So when some denier comes up with some potential finding that purports to debunk the consensus, it is usually straight-forward to reinterpret that finding into further substantiation of the AGW theory.
Thus when deniers try to do the science, the result is almost always an “own goal”.
I think that the Stadium Wave idea is an own goal that Curry will never own up to. She will never admit that it is actually reducing the uncertainty in estimating climate change, not increasing it as she claims → own goal.
Joshua,
I don’t know. Cap acknowledged that some of what he/she was doing was hand waving, which I thought was something of a success.
For an example of why the “handwaving”, The average estimate of the southward flow across latitude 55S is 190 Sverdrupt +/- 60, which is like adding or subtracting a couple of Gulfstream volumes. The average temperature break at the Antarctic Convergence zone is around 3 C over 20 to 30 miles. That southward flow is driven by surface winds and sinking water as it cools driving the majority of the THC. Completely stopping the THC may cause 3 C decrease in global SST with possibly a 6C decrease in NH “surface” temperatures.
There is close to zero data in that region of the ocean prior to 1950 which would be required to make any reasonable estimate of the impact to any level of precision that might be considered useful compared to WHUT overfitting exercises for example. I am pretty confident though that a variation of 10% in the THC flow would have a noticeable impact.
Click to access GMS_StochasticSP.pdf
That is a link to a recent paper trying to improve modeling of the ACC.
==> “I don’t know. Cap acknowledged that some of what he/she was doing was hand waving, which I thought was something of a success.”
Agreed. It was an extremely rare event in the blogosphere. (Cap’n, unlike most of his “skeptical” brethren that I’ve encountered, does have a bit of a sense of humor, tends to let bad faith comments roll off his back, can occasionally engage in good faith discussion himself, and sometimes even makes well-reasoned arguments.)
Perhaps this is a turning point, with an ensuing movement towards good faith, honest discussion that targets mutual enlightenment (and BTW, have I mentioned that I have a bridge in Brooklyn that I could let you have for a great price?)
Still – more descriptive terms would be better, IMO. “Own goal” and “hand wave” are the poor-faith rhetoric, IMO. The first is, of course, always subjective (no one agrees they’ve ever scored an “own goal”) and the second implies bad faith. Why not just say that you find a particular aspect of the argument not very compelling or in need of further explanation?
I don’t think hand waving implies bad faith, Joshua. It underlines an invalid appeal to an authority. There are more neutral ways to elicit substantiation, of course. But the violence behind the term vary according to cases.
I would never mean to harm Cap’n by saying he handwaves. I like Cap’n, and he’s one of the reasons I read Judy’s. We don’t agree on much, but good humor seems to minimize the impact of our disagreement. Our main one is about sugar anyway.
His red neck physics is more solid than it may appear at first. At least that’s my experience. He thinks by himself, and this should *always* be encouraged.
I have yet to find anyone who thinks exactly like me, and if I waited such an event to make friends, I’d feel quite lonelier than I am.
No, that last bit is false. Maybe you missed my comparison of Cap’n to Prof. Irwin Corey. Maybe you don’t know who Corey is — well, if not, he is a comedian who made a career out of getting laffs off of lectures filled with pretentious-sounding scientific “word salad” .
Corey knew it was all a joke, I am not so sure of what Cappy’s agenda is.
WHT –
I can’t evaluate Cap’n’s science enough to determine whether his technical arguments are word salad ala Irwin Corey or Sarah Palin.
But I have had extended exchanges with him on topics where I can follow the discussion, and where he seems to make coherent arguments, (even if often they are based on flawed premises or derived from subjective filtering of evidence – probably due to him being off his bacon).
Willard –
==> “I don’t think hand waving implies bad faith, Joshua. It underlines an invalid appeal to an authority.”
In my experience, the term is used overwhelmingly in a Jell-O flinging context, to imply that someone is intentionally trying to distract from a weak point in an argument. Sure, the expression can be used to simply imply that a point is not fully explained. In fact, someone can use it to describe that their own argument contains a shorthand for a longer explanation that would be beside the main point being discussed.
The problem that I have with the term, aside from that it is usually a marker for bad faith exchange – is that it is so over-used (like “own goal”) that it essentially becomes meaningless.
Why not simply be more descriptive in ways that are clearly not intended in bad faith.
I’m glad to see Cap’n here, because he’s one of the few “skeptics” that I’ve seen make (what seem me to be) well-reasoned arguments. Because no one (or at least very few) folks at Judith’s will engage with him from a contrasting perspective, I can only rely on my unscientific parsing to evaluate the science of his arguments. If he engages here, then I can get a better window into his “skepticism.” So I have a personal stake in seeing him engaged in positive ways – which has happened thus far for the most part.
From reading Joshua and Willard on Climate Etc, I recall that they have admitted on occasion that they are more students of behavior than being experts at physics.
Cap’n is really out of his environment in this forum. His “redneck physics” is condoned where he surrounds himself with the Klimate Klown Klan, but shouldn’t be here.
I tried finding one of his word-salad concoctions — here is one:
His schtick is to string together a bunch of plausible sounding phrases, and then end it with a “good ole boy, aw shucks” comment to try to ingratiate himself with his low-information audience.
Why he does this, I do not know. I do know that it is invariably wrong and not worth the time to comment on. Curry obviously condones his antics because he adds to the FUD.
==> “From reading Joshua and Willard on Climate Etc, I recall that they have admitted on occasion that they are more students of behavior than being experts at physics.”
FWIW –
I’m a bit uncomfortable with a suggestion that Willard and I are in any way comparable w/r/t understanding physics or studying behavior. I don’t understand the physics at all, and I’m not so much a student of behavior as an observer, and arm-chair speculator, about behavior (Willard seems to actually study behavior).
Web,
Cap’n was responding to Chief’s:
In my humble opinion, Cap’n called Chief’s appeal to perfection by pushing it to its limit. No need for any equations to get that, Web. You might need another example to prove your point.
Please try again.
Why does Cappy call his blog “Redneck Physics”?
Would you pay attention to something called “Redneck Ph@rmaceuticals” ?
all the stuff should go into the spam bucket.
Cap,
I’m still not really following your argument. Let me explain where I’m coming from.
How we warm in the coming century will clearly depend on what emission pathway we choose to follow. If we follow the most extreme (RCP8.5) then we would increase anthropogenic forcings by about 6 Wm-2, relative to today, by 2100. We currently have an energy imbalance of about 0.5 Wm-2, so if we didn’t warm at all we’d have an energy imbalance in 2100 of 6.5 Wm-2. This is completely implausible. We would have to warm.
An increase in temperature of 1K produces a Planck response of about 3.5 Wm-2. Using observational evidence and climate models, a reasonable estimate for the non-Planck feedback response is about 1.5 Wm-2K-1. So, 1 degree by 2100 would reduce the energy imbalance to 4.5 Wm-2 (6.5 + 1.5 – 3.5). Again, still too high to be plausible. A 2 degree rise would reduce it to around 2.5 Wm-2 (4.5 + 1.5 – 3.5). Still 5 times higher than today. A 3 degree rise would bring it down to around 0.5 Wm-2 (2.5 + 1.5 – 3.5).
So, a reasonable estimate for feedbacks would suggest that anything less than 3 degrees by 2100 if we follow an RCP8.5 pathway is probably implausible. If it’s to be lower then feedbacks have to be lower, but even if there are no feedbacks we’d still need around 2 degrees of warming to keep the energy imbalance below 1 Wm-2. However, there is little evidence to suggest that the feedback response would be zero or negative.
So, that’s where I’m coming from and what I was hoping you could do is explain how ocean cycles could prevent us from warming by that kind of amount in the coming century. Again, the how much we warm will depend on our chosen emission pathway, but we could do a similar kind of calculation for other pathways. In other words, how do ocean cycles prevent us from warming if our emissions are producing an ever increasing planetary energy imbalance?
Oh, and a quote and a link might be nice to substantiate this:
> I recall that they have admitted on occasion that they are more students of behavior than being experts at physics.
Denigration might prove easier with contrarians, Web. I will use your own hate to make you eat your shorts. Try me.
ATTP, “we have to warm”, Yes, but we don’t have to have all positive feedbacks. I don’t see any reason to assume a tripling of the basic forcing change we introduce . The mixing issue tends to be a negative feedback, but since there is likely at least a 60 to 150 year lag, how much I don’t know. But if more heat is transferred to deeper oceans for what ever reason, it will have less impact on the surface in a short time frame and a smaller impact over a longer time frame. That is a equilibrium problem, what should be considered :”nornal” for the oceans? Since water vapor just responds to temperature and wind, gradual longer term warming could easily be confused with anthropogenically forced warming, making it easy to over estimate Anthropogenic impacts.
Given the current state of the art GMC modeling, some common issues should be producing the over estimations. Updating just the ENSO region temperatures improves the performance of some, so the choice of “equilibrium” condition looks pretty likely to me and evidently quite a few others who are busily re-analyzing ocean heat transfer. After all the first step in applying Occam’s razor should be “where did I screw up?”, right?
Cap,
I’m not sure what you mean by this. Either the overall feedback is positive or negative. Some individual feedbacks are positive (water vapour) some are negative (lapse rate), but the evidence suggests that the overall non-Planck feedback response is positive.
How is the mixing issue a feedback? I don’t think it is, at least not in the sense that I’ve been using it.
Except that an anthropogenic forcing of 2 Wm-2, a planetary energy imbalance today of 0.5 Wm-2 and a rise in temperature of 0.9 degrees, gives a non-Planck feedback response of 1.5 Wm-2K-1. You don’t need to climate models to get that.
I think you’re misusing Occam’s Razor. Occam’s razor simply tells you that you should use the simplest possible approach that incorporates all that physics tells you should be incorporated. It isn’t a way to determine whether or not something is valid.
ATTP ventures:
I think this could be made into a stronger statement without going beyond what the evidence supports. If feedbacks were not net positive, how do we explain paleoclimate and modern observed variability?
Plenty of examples in this thread, Willard. Cap may not be a sky dragon, but his views do seem to be constructed substantially on hand waves and as we see it’s hard to get him to coherently answer even the simplest, most direct of questions. But actually I’d disagree with the Irwin Corey analogy — Duane Gish seems to be a much better fit.
ATTP, “Except that an anthropogenic forcing of 2 Wm-2, a planetary energy imbalance today of 0.5 Wm-2 and a rise in temperature of 0.9 degrees, gives a non-Planck feedback response of 1.5 Wm-2K-1. You don’t need to climate models to get that.’
Using the average ocean reference I recommended you would get a temperature rise of closer to 0.8C per 3.7Wm-2 for total forcing and the planetary imbalance today is about 0.6 Wm-2 +/- 0.5. That would give you an ocean imbalance in the range of ~0 to 0.42 Wm-2. Variations in the rate of ocean heat uptake can be mechanically driven without requiring forcing, meaning that that long term trend in the Oppo 2009 could be adding to current estimates of forcing
So let’s look at best estimates of anthropogenic forcing, CO2 is pretty solid, does anyone know what “normal” aerosol forcing should be?, are we really certain that clouds will be a positive feedback? I say that what we do know is that CO2 doubling will add ~3.7Wm-2 which should have an impact of between 0.8C and 1.5C depending on your preferred reference and should take centuries to be realized, if you use the ocean reference.
Now if you like you can pick a range of possible “sensitivities” an using a Mauna Loa era baseline back calculate what your estimates indicate “normal” should be.
If you consider the LIA anomaly “normal” “sensitivity” would be higher. If you consider the LIA and the 1910 anomaly “abnormal” your sensitivity estimate would be lower. So if you use occam’s razor and your estimates are tending to run high, does that mean it is more likely the data is wrong or your assumptions?
I apologize Willard. So I will correct and say that you are a smart guy when it comes to physics, but it appears that you would prefer to not indulge in discussion of physics topics.
But then the question of Cappy D comes up. How could anybody be fooled by Cappy that also has a deep knowledge of physics?
Steve Bloom said:
yes, the Gish Gallop is often evident.
Additionally, Cappy has a mix of the Chris Farley character that puts “air-quotes” around all his words.
This is obviously related to the hand-wavy affliction he displays, and serves as a mechanism that shields him from direct attacks.
Say that I were to write this: I am actually “sure” what I am “talking” about. The air quotes around “sure” and “talking” indicate I am uncertain on what those terms actually mean, and so don’t call me on it if what I say is untrue.
Is it really that hard to read these guys?
Cap,
Certain? Well, the current evidence suggests that it is slightly possible. Also, as BBD would probably point out, paleoclimate is inconsistent with large negative feedbacks.
I don’t understand what you’re getting at. My point is that it is difficult for the planet to sustain an imbalance in excess of 1 Wm-2 because a large imbalance will simply drive faster surface warming. If we produce a large change in external forcing then we will quickly warm to reduce the planetary energy imbalance. I’m not following what you’re getting at with respect to the oceans and the ocean reference. It doesn’t seem all the relevant to me. Can you explain it further. I’m also not sure where you 0.8C to 1.5C is coming from.
A greenhouse effect producing an average surface temperature 288K with a non-greenhouse temperature of 255K suggests that the outgoing flux is
times the surface flux. Hence if we write the change in outgoing flux as 
, then if 
and 
, you get 3.3 Wm-2 for a 1 degree rise in temperature and it would need to rise about 1.1 degrees to match a change in forcing of 3.7 Wm-2.
So Cappy shows a graph of SST with two fits at 1.1 and 2.23 TCR.
Average the two and one gets 1.665C.
But this is only ocean — adding land to this will give a global average at or slightly above 2C for TCR. This is near the consensus value.
Should I say thanks, or ask enough with the Stump the Chump act ?
WebHub,
Some of your comments are bordering on disrespectful. I realise that it can be hard to show respect for someone you do not, but if that’s the case then it’s probably better to ignore the commenter altogether. It’s fine though, to point out their mistakes.
Yes, I meant to say something earlier but got distracted. I’m typically happy to provide more leeway to those who remain pleasant and at least try to answer the questions. Can we bear that in mind please.
ATTP, “A greenhouse effect producing an average surface temperature 288K with a non-greenhouse temperature of 255K suggests that the outgoing flux is 255^4/288^4 times the surface flux. Hence if we write the change in outgoing flux as 255^4/288^4 4 \sigma T^3 dT, then if T = 288 and dT = 1, you get 3.3 Wm-2 for a 1 degree rise in temperature and it would need to rise about 1.1 degrees to match a change in forcing of 3.7 Wm-2.”
Right, that assumes both 288K and 255K are normal. So using your selected references, 1.1 would be your sensitivity and your response time would be extremely quick. If you use the “average” ocean temperature of 277K (334Wm-2) and assume it is in “equilibrium” or a steady state with DWLR estimated at 334Wm-2 (277K) you would be using a difference set of references to avoid duplicating assumptions, and those frames of reference would require a longer response time. Since the “surface” that is actually changing is the effective radiant layer you could use that as a reference. That is part of the joy of thermodynamics, you can select different frames of reference and if every thing is properly considered, they should all converge on the same solution. It is good IMO to compare frames since your 288K versus 255K must make assumptions as to whether latent heat will cool that surface like it does in most worlds or some how heat that surface.
As for Webster’s complaint, the 60s-60n SST should be actual liquid surface the majority of the time simplifying my assumptions and if you want to relate that to any other surface you could consider initial temperature and specific heat capacity differences and get the same results.
> Occam’s razor simply tells you that you should use the simplest possible approach that incorporates all that physics tells you should be incorporated.
Actually, that’s an extrapolation of Occam’s razor, which was about entities, not explanations, methods, or whatnot. And even then, except for God itself, it was a judgement call:
http://plato.stanford.edu/entries/ockham/
On reflection, I agree there’s a big hunk of Prof. Irwin Corey as well. In honor of the World’s Greatest Authority’s 100th birthday just a month ago, here’s my favorite bit of his (referencing his performance attire of sneakers and somewhat tatty formal wear):
Cap,
Again, your comment isn’t really making sense, but I think I’m seeing where you’re coming from. You’re using the average temperature of the ocean, not the average surface temperature, right? Here’s the issue, though. What determines whether or not we’re in energy balance, is the surface temperature, not the average ocean temperature. Therefore if we build up a large planetary energy imbalance, surface temperatures will have to rise to reduce this imbalance. From what I’ve read and what I’ve done myself, an imbalance of greater than about 1 Wm-2 is difficult to sustain.
In some sense you do have a point. If we are out of energy balance, retaining equilibrium will require that even the deep ocean gains energy. However, energy transport to the deep ocean is diffusive and therefore slow. Hence, what we would expect is that the well-mixed layer and the land and atmosphere warm rapidly until we are tending towards equilibrium (which would take decades or a few centuries) and then we’d retain a small planetary energy imbalance that essentially provides the excess energy for heating the deep ocean. This could well take thousands of years, but will probably be associated with us only being a few tenths of a degree away from the final equilibrium temperature, so not particularly significant given the kind of temperatures rises that are projected.
The world’s foremost authority.
Isn’t that what slogging through blog comments is all about? Figuring out who is full of it, and who is not?
I will say that I have encountered a Gish Gallop from Cap’n on occasion, most recently when he responded to a simple basic point, which I repeated, with multiple long excerpts none of which addressed that point.
It is interesting for me to read this exchange. Will Cap’n be able to explain his argument so that Anders can understand it? If not, is that because the argument is word salad or because of Anders’ limitations or biases? Stay tuned for the next episode!
Joshua
Anyone who asserts, as Cap did to me, that there has only been permanent Antarctic ice for ~800ka isn’t worth serious attention. I told him so at the time and warned him that I was bookmarking the comment for future reference.
He is flailing around for anything – anything at all – that can be used to confuse and distort the actual scientific understanding of CC. It is extremely difficult to take a neutral view of this. My sympathies are very much with WHUT.
In fact, I was thinking a bit more about what I think Cap is suggesting and I think it is essentially that the entire ocean would warm at the same rate. This is wrong. The upper ocean (100m or so) is well-mixed and so – to a first approximation – could be regarded as in thermal equilibrium with the atmosphere. Energy is then transported to the deep oceans via diffusion (I think). Therefore, in a simple sense, we have two timescales. The atmosphere, land and well-mixed layer warms quickly, while the deeper ocean warms more slowly. Of course, if the deep ocean is to warm that would require a persistent energy imbalance, but since it is a slow process, this doesn’t have to be large. This is my understanding and I realise that it is much more complex in reality, but I think this is a reasonable first approximation. Happy to be corrected if there is something fundamentally wrong with what I’ve said.
Technically speaking, this is not a Gish Gallop. All of Cap’n’s points are interconnected, and articulated in a way that we’d expect someone with some relevant background knowledge to make. Of course, most of these points are talking points, but we should be able to distinguish. Cap’n’s performance for (say) Sir Rud’s at Judy’s. Also note that a master of Gish gallops like Mike Morano would use it in on oral exchanges, not in an online document that a division of labor would help see through it. Gish gallops rely on finite resources, both in time and in knowledge.
To dismiss Cap’n’s contribution as a Gish gallop makes a few ClimateBall mistakes.
First, it does not address the articulation of the points. This is what should convince a reader who can’t evaluate the claims. This is also where the weaknesses are I believe in Cap’n’s case. If Cap’n doesn’t make sense, it need to be shown. Cue to AT’s claim about nonsense at Andrew’s.
Second, Cap’n presents an opportunity to sell one’s case. That Cap’n’s points get addressed matters less than presenting one’s viewpoint. INTEGRITY ™ games are races, not boxing matches. Food fights help no one, except ninjas, of course. I might be biased on that point, though.
Think of it that way. When a ClimateBall player tells me I make no sense, it signals a weakness. If true, I can clarify what I mean. If untrue, I can clarify what I mean AND show a lack of charity, or at least dismissiveness. The best thing one can say facing what appears to be nonsense is to say one doesn’t understand it. Unless, of course, absurdity can be derived, which proves it’s a matter of logic.
In doubt, ask questions.
About this exchange we are having with a Top 10 commenter at Curry’s blog, Cap’n Dallas.
If I write something to explain a physical phenomena — using an analogy or hand-waving, for instance — and someone does not understand it, I can regroup and attack it from a different angle and try again. If math is required, I will go deeper or more general depending on what the questioner can deal with technically. I didn’t learn this in a vacuum, but from taking classes in physics and science in college and then working in a cooperative, give-and-take research environment.
But the problem with the Cap’n is that further questioning will not lead anywhere, other than a deep rabbit-hole. Try to ask him what his atmospheric “reference shells” are all about. He has something abstract in his mind that he can not articulate mathematically or in any other way, but he is persistent in his comments at Curry’s blog. I have asked him what his scientific education level is and he said that it is HVAC training at the equivalent of a VoTech school, as I recall. I know that shouldn’t matter, but that is a fact and education level does serves as a prerequisite for many functions in the real world.
I study skeptical behavior as a hobby, partly because my advisor’s advisor was Professor Robert Park, who is renowned for writing books such as “Voodoo Science” and that is what got me interested in these skeptical blogs in general. Trying to figure out skeptics such as Cap’n D is interesting, but also frustrating, and so if I have offended anyone I am sorry.
> I think it is essentially that the entire ocean would warm at the same rate.
I rather think that Cap’n suggests that there may be some heat exchange that we ignore and that it may matter. We just don’t know for sure. It’s just that we have evidence that it could be possible.
Never underestimate the power of indefiniteness. This is what powers plausible deniability. If care is not taken regarding what Cap’n says or not, this will turn into what Cap’n hasn’t said, and then how alarmists can’t read. Et cetera.
And then there’s no physics, but ClimateBall ™.
BBD –
Can you explain your use of terminology here (apologies in advance for my ignorance)?
~800ka
As near as I can gather you should be talking in units of time there, but as I understand it, ka is a chemistry term? Do you mean that he has stated that there has only been permanent Antractic ice coinciding with a specific chemical composition, and that such a statement is wrong? If so, why did you link that graph you provided?
Cap’n –
I don’t want to pile on here, but at some point I would appreciate it if you could clarify your response to BBD’s comment about your statement on Antarctic ice. I wouldn’t conclude from this one issue that you are therefore not worthy of attention (anyone who appreciates bacon has to be worth at least some attention), but it would be nice to have some simple clarification.
No need to get into a very technical explanation or rehashing of events (too much potential for subjectivity there) – just a simple yes or no: Has there only been permanent Antarctic ice for ~800ka?
>Try to ask him what his atmospheric “reference shells” are all about.
This has been done in the exchange referenced earlier. Cap’n responded by appealing to Nick Stokes’ work, then to a post at Gavin’s. I don’t recall what happened afterwards, but I don’t think it was that definitive.
I’m on my tablet right now, and this is my last vacation day. I might have less time this autumn.
Thank you for the kind words earlier, Web. I trust you mean well. It’s just that you’re making a strategical mistake. When you have the advantage, play like you’re winning and you will.
Let’s generalize Occam’s razor: in ClimateBall, don’t seek unnecessary complications.
BBD –
DId you mean at ~800ka (instead of “for”) and the graph shows a time period, where the chemical composition was different, that coincided with permanent Antarctic ice?
OK, let’s try it with this statement by Professor Corey:
How do you show that Corey’s statement doesn’t make sense? Even though he is mixing mechanical concepts (“inertia” and “centripetal”) with chemical (“catalyst” and “catalytic agent”), he could be talking metaphorically. It is also a non-sequitor, but that could be a fragment of thought. Yet we know that it is Corey saying this and thus it is patent nonsense.
To try to parse similar comments by Cap’n out of Good Faith takes an enormous amount of time, and we still don’t know whether Captain’s intent is just to lead us on down a rabbit-hole, ala a redneck version of punk’d aimed at us gullible scientists. The evidence is all there.
Do people really enjoy being punk’d? Especially when we treat the subject as seriously as some of us do?
Joshua
ka = kiloyear. Standard abbreviation for eg. ‘800,000 years ago’.
The graph is Caps. I think you may be looking at the wrong comment.
BBD – thanks.
> It is also a non-sequitor, but that could be a fragment of thought.
Non sequirurs are everywhere. Even in deductions. Which we seldom have in empirical sciences.
This is a bug, but also a feature. Contrarians exploit such deductive gaps all the time. This is why winning ClimateBall games is about logic more than facts.
But logic ain’t enough. One must put forward arguments with eirical content. The name of the game is to be able to substantiate the claims made.
So the winning strategy ought to be two-fold. First, render the logic explicit in a way that the gaps are rendered obvious. Second, provide an evidence basis that shows how weak alternative explanations are.
It would be tough to catch Cap’n saying an untrue claim. He’s not claiming anything specific. There’s no need to claim anything to undermine or show the limits of established viewpoints.
The main difficulty is that science process via the best explanation. If Cap’n has nothing to offer, what he criticizes stays on the table. If every time Cap’n tries to undermine the mainstream views they are reinforced and clarified and substantiated, he’ll never won the arms race. In fact, communication channels get cut, usually, as Cap’n now has something to lose: the race to the most plausible explanation.
The only way to win is for him to act in a way that food fights ensue and insecurities get exposed.
==> “The only way to win is for him to act in a way that food fights ensue and insecurities get exposed.
Win?
Besides BBD’s example, one of Cap’s favorite Climate Etc arguments is to invoke the fact that the average temperature of the entire ocean is meaningful in terms of radiative equilibrium. And that this somehow defines the eventual surface temperature. Try to figure this one out:
Yet as AT said, only the surface temperature and albedo is important to defining the radiative flux. So then when Cap’n also talks about “reference shells” in the atmosphere, we have to wonder if this is all just intentional random word-salad on his part. He definitely exploits his HVAC knowledge, but more out of being able to flippantly twist the terminology to increase FUD than at getting at some objective truth.
WHT –
==> “and we still don’t know whether Captain’s intent is just to lead us on down a rabbit-hole, ”
FWIW, that possibility doesn’t seem very plausible to me. I think that he thinks he is right and that he makes sense and that he is providing a more valid interpretation of climate science.
For your speculation to be true, he would have to be so selfless that he is willing to spend gobs of time exposing himself to looking foolish, just on the off chance that he might fool some equally invested participant in the debate who has an alternative perspective. Have you ever seen Cap’n convince anyone to change their view on anything through these online discussions? I suspect not. It’s theoretically possible that he might invest so much time in such a futile effort, but doesn’t seem likely to me. It’s not like he’s making simplistic arguments like “CO2 is a trace gas” on websites that are populated by relatively less interested non-climate fanatics.
And anyway, as a general rule, IMO, interpretations of intent are pretty unscientific w/o enough evidence to pass a necessarily high bar of evidence. Why not just leave it at arguments that refute what he says at a highly technical level for those who can follow those arguments, or try to explain the faultiness of his thinking for observers like me? Who do you hope to reach by your rhetorical flourishes? (Although I have to agree that they are amusing at times). What is your goal? They won’t convince anyone who already agrees with you on a technical basis. And they don’t create a convincing argument for those who don’t. They only possible way to get a solid outcome, IMO, is to explain the flaws in his reasoning in ways that those who haven’t already come to a technical conclusion might benefit. Do you own Jell-O stocks?
> only the surface temperature and albedo is important to defining the radiative flux.
Why?
Never mind the FUD, push your own peanut, dammit!
If there’s mainly bashing, then there’s no significant physics.
TBC, and this may or may not be what Web means, my Gish Gallop judgement is based on Cap’s habit of providing a (wrong) answer but then (this is the GG part) adding a further claim. IIRC this is the technique as Duane Gish practiced it, since simply refusing to answer any questions outright doesn’t look good to an audience. To the extent possible he would try to cast the new claim as a meaningful answer, which Cap also does. As the latter speaks in lark-taking generalities and does seem to be happy to go on endlessly, where does it end?
Psychoanalyzing him as an individual isn’t going to be interesting, as there’s no means of establishing sincerity or the lack thereof. FWIW I think the smart money is on some variety of insincerity.
You misunderestimate the thought process of a self-identified redneck.
Why, oh why, would a redneck pay money to outfit his truck as a “coal roller” ?
Why would they want to expose themselves to look so foolish?
The old notion of knowledge is a true and justified belief. We might have a hard time arguing directly for truth. So what’s left? Expression of pure beliefs, or justifications.
This ain’t postmodernism talk:
http://plato.stanford.edu/entries/logic-justification/
Providing justification is the only way to win in a decent time span.
Would we rather spend time justifying not to trust Cap’n, or to justify everything that follows from and then there’s physics?
The motto of the redneck is that they do stuff because they can. Thus, rednecks that self-identify as such are also the ones that are the coal-rollers, thumbing their noses at the rest of society.
My guess is that Cap’n comes up with is odd-ball arguments because he is thumbing his nose at dedicated scientists.
How many other pranksters are out there on the interwebs that contribute word-salad to blog commenting sections just because they can, and no one is stopping them?
Consider that Australia have their own version of the redneck, called the Larrikin. And these guys are very busy on the krank landscape, way beyond what the base population would predict. How else do you explain their numbers? It’s almost a cultural thing.
“That’s not a knife … THAT’S a knife”
“That’s not a theory … THIS is a theory”
==> “My guess is that Cap’n comes up with is odd-ball arguments because he is thumbing his nose at dedicated scientists.”
I have noticed that he seems to have a chip on his should against credentialed academics.
ATTP, “However, energy transport to the deep ocean is diffusive and therefore slow.”
Nope, diffusion is only a small part of heat transfer in the oceans. There is surface mixing due to wind stress and the THC is due to a combination of thermal, density and mechanical processes. Actual heat transfer and how it impacts “average” ocean temperature is a complex fluid dynamics problem. The process is “slow” but not constant. A variation of possibly 30 million cubic meters per second THC flow would have roughly the impact of a Gulf Stream flow. That would be a 15% change in the ACC.
Now if the “actual” sensitivity of climate to a doubling of CO2 is “High” and the mixing “slow” enough, you could assume it is negligible, but the lower sensitivity is and the faster the mixing changes are, the less likely that assumption is valid. 300+ years for 0.8
C is “slow”, but appears to be relevant to climate change.
The rest of your comment is correct, I am simply using a different frame of reference and time scale that better matches ocean paleo data.
Cappy said:
What on earth do you think that vertical eddy diffusion is?
I have had this discussion many times with Cappy, and he still doesn’t seem to get that diffusion is simply a random walk model of a physical phenomenon. The mixing itself could be a random walk of a set of eddy currents randomly pushing surface-heated water up and down.
This gives an effective ocean thermal diffusivity of 1 cm^2/sec, which is that of copper. This is more than enough to move the heat downward. This number for diffusivity is what Hansen used in his 1981 paper and it is still operable.
Cap,
But that’s kind of the point. If climate sensitivity is low and if vertical mixing is fast then …..
ATTP, “But that’s kind of the point. If climate sensitivity is low and if vertical mixing is fast then …..”
Then you can have a can of worms comparing fast response, GMST to slow response, Paleo reconstructions. The ocean frame of reference would naturally smooth response which would be more indicative to actual internal energy changes.
Based on the 1250km interpolated GISS and the new C&W GMST reconstructions, very low temperature anomalies are providing a good deal of the GMST increase. When you use extreme temperature ranges, the “average” temperature can have less information about the “average” energy. In thermo, absolute temperatures are needed to determine efficiencies and “average” absolute surface temperatures are not very well “projected” by the models. THAT tends to be handwaved away by many, but it should be another clue.
Like due to rapid vertical mixing, the warmest parts of the ocean have a flat to declining trend in “surface” temperature. There would be a roughly 8 year lag as the bulk layer settles and then a longer lag while the bulk layer equalizes with the deeper oceans. The 30S-30N region of the oceans represent the majority of “surface” energy. So do you “project” based on more highly variable lower energy anomalies or the bulk of the energy?
I go with the majority of the energy and the IPWP is a pretty fair proxy for it.
Cap,
But considering the past 50 – 100 years, it appears that surface warming is associated with a few percent of the planetary energy imbalance. Ocean warming is associated with about 93%. Now consider that anthropogenic forcings could rise by a futher 6 Wm-2 by 2100. Ask yourself how much bigger the fraction associated with ocean warming would need to be to avoid surface warming being higher than – on average over the next 95 years – 0.1oC per decade.
Similarly, you could ask what would be the largest planetary energy imbalance that we could sustain without surface warming exceeding 0.1oC per decade if we follow a high emission pathway (an increase in anthropogenic forcings of 6Wm-2 by 2100).
I think that if you considered both of these scenarios, it precludes the oceans being such a large heat sink that it can significantly reduce the rate at which we’ll warm over the coming century if we follow a high emission pathway.
ATTP, “But considering the past 50 – 100 years, it appears that surface warming is associated with a few percent of the planetary energy imbalance. Ocean warming is associated with about 93%. Now consider that anthropogenic forcings could rise by a futher 6 Wm-2 by 2100. Ask yourself how much bigger the fraction associated with ocean warming would need to be to avoid surface warming being higher than – on average over the next 95 years – 0.1oC per decade.”
Yep, if you consider the past 50 to 100 years it would appear that sensitivity is high. Consider the past 120 years, a little lower. The problem with “surface” temperature though is that isn’t a very great indication of change in energy. If you had dew point temp to go with the dry bulb, then you would have data sufficient to come to a reasonable conclusion without adding more assumptions to the list. SST is better, not ideal by any stretch, more more indicative of energy. “Average” ocean energy is a great indication of change in energy, but the time constant sucks. Nothing is perfect so you have to use as much as you have to make an intelligent estimate.
You can redo that with any data set you like, but I used GISS and ERSSTv3b with the Oppo 2009 IPWP. If you are a glass half empty kinda pep, pick the valleys and publish. A glass half full kinda pep, pick the peaks, but using CO2 as a reference, your “sensitivity” is going to indicate what you think is “normal”. 1.1 TCR indicates that the 20th century mean is about equal to the Oppo2009 2000 year mean and about equal to “pre-industrial”. Since the 1250km GISS interpolation includes more low humidity, low temperature regions, it indicates increasing temperature, but not more energy stored. Now if you fit the CO2 reference to the baseline trend of your data set, you can get a rough estimate of “natural” versus anthropogenic since for some reason anthropogenic has come to mean carbon, a lot of possible anthro influences are lost in the mix.
“I think that if you considered both of these scenarios, it precludes the oceans being such a large heat sink that it can significantly reduce the rate at which we’ll warm over the coming century if we follow a high emission pathway.”
Using “Average” ocean, the oceans are not a heat sink but a thermal reservoir. The heat sink for the oceans is the poles where mixing efficiency determines how much goes into the reservoir and how much is lost to the sink. One reason I use 60s-60n for SST is because that is typically sea ice free. Sea ice covered ocean is part of the sink and if you compare 90s-60s and 60n-90n SST you can see how the efficiency differs and tend to get out of phase. That is what drives the ocean oscillations along with the shift in wind patterns. That is a bit of a chicken egg situation though.
Cap,
Sure, but the “surface” temperature determines our energy balance.
ATTP, “Sure, but the “surface” temperature determines our energy balance.”
Which surface? The current “surface” temperature is a mixture of 70% ocean subsurface temperature measurement and ~30% land above surface measurement. The “radiant” surface of the oceans has a little more to offer. That surface varies considerable with surface wind velocity. Increased surface wind velocity would increase evaporation in addition to cooling the skin layer.
ERSSTv3b is revised by not using satellite observations since they tend to run cooler due to additional water vapor. However, a “space view” of the “surface” should be more relevant to atmospheric CO2 forcing. With the poles as a heat sink, the radiant surface would vary with the location of the higher energy regions which are often inversions. There is no “prefect” metric, so if your results rely too heavily on one, and one that changes with each revision, there might be more involved.
Cap,
The radiation we emit into space, comes from the surface and is set by the surface temperature. Of course, as you say, it is a complex mixture of land and ocean, but ultimately we will tend towards a state in which emit enough energy from our surface so that the amount that escapes into space matches the amount that we receive. If our surface temperature is lower than this, we will emit less and we will warm. If above, we’ll emit more and we will cool. Of course, overall energy balance will require that the entire system is in equilibrium, but that doesn’t mean that the entire system will warm at the same rate (which is what you seem to be suggesting).
If we continue to emit GHGs and increase the anthropogenic forcing, the only way to retain energy balance is for the surface temperature to increase. The rate at which it does so will determine the total amount of energy that we accrue. The point that I’m trying to make is that if you consider the well-mixed layer of the ocean (upper hundred metres), the land/atmosphere, and the poles, the surface is typically associated with absorbing a few percent of the energy associated with the energy imbalance and it seems unlikely that this energy imbalance can be much greater than 1 Wm-2. Therefore, if we know our emission pathway, we can estimate the rate at which the surface will warm. The idea that the deep oceans can accrue energy at an ever increasing rate so that the surface warms very slowly for the next 100 years seems physically implausible.
I have no idea what you’re getting at in your second paragraph, though.
ATTP, “If we continue to emit GHGs and increase the anthropogenic forcing, the only way to retain energy balance is for the surface temperature to increase.”
With diurnal and seasonal variation there has to be some surface capable of retaining heat for long enough to be significant. That would be primarily the oceans. The lower thermal capacity land mass would warm with more direct forcing and ocean land transfer. The atmospheric boundary layer could also rise to compensate for the increased latent. How all that averages out would determine what happens to the “surface” temperature.
“I have no idea what you’re getting at in your second paragraph, though.”
ERSSTv3b is revised by not using satellite observations since they tend to run cooler due to additional water vapor. However, a “space view” of the “surface” should be more relevant to atmospheric CO2 forcing. With the poles as a heat sink, the radiant surface would vary with the location of the higher energy regions which are often inversions. There is no “prefect” metric, so if your results rely too heavily on one, and one that changes with each revision, there might be more involved.
Determining a “surface” temperature isn’t all that easy. Now that we have more satellite data, that has to be integrated with the pre-satellite data and the “surface” used as the baseline 288K and 255K reference has to be sorted out. Satellite data in general indicates a lower rate of warming which is problematic for higher sensitivity enthusiasts. ERSST originally used the satellite SST in their optimal interpolation version, but stopped once the two methods started diverging. Now C&W are using satellite data for interpolation (kriging) and getting a higher temperature response mainly from Arctic winter warming events where early data is very sparse because no one was all that excited about living through extremely cold Arctic winters on purpose. If you are going to compare long term records you need to keep consistent long term records, not muck about revising methods while forgetting about the ones that got you to this point.
With kriging, interpolating the poles has two major issues, first the poles are unique as in a corner, meaning there is no good way to krige the poles. Second, the extremely lower temperatures and humidity causes a great deal of out of phase warming/cooling that shouldn’t have the same weight as a warmer more humid regions. The temperature has to reasonably well represent energy or the zeroth law of thermodynamics will bite someone.
Cap,
It doesn’t actually matter whether or not we can determine what the surface temperature is. My point is very simply that as we continue to increase anthropogenic forcings the surface temperature will need to rise so as to increase the outgoing flux and move us back towards energy balance.
ATTP, “It doesn’t actually matter whether or not we can determine what the surface temperature is.”
Ah, but it does. Your 288K ~390 Wm-2 reference surface and your 240 Wm-2 ~255K radiant reference surface are assuming that the energy associated with the references directly relates to an ideal S-B temperature and vice versa. There can be a large difference between the two. You are correct that continued increase of CO2 would increase the “surface” by some amount, but your “surface” is poorly defined. At some point latent surface cooling could almost completely offset GHG “warming”. Remember that 288K versus 255K assumes no or positive feedbacks only which is an ideal response. Ideal models tend to provide bounds not accurate estimates, in thermodynamics anyway.
Cap,
Not if we want to simply know whether or not it will warm if we increase anthropogenic forcings.
Again, no. Given the amount of energy we receive, we will radiate the same amount of energy as a 255 K blackbody if we are in thermal equilibrium. Of course, our actual spectrum is not a perfect blackbody, but that does not change the we will radiate the same amount of energy as a 255K blackbody.
What? The 288K surface temperature is a consequence of positive feedbacks. How else can the surface be so much warmer than the effective temperature?
It seems to me that you’re playing the “it’s really complex therefore we don’t know anything” game. Of course, reality is more complex than the simple physics I’m using here, but these are still reasonable representations.
CD,
The temperatures 288 K and 255 K are both calculated from observations. They tell about the real Earth. There’s no need to assume anything about the feedbacks. They are, however, values produced by the real mechanisms of the real Earth with all the feedbacks that the real Earth system has.
ATTP as an example, your 288K 390 Wm-2 surface also includes about 90 Wm-2 of latent cooling and about 20 Wm-2 of convective cooling. You could determine an “effective” temperature based on 390 + 90 + 20 = 500 Wm-2 which would have an ideal S-B effective temperature of 306 K degrees. That would provide another bound for your estimates. Kimoto tried to provide a simple explanation but was generally dissed by the powers that be.
http://multi-science.metapress.com/content/8r0352171238x3v4/
Finding an exact solution for a planetary scale problem could be a little complicated.
Pekka, “The temperatures 288 K and 255 K are both calculated from observations. They tell about the real Earth. There’s no need to assume anything about the feedbacks. They are, however, values produced by the real mechanisms of the real Earth with all the feedbacks that the real Earth system has.”
If the current models were performing better I would agree. They aren’t so I look for reasons why. Now since Hansen has said that 288K is more likely 287K and Stephens et al indicate an uncertainty of +/- 17.0 Wm-2, I guess I am a touch more skeptical that some.
ATTP, “What? The 288K surface temperature is a consequence of positive feedbacks. How else can the surface be so much warmer than the effective temperature?
It seems to me that you’re playing the “it’s really complex therefore we don’t know anything” game. Of course, reality is more complex than the simple physics I’m using here, but these are still reasonable representations.”
No I am playing the there are other frames of reference allowed to verify estimates. You can get reasonable estimates without having to solve every complexity, but you should never forget that that complexity exists.
Cap,
Sorry, I’m not following what you’re getting at at all.
So what? Really, we’re discussing whether it’s 287 or 288?
This has nothing to do with current models. This is just the greenhouse effect.
Of course, but using complexity to argue against something is a bit tedious.
ATTP, then I am afraid you are married to a theory. The goal should be to more accurately predict the impact not declare that there will be an impact. Since we are anticipating a 3.7 Wm-2 impact, +/- 17.0 Wm-2 should be considered. Hansen’s 287 instead of 288 would be about 7.5 Wm-2 if you consider latent and convective.
Cap,
I think you’re simply muddling up different things there. The +-17 Wm-2 is not the uncertainty in the radiative influence of doubling CO2, it is variability in the surface flux. The Hansen number is presumably some sense that we can’t be sure what the actual surface temperature is to within a degree, but that doesn’t mean that adding CO2 won’t warm us. Whether a reasonable average surface temperature is 287 or 288, 1 degree warmer is still 1 degree warmer.
CD,
The flux from the surface to the atmosphere is what the atmosphere can take, and then release to space. That’s the only way of determining the flux in practice, and that’s the state that will be reached rapidly after all changes in conditions.
Pekka, right, but the flux from the surface to the atmosphere is ~ 390 +/- 7 plus 88 +/- 10 plus 20 +/- 5, it is not 390 plus or minus zero. It can be very tedious actually solving a problem. The ocean “average” energy is just another reference with different issues.
Cap,
where does this come from?
ATTP, “The +-17 Wm-2 is not the uncertainty in the radiative influence of doubling CO2, it is variability in the surface flux. ”
Right and the surface flux and radiative influence are supposed to be in a conditional steady state or “assumed” to be effectively in equilibrium. If you “pick” different initial conditions you will get different answers.
ATTP, Where?
http://curryja.files.wordpress.com/2012/11/stephens2.gif?w=500&h=241
I was going from memory but there is one of the sources.
Wrong link,
That should look better.
Cap,
Okay, I’ve worked out where your numbers come from. Firstly the only one of those associated radiatively with a temperature is the 390 +- 7 Wm-2. The other two are energy fluxes, but are – I believe – associated with convection. That’s why, I think, the lapse rate is not the dry adiabatic rate.
Noone’s claiming it has to be in exact equilibrium all the time. It will tend to equilibrium and will vary about equilibrium.
I don’t follow this. This isn’t the start of a “but chaos” argument, is it?
Cap,
I think what you’re getting wrong is that if we didn’t energy into the atmosphere through thermals and latent heat of evaporation, the lapse rate would be steeper and the surface temperature would be correspondingly higher.
ATTP, the predicatable lapse rate starts above the atmospheric boundary layer which is a surface but not THE surface. How co2 forcing impacts THE surface is the question.
“I don’t follow this. This isn’t the start of a “but chaos” argument, is it?”
Chaos is an interesting subject but IMO depends more of the level of precision you desire than anything else. You can create a chaotic problem, which is one of the reasons Thermodynamics allows the use of difference frames of reference. I am more about old school efficiency and instability which you can call anything you like. Which is why I mention the model ensemble mean. That is data that should be used. They are running higher than “projected”. Why? That is kind of the whole object of models.
Cap,
Really? The entire troposphere has – on average – a vertical temperature profile set by the lapse rate. It’s not always precisely the same everywhere, but – on average – its about 7 K/km. If it were the dry adiabatic rate, it would be 10K/km. The point I’m making is that your thermal and latent heat fluxes are indicators that the vertical temperature profile is shallower than the dry adiabatic lapse rate.
Remind me of the topic of the thread again?
VTG,
I’m a bit lost myself.
ATTP, “Really?” yep, just add water and you can change the surface temperature. Since that water is dependent on actual absolute temperatures you have an old school thermodynamics problem at the “surface” where radiant energy takes a smaller role. “Natural” or unknown warming from the past would impact the water cycle and would be hard to separate from “radiant” forcing. Use a slower moving frame of reference, “Average” ocean energy, you have less noise to deal with.
Now since the models tend to predict tropical tropospheric hot spots and most data shows no indication of a hot spot, there is likely something missed. That could likely be to the inversion above the troposphere and advection of O3 and H2O by brewer-dobson circulation. The dry adiabatic lapse rate is an ideal model that basically provides a limit. The “weather” that changes in the troposphere is pretty much chaotic, so if you want a chaos problem there is your opportunity.
All models are wrong. It’s just such a shame they’re also useful.
http://www.skepticalscience.com/tropospheric-hot-spot-advanced.htm
The topic is the 50%-50% estimate. One of the 50% would be something other than CO2 equivalent forcing. That be “natural” variation or simply limits in the accuracy of the combined assumptions. Dr. Curry generally uses the Italian flag and has region set aside for unknown unknowns.
From the post “The feedback response to the natural warming is quite a bit smaller than the Planck response due to the natural warming. This would seem to make long-term natural warming quite difficult. Presumably natural warming can only be long-term if the feedback response exceeds the Planck response.”
Water vapor feedback is considered to be twice the CO2 forcing and is dependent on absolute temperature. How can “natural” warming impacts be considered “small”?
How can “natural” warming impacts be considered “small”?
Well, ATTP asserts they must be so unless feedbacks are > Planck feedback, an argument based on energy conservation.
The only way around that is that energy is being transported to the surface from somewhere else. The only credible candidate for that is the ocean.
Remind us what’s happening to ocean heat at the moment?
Cap,
The feedback is a response to the change in temperature due to anthropogenic forcings.
You’ve been quite pleasant and polite, but this is starting to verge on denial and I really have no great interest in such discussions. You can believe whatever you like, but I don’t really want to waste too much more of my time.
“The feedback is a response to the change in temperature due to anthropogenic forcings.”
Spoken with authority. Land responds differently to anthropogenic forcing than ocean. Difference the land surface temperature from the ocean SST and what to you get? There is an indication of atnthro as there should be, but is it “all” due to anthro?
vtg, “Remind us what’s happening to ocean heat at the moment? ”
It is increase at a rate that would produce about 1 C of warming in about 400 years provided all things remain equal.
Ok capt, so we agree that current warming is not driven by natural heat release from the oceans
We also seem to agree that the very high feedbacks to temperature fluctuation necessary for spontaneous warming don’t exist.
So I guess we also agree that the warming is, in fact forced.
The only remaining point at issue is the source of the forcing. Do you have anything other than anthro to suggest?
vtg, “The only remaining point at issue is the source of the forcing. Do you have anything other than anthro to suggest? ”
Actually, there is “other” anthro that is likely to be more significant that estimated along with the decreasing LIA recovery. LIA recovery is of course nearly forbidden as a topic, but I find “assuming” it magically stopped circa 1900 or 1950 a bit odd IMO. CO2 equivalent forcing provides as good a reference as we have and depending on your choice of temperature reference indicates a range of sensitivity from 0.8 to about 2.6. The 2.6 though has a caveat related to the absolute versus anomaly issue. Arctic winter warming from -35C to -25C is unlikely to trigger any water vapor feedback. So while anomaly is very helpful, it has limits that have to be considered in a real world thermo problem.
Capt,
Sorry, absolutely no idea what your last post was about. We agree:
– not oceans
– not high sensitivity
– must therefore be forced
So,what are possibilities for changes in forcing?
Other than anthro, of course.
Capt,
It’s not forbidden, it’s just silly. If you have a physics background, you can work out why.
Shame that you all got sucked into Cappy’s self-described version of “Redneck Theoretical Physics”. This is a world that only he can communicate in, and everyone else is left twisting in the wind.
He fits in quite naturally at Judith’s blog, but not here.
Cap may have a units conversion problem, amongst others.
“The 0-2000 m layer of the world ocean has warmed by ~ 0.09°C (~ 0.16°F) [24.0±1.9×1022 J] during 1955-2010.
For perspective, if all the heat stored in the world ocean since 1955 was instantly transferred to the lowest 10 km ( 5 miles) of the atmosphere, this part of the atmosphere would warm by ~ 65°F.
This of course will not happen. It is simply illustrative of the amount of heat stored in the earth system since 1955.”
— Levitus et al. (2012), GRL.
ATTP, “It’s not forbidden, it’s just silly. If you have a physics background, you can work out why.”
I look forward to being corrected. The reason I used Oppo2009 is to estimate the time constant for recovery. Unfortunately, there appears to be volcanic influences that are slightly more significant than typically given credit and solar TSI reconstructions are going through a bit of a controversial time. The Oppo2009 reconstruction still roughly fits a weakly damped response and matches well with instrumental up to its termination in 1955. There are a few newer papers that are looking into long term memory and long term persistence which could easily exhibit a weakly damped recovery curve.
Pirates.http://openparachute.files.wordpress.com/2011/02/skeptic_forcing1.png
Capn,
back on topic…
We agree:
– not oceans
– not high sensitivity
– must therefore be forced
So, what are possibilities for changes in forcing?
vtg, “– must therefore be forced
So,what are possibilities for changes in forcing?”
You seem to misunderstand me. Response would be forced but when is a issue when it takes hundreds of years. That “silly” little LIA recovery issue might take a while to settle out.
Also anomaly is not always a good indication of energy. So while there is forcing, the response may not be all that easy to measure. So there is CO2 equivalent forcing of ~3.7 Wm-2, Black Carbon forcing beginning long before 1900, land use impacts most specifically those that impact the water cycle.
So what happens to be your best guess of TCR?
This is exactly what happened whenever I asked Cappy an awkward question. IMO it is not acceptable.
Capn/BBD,
yup, that’s me done.
We agree that internal variation isn’t an explanation; you wish to posit a change in forcing form LIA (say 2-300 years ago) caused 0.4 degrees of temperature rise over the past 60 years.
That’s not credible; we could call it “extremely unlikely”!
VTG, I tend to believe that 0.4 C is unlikely, but barely. Most of my estimates are in the 0.2C to 0.3 C range, but that really depends on what temperature series you use. Surface air temperature has a lot more variability with some antiphase over/undershoots, so by using 60s-60n SST I get a more stable reference. That requires more work to estimate “global” impact, but land tends to have about a 2 times amplification factor. How you estimate sea ice is also up for grabs.
Here is a paper that might help you see where I am coming from.
Click to access stenchikov_jgra_2009.pdf
Unfortunately, volcanic, solar and paleo are all a bit sketchy, but the GFDL appears to be making some head way.
Greg Laden has a nice little takedown of Judith’s latest rant [ Fraudulent(?) hockey stick] against Michael Mann .
Curry has a habit of inserting a (?) which she thinks apparently absolves her of any responsibility. Ain’t that special (?)
Yet, sometimes I think that everyone may be getting punk’d. Listen (?!?) to this from Curry’s commenter with the initials B.S.
In a world of odd, this left me dumbfounded.