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Comments 29651 to 29700:

29651. TheCheshireCat at 06:07 AM on 19 May 2015
       Inoculating against science denial
       

       Bland Denial is merely one component of the strategy first published by Peter Clyne in "How not to pay your debts - a handbook for scoundrels". Clyne proposed that successful evasion (of scientific truth, or obigations, or indeed debts) required these 4 steps: Deny, Delay, Confuse, Part-Pay (in an endlessly recurring sequence with slight amendments for each recycle). For example:

       1. Deny: (climate change is a myth)
       2. Delay: (More research is needed, wrong to act precipitously)
       3. Confuse: (Climate change is multifactorial, therefore wrong to focus on one single cause)
       4. Part-Pay: (okay climate change is here, but its not man-made)

       Spice this up with some crooked language and logic, as Cook suggests, and there you have it. Add to this industry sponsorship of scientists and regulators to add some much-needed bias, and, well, here we are.

       I'm reminded of the Upton Sinclair quote: 'It is difficult to get a man to understand something, when his salary depends on his not understanding it.'

       Alice.

29652. Tom Curtis at 06:05 AM on 19 May 2015
       Breathing contributes to CO2 buildup
       

       Art Vandelay @38, any carbon in animal matter has first existed as carbon in plant matter.  Any carbon in plant matter was in turn first extracted from the atmosphere by photosynthesis.  The food chain may be extended in that, for instance plants (planckton) may be consumed by carnivorous planckton, which may in turn be consumed by planckton eating fish, that may be consumed by low level carnivous fish, that may be consumed by a top predator like Tuna, that may in turn by consumed by humans - but that does not alter the fact that every molecule of carbon in humans was first extracted from the atmosphere by photosynthesis (ignoring plastic based prosthetics).  Therefore your argument fails because it reverses the logical order of the process, assuming in effect that the CO2 in humans comes into existance by a creative act and needs to be then, later extracted by photosynthesis.

       Given this, there are only two ways that human respiration can increase atmospheric CO2.  The first is if the whole cycle ceases, so that CO2 respired is not then taken up by plant matter.  The second is if the whole cycle changes its time constants so that the carbon in the cycle spends relatively less time in biomatter and relatively more time in the atmosphere.  For both of these, because they involve the whole cycle and not just human consumption it is not particularly appropriate to look at it in terms of respiration.

       Of the two methods mentioned above, it is known that the first is not occuring.  The second, however, is occuring, but is already accounted for in carbon budgets under the label of Land Use Change (LUC).  Land Use Change, however, includes a large number of inputs in addition to changes in the relative rate of respiration.  It includes, specifically, deforestation for the timber industry; and deforestation for land clearing (in which the timber is simply waste, and does not enter the human carbon cycle).  These components dominate the LUC budget, so it is not possible to extract from the LUC figures any meaningful estimate of the change in relative times of carbon in the atmosphere from those figures (SFAIK).  

       One thing that is known, however is that net biosphere productivity is a sink for CO2.  That is, once you add up all of the effects of deforestation, changes in agricultural practises, growth of urban areas, draining of swamps etc, and subtract from that the effects of increased plant growth due to increased humidity, the fact that human timber is better protected from decay than natural equivalents, (and hence precipitation) and any carbon dioxide fertilization effect, the total biosphere is absorbing more CO2 from the atmosphere than it is emitting.

29653. Phil at 04:35 AM on 19 May 2015
       Breathing contributes to CO2 buildup
       

       KR @39
       

       Now, if a population increases, there is a corresponding sequestration of carbon in biomass - and in that fashion the 7 billion people on the Earth represent a carbon sink, not a carbon source.

       But this may be offset by a decrease in other animal populations. Admittedly the rise in human population may have also produced a concomitant rise in domestic animals, however the population of wild animals has crashed over the past century. The population of non-photosynthesising organisms is dependent on the population of photosynthesising ones, and that in turn is dependent on the land mass available to them, along with the "ingredients" for photosynthesis. Of course land use change (specifically de-forestation) has been a significant carbon source, offsetting any increase in other forms of biomass.

29654. KR at 02:25 AM on 19 May 2015
       Breathing contributes to CO2 buildup
       

       Art Vandelay - "...the fact that we're net emitters (of CO₂) rather than net absorbers of it, unlike plants"

       Um, No. Aside from our fossil fuel emissions any stable population of organisms is carbon neutral, as the carbon in them comes from the environment and upon death returns to the environment. While carbon-containing food comes from the environment and is itself cycled back as (among other things such as fertilizer) CO₂. 

       Now, if a population increases, there is a corresponding sequestration of carbon in biomass - and in that fashion the 7 billion people on the Earth represent a carbon sink, not a carbon source. Breathing, however, is simply not a net cause of rising CO₂. 

       But then we go and burn fossil fuels that have been sequestered for hundreds of millions of years, and we go straight from carbon neutral to immense net emitters... sigh.

29655. bozzza at 01:43 AM on 19 May 2015
       Monthly global carbon dioxide tops 400ppm for first time
       

       I've always wanted to know if this would work...

29656. Art Vandelay at 01:09 AM on 19 May 2015
       Breathing contributes to CO2 buildup
       

       RJS

       I liked your water baloon analogy.

       The debate in some of the climate threads in cyberspace over whether the respiration of 7 million human inhabitants adds significantly to AGW is obviously alive and well, particularly among skeptics. 

       On the face of it the total emissions from animal respiration are considerable but of course we know that the carbon cycle is also a closed system.

       Having given this some thought though I'm of the view that respiration from 7B people must increase atmospheric CO2 if for no other reason than the fact that we're net emitters rather than net absorbers of it, unlike plants. 

       To maintain an equilibrium it's obviously necessary for respired CO2 to be offset by photosynthesis in plants, which requires us to grow synthesising plants at the same rate that we're consuming them.  We all agree on that I'm sure.  

       However, the net effect is to amplify the carbon cycle in much the same way that higher tropospheric temperature amplies the water cycle.

       In the same way that the atmospheric transportation of water increases with temp so too does the transportation of CO2 into the atmosphere from increased animal respiration, resulting in an increase in the static level of atmospheric CO2 that's proportional to the population.   

       Since the laws of physics can't be broken the only way that this is possible is by converting O2 into CO2 and by transporting sequestered carbon (from trees and plants) into the atmosphere. Although humans grow crops to maintain the equilibrium they've needed to remove existing trees and plants to accomplish it, so effectively the amount of carbon that's stored in plants must have decreased as population has increased.  

       To what measnureable extent humans contribute to an altered ratio of OC and CO2 in the atmosphere is impossible to measure but I'm sure that it's dwarfed by CO2 borne from fossil fuels, but nonethless I don't think we can or should claim that human respiration from 7 billion people does not increase atmospheric CO2 to some degree.

29657. CBDunkerson at 22:38 PM on 18 May 2015
       Monthly global carbon dioxide tops 400ppm for first time
       

       chriskoz, aviation accounts for ~2% of emissions. Adding in the few categories of large ground vehicles which require an energy density that only fossil fuels can currently deliver might raise it to 3%. Thus, while I agree that we will likely continue to see some fossil fuel use for decades to come, I stand by my prediction that the peak of fossil fuel usage is less than a decade away.

       Indeed, China may have already turned the corner. India and the rest of the 'developing world' countries which had been driving increases the past couple of decades aren't far behind.

       Obviously, it will take time to replace the existing fossil fuel infrastructure with renewables, but we are very near (possibly even past) the turning point. Total CO2 emissions basically held steady last year despite global GDP growth. Trends so far this year suggest that CO2 emissions may well drop.

       We talk about environmental tipping points, but such things also exist in politics and economics. We are very close to the point where renewables finish supplanting fossil fuels as the darlings of the global economic and political castes. Soon they will be growing not just because they are better, but also because they will be propelled by the same forces which have thus far been deployed to hold them back.

29658. MA Rodger at 22:18 PM on 18 May 2015
       Models are unreliable
       

       Klapper @923.

       You conclude "So both the TOA spread from model to empirical and the SAT warming rate spread agree the models look to be running too hot." but your inclusion of "TOA spread" in this statement is entirely unsupported.

       Imagine a world and a model-of-that-world with the model running hot. We impose forcings of equal size onto both. The model SAT rises faster because it runs 'hot'. But all things being otherwise equal, that would reduce the TOA imbalance as a higher SAT leaches more energy back into space. Thus my comment questioning whether high TOA could not be seen as a symptom of a 'cool' model.

       But in climatology, things are never 'otherwise equal'. A 'hot' model with increased SAT presumably results in higher 'forcing levels' due to higher positive feedback. Now if the world & the 'hot' model had an SAT that were equal, their conforming increase in SAT would have equalised different proportions of the initial forcing as the level of feedback is different. In the model because of the larger feedbacks, this equalisation will be less - there will be more of the forcing remaining - more TOA imbalance. So we can propose that the TOA imbalance would differ because proportinately less forcing would be equalised in the model. The difference would be most dramaitc in a 'well-equalised' situation, where most of the forcing has been equalised. But let us assume the forcing is roughly half equalised in the world with the 'hot' model showing 33% more TOA imbalance, 33% less forcing equalised, but the same SAT. This implies ECS in the model is 50% too high.

       But if in the model both TOA imbalance were higher and SAT were higher (this last the Klapper definition of a 'hot model' and exemplified by the CMIP5 projections 2006-2014) , ECS would have to be now greatly different to balance the books. @923, a value is suggested for the model ΔSAT = 150% of world values yielding a model:world ECS of 2.25:1. But this does not actually relate to the post-2006 period. To compensate for both TOA imbalance and the differences in SAT we are therefore talking, what, ECS proportionately 3:1, 4:1, more.
       Given the CMIP5 models perform well prior to 2006, is it then at all likely that ECS in the models is so wrong? So how can we simply attribute the post-2006 performance to them being 'hot models'?

29659. Tristan at 13:42 PM on 18 May 2015
       Climate sensitivity is low
       

       @DB, thanks for checking, those arguments definitely sound like ones he'd make, though I dont know if that's him.

       @michaelsweet, thanks, can't blame a layperson for using hadcrut in this instance, and I'm waiting for his response on the as-yet-unrealised warming.

       @MARodger, the best moment I've had recently was when someone told me that you couldn't use EVs for continuous random variables, and when I pointed him to a description of how you could he claimed "Queen's Gambit" and that he just was proving that I could spot a cherry pick. Which, I dunno, means he can accuse me of dishonesty in the future if I fail to agree with him that something is a cherry pick? Guess he got me.

       @TomC, thanks, I actually posted that very graph before coming here, to which Bobl responded: my math is pretty much indisputable. I expect if he did [post it at Sks] I’d not get one refutation, they’ll either pick an irrelevancy like Tristan did, or for example want to pick a higher figure for the warming from 1850.

       Every few months I go back, thinking, "maybe there'll be some people who respond in a reasonable manner", but the content is 40% rhetorical games, 30% slurs, 20% crazy,  and only 10% the sort of argument I'm looking for. And then you I moderated for...who knows. I was told narcissism. I guess for not showing enough deference.

29660. KR at 13:09 PM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       Owenvsgenius - See IPCC AR5 on detection and attribution for a summary of the literature on what percentage of recent warming is attributable to anthropogenic factors. The mean estimate is that ~110% of the warming over the last half-century is due to us. 

       I believe the other references you've been given on ocean sampling are a good start, and will defer additional comments in that regard until you've done some reading.

29661. bozzza at 11:42 AM on 18 May 2015
       Ice loss in west Antarctica is speeding up
       

       owenvsgenius, have you ever heard of dimensional analysis?

29662. scaddenp at 11:27 AM on 18 May 2015
       Ice loss in west Antarctica is speeding up
       

       Antarctica as a whole is losing ice (eg see here) at rate in order of 150Gt per year.

       There is some expansion of sea ice around the continent (which at first glance is paradoxical as the sea warms) with complex causes. Note that an increase in sea ice in winter (when there is no sun) in no way offsets loss of arctic ice in summer (which causes a loss of albedo).

29663. scaddenp at 11:16 AM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       I think the information on you want (level of uncertainty in ocean indicators) can be found Schuckmann and La Traon

29664. Tom Curtis at 11:04 AM on 18 May 2015
       New study finds a hot spot in the atmosphere
       

       chriskoz @11, in my comment @3, the first two images are the images used in the RealClimate post to show that both CO2 and solar forcing result in a tropospheric hotspot.  The third image is, as you show the effect of halving CO2 (after 100 years).  The fourth image, for comparison, is the effect of maintaining 1/3rd Pinatubo forcing for 100 years.

       I would certainly be interested in, and gratefull for, Chris' rerunning of the GISS model for the equivalent experiment.

       I cannot comment on Ben Santer's input as I have not seen it.  Could you provide a link.  Further, if he is commenting on the topic somewhere, and you can respond, could you ask his opinion of my point 4 immediately above.  Specifically, what is the algorithm for "MSU Space"?  Does converting to it have the effect I postulate?  Also does he have any graphs of absolute temperature values with altitude in MSU space as the test of the effect of using MSU space?

29665. bozzza at 10:56 AM on 18 May 2015
       2015 SkS Weekly News Roundup #20B
       

       Precisely correct, Bjorn Lomborg is blind to intergenerational inequality. His political message is a global one: that carbon emissions be allowed to warm the earth by three degrees. (What was his choice of measurement btw as I  cannot recall?)

29666. Tom Curtis at 10:55 AM on 18 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Dayton @9 & 10, Michael Mann writes:

       "Just compare the GHG signal in Santer et al '13 (which shows a hot spot) and the volcanic (which doesn't, and shows a change of sign at 500 mb, which is very close to the 595 mb PEAK of the TMT weighting function--if there were a mid-tropospheric hotspot, it should be seen in TMT)."

       My emphasis.

       Below is a figure showing the trend warming rates from 1979-2012 in the troposphere by altitude for all CMIP5 RCP8.5 models:

       

       The source of the diagram is John Christy, which is dubious in some respects, but I presume he has not misrepresented the model outputs.  That being the case, the CMIP5 models show a clear upper tropospheric hotspot with a multimodel mean peak warming at 250 mb.  Despite this the trends from 1979-current are:

       GISS 0.158 C/decade

       RSS TLT 0.121 C/decade

       RSS TMT 0.077 C/decade

       RSS TTS 0.011 C/decade (from 1987)

       RSS TLS -0.269 C/decade.

       Clearly the trends decline as the mean altitude of measurement rises, with the TMT trend being less than either the TLT or surface trends, and greater than any trends above it.  It follows that if Mann's claim highlighted above is true, then there is no tropospheric hotspot contrary to the model predictions.  In other words, if Mann's highlighted claim is true, the models have been falsified on a fundamental issue that is vital to estimates of climate sensitivity and future warming.  Michael Mann may want to claim in response that his claim is only applicable to volcanic warming, and not warming in general.  If so that is just the rankest special pleading.  If not he either has to accept my claim @8, point (3), above, or radically revise his reliance on models, and his view as to the dangers of AGW.

       Further, the GISS Model E vIII 1880-2000 all forcing response by altitude is shown below:

       

       As you can see, the peak warming is around 350 mb (337.5 mb).  That is in fact lower than the CMIP5 multimodel mean, and also lower than the CMIP5 versions of the GISS Model E (six versions, shown with dotted lines of various shades in the first figure above).  That discrepancy may be simply due to the different forcing periods, but if anything the evidence is that the altitude of peak warming has shifted upwards from CMIP3 to CMIP5, not downwards as would be required for the GISS model E images I have been using to be in need of significant correction.  

       As an aside, there is certainly no reason to prefer the data from cone CMIP3 era model, ie the Parallel Climate Model (PCM) as shown in the IPCC reports and used by Mann over another model of the same vintage (GISS Model E vIII).  As a further aside, the peak cooling for the one third Pinatubo forcing shown @3 is also at 337.5 mb).  This point should be irrelevant in that I originally rebutted Mann's claim that,  "if global warming really *were* due to a (natural) decrease in volcanic activity over time ... then we would expect to see an increase in global surface temperatures WITHOUT any mid-tropospheric "hot spot"".  Mann now appears to be trying to make the issue about the exact altitude of peak warming, which shifts the goal posts.  He also misrepresents the altitude of the peak warming (or cooling) in the GISS model, claiming (@10) it is about 140 mb higher in the atmosphere than actually shown by the model.

       3) Fairly abviously, the PCM models shown @10 do not use a period with significant volcanic forcing, with the consequent that any coldspot is too small to register for the volcanic forcing given scale.  The same also applies with sign reversed for the solar forcing.  That is telling in that solar forcing is definitely one of the forcings which does show a hotspot, but shows no hotspot in the PCM figure.  As Mann accepts that solar forcing generates a hotspot, he must attribute the lack of a visible hotspot in the solar forcing panel to the small quantity of warming relative to the temperature scale used.  He cannot therefore consistently argue that that is not also the case with respect to the volcanic forcing.

       4)  Finally, with respect to figure 2 from Santer et al (2013) (see your post @6 above), Santer et al write:

       "Zonal-mean atmospheric temperature trends in CMIP-5 models (A and D–G) and observations (H and I). Trends were calculated after first regridding model and observational TLS, TMT, and TLT anomaly data to a Graphic latitude/longitude grid, and then computing zonal averages. Results are plotted in “MSU space,” at the approximate peaks of the TLS, TMT, and TLT global-mean MSU weighting functions (74, 595, and 740 hPa, respectively)."

       My emphasis.

       It is not explained what "MSU Space" is, although it is almost certainly not a linear function of temperature with altitude.  More likely, at each altitude, the value shown is the weighted average of the TMT, TLS and TLT trends, with the weighting determined by the relative weight of each channel at that altitude as shown in my post @8, although different algorithms with similar effect could also be used.  As such, it loses vertical structure.  That is because it first reduces the vertical structure to just three values, and then tries to recompose it from those three values.  It is, in effect, a complex smoothing of the data.  As such it will not more show the tropospheric hotspot than will the TMT channel (for reasons given above).  What it will show is what will be found by attempts to reconstruct the vertical temperature signal from the MSU or AMSU channel outputs.  That, of course, is very useful for comparison with satellite data, but renders the graphs positively misleading about the detailed vertical temperature structure of the atmosphere.

29667. Daniel Bailey at 10:47 AM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       @ Owenvsgenius

       Here's a couple to give you a head start on your research:

       1. ESRL NOAA
       2. Abraham et al 2013
          

       Google Scholar wants to be your friend.  Call him.

29668. bozzza at 10:46 AM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       Owenvsgenius, you can't measure everything: this is called 'the uncertainty principle'. Thus all measurements have to be verified by other means making repetition of results central to scientific method!!

29669. chriskoz at 10:09 AM on 18 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Curtis @3,

       Looks like Mike Mann did not even change the details of his hypothesis based on your input. And as it turns out MM hypothesis is backed by Ben Santer, your inquiry to the authority of Gavin Schmidt on the subject is unlikely to change anything. Meanwhile Chris Colose offered to run GISS model you claim about volcanic hot spot is based on, to run it and check the apparent discrepancy: we are all eager to see the results, thanks Chris!

       Meanwhile, pardon my punt, I don't see the extraordinary evidence you need to provide in support of your extraordinary claim taking on the top scientists. If particular, your third image is just a hot spot cooling due to a loss of 50% of CO2, as seen in the NASA link you cite. Where is the "1/3 rd Pinatubo level volcanic forcing" picture where you claim "the patterns in the tropics are very similar"? Maybe you've seen but missed that picture. Please provide it for the benefit of us better understanding your point.

29670. Owenvsgenius at 10:02 AM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       Can anybody tell me the spacial resolution and coverage of ocean temperature surveys? This question impacts the subject matter directly, as models use survey data

       Moderator Response:

       [JH] Perhaps you should do your own research on this matter. 

29671. Tom Curtis at 09:43 AM on 18 May 2015
       Climate sensitivity is low
       

       Bobl writes, "Now the IPCC says that 50% of warming is probably coming from humans and 50 % is natural variation ...".

       What the IPCC actually wrote was that:

       "More than half of the observed increase in global mean surface temperature (GMST) from 1951 to 2010 is very likely due to the observed anthropogenic increase in greenhouse gas (GHG) concentrations."

       where "very likely" means "90-100%" likelihood.  In other words, what the IPCC claimed was that there is a less than 10% chance that only 50% or less of 1951-2010 warming was due to anthropogenic forcings.  That is sufficiently different, indeed contradictory of what Bobl claimed the IPCC wrote that prima facie, he is a bald faced liar.

       Indeed, it is worse than that.  The IPCC also provided a figure with the mean and uncertainties of attribution.  This allows you to generate the Probability Density Function (PDF) of the AR5 attribution, as was done by Real Climate:

       

       From this, in turn, it can be determined that the actual likelihood of less than 50% anthropogenic causes of warming since 1951 is 0.06%.  It follows that at best Bobl is calculating the lower bound of the 99.9% probability range of the "climate sensitivity".  To perform the calculation correctly (ignoring other errors), he should have used an attribution of 107.7% (the mean value of the PDF).  Correcting for this factor alone would more than double his "climate sensitivity" estimate.

       It should be noted, of course, that the IPCC attribution statement only covers the period 1951-2010.  It cannot be arbitrarilly extended to cover periods back to 1900, 1880 or 1850.  Natural forcings were negative from 1850 to about 1910, strongly positive from then to 1940, and remained positive to about 1950, as they more than recouped the losses to 1910, and have been effectively neutral or slightly negative since then.  The result is that 70% is a better estimate than 108% for the anthropogenic contribution since 1900 (or 1880), but 100% is probably more accurate for the anthropogenic contribution since 1850.  These figures, of course, are highly uncertain and not particularly precise.  Sufficiently so that I consider estimating climate sensitivity from temperature differences between two dates with the first date prior to 1950 to be essentially a waste of time.  If you are going to make those estimates, you should greatly increase the data used  to counter the uncertainties.  You do this by fitting a Transient Climate Response (TCR) function to annual data as Kevin Cowtan has done.  The result is a TCR around 2 C per doubling of CO2, with an Equilibrium Climate Sensitivity necessarilly greater than that.

29672. Owenvsgenius at 09:09 AM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       KR, I would like to point out that we do not posses the coverage needed to properly survey the ocean and its depth to come up with anything concrete. Our surveys currently rely on a lot of speculation

       Moderator Response:

       [TD] You need to back up your contentions with data.

29673. Owenvsgenius at 09:01 AM on 18 May 2015
       The climate 'hiatus' doesn’t take the heat off global warming
       

       KR, so what you are saying to Ryland is...that %100 of all warming is due to human CO2 forcing which is offset by tiny amounts of natural cooling...in other words the main driver if climate, using your reasoning, is offset by blips in natural variability...that again, naturally occurring blips cancel out that warm feeling we're all looking for. So what is the primary driver then?

       Moderator Response:

       [JH] Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

29674. Owenvsgenius at 08:26 AM on 18 May 2015
       Ice loss in west Antarctica is speeding up
       

       Its an interesting survey. However the title is misleading, as the Antarctic ice, to the best our ability to survey, is growing. Yes a certain peninsula, which is subject to warmer temps, by warmer I mean less than 0 C average summer temp, has lost some ice...so what

       Moderator Response:

       [JH] Unless you can back-up your assertions with proper documentation, they are just your personal opnions which very little weight on this website. Sarcasam is also frowned upon.

29675. Klapper at 06:19 AM on 18 May 2015
       Models are unreliable
       

       @MA Rodger #922:

       "Wouldn't such a 'hot model' not run with reduced TOA energy balance?"

       If the TOA energy balance was zero (incoming = outgoing), we would for that instant be neither gaining nor losing energy, so although there may be temperature change by heat transfer from one global heat sink to another, total global heat stays the same. An  AOCGC model with a positive TOA imbalance (incoming > outgoing) is gaining heat, either in the atmosphere or the ocean, or ice conversion to water (or all three), but it's unlikely you would not see a temperature rise in both the ocean and the atmosphere over longer periods. The higher the positive imbalance the faster the temperature rise, although SAT rise is obviously subject to the percentage of heat sinking into the ocean vs. the atmosphere.

       In fact this is what we see in SAT. Over the last 35 years the ensemble modelled temperature rise is 0.25C/decade, while SAT only rose about 0.15 to 0.18C/decade depending on SAT dataset. So both the TOA spread from model to empirical and the SAT warming rate spread agree the models look to be running too hot.

29676. MA Rodger at 05:36 AM on 18 May 2015
       Models are unreliable
       

       Klapper @920.
       You write "I like to post numbers and let people decide for themselves" which is rather generous of you. But you do also present an opinion, writing "I still think the models run hot after this exercise." This implies that in light of your "exercise" you see nothing to contradict your contention that "models run hot." Indeed, you go on to argue that your "exercise" lends support to your 'hot model' thesis. "The average error on the over the last 35 years, model TOA forcing to OHC et al is +0.27 W/^2, so the models are definitely warmer in this analysis period." (My emphasis)

       But your 'hot model' thesis is surely to do with the modelled global temperatures being too hot due to their modelled temperature rising too fast. Wouldn't such a 'hot model' not run with reduced TOA energy balance?

29677. MA Rodger at 05:30 AM on 18 May 2015
       Climate sensitivity is low
       

       Tristran @357.

       I must say that JoannaNova comment thread is a classic. I think they could be sitting on a new direction for comedy. "Exactly Tristan, where are the published figures on jet stream friction, where are the published figures on kinetic energy of global rainfall…. though you can calculate that one, it’s about 0.05 Watts per square meter, comprising about 10% of the imbalance energy." Never one to shirk a challenge, if raindrops hit 20mph & average global rainfall 900mm, Bobl is only a triffling 5000% out!!

       As for his question, if you use the forcings from AR5 AII Table 1.2 (which are a little higher than CO2 forcing alone), & the global numbers@359 (but assuming 0.86W/m2 imbalance) you get an ECS = 2.8ºC but most folk consider energy balance methods do underestimate ECS. The figure is also sensitive to negative forcing levels with their big error-bars.

29678. michael sweet at 02:19 AM on 18 May 2015
       Climate sensitivity is low
       

       Tristan,

       I used the Northern Hemishpere data instead of the global data (my link is to the correct data).  1880 was -.22 and 2014 was +.68.   That gives .90 observed and 1.6 including warming in the pipeline.  That is 2.3C per doubling or 4.1 incuding warming in the pipeline.  Multiplying by 1.06 gives 2.4 observed warming and 4.3C at equilibrium.

29679. michael sweet at 02:09 AM on 18 May 2015
       Climate sensitivity is low
       

       Tristan,

       If Bobl claims that his estimate is "truth telling" it is easy tp see why he has trouble at SkS.  

       Checking the GiSS temperature records I find that in 1880 the anamoly was -.38 degrees while 2014 was +.86 degrees (it is more accurate to do a least squares fit but Bobl did not say how he got his numbers).  I find that to be 1.24 degrees since 1880.  The records previous to that are incomplete and inacurate.  Bobl is probably using HADCRU which is well known to underestimate warming since it does not cover the entire globe.  Since this year is currently running .15 degrees above last year and there is an El Nino that will increase temperatures later this year it will not be surprising to see 1.4C globally this year. At .15/decade it will only be 40 years to the 2C disaster threshold.

       Bobl knows that the current temperature is not in equilibrium  with the forcing.  He has left this amount out of his calculation.  Estimates range around .7C in the pipeline.  That makes 1.94 degrees for an estimated final temperature with current CO2 concentrations.  Using 1.24 degrees I get 3.18 degrees per doubling and using 1.94 I get 4.97 degrees per doubling (!!).  The IPCC estimates there is greater than 95% chance of 50% of warming being due  to humans with 106% the best estimate (Bobl knows that too).  The 3.18 must be multiplied by 1.06, not by .50.  That rounds the estimates to about 3.2 degrees per doubling for observed warming and 5 degrees including the warming in the pipeline. 

       The agreement is that above 2C is a disaster, not that below 2C could be good.  Warming is accelerating so I expect 2C to happen in my children's lifetime.  

29680. Tom Dayton at 01:48 AM on 18 May 2015
       New study finds a hot spot in the atmosphere
       

       Mike Mann updated his post on the hot spot.  This is the last time I'm going to copy over his posts and comments.  Please go to his FaceBook page if you want to read and comment more.

       UPDATE to "The Tropical 'Hot Spot' and Global Warming"

       In response to some interesting comments in the comment thread of my previous post, I've decided to add some additional discussion (and two new figures). Figure 1 is a modified version (from Karl et al '09) of a figure that appeared in the CCSP SAP 1.1 report "Temperature Trends in the Lower Atmosphere" in 2006 that compares the PCM model-predicted patterns of response to the various forcings (based on Santer et al 2000). What I like about this particular figure is that the tropopause (border between troposphere and stratosphere) is explicitly shown, which helps to guide the interpretation of the results. The difference in the relative vertical patterns of response to the various forcings is clear here. Greenhouse gases and Anthropogenic Sulphate aerosols show a clear mid-tropospheric amplification. Volcanic forcing does not. Note that the peak warming in the response to greenhouse gases alone (i.e. the center of the "hot spot") is very close to the tropopause, but the response to all forcings combined shows a peak "hot spot" that is well below the tropopause. That is true because the other forcings do not follow the same vertical pattern of response as the GHG forcing alone.

       Figure 2 is from the same report, and it is especially instructive as it shows the response of 4 different models (trend from 1979-1999) to the same imposed late 20th century forcing changes (greenhouse gas increases are the single largest forcing contribution). A "hot spot" of sorts is observed in each case, but note the dramatic variation in the vertical pattern and in the "shape" of the hot spot. GFDL for example has a very well defined hot spot peak at 300mb (and both PCM and CCM3.0 have peaks just above 300mb), while GISS-EH (the model used in the Skeptical Science post mentioned earlier) has a peak that is centered higher up, closer to 200mb. This speaks to the importance of varying convective and cloud parameterizations that govern the dynamical responses. There is no simple, universal response common to all models subject to all forcings. And I will leave it there...

       Figure 1:

       

       Figure 2:

       

29681. Tristan at 00:30 AM on 18 May 2015
       Climate sensitivity is low
       

       Apologies for this one folks. Bobl over at joannenova is adamant that he has been banned from sks for his truth-telling, and I told him I'd ask a question for him. A couple commentators now have a bee in their bonnet given I tried to address it myself, so here you have it:

       
       In 1850 the temperature was about 0.75 deg C lower than now, the CO2 was supposed to have been about 270PPM. Now it’s 400 PPM.

       We know from Arhennius that deltaT = k ln(CO2-2/CO2-1)

       So, therefore 0.75 = k ln(400/270) and therefore k=0.75/ln(400/270)

       k = 1.91

       So lets then calculate the warming for a doubling

       DeltaT = 1.91 × ln 2 = 1.34 degrees per doubling between 1850 and 2014

       Now the IPCC says that 50% of warming is probably coming from humans and 50 % is natural variation so if we assume that 50% of all the warming from 1850 to now is CO2 induced (which it is not, the bit from 1850 to 1950 is unlikely to be CO2 related) at best we causing just 0.77 degrees of warming due to mans gasses, and the other 0.77 degrees must be something else which won’t necessarily accumulate.

       0.77 degrees per doubling implies feedback was negative over the period from 1850 to 2014.

       Given CO2 warming over the last 130 PPM was at best 0.37 to 0.75 degrees and the implied climate sensitivity from that is therefore 0.77 to 1.35 degrees per doubling, therefore the magic 2 degree figure (noting that the IPCC says up to 2 degrees of warming will be positive for the human race) is likely 500 – 1000 years away from happening, why are we even worried about it?

       Moderator Response:

       [DB] "Bobl over at joannenova is adamant that he has been banned from sks for his truth-telling"

       There is only one SkS user with "bob" prefacing their user name that is banned from this venue and that is user "Bob Smith", who had his commenting privileges revoked for being a sock puppet of yet another SkS user.

       Bob Smith at 18:47 PM on 18 December 2012

       IPCC Draft Report Leaked, Shows Global Warming is NOT Due to the Sun
       I am a retired Professional engineer, not a scientist but let me make a few comments: You have scared the governments into giving you the enormous amounts of their taxpayers’ money that you use to maintain your lavished lifestyle. For instance, the lead authors of this report will have their meetings on Tasmania Island, a place that is as far from everywhere as you can possibly get, with air fares in thousands dollars each and with huge CO2 footprint to match them while we, ordinary people, suppose to walk or bike to work. Last month there were 14,000 of you, including 7,000 environmental activists, on all inclusive holiday at the taxpayers’ expenses in Doha. And just the accommodation, air fare and meals for these activist cost some $50 million. And last year it was Rio and before that Durban and Cancun. CO2 and the resulting warming suppose to run out of control but you must be an organization with the largest CO2 footprint in the world. And money you spent has also enormous CO2 footprint for before you can spent it on your salary, reports grants and perks ,like travel, the taxpayers must generate good and services to make them. This is not how the people claiming that CO2 and warming is out of control ought to behave. You are also in a huge conflict of interest for unless you can keep the public scared of the warming your paycheques, careers and perks would be gone. And that applies to the authors as well as peer reviewers. And there is more.

29682. Klapper at 20:01 PM on 17 May 2015
       Models are unreliable
       

       @Rodger MA #919:

       There is on point on my graph where the models do seem to make more sense than the empirical data, namely the early 90's when the model shows a sharp TOA forcing reduction due to a 2 W/m^2 spike in upwelling shortwave.

29683. Klapper at 19:55 PM on 17 May 2015
       Models are unreliable
       

       @MA Rodger #919:

       "...with my noting that you are ignoring mountain glaciers..."

       As you pointed out the montane glacier effect was insignificant to the graph I was producing, being 0.005 W/m^2.

       "...The moderator response @911 suggested it was inappropriate for you to be posting such this work-in-progress down this thread..."

       The moderator can delete my posts if it's inappropriate. I'll consider this project done and won't however post my next project which is to compare TOA net forcing with ENSO, the AMO and the PDO.

       "... I ask this becuse you could well be setting yourself to support the opposite..."

       I like to post numbers and let people decide for themselves. I still think the models run hot after this exercise. The average error on the over the last 35 years, model TOA forcing to OHC et al is +0.27 W/^2, so the models are definitely warmer in this analysis period.

       In your #912 post you state OHC to 2000 metres weighs in roughly at 1 W/m2, but I disagree. The actual number is 0.89 for a trend centred on Nov 2012 and 0.80 for a trend centered on August 2012. However, I think the issue with your choice of period is that it starts with a strong La Nina and ends with an El Nino (which I intend to investigate further). So is it representative of longer term forcing elements?

       Moderator Response:

       [JH] Please do not use the SkS comment threads as a "blackboard" for your next project. 

29684. MA Rodger at 18:48 PM on 17 May 2015
       Models are unreliable
       

       Klapper,

       I would caution you to slow down with your inputs into this comment thread and consider what you are responding to, rather than bash out the first rebuttal that come into your head.

       As an example of this, your response @913 began @910 with my noting that you are ignoring mountain glaciers which you indicate @911 you are happy to do yet @912 I call it 'airburshing away part of the method.' Your response @913 sets out with this in mind but fails to deliver. Instead we get an account of what you see as failings in Hansen's analyses.

       The moderator response @911 suggested it was inappropriate for you to be posting such this work-in-progress down this thread. Given these recent responses of yours are proving so inadequate, I am inclined to agree.

       Perhaps then it would be better to ignore direct comment on your analysis and rather ask why you feel any result that were obtained has any bearing on what you call "my point was that the models run too hot."? I ask this becuse you could well be setting yourself to support the opposite.

29685. Tom Dayton at 14:42 PM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Curtis:  Mike Mann read your most recent response, and replied:

       After having read Tom's response to my response at SkS, I'm now not inclined to take the critique too seriously. First of all, his argument that there is little tropospheric IR signal in the Robock radiative forcing series is just wrong. The positive IR radiative forcing anomalies near 300mb (well into the troposphere) at the equator are similar in magnitude to the negative short-wave anomalies at the surface. This is not neglible. He has misinterpreted Figure 1 shown above--this is an adaptation of the key IPCC AR4 figure on fingerprint detection (based on simulations w/ PCM by Santer et al '03). I'm surprised he doesn't recognize it, since it is actually featured in main post at SkS on the hot spot. Over the shorter more recent interval shown in Santer et al '13, the volcanic surface forcing is indeed positive (that is a completely different interval and thus very different drend from the 20th century trend analyzed in Santer et al '03). But the sign of the net surface forcing, whether negative (for the 20th century trend) or positive (for the more recent trend), isn't the point. The point involves the vertical pattern of the response. And there is no way to reconcile that pattern of response w/ the GISS result Tom shows in his plot. Fully recognizing the complicating issue of the TMT/TLT vertical weighting functions (which Santer et al take some pains to deal with in their interpolation scheme) there are real discrepancies here. Just compare the GHG signal in Santer et al '13 (which shows a hot spot) and the volcanic (which doesn't, and shows a change of sign at 500 mb, which is very close to the 595 mb PEAK of the TMT weighting function--if there were a mid-tropospheric hotspot, it should be seen in TMT). That discrepancy cannot be explained away by the vertical weighting functions. So I think I'll go with the CMIP5 results shown in Santer et al '13 over the results of a single (GISS) model, which is certain to have its own peculiarities w.r.t. convective parameterizations, etc. Suffice it to say, I feel comfortable stating that my original post stands without need for any modification. And since Tom C chose to question my qualifications for talking about climate dynamics and climate models, I'll let the roughly 90 of my 170+ publications that deal with climate modeling and climate dynamics speak for themselves.

29686. Tom Curtis at 11:46 AM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Dayton @4-7:

       1) The model used was the GISS Model E vIII, as can be found out by tracing back the links through the Real Climate link I provided.  As such I suspect it is the same model that was used for the second figure in Mann's original article, with Mann's figure differing in being rapped around the hemicircle, and not being to scale relative to the real thickness of the atmosphere.  Importantly, Mann's figure also differs in showing the effects of historic forcings (which are very different in magnitude between the various forcings) rather than the effects of forcings of approximately equivalent magnitude:

        

       2)  Santer et al (2013) shows historical forcings from Jan 1979 to Dec 2012.  Santer's graph shows an overall positive volcanic forcing, with a negative forcing in southern polar latitudes, and no forcing in northern polar latitudes.  That is, it shows a very different regional pattern (and a far smaller forcing) than does Pinatubo.  Consequently I would hesitate to draw any inference from the differences in pattern between GISS model E and the CMIP5 mean.  Such differences are as likely to be due to the different geographical pattern of the forcing as to any difference in model physics.

       3)  Each of the TMT (Channel T2), TTS (Channel T3), TLS (Channel T4) include a portion of the lower stratosphere in their weighting functions:

       

        The result is that all are downgraded by opposite signed signals contaminating the data.  This is particularly the case for the TMT (T3) channel which obtains approximately a third of its data from the stratosphere, and hence with opposite sign to the upper tropospheric signal.  (This is also why certain deniers prefer to use the TMT channel as representative of tropospheric temperature trends.)  As Santer et al graph by anomalies for these channels, I presume they have taken a weighted temperature function by altitude to match the weighting of the satellite channels, and will suffer the same problem.  This by itself would lead us to expect a reduced TMT temperature response relative to the TLT response as shown by Santer et al, even with the GISS Model E temperature response.

       4)  Beyond that, it is possible that the CMIP5 models show a different response to volcanic forcing, and that consequently the Real Climate article and GISS model E data are out of date.  If Mann could get Gavin Schmidt to comment on that point, I would be very interested.  As it stands, however, I do not find his counter argument convincing, and nor is this topic close enough to Mann's core areas of expertise that I would take him as an authority on this aspect of AGW.

29687. Tom Dayton at 10:05 AM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Curtis:  Mike Mann continued at FaceBook:

       I suspect the model simulations shown by Tom may have a very different convective parameterization than the models employed in the CMIP5 average shown by Santer et al. The latter is consistent with maximum precipitation rate (and latent heating) in the lower-to-mid troposphere, with greater stability (and less latent heating) in the upper troposphere, while the results shown by Tom suggest a great degree of convective heating and instability all the way to the tropopause. The convective dynamics described by the two situations are greatly different.

       I'm interested to hear Tom's response. I open to being disproved on this, but thusfar I'm troubled by the inconsistencies in what he has posted vs. what is shown in the peer-reviewed literature by Santer and others...

29688. Klapper at 10:04 AM on 17 May 2015
       Models are unreliable
       

       @Tom Curtis #917:

       "...and less than the error you made in correcting him @913.."

       I didn't actually correct him at 913; I stated I thought he was double counting but did not quantify the amount he was double counting by. However, in my graph presented in #916, I use the 0.068W/m^2 as the total below 2000 metres, as per Purkey & Johnson Table 1, and elimate the 0.027 W/m^2 for the > 4000 m component of heat gain, so my assumption for heat gain since 1990 in my graph is that > 2000 m OHC gain = a constant 0.068W/^2.

29689. Tom Dayton at 10:03 AM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Curtis, I'm being go-between you and Mike Mann, because though he is popping over here to read your comments, he can't post here because he does not have an SkS account and doesn't want to get one because he already is too busy. (I don't buy that excuse, because I know the only way he can accomplish all the things he already accomplishes is by having an army of clones of himself.  What's one more clone?)  He wrote on FaceBook:

       Tom: in fact, I've having a lot of trouble reconciling the trends shown in (the other Tom's) post at SkS and this plot from Santer et al '13. Tom's plots show maximum amplitudes in the way upper troposphere, while Santer's corresponding plots show greatest amplitudes in the lower-to-mid troposphere. In Santer's plot, the SIGN of the temperature anomaly associated with volcanic forcing actually reverses at the mid-troposphere (roughly 450 mb)! Perhaps there is something I'm missing or misunderstanding about the plots Tom has posted. They certainly don't seem consistent w/ Santer et al. The "hot spots" (or "cold spots" if you like, depending on sign of forcing) are located at greatly different altitudes.

       

29690. Tom Curtis at 09:09 AM on 17 May 2015
       Models are unreliable
       

       Klapper @915, that is far from obvious.  Specifically, Purkey and Johnson write:

       "We make an estimate of the total heat gain from recent deep Southern Ocean and global abyssal warming by adding the integral of Qabyssal below 4000 m to the integral of QSouthernOcean from 1000 to 4000 m (Table 1). The 95% confidence interval for Qabyssal is calculated as the square root of the sum of the basin standard errors squared times 2, again using this factor because the DOF exceed 60. The warming below 4000 m is found to contribute 0.027 (±0.009) W m−2. The Southern Ocean between 1000 and 4000 m contributes an additional 0.068 (±0.062) W m−2, for a total of 0.095 (±0.062) W m−2 to the global heat budget (Table 1)."

       That is exactly what Hansen did, and as he was following the recomendation of Purkey and Johnson, prima facie he was correct to do so.  Further, Levitus et al (2009), from which Hansen obtains his 0-2000 meter data, write:

       "We acknowledge that ocean temperature data are sparse in the polar and subpolar regions of the world ocean but we still refer to our OHC estimates as global. We do this because the OHC estimates are volume integrals so that only relatively small contributions are expected from the polar regions to our global estimates." 

       That appears to suggest that like Levitus et al (2005) (of which Levitus09 is an update), Levitus et al (2009) does not include OHC for the Southern Ocean.

       If you want to make the case that the 1000-2000 meters of the Southern Ocean from Purkey and Johnson should not be included, you need to show either by obtaining a definitive statement from Levitus, or by comparing the gridded data, that Levitus et al (2009) included 0-2000 meter data for the Southern Ocean.  Absent that, and given that excluding warming through too sparse sampling is as much of an error as including too much by double dipping, it appears that Hansen has proceeded correctly.

       Finally, even if he has inadvertently "double dipped" the error involved is appreciably less than the error of the total calculation, and less than the error you made in correcting him @913.

29691. Klapper at 08:57 AM on 17 May 2015
       Models are unreliable
       

       @All #91x:

       Here is a graph of the total inputs. OHC 0-2000 is from NODC, pentadal in the early years and quarterly since 2005, land is from Beltrami et al 2002, > 2000 m OHC is from Purkey & Johnson, ice melt is from PIOMAS/my own model for Antarctica sea ice, Ice sheet melt is from GRACE and earlier some generic Wikipedia numbers, atmosphere is from RSS TLT. I started using 5 year trends, then switched to 6 since that is what Hansen used, but then switched back to 5.

       

       Five years might still be a bit short. OHC seems susceptible to even quarterly steps in the rolling trend. For example the 5 year trend centered on August of 2012 is 0.89 W/m2, while May of 2012 is 0.80 W/m2. I think this is the effect of ENSO causing wobbles in heat gain.

29692. Klapper at 07:37 AM on 17 May 2015
       Models are unreliable
       

       @Tom Curtis #914:

       "...in table 1 they also mention 0.068 W/m^2 globally for below 2000 meters..."

       If that's the case then Hansen has still made a mistake has he not? He used 0.068W/m^2 for 2000 to 4000, but that number is from 2000 to bottom is it not? In other words he double counted the 0.027W/m^2.

29693. Tom Dayton at 07:23 AM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Mike Mann on FaceBook followed up in his reply to Tom Curtis's above comment:

       I did take a look at the piece. First of all, I am not ignoring convective transport of heat. What I am saying is that the convective transport of heat (which would normally lead to a "cold spot" in this case) is offset by the radiative forcing at least partly, eroding (if not erasing entirely) the cold spot. Now, I don't know the details of the calculation he's showing, because he hasn't stated where it comes from. I'd really like to see the details, i.e. how the forcing was implemented, etc. because it appears to be at odds, in terms of the pattern of response, with that shown in Santer's work.This figure is from Santer et al (2013) PNAS. Look at the amplitude of the response to the volcanic forcing events in the mid-to-upper troposphere vs the surface, e.g. Pinatubo, we see about -0.25C peak cooling for "TMT" (mid-to-upper tropos) and about -0.5C peak cooling in the lower troposphere. I don't see how that can be consistent w/ what Tom is showing in his figure.

       

29694. Tom Dayton at 07:18 AM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Curtis, I asked Mike Mann to reply to your comment. Here's what he wrote over on his FaceBook post:

       I've explained (and shown) carefully in the post above that there is no hotspot associated with a global warming trend resulting from changes in volcanic forcing (this is also true for ozone forcing-related trends). The problem with the RealClimate post is that it doesn't acknowledge this exception to (Gavin's) argument. The argument works for GHG, it works for El Nino, it works for Solar. IT DOES NOT WORK for volcanic forcing (or ozone forcing, or any forcing which has a similarly complex vertical radiative forcing profile associated with it). I have confirmed my take on this with Ben Santer.

29695. Tom Curtis at 06:45 AM on 17 May 2015
       Monthly global carbon dioxide tops 400ppm for first time
       

       PluviAL @12, I am rather less sanguine than you about extracting water from the atmosphere in deserts, which are deserts (after all) because of the low relative humidity of the atmosphere over those latitudes.  The only technique I know of that could reliably extract the moisture woud be to be to massively cooling the air, a process that will require a lot more energy than could be extracted by the condensation of water.  Indeed, I suspect that extracting energy from water condensation would run up against entropy problems very quickly, and hence also not be feasible.  However, if you invent a device that can do it, more power to you.  On this I would be happy to be proven wrong, if only for the opening up of agricultural land on the fringes of deserts, and to regreen regions recently suffering desertification such as the Sahel.

29696. Tom Curtis at 06:30 AM on 17 May 2015
       Models are unreliable
       

       Klapper @913, you are mistaken about Purkey and Johnson.  Specifically, while they mention 0.027 W/m^2 below 4000 meters globally, and 0.068 below 1000 meters "south of the Subantarctic Front of the Antarctic Circumpolar Current" in the abstract, in table 1 they also mention 0.068 W/m^2 globally for below 2000 meters.  That the two values coincide does not make it a mistake to use the second figure (from table 1) in estimated OHC change below 2000 meters.

       Indeed, Purkey and Johnson quantify the below 1000 meters Antarctic change in OHC because prior estimates of OHC failed to determine the change in polar waters.  Ergo, arguably, the 0.032 W/m^2 between 1000 and 2000 meters in the Antarctic should also be added.  Indeed, Purkey and Johnson do in fact argue that in the conclusion, estimating that the total contribution from Antarctic Bottom Water (ABBW) to be 0.1 W/m^2 globally averaged.  Therefore Hansen may have underestimated additional contribution to OHC based on Purkey and Johnson's paper.  Whether he has or not depends on exactly which 0-2000 meter estimate he used, and whether or not it included the 0-2000 meter warming in the Antarctic.

29697. Tom Curtis at 06:03 AM on 17 May 2015
       New study finds a hot spot in the atmosphere
       

       Tom Dayton @1, in this case Michael Mann is wrong.  As the RealClimate team have explained, the tropospheric hotspot is a result of the lapse rate feedback, ie, the change in decrease in temperature with altitude due to the increased heat capacity of the atmosphere resulting from a higher absolute humidity with increased warming.  The RealClimate team illustrate this by comparing expected warming and cooling by latitude and altitude for a doubling of CO2, and an equivalent increase in solar forcing:

        

       

       The patterns are broadly similar, although the CO2 forcing results in a stronger arctic warming (but note the difference in scales).

       Unfortunately, it is not possible to similarly compare the result of CO2 forcing to a loss of background volcanic aerosols as the background level of aerosols is not that large.  We can however compare the cooling due to a loss of 50% of CO2, and due to a 1/3 rd Pinatubo level volcanic forcing:

       

       

       As you can see, for these negative forcings, the patterns in the tropics are very similar.  At the poles, however, the increased volcanic aerosols result in stratospheric cooling, unlike the stratospheric warming resulting from reduced CO2.  Further, the peak arctic cooling is further south with volcanic aerosols.  Again the scales are different, but the forcings are not SFAIK of equivalent strength.  The patterns, however, are the important feature.

       The polar stratospheric cooling with increased volcanic forcing may be partly due to the location of the aerosol cloud, which is not global (and was tropical in Pinatubo's case) and ergo will have different regional effects.  It is, however, at least partly due to a decreased warming of the stratosphere from upwelling IR radiation due to the cooler troposphere not being compensated by increases short wave radiation reflected of the stratospheric aerosols due to the low insolation at the poles.  Ergo, it is at least in part a feature we would expect of any volcanic cooling, although the exact boundaries of warming and cooling zones will vary depending on the latitude of the volcano causing the cooling.

       The important thing about this comparison for our discussion is that there is definitely a tropospheric cool spot for both reduced CO2 and the volcanic forcing.  As can be seen by comparing the doubled CO2 and halved CO2, the patterns of change in temperature are the same for both.  It is just that the signs of the change are different.  The same would be true for a reduced volcanic forcing.  That is, it would show a similar pattern to the increased volcanic forcing, only with warming where the volcanic forcing shows cooling, and vice versa.  Ergo a reduction of background volcanic aerosols would definitely result in a tropospheric hotspot, contra Mann.

       I believe Mann has been decieved on this because:

       1) He fails to note that the observed heating for Pinatubo through radiative absorption and re-emission of the aerosols is primarilly above the 100 mb line, ie, the tropopause:

       

       2)  And because he focuses only on radiative heat transfer, ignoring the convective heat transfer effects that drive the change in lapse rate.

29698. Klapper at 05:46 AM on 17 May 2015
       Models are unreliable
       

       @MA Rodger #912:

       "...suggests some part of the method employed in Hansen et al (2011) Section 9 is being airbrushed away..."

       Hansen made an error in Section 9 of Hansen et al 2011. Here's his quote: "The third term is heat gain in the global layer between 2000 and 4000 m for which we use the estimate 0.068 ± 0.061 W/m2 of Purkey and Johnson (2010)."

       The 0.068W/m2 from Purkey & Johnson is not for the 2000 to 4000 zone, but the 1000 to 4000 zone, only in the southern ocean, which means he is double counting some heat (1000 to 2000 in the southern ocean). The Purkey & Johson paper is clear about this, as is the text in Hansen et al 2011 elsewhere in the paper. Keep in mind since the J&P 2010 paper is showing neglible abyssal warming in the northern ocean (see Figure 8 in that paper), its not clear the 1000 to 2000 overlap in the southern ocean is a wash with the "missing" 2000 to 4000 in the northern ocean.

       As for your last comment: "which weighs in at roughly 1.0W/m2 (2010-2014)", I checked the numbers and the W/m^2 is 0.89. However, keep in mind the model CMIP5 is still increasing and so the model projected imbalance average 2010 to 2014 is 1.04, plus sea ice has been gaining 2010 to 2014 so you have at least one of your factors going negative, albeit one of those that have negible leverage.

       You've stated there are "problems" with using TLT as a calculator for net energy change in the atmosphere but surely it's better than what Hansen did which was to use a metric representing maybe the lowest 5 metres of the atmosphere. TLT and TMT combined would likely be the best and certainly more representative of the atmosphere than any SAT data set which has much poorer spatial/volume coverage.

       As for land heat, I would not use Hansens method. I think actual data from the boreholes is better, than a heat flux model. Using the 2002 paper by Beltrami et al, the heat flux from borehole temperature profiles was .039W/m^2, but that is land only. If you calculate this to a global TOA basis (and delete the ice covered continents Greenland and Antarctica) you end up with an average heat flux into land of only 0.010 W/m^2, making it another neglible component of the global energy balance. The recent decadal flattening of the surface temperature would indicate land heat flux is likely no higher now than the 1950 to 2000 average which is the basis of the Beltrami number.

       In summary, my point was that the models run too hot. It is true that recently OHC gains come close to the model TOA imbalance, but then that happened back in 2002-2003 also and then the rate of ocean heat gain faltered somewhat. The bottom line is that even now, using very short periods to estimate the imbalance, the projected TOA imbalance of the models is higher than the actual TOA global energy imbalance as best we can calculate them.

29699. Mal Adapted at 04:48 AM on 17 May 2015
       Lukewarmers – the third stage of climate denial, gambling on snake eyes
       

       OPOF, I'm pretty sure that the ostensible rationale offered by some lukewarmers is disingenuous.  They know it's unacceptable to leave the cost of AGW to be paid by poor people in other countries.  When they assert that the costs of AGW won't be high enough to justify mitigation, what they really mean is that they don't expect the costs to themselves or anyone they care about to be high. Their attitude (for which there is ample historical precedent, to be sure) is expressed by the Deacons' grace: "Lord bless me and my wife, son John and his wife, we four and no more."

       Such people will only support mitigation if they can be persuaded that their personal costs will in fact be high.  If they see their or their families' lives, homes or livelihoods threatened by heat waves, droughts, severe storms and rising sea levels, they'll call for action.

29700. One Planet Only Forever at 03:06 AM on 17 May 2015
       Lukewarmers – the third stage of climate denial, gambling on snake eyes
       

       Mal Adapted,

       It is worse than those people not caring about the cost someone else will pay.

       Every economic evaluation that compares 'current day benefits that do not truly focus on assisting the least fortunate advance to a sustainable better future' with 'some calculation of future costs' is fundamentally unacceptable on two counts.

       1. Any unsustainable and damaging activity like the burning of fossil fuels really should only be for the temporary effort to transition the least fortunate to a sustainable more fortunate future. Global GDP has grown faster than the population, even African GDP has grown faster than the African population, and the wealthiest have gotten much wealthier yet many people remain stuck in desperate poverty.
       2. It is unjustifiable to compare the benefits obtained by some in a current generation with the resulting costs and damage that will be faced by future generations. And it is almost criminal to overstate the benefits that a current generation would have to give up and compare those with understated future costs and consequences, especially when ignoring the damage done to the environment that is not considered because it has no current legal or economic cost evaluation method (the robust diversity of life is priceless, and that is why it is ignored by the 'cost comparers')

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