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Comments 41251 to 41300:

41251. grindupBaker at 20:03 PM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Tom #96: I disagree that "It will not with a dominant focus on OHC". I think any other way is a reverse description. I see it as: Radiative imbalance moves heat into oceans over long term. All the while it moves around the land & sea surface with complexity due to atmosphere and water in it. Land & sea surface must reach a higher temperature to balance and stop warming, it tries but the oceans keep stymying its efforts in rather jittery ways because ocean mixing isn't a smooth process. One day if the imbalance remains steady for long enough then the oceans will be ~85% sated and at ~85% and the surface temperature will finally rise to its new level (until the next big change in radiative balance).

       Land surface flora & fauna will be battered by the surface temperature rise that is trying to stop the warming, but that's irrelevant to the Group I climate science. ENSO is currently the big repetitous example of "oceans keep stymying its efforts in rather jittery ways".

       I contend that is the logical way to picture the physical processes. Incidental to it, I think the science is going to need the nuclear "half life" equivalent for ocean heat balance because I doubt the oceans have ever been 100% at balance with whatever is the surface temperature and never will be. I stand to be corrected but I see graphs depicting Greenland surface temperature shooting up & down during the glaciation. I've suggested above 85% of the balance point of the oceans with the surface temperature.

        

        

41252. KR at 13:27 PM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       When surface temperatures follow the forcing trend, they are in and of themselves a signicant part of the conversation, sufficient to carry the discussion. (Based, of course, on a reasonable view of the statistical uncertainty of short trends in the the presence of short term variations)

       The rest of the climate has, of course, also followed the forcings including anthropogenic greenhouse gases, and warmed as well over the last 50 years or so. Currently, however, given a (short term) variation in surface temperatures, as well as quite likely some variations in the forcings - those variations are being used as rhetorical ammo by 'skeptics' who are less concerned with facts than with winning debating points.

       And therefore those with a more global view are pointing out the rest of the climate, warming as it always has, to demonstrate that the short term variations in surface temperatures are indeed not evidence against the physics of the last 150 years. That doesn't mean the 'skeptic' tactic of cherry-picking short term variations makes sense. 

       If the 'skeptics' actually understood or valued measures of statistical certainty regarding air temperatures, it wouldn't be necessary to point to the rest of the climate. Meaning that their own lack of math is being used as another debating point. Shame on them. 

41253. One Planet Only Forever at 13:25 PM on 23 October 2013
       Why trust climate models? It’s a matter of simple science
       

       This is a nice capsule summary of modeling and why models are useful.

       An added reason for the development of models is short-term forecasting to help decision makers understand their likely conditions for near-term things like farming, shipping, off-shore operations, and weather related disaster relief planning.

       It is important to note that climate models cannot reliable forecast the significant but random or irregular impacts like major volcanic eruptions and the ENSO changes. The models can have these items as input from past history and reasonably produce the historic results, but the models cannot reasonably forecast these impacts. However, these impacts are not "drivers" of long term change. So the models can reliably forecast the "norm" into the future with the understanding that random factors like major volcanic eruptions and ENSO changes will create departures from the norm.

       The models are reliable even when they do not predict the long-term ENSO influence, because they are not able to predict the ENSO far into the future so they don't try to. However, as more is learned about the intricate behaviour of the ocean currents the models will be able to include reasonable long-term predictions of ENSO.

41254. Doug Bostrom at 09:44 AM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       I should add that if we really do think we're seeing a slowdown in warming that is not caused by ocean dynamics then we can all kick our heels for joy and stop discussing anthropogenic global warming right now.

       The alternative explanation to the ocean would seem to presuppose that radiative imbalances can come and go according to principles that entirely elude us. That doesn't seem likely, not at this juncture. 

41255. Doug Bostrom at 09:39 AM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       It doesn't count for much (anything, actually) in the grand scheme of things but some of us (me, for instance) have always been bothered about our myopic focus on surface warming. Well, I say "always" but by that I mean since the moment the massively-obvious-in-hindsight disparity between ocean thermal capacity and that of the air was pointed out to me. I became interested in the climate change topic somewhere around 2005 and it was shortly thereafter that it became apparent most of the action was going to be in the watery part of the Earth, indeed that most of the dynamics even in the air were going to involve water and phase transitions of various kinds. 

       The gaseous atmosphere is like a cartoon character grappling onto the wheel of a wagon, battered and pummeled by something much more energetic. The faster the wagon goes, the worse the beating, punctuated by coincidental moments of relative peace.  The wheel is the surface of the ocean and wagon it's attached to is the bulk of the water.

       Tom's right that a really extended period of not much happening in the wee gassy part of Earth would be a cause to reexamine assumptions. Though Tom is much more scrupulously connected to the details and thus better able to say, for my part I'm not sure even then we'd be looking at a fundamental collapse of the  concept of AGW. The system we're in is being shocked in a novel way; how the dynamics of this thing unfold is something we can roughly predict but it's clear that some biggish details elude us, as evidenced by the (sorry to mention it yet again) Arctic sea ice scenario. 

41256. DSL at 07:46 AM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Tom, I see what you're saying.  I get it, and perhaps I'm pulling an "if by whiskey," but when I say "AGW," I mean the greenhouse effect enhanced by humans digging up carbon and burning it, and by humans directly altering the biosphere.  I don't mean "a positive trend in GMST."  I mean a trend above what we would expect from natural forcings.  If you had that 50 year plunge, how high on the list of things to check would the enhanced greenhouse effect be?

       When I discuss this issue with the general public, and especially with doubters, it's clear that in their minds, "global warming" means a positive trend in GMST, and that if there is no trend in GMST, climate scientists are 1) engaged in fraud and/or 2) don't know what they're talking about.  Of course, neither condition is true, even if GMST is flat over the short term.  In other words, I'm not working this over for the sake of being absolutely precise; I'm working it over in order to find the best way to start a productive engagement with members of the general public.  One of the ideas I want to de-bunk is the idea that GMST != "global warming."  Even if it's technically true, it's not a healthy place to work from.  Svante Arrhenius expected the enhanced greenhouse effect to play out in GMST, but he didn't use GMST as a starting point for the theory.

41257. vrooomie at 07:06 AM on 23 October 2013
       2013 SkS Weekly Digest #42
       

       Doug, I second John's suggestion...a spiffy blog post is in the making, with what you've posted, and your considerable gift of elucidation.

41258. Tom Curtis at 06:45 AM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       DSL @95, climate scientists have used rising GMST as evidence of global warming.  An example is Meehl's analysis of temperature record ratios, and multiple other examples could be found.  Further, if the temperatures were to plunge for long enough it would falsify AGW.  IF, for example, temperatures were to plunge (trend less than -0.1 C per decade) for the next five years despite a series of strong El Ninos, a lack of volcanoes, and strongly rising anthropogenic forcings, I think AGW would be falsified for practical purposes.  No theory is ever completely falsified, in that new data and new understandings of old data can rescue the most moribund theory in principle; but in the above scenario the likilihood of AGW being rescued would be small IMO.   

       Given the reliance of climate scientists onincreased global temperatures as evidence of AGW, there is some justice in claims that defenders of climate science have shifted the goal posts in response to the so-called "hiatus".  As a result, I do not like discussions of the "hiatus" that focus exclusively, or almost exclusively on OHC.  Of course, the shift of focus is not an ad hoc response to criticism.  It is justified by the theory, and partly driven by the availability of better OHC data.  Further, the climate scientists never relied solely, or even mostly, on rising GMST as evidence of AGW.  The so-called "hiatus" has forced climate scientists (and defenders of climate science) to provide a better, more nuanced account of AGW - or at least it should.  (It will not with a dominant focus on OHC.)  That is a good thing.  However, reasonable observers will note that the shift in focus merely results in defenders of climate science discussing in more detail features of the theory that have existed all along.

       I have some concerns about SkS coverage of the "hiatus" on the basis of an excessive focus on OHC, and an insufficient focus factors which would have caused a decrease in GMST absent AGW.  That is, I would like to see a little more focus on ENSO, and declines in forcings from other sources, and slightly less focus on OHC.  Such a shift would, IMO, give a more balanced opinion.  

       Your post @90, however, goes to far in leaving temperatures out of the equation.  I plunging global temperature for 50 years not falsifying AGW?  Really?  Not without the most extraordinary circumstances.  Given that a grand solar minimum equivalent to the Maunder Minimum would only cause an (from memory) 15 year hiatus in temperature increases, the extent of volcanism, asteroid impact, or decreased solar activity required for falling GMST for 50 years and AGW being true will constitute a catastrophist nightmare in its own right.  

41259. scaddenp at 06:22 AM on 23 October 2013
       It's waste heat
       

       I'll try and be more specific. If you take a textbook example and say ask how much will body increase in temperature if you add x extra joules to it, then looking at heat capacity is certainly the way to go. But that is not the relevant equation, because you are ignoring energy transfer out of the system. The text book is fine but you have to read all the chapters. You appear to have read the chapters on conductive heat transfer and missed the one on radiative transfer.

       Perhaps

       Principles of Heat Transfer, Kreith (1965) or

       Fundamentals of Heat and Mass Transfer, Incropera and DeWitt (2007) for more modern.

       Or if you are more my age, then

       Heat and Mass Transfer, by Eckert and Drake (1959)

41260. Bob Lacatena at 01:49 AM on 23 October 2013
       Does the global warming 'pause' mean what you think it means?
       

       Dean @16,

       But if the climate system even accumulated more heat during the "pause"... how can this be consistent with the IPCC assessment update, including a fair chance (17%) of sensitivity being even <1.5?

       The simple answer is that if the deep ocean is, in effect, able to act as a bottomless sink for at least some of the heat, then the system is able to absorb more energy with less change in atmospheric temperatures, thus effectively reducing climate sensitivity (same forcing, less actual temperature change).

       The more complex answer is that the basic, accepted equation for computing Effective Climate Sensitivity based on short term observations is:

       ECS = F2x•∆T / [ ∆F – ∆Q ]  :    Forster and Gregory, 2006

       where ECS is the Effective Climate Sensitivity, F2x is the forcing due to a doubling of CO2, ∆T is the observed change in temperature of the period, ∆F is the observed or estimated/computed change in forcing over the period, and ∆Q is the observed change in heat content of the entire system (atmosphere plus oceans plus land plus ice melt).

       When applying a reduced observed temperature of the past 30 years with a monotonic heat gain over the same time period, the net result is a lower sensitivity.

       Of course, all of this assumes that the short tail of the pause is significant, i.e. that it is reflective of the longer term trend, so that the 30 year period of observations is indicative of what is to come.

       Alternately, we might see a "rebound" effect from the deep ocean warming, much as we saw following the Pinatubo eruption, where temperatures climb dramatically.  We could also see a double-rebound effect if that is combined with a less-quiet sun, a reduction in dimming aerosols, and less preponderance of La Niña events.  In that event temperatures, and a newer, revised estimate of climate sensitivity, would sky rocket.

       But for now, when considered with the full body of evidence and the variety of methods of computing climate sensitivity, the observational method points to at least a lowering of the lower bound of the expected range of climate sensitivity.

41261. DSL at 01:08 AM on 23 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Tom, have "climate scientists used GMST as evidence of global warming"?  You're pointing out that surface temp is critical to understanding the results of the initial forcing, but an increase in GMST is not evidence for the existence of the initial forcing (the human-enhanced greenhouse effect).  Again, if surface temp were plunging, would it falsify AGW?  No.  But claiming that GMST is evidence of global warming allows a plunging surface temp to be read as a falsification of AGW.

       I could also point out that the increase in RF via enhanced GHE did not occur in a vacuum.  It developed dynamically with existing ocean energy conditions. Surface temp is also a function of OHC and ocean circulation, and vice versa.  

41262. Phil L at 00:44 AM on 23 October 2013
       2013 SkS Weekly News Roundup #42B
       

       Meanwhile more and more petroleum products are being shipped by rail.  Another derailment in Alberta is burning out of control.  Luckily this most recent derailment one wasn't in an urban area like the recent disastrous derailment in Lac-Mégantic, Quebec.  The energy spent railing against this pipeline would be better spent pushing for a fee and divadend on carbon.

        

41263. John Hartz at 00:38 AM on 23 October 2013
       It's waste heat
       

       Old Sage:

       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.

41264. Dikran Marsupial at 00:19 AM on 23 October 2013
       It's waste heat
       

       Old Sage wrote "I am puzzled by the fact that I am not aware of anyone who says that 250ppm or 450 ppm of CO2 is the cause of warming has put it in the context of the concentration required to render the atmosphere totally opaque."

       AFAICS, you appear to be labouring over a fundamental misunderstanding of the mechanism underpinning the enhanced greenhouse effect.  The absoption of IR emitted from the surface by CO2 is a red-herring; what matters is the temperature of the layer in the atmosphere from which IR can escape without being absorbed by the CO2.  See this RealClimate article by Spencer Weart and Raymond Pierrehumbert.

       "The only reason I can see for pinning warming on CO2 is that it is increasing and is a useful parameter for sticking in a model, well"

       Well perhaps you should read up on the basic mechanism of the EGHE before making pronouncements.  The basic mechansim was set out quite clearly by Gilbert Plass in the 1950s.  You are unlikely to convince anybody with your theories until you can show that you have at least read up on the basics of the mainstream scientific understanding of climate change.

       Moderator Response:

       [JH] I deleteed Old Sage's most recent post because it was sloganeering. I am letting this comment stand because it accurately quotes statements made by Old Sage in his post. Other repsonses to Old Sage's post will be deleted.

41265. John Hartz at 23:20 PM on 22 October 2013
       2013 SkS Weekly Digest #42
       

       Doug:

       Perhaps you could channel your musings into a blog post article. As fate would have it, Dana is on a two week vacation in Australia. We therefore need other authors to step up to the plate and knock it our of the park. (World Series time in the US.)

       I'm watching CNN. It just reported on the wildfires. Quoted an offical who said, "As bad as it gets!" 

41266. chriskoz at 17:15 PM on 22 October 2013
       2013 SkS Weekly Digest #42
       

       doug_bostrom,

       I chipin to your conversation.

       The factors that contribute bushfires in AU are not only the record high temperatures (as proven in your last post) but also:

       - large amout of burnable biomass in scherophyl forests

       - dry conditions

       - wind

       The last factor is unpredictable (weather) but the first two are changing with changing climate. In particular, recent studies concluded the intensification of LaNina/ElNino cycles on E coast; means more intense LaNina floods and drier/hotter ElNino. This is exactly what we've experienced in last few years: remember record floods of 2010-2011 which even contributed to the unusual sea level negative departure from the satellite treands by 7mm? I've been watching the rainfall data in the fire affected area (Blackheath NSW where I own the house which is now under threat to burn) during that time. The rainfall anomally was high (some twice as much fell) and summers mild, contributing to the high understory growth. Then came the record dry spring - the driest in my memory - only some 70mm fell in 3 and half mounts to date. Did ElNino return? To my feeling it did! But if the ENSO index is globally neutral yet, what would happen if the index becomes truly positive?

       I saw some comments "bushfires have always been part of AU life and cliame change has nothing to do with it" (ala "climate has always been changing" argument) but the silly commenters don't understand that ENSO fluctiations are driving the bushfire conditions and that said fluctuations are predicted to intensify. And what we're seing today is the result of such intensification. And remember, this is just the pre-season (the begin of official suthern summer is still 2 month away), it can only become worse next time, if such conditions align in the middle of summer...

41267. Doug Bostrom at 16:16 PM on 22 October 2013
       2013 SkS Weekly Digest #42
       

       Carrying on my conversation with myself, it strikes me that this year's early and large fire situation in Australia is roughly akin to what hurricane Sandy was to the US, except perhaps more so. We have: 

       -- Historically hottest September on record for Australia, following...

       -- Australia's warmest winter on record, which came after...

       -- Australia's hottest summer on record, as part of...

       -- Australia's warmest 12 months on record, which contained...

       -- Australia's warmest day, week and month on record, appearing likely to lead to...

       -- Australia's warmest calendar year on record. 

       Yet when I look at comments attached to the Figueres article above, I see familiar, confidently expressed opinions that this year's fire situation in Australia is quite normal, nothing out of the ordinary, to be expected, and most of all definitely not connected with climate. 

       Really not climate, for sure? But the climate -has- changed:

       

       So how can people say with such certainty that this year's unusually large, early and dynamic fires have no relationship with climate? Last year's fires occurred in the context of warm and dry conditions, something everybody agrees encourages fires. This year's fires are happening in similar context.  If we see year-on-year increases in fire activity and those years are accompanied by atmospheric changes that are larger than weather and these changes tend to encourage fires, then what's a reasonable, consistent explanation for how these fires are unconnected with climate? 

41268. Tom Curtis at 16:15 PM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       DSL @90, of the theory of the greenhouse effect can be summed up in a single equation, that equation is:

       ΔT=(ΔF-ΔQ)/λ

       where ΔT is the change in Global Mean Surface Temperature, ΔF is the change in forcing, ΔQ is the change in global surface heat content (of which approx 90% is OHC), and λ is the climate sensitivity factor.

       Consequently GMST is integral to understanding the greenhouse effect, and to predicting the consequences of a change in greenhouse gas concentration.  That does not mean GMST can be understood in isolation. ΔQ is also essential to understanding the theory, and any body claiming the so-called "hiatus" disproves AGW has forgotten that; but we should not go overboard and ignore the central role of surface temperature in the theory.  Afterall, the upward IR flux is a function of surface temperature, not of OHC.    

41269. grindupBaker at 15:48 PM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       @Andrew7x8 #89 I agree with your point but there's no progress without change so suggest you attempt to explain that GMST is a pretty good proxy for climate warming & cooling when comparing blocks of at least 30 years with other ones and it's all we have for comparison from 650,000,000 until ~100 years ago, but we are finally starting to get the real deal, ocean heat, measured well and we can increasingly expect that to be the quantity measure this century because it's going to be a true measure even from one year to the next. Point out that it makes the topic interesting because if GMST were to soar +0.5C next year with no identified cause from insolation, albedo, aerosols or greenhouse gas change then people could correctly say "well, it's hotter than hell but at least global warming has completely stopped for now" right ? If Arctic icebergs discharged into the Atlantic increased, they'd cool some  Atlantic surface water, reduce surface temperature and increase global warming. Fascinating. 

41270. scaddenp at 14:08 PM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Well I think Andrew does have point. GMST is where we live so that is what we notice. However, if you are going to have people claiming climate science is wrong because GMST is rising more slowly, then you do need to look at bit further afield than just the very noisy GMST. However, until we got Argo in 2002, ocean temperatures estimates had large error bands especially below 700m.

41271. DSL at 13:18 PM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Andrew, further, and again, 90%+ of the effective thermal capacity of the climate system is wrapped up in the oceans.  Another 2-3% is in global ice mass loss.  Using surface temperature to assess global warming is like writing a review of a restaurant based on drinking a glass of water and eating one appetizer.  Can doing that tell you something about the restaurant?  Absolutely, but you'd never actually write the review based on just the appetizer. 

       I hope.

41272. DSL at 13:14 PM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       No, Andrew.  The theory of anthropogenic global warming (AGW) is not based on any surface temp record.  It is simply the greenhouse effect plus the proposition that humans are responsible for the recent rapid rise in atmospheric CO2. 

       Even if the surface temp were plunging negative for 50 years, the theory would still be in evidence.  It would simply be colder without AGW.

       You need to make a distinction between the theory of anthropogenic global warming and modeling of future elements of climate.  That distinction has always existed in the science.  AGW is not based on the output of general circulation modeling.

41273. michael sweet at 12:10 PM on 22 October 2013
       It's waste heat
       

       Ols "Sage" has yet to supply a single reference supporting his absurd claims about heat in the atmosphere.   He is sloganeering and should be required to support his position to continue posting.  He is completely ignorant about heat transfer and he refuses to read the informed posts that Tom has, again, made for him.

41274. Andrew7x8 at 12:04 PM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       I read "The history of climate science" and "The Big Picture", as scaddenp suggested.

       I noticed that the first sentence of "The Earth is Warming" in "The Big Picture" is:

       The Earth is Warming
       We know the planet is warming from surface temperature stations and satellites measuring the temperature of the Earth's surface and lower atmosphere.

       Surely the public and mainstream media are focused on GMST, because climate scientists used GMST as evidence of global warming. It is unfair to blame the public and mainstream media if the "goalposts" are moved.

41275. scaddenp at 09:15 AM on 22 October 2013
       It's waste heat
       

       And a further note - in addition to an atmosphere that doesnt radiate,  old sage's calculation requires  that somehow waste heat cant warm the ocean (the upper 2.5m having same heat capacity as entire atmosphere).

41276. Doug Bostrom at 08:29 AM on 22 October 2013
       2013 SkS Weekly Digest #42
       

       Chief UN climate herder Figueres makes a radical proposition: yes, climate politics, climate policy and climate outcomes are connected.

       UN climate chief Christiana Figueres calls for global action amid NSW bushfires

       Of course she'll be denounced as rude and insensitive. It's sort of the global equivalent of the 2nd Amendment discussion. 

41277. scaddenp at 08:26 AM on 22 October 2013
       It's waste heat
       

       I'd like to know why old "sage" thinks Planck's Law doesnt apply to gases? And where all that radiation cames from that satellites measure if he believes it is heat is somehow trapped in the atmosphere?

41278. Doug Bostrom at 07:59 AM on 22 October 2013
       2013 SkS Weekly Digest #42
       

       Here's an article that may have some fairly profound implications:

       Contribution of ocean overturning circulation to tropical rainfall peak in the Northern Hemisphere

       The final sentence of the abstract is a candidate for masterpiece of understatement. 

41279. Tom Curtis at 05:58 AM on 22 October 2013
       It's waste heat
       

       Old Sage @140, argues correctly that N2 and O2 are transparent to IR and visible light (mostly), and that therefore they are poor emitters or IR radiation.  He does not follow through and note that CO2 and H2O are strong absorbers of IR radiation, and therefore strong emitters of IR radiation if the wavelength of absorption lies within the blackbody spectrum at the temperatures of at which they absorb.  Here is the main absorption band of CO2 with respect to the black body curve of bodies at typical Earth surface temperatures:

       

       The CO2 absorption band at about a wavenumber of 700 cm^-1 clearly lies near the center of the blackbody spectrum, and will radiate strongly without need of ionization at normal Earth surface temperatures.  Additional absorption bands due to H2O (0-600; 1300-1600), O3 (1050) and CH4 (1300) are also visible, and will also radiate strongly at normal Earth surface temperatures.  Old Sage proves his sagacity by simply ignoring the implications of the argument he is happy to deploy whenever they are inconvenient to his position.

       Of course, the above graph only comes from a model.  We need an empirical test.  One possible test is that if we look up at wavelengths in the IR spectrum in which CO2 is expected to radiate, we will see a strong IR signal.  Conversely, were no constituent of the atmosphere is expected to radiate, we expect to see no such signal:

        

       The graph shows the IR spectrum at the same location, with one image (a) looking down from altitude, while the other (b) looks up from the surface.

       This has all been explained to Old Sage before, but confident in his own wisdom, he pays attention to neither the well worked out and confirmed theories of physicists; nor to the implications of the observations themselves. 

41280. jdixon1980 at 05:44 AM on 22 October 2013
       Two degrees: how we imagine climate change
       

       Natural warming occurring 30 times slower than the current AGW sounds more or less consistent with the fact that today's rate of increase of CO2 in the atmosphere is about 100 times faster than the rate of increase when the last ice age ended:  See http://ens-newswire.com/2013/05/11/atmospheric-co2-hits-400-parts-per-million-mark/

41281. Doug Bostrom at 05:38 AM on 22 October 2013
       It's waste heat
       

       Does artifact waste heat have special properties which make it selectively resistant to entropy via radiation at the top of the atmosphere? If so, the person who knows how this works should definitely keep clam until they've filed patent applications. :-)

41282. jdixon1980 at 05:36 AM on 22 October 2013
       Two degrees: how we imagine climate change
       

       panzerboy @7: "Perhaps someone could point out where this 10,000 times rate comes from, or the error in my arithmetic?"  

       Someone already did, chriskoz @3: "That statement is not in the right ballpark (rate too fast), because in reality AGW's happening in hundreds of years, so ~1000 times faster that Milankovic forcings."   (you responded @5)

       In other words, it was apparently an error, typographical or of calculation or understanding.  

       panzerboy @8: "exaggeration" suggests a deliberate overstatement, but if "10,000 times" were intentional "alarmist" misreporting, why would the author in the same breath understate the length of a Milankovitch cycle period by a factor of 1,000 (or of the warming swing of the cycle by a factor of about 10) by saying "hundreds of years," if he were trying to overemphasize how much slower "natural" temperature swings have been than the current anthropogenic one?  

       I rather suspect that both "hundreds of years" and "10,000 times" were honest mistakes.  I have a hypothesis of how at least the "hundreds of years" mistake may have come about - take a look at the context: 

       
       "But these events happened 18,000 years ago, over a timeframe of hundreds of years . . ." 

       If "hundreds" were replaced with "hundreds of thousands" the sentence would read a little funny.  It would be strange to say that events occuring over a hundred thousand years "happened" 18,000 years ago, because the events had to begin happening much longer ago than that.  On the other hand, an event that occurred over the course of a couple hundred years could be referred to as "happening" 18,000 years ago - the event could have both begun and ended 18,000 years ago plus or minus 1,000 years.  Based on that reasoning, maybe an editor at The Conversation assumed that the author meant to say "hundreds" rather than "hundreds of thousands," and made a last minute change before publication without consulting the author.  It seems to me that the change should have been from "these events happened 18,000 years ago, over a timeframe of hundreds of years" to "these conditions culminated 18,000 years ago, having occurred over a time frame of [hundreds of thousands / a hundred thousand] years."  

        

       Re: "more likely 30x slower" - I am not a climate scientist, but that does sound like it could be accurate based on my understanding that the warming leg of the Milankovitch cycle is typically only a few thousand years, and the current pace to +2 degrees C is about 200 years, 200 x 30 being 6,000.  However, I wouldn't jump to accuse the author of "exaggeration," if for no other reason than the fact that one who deliberately exaggerates would not tend to do so in opposite directions.  

41283. old sage at 05:06 AM on 22 October 2013
       It's waste heat
       

       Michael Sweet - damnit man get your graduate level books on the kinetic theory of gases out before you get hysterical about heat transfer mechanisms you clearly do not understand. At the simplest level taking 98% of the atmosphere - N2 and O2 - is transparent to visible and i/r radiation- so poor absorbers make poor emitters at school book level. Check out the values of the virial coefficients and make an effort to understand them. Atmospheric gases pass heat around by kinetic movement, they need to get up to thousands of degrees - or break down in vacuo under high voltage - before they radiate.

       Scad:  weight of atmosphere = 5.1x10^18 kgs approx  1.7x10^20 mols

       Oil production 3.1x10^10 b/yr each giving 6.1x10^9 joules = 4.5x10^19 cals

       
       Specific heat of gases in atmosphere all about 6 cals/mol/deg. That equates to 4.4x10^-2 degrees rise in T. Then you must add in gas, nuclear, coal - I've done this but cannot lay hands on figures just now but it just about doubles the effect. That is using the measured and recorded outputs for sale (2012) - how inefficient are these industries so what extra would you add?

       QED

       Climate models are bedevilled by large numbers which in the absence of man's mining of surplus solar energy from millenia past, not to mention that in the nuclear atom from creation, balance.   It is a strange coincidence that this extra impost together with other impacts of man's industry is about right as explanation.

        

        

        

41284. vrooomie at 04:41 AM on 22 October 2013
       2013 SkS Weekly Digest #42
       

       Rather than Atlas, perhaps it should have been Sisyphus, letting the Eaarth (<----not a typo) just roll down the hill...:(

41285. grindupBaker at 03:45 AM on 22 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       @DSL #87 Re your closing paragraph, but persons genuinely attemping to  explain this phenomenon to the public in the past have also focussed on GMST. It's been my assumption that climate scientists have discussed GMST as the "warming" because that's what they can get (to varying degrees of coverage) from paleoclimate proxies. I've assumed they don't have paleo-ocean-heat-Kj otherwise it would have been discussed. Logically, this part of the topic would be split into the ocean warming heat and the surface symptoms. Thus they've given the mischief makers a nice phoney tool through no choice of their own. Based on my observations of others' comments there's a significant portion of the public who will never be able to grasp this topic.

41286. kar at 01:31 AM on 22 October 2013
       Science of Climate Change online class starting next week on Coursera
       

       I think I see a way to improve the lecture a bit:
       The videos (as in the above example tagged: here (8:13) ) which is less than 10 minutes lecture - is a more than 400MB huge *.MOV file.

       Maybe the lecture videos should be added into YouTube-format for easy broadcasting without having to download locally?

41287. Stephen Leahy at 00:52 AM on 22 October 2013
       ONLY HOURS Left to Be Part of a New Collaborative Approach to Media Coverage of Climate
       

       Thanks Doug. You make our case better than I did!

41288. DSL at 23:20 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Not alone, Andrew.  I've argued with people who claim that there is a natural cycle at work over the last 150 years.  They've pointed to Excel graphs that show GMST smoothed to the point that it looks kinda like a sine wave.  They then argue, based on that pseudo-sine, that we're about to go into a period of cooling.  I ask if they believe that solar variation drives temperature.  They say of course it does.  I then point out that solar has matched GMST pretty well over the last 1000 years, but over the last fifty solar has been flat or falling.  Temp, however, has risen rapidly.  I then ask where that leaves their sine.

       The surface signal is composed of solar input, greenhouse forcing, anthro and natural aerosols, ocean-troposphere oscillations, and a variety of feedbacks.  The short-term oscillations provide uncertainty in attributing and projecting the short-term trend.  The long-term trend is dominated by solar, GHG, and aerosol changes.  GMST is the result of all of that in one trend line.  

       Worse yet, the surface/troposphere is a tiny portion of the overall thermal capacity of the system.  The oceans are the overwhelming thermal capacitor of the system.  Thus, even if you could draw any conclusions from GMST, you couldn't draw any conclusions about global warming.

       Why, then, does mainstream media focus on GMST?  One or more of the following: 1) the writer thinks the audience is too dumb to understand the details; 2) the writer doesn't understand the details; 3) the writer doesn't want the audience to understand the details; and 4) the writer thinks the audience doesn't need to understand the details, since GMST is the most directly relevant result.

        

41289. scaddenp at 17:47 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Andrew, the physically situation is easily examined physically and has been done so. I suggest you look at the "The history of climate science" and "the Big picture" button at the top of the home page for starters on this. The radiative properties of GHG have been known for a long time. The increase in radiative forcing is directly measured. However, the physics might be understood, but that doesnt necessarily make it easily modelled. It is especially hard to make short term projection - for much the same reason as micro temperature changes within the beer. Its easier to predict next's year monthly average in summer than to predict the daily temperature in 10 days time. Climate models have no skill at predicting surface temperature on decadal scales and dont pretend to be. They are skillful at long term trends. 

41290. Andrew7x8 at 17:21 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       DSL and scaddenp, thanks for the reply. Imagine that the physical situation cannot be investigated for some reason (possibly temporarily). Is there any scientific statement that can be made by examining how the temperature changed over time. For example, it may have tended to a limit, changed linearly, increased exponentially, or shown some periodic behaviour. Can any scientific statements be made based on the temperature record?

41291. grindupBaker at 17:06 PM on 21 October 2013
       Does the global warming 'pause' mean what you think it means?
       

       @Dean #16 You might want to first look 1 step back at the foundation. GEOPHYSICAL RESEARCH LETTERS, VOL. 40, 10 May 2013 pp 1754–1759 is 6 pages of "Distinctive climate signals in reanalysis of global ocean heat content" by Magdalena A. Balmaseda, Kevin E. Trenberth and Erland Källén with the graph  & description of the ORAS4 reanalysis. Sure, they use models which can therefore be argued but my inference is that these are to interpolate in time & space between ocean temperature data from the 7,000 Argo floats & huge numbers of XBTs (I seem to recall climate scientist saying 240,000 in a video) which are sparsely spread at depth and back in time decades ago. Where you and I would simply average between the two distant measurements, I presume their fancy computers do a better job than a linear interpolation by simulating how the ocean moves. But basically it's underpinned by 7,000 Argo floats <huge numbers> XBTs.  With all the work they've done it just doesn't look like they could have messed it up so badly that the 137 ZettaJoules they graph being added to the oceans from 2000 to 2012 could be off by any amount that's a game-changer. I doubt very much that the climate sensitivity IPCC uses is based on what's been seen, I think the big increase since 2000 is at the lower IPCC feedbacks. I infer that IPCC is using the models and I infer that they show increasing feedbacks so what we've seen so far hasn't even reached the lower end of the forcing+feedbacks they expect.

41292. Doug Bostrom at 15:42 PM on 21 October 2013
       ONLY HOURS Left to Be Part of a New Collaborative Approach to Media Coverage of Climate
       

       Let alone climate science coverage, more and more as a public we're expected to offer useful guidance on policy hinging on science in general.  Without the help of competent science journalism we may as well be making decisions by throwing darts over our shoulders. As Stephen says, tragically for all of us science journalism is a vanishing species of news content, even as it is more necessary than ever before.

       The project Stephen describes will help provide a vital breath of life to science journalism in general, beyond the topic of climate change; fostering and encouraging young journalists to cover scientific topics will be richly rewarding for us all as we try to shape our future in a properly informed manner.

       So go forth and multiply! Don't look left, don't look right, just go. 

41293. scaddenp at 13:13 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Andrew, further to that - accurate prediction is about understanding what is happening and why. Quantification means being able to model the process with well-understood physics.

41294. scaddenp at 13:08 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Andrew, the question is why is the bottle of beer warming. If you postulate that say it is warming because the air temperature around it is warmer than the beer, then you could determine things like thermal properties of glass and beer, and then see whether observed warming was consistant with Fourier law. That doesnt mean hypothesis is proved - there could be a say a chemical reaction due to an additive to beer and an masking refridgerator element to give rates consistant with Fourier law - but it does give you some confidence in then using simple heat transfer to predict the future state of the bottle temperature.

       However, if you had a network of very accurate thermometers within the beer, then you would observe more complex temperatures changes going on within the fluid because of internal convective currents within the bottle. Predicting the evolution of temperature on these thermometers would be a very complex task with a lower degree of predictability. However, if the beer is cold and room is warm, you have little difficulty in predicting the average temperature of the beer  over say 10 minute intervals and how fast it will warm to room temperature.

41295. DSL at 13:04 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       Andrew7x8, no.  Analysis of the physical situation is required.  Simply extrapolating a trend in that way can leave one literally dead.  If I stand in the middle of the street and am not hit by a car for 10 minutes, does it mean that I will never be hit by a car?  If we know why the bottle is warming, we can assess how long the conditions are likely to persist.  We know why the climate system is warming, and that--not the surface trend--tells us that it's likely to persist for centuries.

41296. jerryg at 12:45 PM on 21 October 2013
       Does the global warming 'pause' mean what you think it means?
       

       Michael M - didn't they have a higher confidence level above 4.5 C than they had for less than 1.5?

41297. Andrew7x8 at 12:23 PM on 21 October 2013
       Why climate change contrarians owe us a (scientific) explanation
       

       If a scientist observed a bottle of beer warming on a table, and noted how the temperature changed over some time interval, could they make a scientific statement about the warming, and/or predict the future temperature?

41298. scaddenp at 11:01 AM on 21 October 2013
       It's waste heat
       

       And just a more realistic calculation:

       With average surface temperature at 288K you have surface heat flux of 390W/m2 (see Keihl and Trenberth for measurement details - but matches Stefan-Boltzmann law pretty well - try it yourself). Increase heatflux by 0.028W/m2 and you get a temperature increase from S-B law of 0.0052, with emissivity of 1. A very long way from 1/10 degree.

41299. Doug Bostrom at 09:16 AM on 21 October 2013
       2013 SkS Weekly Digest #42
       

       First-person views of adaptation to climate change, via Australian firefighter helmet cameras. 

       Adaptation is a deceptively soft word. 

41300. scaddenp at 08:20 AM on 21 October 2013
       It's waste heat
       

       "Given that waste heat is readily shown to equate to warming the entire mass of the atmosphere by some 1/10 deg p.a."

       No it doesnt. Perhaps if you show us your working, it might help pinpoint your misunderstanding but you seem to be missing the very basics of physical understanding here. You cant just turn bits of physics off (like Planck's law) and try an compartmentalize things by looking at only part of the processes at work.

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