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scaddenp at 08:26 AM on 22 October 2013It'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?
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Doug Bostrom at 07:59 AM on 22 October 20132013 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.
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Tom Curtis at 05:58 AM on 22 October 2013It'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.
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jdixon1980 at 05:44 AM on 22 October 2013Two 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/
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Doug Bostrom at 05:38 AM on 22 October 2013It'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. :-)
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jdixon1980 at 05:36 AM on 22 October 2013Two 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.
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old sage at 05:06 AM on 22 October 2013It'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.
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vrooomie at 04:41 AM on 22 October 20132013 SkS Weekly Digest #42
Rather than Atlas, perhaps it should have been Sisyphus, letting the Eaarth (<----not a typo) just roll down the hill...:(
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grindupBaker at 03:45 AM on 22 October 2013Why 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.
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kar at 01:31 AM on 22 October 2013Science 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?
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Stephen Leahy at 00:52 AM on 22 October 2013ONLY 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!
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DSL at 23:20 PM on 21 October 2013Why 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.
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scaddenp at 17:47 PM on 21 October 2013Why 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.
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Andrew7x8 at 17:21 PM on 21 October 2013Why 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?
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grindupBaker at 17:06 PM on 21 October 2013Does 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.
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Doug Bostrom at 15:42 PM on 21 October 2013ONLY 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.
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scaddenp at 13:13 PM on 21 October 2013Why 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.
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scaddenp at 13:08 PM on 21 October 2013Why 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.
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DSL at 13:04 PM on 21 October 2013Why 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.
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jerryg at 12:45 PM on 21 October 2013Does 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?
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Andrew7x8 at 12:23 PM on 21 October 2013Why 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?
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scaddenp at 11:01 AM on 21 October 2013It'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.
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Doug Bostrom at 09:16 AM on 21 October 20132013 SkS Weekly Digest #42
First-person views of adaptation to climate change, via Australian firefighter helmet cameras.
Adaptation is a deceptively soft word.
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scaddenp at 08:20 AM on 21 October 2013It'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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michael sweet at 08:09 AM on 21 October 2013It's waste heat
Old Sage,
You need to go back to High School. In my High School AP Chemistry class, the students learn that heat is heat. It does not matter if it comes from the sun or from waste heat, it is the same once it gets into the atmosphere. When you say absurd things like:
"Waste heat is almost entirely applied to the kinetic heat of atmospheric gases and it is trapped until transported by mass transfer down prevailing winds to cooler regions. It cannot get out by radiation."
and
"Gases under the conditions applying to the vast bulk of the atmosphere do not convert their kinetic energy into e-m radiation."
everyone else knows that you have no idea what you are talking about. Please provide scientific references for your wild claims. I note that you have provided no references, only unsupported assertions of fact. In fact, like all the rest of matter in the universe, the atmosphere radiates black body radiation. The energy from waste heat is radiated into space like the much greater amount of energy that is received from the sun. What possible mechanism could differentiate the heat from the sun and the heat from waste heat? Heat is heat.
Keep in mind that this is a scientific board. Other people know what they are talking about even if you do not.
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chriskoz at 06:57 AM on 21 October 20132013 SkS Weekly Digest #42
An interesting news on the NSW fires worth pondering on.
state of emergency declared as bushfire conditions worsen
Extraordinary precaution policy have been activated by the premier - forced evacuation by police and demolition of buildings if necessary. That's what he said inexplanation:
"I'm sure it will be [controversial]. There isn't much in the fire-management business that isn't controversial … But I'd rather be copping criticism in two or three days' time for what didn't occur."
Note that this is the same person who denies the necessity to address global warming (essntially repeats the talking of his federal counterpart and colleage Tony Abbott) thus does not make a connection between those two issues. Obviously, he may not be facing the consequences of the related issue yet, but his successor definitely will.
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Tom Curtis at 06:22 AM on 21 October 2013IPCC model global warming projections have done much better than you think
John Hartz @114, the Summaries for Policy Makers are "approved" by the IPCC, ie, subject to line by line debate and voted on, line by line. In contrast, the reports themselves are only "accepted", ie, they are voted on to be accepted as a block. Consequently, while box 9.2 (the discussion of the hiatus) may have been composed with the comments of non-scientists in mind, it was composed by scientists and not subject to individual veto as to its wording. I am unsure as to whether the government representatives would have had to reject all of chapter nine, or all of the WG1 assessment in order to reject the wording in box 9.2, but their failure to do either cannot be regarded as constituting specific editorial control over the wording of the box.
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old sage at 06:06 AM on 21 October 2013It's waste heat
I haven't replied to my various critics here before because I despair of the disconnect between the various scientific principles others have cited and the context in which they haver been applied. What makes Physics a difficult subject for some is that what is true under some conditions can be just the opposite under others.
For instance a factor of 100 is argued above as the difference between waste heat and GHG forcing so the former is therefore irrelevant to global warming. Given that waste heat is readily shown to equate to warming the entire mass of the atmosphere by some 1/10 deg p.a., the two numbers must be describing totally different things. Waste heat is almost entirely applied to the kinetic heat of atmospheric gases and it is trapped until transported by mass transfer down prevailing winds to cooler regions. It cannot get out by radiation. If GHG forcing is supposed to measure the rate at which GHG's are heating the atmosphere, then I'd like to know where it is going because at 100 times waste heat it is unsupportable. Gases under the conditions applying to the vast bulk of the atmosphere do not convert their kinetic energy into e-m radiation.
The energy balance of the earth's atmosphere has been exactly zero to all intents and purposes for thousands of millions of years. The perturbation represented by waste heat applies to scales in balance by natural processes and it is large incomparison with zero. It is moreover, bang on quantum for the scale of consequences observed.
The emphasis on CO2 by the IPCC is tantamount to saying the carbon cycle governs Earth's temperature. In that case, how did it get to support life in the first place? Earth has an extremely robust set of physical properties which have returned equilibrium after cataclysmic events. It could even be argued that the burning of fossil fuels by increasing CO2 and reducing O2 would cause more sunlight to be sequestered by photosynthesis according to proven chemistry principles thus tending to lower energy available for heating - given we had not swapped vegetation for concrete.
We might understand the warming better if we took account of the physical stabilisers. Stefan and T^4 applies to the huge inertia of the global surface. Any perturbation due to an atmospheric source - eg CO2 - of tiny inertia would have to be seriously amplified before any correction kicked in from Stefan.
An exception is water which vapourises relatively easily. Far and away the most responsive physical property to a warmer globe is more vapour. That means more condensate higher up absorbing and re-radiating near the TOA so reducing takeup of solar energy.
Another property is the vigour of the atmosphere related to which will be activity in the plasma which floats upon it and in the earth's field. That will act as a generator as will violent electrical storms and they emit energy in the visible spectrum as well as longer. More than half of that will escape earth due to geometry.
So the CO2 argument is a simplification which buys time for those who worship the totem of economic growth- mostly from population increase - the real source of mans climate impact. It is far more multi-faceted than that but then the drive to claw back energy from sun and wind does indicate that despite the apparent lack of economic justification someone has worked it out. -
Michael.M at 05:11 AM on 21 October 2013Does the global warming 'pause' mean what you think it means?
Vroomi, yes, I also have the problem with the tingly anntennas....
Dean, you may have a problem regarding uncertainty: There is a likelihood, that the equilibrium sensitivity is as low or lower than 1.5 - but you forget that uncertainty is not or friend! Because there ist just (or nearly) the same chance, that the equilibrium sensitivity is as high or higher than 4.5°C. On my part the best message in the whole sensitivity discussion ist that it is very unlikely to be higher than 6 degrees. (Judith Curry once, pushing uncertainties as always, claimed the ES may be up to 10 degrees .... that was the scariest "argument" I ever heard, let alone from a "sceptic")
A discussion to ES, in german: IPCC 5 - Uneinigkeit zur Klimasensitivität
Discussion with AR5 , graphs pages 172(ES) and 173(TS)
PS: Dana, with your Enigo Montoya reference you made my day! :-D -
Dean at 04:41 AM on 21 October 2013Does the global warming 'pause' mean what you think it means?
vrooomie and Matt, I don't think that there is anything particularly wrong with main stream climate science and I respect the IPCC reports as goldmines of scientific information. But I have spent a fair amount of time arguing with "skeptics" and would like to have a consistent understanding of the current state of knowledge.
As I wrote, I cannot reconcile the lowered equilibrium sensitivity (lower end) with Dana's explanations about the "pause", At least one expert has claimed: "The lowering is based on one narrow line of evidence: the slowing of surface warming during the past decade".
But if the "pause" has nothing to do with weaker feedback mechanisms, this a contradiction. Larger natural variations even points to stronger positive feedbacks.
Reading through the report there is quite a lot of mentioning about the period 1998-2012. But there is no systematic scientific reason for this, it is cherry-picking. As a non-expert I don't really want to claim that the IPCC authors are wrong, but lets say I'm rather skeptical against some of their assessments and would like to have confirmation that the lowering wasn't just due to the massmedia/politically driven pressure.
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John Hartz at 02:55 AM on 21 October 2013IPCC model global warming projections have done much better than you think
@VeryTallGuy #112:
Also keep in mind that non-scientists had a hand in crafting the final wording of the WG1 summary report.
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vrooomie at 02:08 AM on 21 October 2013Does the global warming 'pause' mean what you think it means?
"Was he not just asking that, given the ocean's ever-increasing heat content (as per the article) and despite the cool sun/La Nina dominance slowing surface temps very little, how could the IPCC possibly extend the lower bound of projected ECS down to 1.5degC? "
Not sure, and it's why I asked. As a long-time veteran of seeing deniers creep into conversations here and across the Web--and I am NOT asserting Dean is one--I have 'tingly antennae' about curious questions like that, ergo, why I asked, Dean hopefully will lean in and elucidate further on his intent, and I'm happy to hear it out.
Remember that the IPCC bases it reports on the severe side of 'least drama,' given the makeup of its constituent membership: their downgrading CS may or may be a function of that, or, perhaps more likely, is a function of science doing as it always does, and should: consider ALL rational, data-driven conclusions.
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Matt Bennett at 22:09 PM on 20 October 2013Does the global warming 'pause' mean what you think it means?
vrooomie,I'm sure he'll correct me if I'm wrong but I didn't read the second part of Dean's post as questioning the science, as you appear to have potentially identified it?... Was he not just asking that, given the ocean's ever-increasing heat content (as per the article) and despite the cool sun/La Nina dominance slowing surface temps very little, how could the IPCC possibly extend the lower bound of projected ECS down to 1.5degC? Oncologists aside, doesn't he agree with you that this seems an unlikely scenario? -
Doug Bostrom at 05:23 AM on 20 October 20132013 SkS Weekly News Roundup #42B
jyushchyshyn, it's a sad fact that human nature dictates we respond better in aggregate to price signals than common sense. Of course you're technically speaking correct in saying we can solve this problem by ending demand for hydrocarbons as fuel, but in reality we won't do so without encouragement in the form of our wallets deflating more quickly.
Let alone the awesomely nasty nature of Canada's own Mordor, each and every source of petroleum that is removed from our imperfect accounting system helps to contribute a little bit to our price signaling.
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jyushchyshyn at 03:54 AM on 20 October 20132013 SkS Weekly News Roundup #42B
re Canada’s efforts accelerate a global tragedy of the climate commons
Let's stop one pipeline and call the problem of global warming solved, and continue to burn coal, drive SUVs and import OPEC oil.
If you want to stop new pipelines from being built, cut them off at the source. Switch to the new energy sources and there will be no demand for the oil which new pipelines would deliver.
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vrooomie at 02:31 AM on 20 October 2013Does the global warming 'pause' mean what you think it means?
Dean, not sure how to answer your question at 16, but your post certainly does raise my antennae..suppose a team of *extremely* well-educated experts in a given field--say, oncologists--have studied my files, data, and extensive and comprehensive collection of CT scans and arrives at an opinion--a consensus, if you will--of my having an 83% chance of dying from an aggressive cancer.
How would it be rational, for me, to exclaim, "Well, shootfire, boys! That means I have a fair 17% chance of all of you, being wrong!" I'm asking the question because the final part of your post made me twig at the rest. would it be rational for me to proceed with the experts' 83% estimate of my mortality, or to run with the slim chance that 17% of them felt there was no worry?
I am sure the brainiacs among the SkS team can certainly address the first part of your post, and I am also interested in that, given how bad I am at stats.
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Dikran Marsupial at 00:39 AM on 20 October 2013IPCC model global warming projections have done much better than you think
Conventional statistical regression cannot be used to make reliable caual inferences as they are based on correllations, and correllation is not causation. They can be use to show that X can explain Y, but we cannot say that X does explain Y as there may be some other cause that is not represented in the model, or there may be confounding variables, etc. If this were not the case, we could regress GMSTs on the surface area of ladies undergarments and conclude that CO2 does not cause climate change
Underwear (to some extent) can explain global warming, but that does not mean that to any extend underwear does cause global warming. Likewise, the fact that including ENSO in a regression model add explanatory power, that does not mean that ENSO is the cause of the variability it explains.
The use of models similarly shows that ENSO can explain the variability in GMSTs, but it doesn't establish that it actually has caused the hiatus. The reason it does not is because we cannot be absolutely sure that it explains it for the right reason (note constraining SSTs means that the transfer of energy between the air and ocean does not obey the laws of physics correctly).
Now the fact that we cannot obtain certain knowledge from observations means that in practice we need to use other criterion, such as theory, to arrive at the best explanation of the data. Thus I have no problem at all if someone finds the regression models sufficiently convincing to be sure that ENSO is the cause of the hiatus (which is actually fairly close to my position - I'm pretty confident that it is just ENSO), but the regression model itself does not establish a causal link.
VeryTallGuy - generally the IPCCs comments are well thought through, provided they are interpreted as clear statements of the scientific position, expressed by scientists who know the issues well, intended as statements for the record. They are not however generally well worded as statements intended to resolve misunderstandings in the blog debate on climate, nor are they expressed in terms that prevent any possibly (even willfull) misunderstanding. I think the IPCC are doing the right thing in expressing the science in a manner designed for a primarily scientific audience.
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Paul Pukite at 00:02 AM on 20 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
Tom Curtis,
Healthy skepticism is warranted. I have more info here on the general approach:
http://contextearth.com/2013/10/04/climate-variability-and-inferring-global-warming/
The October 1943 spike is the single anthro effect I added apart from CO2. You can turn that off by checking off anthro aerosols. I added that because since the overall agreement is so good, one can really start to look at particular points in time for further evaluation.
All the lags can be modified by the user. You can turn all of them off by setting the lags to zero. The agreement is still good.
The application of the LOD (length of day) is crucial as a proxy for multidecadal oscillations. This ensures conservation of energy and conservation of momentum according to work by Dickey et al at NASA JPL [1]. The fluctuations in kinetic energy have to go somewhere and of course changes in temperature are one place for this dissipation.
As far as volcanic disturbances, I took the significant ones from the BEST spreadsheet of Muller. If you can point me to the volcanic fording data from GISS, I can use that instead. Thanks !
[1] J. O. Dickey, S. L. Marcus, and O. de Viron, “Air Temperature and Anthropogenic Forcing: Insights from the Solid Earth,” Journal of Climate, vol. 24, no. 2, pp. 569–574, 2011.
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Dean at 22:57 PM on 19 October 2013Does the global warming 'pause' mean what you think it means?
There is one thing that I don't understand. It said that the IPCC lowered their likely equilibrium sensitivity interval from 2-4.5 to 1.5-4.5 due to the "pause" (or rather due to simplified models that were very sensible to this kind of short term variability). Independent paleo data, GCM:s and observations of feedbacks does not support any (likely) values <2.
But if the climate system even accumulated more heat during the "pause", as claimed in the blog post, despite weaker sun and (probably) stronger negative aeorosol forcing, how can this be consistent with the IPCC assessment update, including a fair chance (17%) of sensitivity being even <1.5?
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VeryTallGuy at 17:29 PM on 19 October 2013IPCC model global warming projections have done much better than you think
Dikran, Tom,
thanks for the perspectives, very interesting and appreciated. I must admit, compared to much of the IPCC output the bit on the "hiatus" comes across as not particularly well thought through. -
Doug Bostrom at 14:39 PM on 19 October 20132013 SkS Weekly News Roundup #42B
Re the mess caused by the shutdown, I'd like to see a clearinghouse set up for researchers to describe the impact on their work.
I know of a major meeting here in Seattle to do with earthquake resilience that was thrown into chaos thanks to the GOP's psychotic clown posse. Researchers coming in from New Zealand and other places at great expense arrived to find that their USGS counterparts could technically face fine and imprisonment* for meeting as agreed, ages ago. Not only were we wasting our own time but that of others. We're also destroying our credibility as reliable partners.
Other people I know faced similar absurd problems. Seeing all of this waste summarized in one place would be helpful and instructive.
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bwilson4web at 13:53 PM on 19 October 2013Does the global warming 'pause' mean what you think it means?
Maybe I missed it but claiming something about a change in the slope of global warming is nonsense. Now if the sign of the slope changed, I'd be interested but to quibble about the value of the slope?
The honorable global warming deniers are face with some hard, undenible facts. Arctic shipping through the NorthEast and NorthWest passage exceeded 1 million tons in 2013. It was 1.2 million tons in 2012 and similar numbers of ships, tonnage unknown, in 2011. The practical effect, the business effect, is Arctic shipping is open for the third year in a row.
So if this is just a slope problem and not a sign, hammer them away with "Is it cooling now?"
Bob Wilson
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Manwichstick at 12:54 PM on 19 October 2013Does the global warming 'pause' mean what you think it means?
I just rebutted a piece by a local TV meteorologist here in Toronto, and I used an "office building analogy" to explain the pause in global warming.
See what you think of it. I'm wondering if I subconciously "borrowed" it from someone here at SKS...
The scientists understand how “temperature” is not the same thing as “heat”. They have a good understanding of how surface temperatures are coupled to global heat content and how ocean currents affect surface temperatures. Farnell’s point is false because surface temperatures can drop while the Earth still warms (over short time periods). The folly of point 1) can be illustrated with this example:
Imagine an office building with 10 floors. Now picture yourself sitting on the 10th floor of the building and making this claim,
“No one must be entering this building since the number of people on the 10th floor has not gone up.”
Imagine making that statement above while simultaneously looking out the window and noticing the number of people entering the building is greater than the number of people leaving the building. Point 1) is like that. Its conclusion does not follow from its premise, and it is observably wrong. -
gws at 09:07 AM on 19 October 2013Does the global warming 'pause' mean what you think it means?
caroza @12
hmmh, an analogy may be a bedroom: the person in bed is the heat source, the blanket the top layer of the ocean, the air in the room all deeper layers; the bedroom is thermally well insolated. Findings, with heat source constant:
- the blanket heats up quickly but then stays at equilibrium Temp., the air in the room will heat up more slowly over time although the blanket does not change Temp. any more
- if you shake out the blanket regularly (ENSO), then put it back in place, it will cool a little temporarily while the room keeps heating
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Tom Curtis at 07:26 AM on 19 October 2013IPCC model global warming projections have done much better than you think
VeryTallGuy, first (and with all respect), Dikran Marsupial has misinterpreted me. I do say that ENSO is the dominant cause of the "hiatus" (better, slowdown), not that it could explain it. Of course, it is always possible that I am over interpreting the evidence, and that Dikran's claim is more accurate given the evidence. That would be the case if global warming would have accelerated absent all factors contributing to the slowdown. In that case, the contribution of ENSO could be sufficient to almost completely explain the reduction in short term observed trend relative to the long term observed trend, but changes of forcings could likewise explain a similar amount. In that case, temperatures without these short term influences would have accelerated to an approx 0.25 C per decade warming trend.
With respect to my actual claim, however, it is not inconsistent with that in the IPCC. To be specific, my claim is that, when compared to all other individual factors influencing the slow down in global temperature rise, ENSO has a significantly larger influence than any other individual factor; and that the influence of ENSO is not much smaller (if smaller at all) then the sum of all other factors. That is what is mean by "dominant". In contrast, the IPCC claims that the sum of the influence of natural variability is not much different from the sum of the influence of changes in forcing. Thus, there may exist natural variability of opposite sign to the ENSO influence, reducing the net impact of natural variability relative to the net impact of changes of forcings. Or the influence of ENSO based natural variability may be greater than the combined influence of changes in forcing, with the two individual factors contributing to change in forcing each individually being significantly smaller than the ENSO influence. In both these cases, both my claim and that of the IPCC would be correct.
A third possibility is that the IPCC understates the influence of natural variability. Given that the IPCC did not have access to Kosaka and Xie (published online in late Aug 2013, and not included in the IPCC references), that is plausible. Equally plausibly, a new study may come out showing Kosaka and Xie's result to not be reproducible, or to have overstated the influence of ENSO (in which case my opinion would revise back towards that of Dikran Marsupial and the IPCC).
So, to summarize:
1) My claim, which assumes a linear base trend in global temperatures, may be incorrect and the IPCC's correct because global temperatures would have shown an accelerating trend absent both the ENSO influence and the reduced forcings;
2) We could both be correct, with the ENSO influence on the lower end of what I expect based on the evidence but still the dominant influence (ie, greater than 50% and >> than any other individual influence);
3) Either I or the IPCC could be wrong, they because they present a snapshot of the science as it existed 6 months ago; or I because the most recent evidence (on which I rely) is overstated in some way.
Finally, I note that the IPCC discuss the influence of the PDO rather than ENSO. That is not a difference between us in that the two are closely related, with PDO states causing dominant influences of La Nina or El Nino (depending on whether the PDO is +ve or -ve) in ENSO; or because the PDO is just a filtered effect of ENSO on the north Pacific. (SFAIK, it is not as yet clear which of these is the case.)
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Tom Curtis at 06:38 AM on 19 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
WebHubTelescope @190, can you direct me to documentation justifying the SALT model method, because on a casual perusal I am far from impressed.
My initial concerns were raised by the tunable, and different lags for different forcings. If you allow yourself to tune lags, I am sure you can get some very good fits between models and observations, but a physical explanation as to why solar forcings should have half the lag of anthropogenic forcings, and nearly one sixth that of volcanic forcings is decidedly lacking.
On closer inspection, I am even more perplexed. The "fluctuation components" show a very large, unexplained "linear" adjustment peaking at 0.396 in Nov 1943, and apart for its rapid fall off, is essentially zero at all other times. That is by far the largest single fluctuation value on the chart, and has no apparent physical basis. The lod adjustment is also unexplained (what does lod stand for?) and is certainly not a component of the GISS model forcings. Further, the volcanic "fluctuation component" does not match the GISS model forcings from the 1920s to 1940s.
Without documentation, it appears from the "fluctuation components" chart that arbitrary "fluctuations" are added as necessary to ensure a fit between model and observations. If so, we should be less than impressed that a fit is then found.
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caroza at 05:41 AM on 19 October 2013Does the global warming 'pause' mean what you think it means?
dana @ #5, would it make sense that as the oceans warm overall, upper layers might cool? I remember reading years ago (can't remember where, sorry) that as the ocean warms it mixes better and becomes less stratified. I assume that's still true although I don't know what sort of temperature increment results in what sort of degree of mixing. But it occurred to me at the time that as the deeper ocean warmed, if it mixed better with the layer above 2000m then that might cool the upper layer (for a while), given that the volume of water below 2000m is so huge by comparison to the thin upper layer, and relatively cold, so a tendency in the direction of thermal equilibrium might reduce upper layer temperatures.. Is that a possibility? Sort of analogous to the weakening jet stream resulting in weather which is warm by Arctic standards but very cold by British or European standards dumping snow and ice all over Britain and Scotland and making the deniers happy because of the snow in their back garden.
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Doug Bostrom at 05:38 AM on 19 October 2013Does the global warming 'pause' mean what you think it means?
Sou at Hot Whopper has posted a pleasingly concise explanation of the major fallacy of Bob Tisdale's attempt to reply to Dana:
Bob Tisdale rejects the greenhouse effect
The seemingly rude title of the piece is unavoidable due to Tisdale's conclusions; the title is not impolite but is neutrally descriptive of the logical box Tisdale has constructed around himself.
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ajki at 04:17 AM on 19 October 2013IPCC model global warming projections have done much better than you think
Perhaps the best way of showing the effect of removing *some* of the more or less known "internal variables" is... well, show it:
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Paul Pukite at 04:11 AM on 19 October 2013Why Curry, McIntyre, and Co. are Still Wrong about IPCC Climate Model Accuracy
For SteathGuy, I would recommend looking at energy balance models first. Go over to this web site that generates model-based fits to various temperature series and intereract with the graphs:
http://entroplet.com/context_salt_model/navigate
I spend too much time at Curry's site tryin to reason with the skeptics and I at least give you credit for trying to construct a somewhat methodical argument. I just suggest that instead of looking at the GCMs at first, that you try to pull apart the possible independent factors that give rise to subdecadal and decadal climate variability. The snaphot below is a view of an interface that you can play with and see how the various lags have an effect on volcanic disturbances, TSI, etc.
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