I thought I asked about this in a different thread, but I couldn’t find my question.
Are the results of this study inconsistent with the UAH TLT or TMT trends?
[Response: Good question. You can (now) read the paper for yourself and see. The answer is partly that our data covers the pre-satellite era, so you can't tell. But for 1979-on, we don't get the same results as MSU. Our answer to that is not to trust MSU in these regions; I understand that Christy disagrees on that. This too will be an interesting debate - William]
Another question. Are these findings evidence of polar amplification? It seems so, but there seems to be a weak link; the paper states the chages are what would be expected as a result of increasing greenhouse gasses, but is unable to make an unabigous attribution. My impression is that models have known weaknesses in simulating Antarctic climate. Is it reasonable to expect model improvements will resolve this?
[Response: As far as I'm aware, this isn't polar amplification. There is some possible speculation about this being because of the cold dry atmosphere, but at this stage thats just hand-waving - William]
Why are scientists from the British Antartic Survey (http://news.bbc.co.uk/1/hi/sci/tech/4857832.stm) stating that the reason for the warming in unclear and that (IPCC) climate models appear to be incorrect and have not shown this warming.
This is running counter to what realclimate appears to be stating ?
[Response: There is no contradiction. The BBC (of course) over simplifies. In our paper, we looked at 4 ensembles of the HadCM3 model, not the full range of AR4 models. Some of those ensembles showed warming looking like the obs; some rather less like the obs. The average of them showed warming, but not as much as the obs. So, as I say, this complicates the interpretation of these results. Science isn't always neat and tidy! - William]
I know that Science is not always neat and tidy ! However it would be best if Science gave a unified front on climate results, average people reading the BBC article will assume that science is a load of twaddle and climate chnage is just a left wing conspiracy to stop everyone from enjoying themselves.
[Response: Not sure what you mean by Science with a capital S. I mean, the magazine. But whether we mean the magazine or the enterprise of Science, I don't agree with your point: science should be presenting what we know. Arguably, organisations like the BBC have a responsibility to attempt to integrate this for public consumption: sadly they often seem to do the reverse (differentiate things?) by promoting "excitement" - William]
on it but it’s not totally convincing in that it really just says that a lag is not inconsistent with CO2 being a key contributor. It seems to rationalize the lag away a bit.
Can anyone point to some specific research or models that put things on a firmer footing? I am looking for some concrete data or findings or models. Obviously this is currently a hot-button issue and, while I am pretty convinced that CO2 plays an important role (e.g., on grounds of radiative forcing) I would like a better handle on the nuts and bolts of the argument.
All comments/pointers appreciated.
[Response:You are confusing too things a bit. The lag discussed in the RealClimate post you cited (here) is about the very long term record from ice cores, involving warming over thousands of years, between glacial and interglacial conditions. It is very clear from those data that CO2 plays a fundamental role in the magnitude of warming, but not in intiating the warming. On the other hand the modern record -- i.e. the lsat 150 years or so -- shows a much smaller lag. That's discussed in more detail here. There is plenty of concrete evidence, but there is no simple one-to-one relationship between the amount of CO2 in the atmosphere and the amount of warming, because there are many other factors (the sun, aerosols, cloud albedo feedback, etc.). -eric]
Thanks for posting the link to the paper (with the year delay for my library academic access, Science is going to get my $ one of these days…)
After reading the L.A. Times version, a direct read of the paper is in order. It will be interesting to see how those intimate with modeling continue to suss out the results and implications. Question….
I seem to recall significant transient temperature inversions occurring at the poles, at least in the Arctic darkness of winter. Does the Antarctic region experience this? I didn’t see any mention of inversion layers or unambiguous stratification evidence of it in the paper discussion. Would a trend towards an increased standard deviation in the sample data be evidenced?
Would enjoy being corrected or more explication if one has the time. Thanks.
[Response: The interior of Antarctic has a permanent winter inversion, up nto 25-30 oC strong on average; it fades out somewhat towards the coasts (where the stations of this study are). This decouples the surface and the troposphere, to some extent, but wasn't a focus of the paper - William]
Is 600 hPa level well above most of Antarctica’s surface?
[Response: Its certainly above... the pole is at about 700 hPa; Vostok somewhat higher I think. But most of the stations reported in our work are around the edge of the continent, at sea level - William]
The BBC has taken information from the BAS and reported it, as for its accuracy I do not know but the times (a UK broadsheet newspaper) also reports the same results and states the following:
The new research, led by John Turner, of the BAS, shows that the air above the surface of Antarctica is definitely warming, in ways that are not predicted by climate models and that cannot yet be explained. The results are published today in the journal Science.
Again it just seems to show that realclimate evidence is not the same as the BAS and I would ask why not ? Why do the BAS state that no climate models have predicted Antarticas recent results ?
[Response: The paper is the definitive source, sort of. So you should read that. Whats said to the media gets... well, distorted is perhaps a bit unfair, but they are looking for some hook to make the story exciting. In this case, take the RC/stoat entry as your best interpretation, but better still just read the paper. "cannot yet be explained" rather exaggerates the mystery, BTW. Perhaps that didn't come out clearly. We're not particularly short of explanations, its just hard to choose one. See-also my reply to Coby, below - William]
William says in this article that the amount of warming observed is not in agreement with the models. I don’t see the contradiction you are suggesting. Don’t forget that in this instance Science, BAS and RealClimate are all precisely the same person, so you might read more carefully and see if your perceived discrepancies are not actually your own misunderstandings.
[Response: Its not in agreement with a HadCM3 ensemble avg. I could find individual members that do agree reasonably. Or trawling through the 20 AR4 runs I could probably find one to fit. But of course thats not how we want it to work... but bear in mind that there are uncertainties in the obs, and error bars on their trend. My recollection is that the model and obs are (just) not stat sig diff; but then stat sig is something of an art -William]
It is all too tempting to over-interpret the results of a paper like this. At face value, the trends cited in this paper apply only to the period 1971-2003. In some cases, not even that – for instance, Bellinghausen data end in 1996.
I think we shouldn’t interpret this paper much beyond face value. Antarctic temperatures, especially in winter, are characterized by large variability. Where data are available, one can examine trends with different starting and ending dates and find that they very dramatically from the 1971-2003 period cited by Turner et al. All these trends are well within the range of interannal variability, and it seems premature at this point to go searching for a “cause” of the trends.
Another technical point is that 600-hPa is right at the top of the surface inversion at the South Pole (and probably over much of the plateau). That means temperatures at 600-hPa are about the highest to be found in the vertical profile; temperatures just above and below 600-hPa are typically much lower. Any thoughts on the implications of this for a trend study of the 600-hPa temperatures?
[Response: True, but most of the stations for this study are at sea level. A more reasonable concern is how these results do extend over Antartica as a whole - William]
If you look at Turner Fig 1a, temperatures at the 500-hPa level (which is pretty much over the inversion top everywhere), all have lower trends than the 0.7 deg C per decade trend at 600-hPa. The 500-hPa trends max at about 0.65 deg C per decade at Syowa, which implies that the average trend for the continent is lower.
Thanks – I do undersatnd the difference but what I can’t see is how the data from the long term record shows that CO2 is responsible for warming – not causing it but exacerbating it – as opposed to the excees CO2 being a consequence of warming.
I understand that this argument is that of the naysayers but since I am in a bit of an argument over this (with a naysayer) I’dreally appreciate a bit more on this from someone.
[Response:the excees CO2 being a consequence of warming - I thought RC had beaten this to death elsewhere. The excess CO2 is definitely anthropogenic - we know this cos we know we've emitted it. If you want to believe the CO2 rise is natural, you have to believe that (a) just as we started emitting lots of CO2, a sudden natural sink starting abssorbing lots of CO2 (b) at just the same time, a different natural source started emitting just the right amount of CO2. Err, and then there are the isotopic ratios etc - William]
Bob King (#8, #17) — Sounds like you think that scientists had to look at ice cores to decide somehow that carbon dioxide controls the temperature of the Earth?
Where did you find that idea? I’m curious what your source was, because I like to backtrack and figure out where mistakes originate. If I read you right, your idea seems to be mistaken so you question isn’t answerable as asked.
Carbon dioxide and water in the atmosphere limit how fast heat is re-radiated from Earth, yes. That was figured out 110 years ago by a physicist, a famous one. One source for more:
Re 12 William, thanks for that link. The table of height against pressure should give me the info. that I am interested in. From your Figure 1b it could be that the height of the inversion layer has decreased wrt to pressure, but it will be interesting to see if it has decresed in height in real terms. But what that means is still difficult to interpret.
Not at all. I am aware that CO2 is a green house gas. If there was an 800 year lag during which warming started without a CO2 build-up then, presumably, other factors are at work – e.g., orbital variations etc. How do we know how much of the subsequent warming is due to CO2 build-up and how much to whatever initiated the warming in the first place. And what eventually terminated the process?
In principle, CO2 buildup could have been a result of ocean warming from other mechanisms and not a principal player.
In other words, is the statement that CO2 is a major player in past global warming events based on models of radiative forcing or is there other independent evidence?
Thanks for the reply to my #9. If my exploration sounded in any critical, please forgive me.
As David Schneider in #16 asks, “Any thoughts on the implications of this for a trend study of the 600-hPa temperatures?”
By way of explanation, midst my neophyte ruminations, I’m still trying to visualize a qualitative temporal spatial Antarctic model to see what is going on… Relating the Circumpoloar current (ACC), a scheme for what the so called Antarctic Oscillation (AAO) is?
I seem to remember reading in Three Dimensional Climate Modeling that the Polar Convective Cells are weak (Washington, 2005?)–but there often seems to potent cyclonic storm activity fueled by heat differentials that step up to action…
All of the above which is not a topic of your journal contribution. Thanks again for the reply, and sharing the paper. The terrain is new to me, clearly.
I’m sure it is based on models, which are based on physical principles. What else could it be? Even the exact role CO2 plays today is based on models (based on physical principles). The orbital cycles are regular, the GHG levels are recorded in the ice, I’m sure the geologists have an idea of where the edge of the glaciations were over time. All the forcings there are records for go into a model and if it matches the temperature trends then hooray. If not, there is data missing or the models need more work.
#16 #20,, That is a hot topic, inversions (or the lack of steep inversions) are key with the whole process of Polar warming. I’ve recently noted higher temperatures, at the top of the inversion (the warmest temperature on profile), which eventually warms the surface air layer below , giving a weaker inversion lapse rate. Ultimately inversions may altogether occur less consistently has they use to be, trending towards a more summer like evening temperate profile. This is proved without Upper Air soundings by observing sunrise or sunset skimming, which is caused by refraction, in essence, the greater time the sun stays above the horizon, making longer days, the steeper the inversion, which may be defined by (relative to the peak inversion temperature) very cold surface air, of which colder air naturally increases refractivity. A healthy polar winter causes much longer days, while a warmer winter from the same location has significantly shorter days.
A question about the paper’s interpretation of “decoupling” of the surface and troposphere and William’s use of the term in his response to #9:
Aren’t Antarctic surface temperatures in fact coupled to changes in the atmosphere above the surface? For example, whenever a cloud passes or the winds blow, surface temperatures respond – more so than in a situation of no inversion. And, by definition, much of the Antarctic plateau surface is in the middle troposphere to begin with (3-4 km above SL). The tropopause is, in summer at about 8km. In winter, it’s not that clear where it is. Besides the inversion, there is another interesting feature of the vertical temperature profile in the Antarctic winter: there is no real temperature tropopause; temperatures just keep decreasing with height until they reach about -90 C at roughly 20km, which permits the formation of polar stratospheric clouds.
[Response: The Ant Plateau isn't in the middle trop (unless you insist on defining the trop purely on the basis of height, and use default mid-lat values). The middle trop is the middle of the troposphere, and the sfc of the plateau is characteristic of a sfc. But anyway, the decoupling: obviously the sfc will respond, be coupled, to some extent with the atmos. But it is rather less so in the case of a strong inversion since vertical motion is inhibited - William]
Re #25 Wayne, I think your reply has pointed me to the answer to this conundrum. The radiation calculations are perfomed using a vertical column of the atmosphere, but during polar winters the solar radiation is parallel to the surface. CO2 absorbs in the solar frequencies as well as in the terrestrial infra red. Therefore with a greater concentration of CO2, more radiation is absorbed and causes more heating in the the troposphere. The models do not see that warming because they are only concerned with the vertical component of the solar radiation which is nil.
Wait, Alastair! sunlight parallel to the surface of the globe? Straight lines, curved surface; polar winter — no UV reaching the polar stratosphere, no ozone catalysis, in a very large area for months — no IR from sunlight either.
Well, thanks but that link’s exactly where I started. I don’t see the answer there. Anybody?
Is the evidence that CO2 was a major player in past global warming events based entirely on numerical models of radiative forcing or is there other independent evidence (beyond the observation of a lagged correlation between temp rise and CO2 levels increasing)?
Models are fine and compelling (for me at least) but I’m interested in any other independent evidence that might exist.
Re #28 Oh, dear :-( I was thinking of the situation over the poles during the equinoxes. It won’t last all winter. It will be pretty dark at the poles in mid winter, even at 5,000m. Oh well, back to the drawing board.
Thanks – I missed your response. I was thinking in terms of, e.g., evidence that ruled out other causes (e.g, increases in solar radiation might be detectable??). Also I’m curious if there are simulations along the lines of correlating these warming events with Milkanovitch cycles.
Bob, I think you’re asking whether there are past climate examples of large scale combustion of fossil fuel, or burning of carbon-containing rock (vulcanism?), producing atmospheric carbon dioxide increases, from a “cold start” — like we have going on now. Is that right? What besides human activity can cause a spike in atmospheric CO2, and can it happen without human activity?
There might be. I recall a suggestion that at one time the western US “badlands” were fossil coal beds that burned, once exposed by erosion (lightning fires). Can’t cite it at the moment, no time to hunt, see if you can find any mention of that geologic era, or the Deccan Traps vulcanism, as examples.
But what, exactly, is your friend the skeptic having a problem with? I think — and I’m not a climate scientist, I’m an oversimplifier (wry grin) who hopes to be corrected here — that the basics are:
1 — no matter what starts warming, CO2 is increased after warming starts (ice core records);
2 — increasing CO2 holds more heat in the atmosphere, warming Earth (Ar;rhenius, other physicists)
3 — go to 1
4 — removal of CO2 from the atmosphere is slow (look up “plankton cooled a greenhouse”)
It stems from a recent piece in the Guardian newspaper by a molecular biologist called JohnJoe McFadden. His arguments are pretty flimsy and boil down to him arguing that observing a correlation doesn’t imply cause. This stimulated a discussion/argument with someone I know who basically agrees with McFadden. Now, I think the case is obvious and along the lines you suggest. But, given that McFadden decries models I am looking a bit more closely at what the full gamut of evidence is. In particular, (i) what specifically started the warming (ii) are there other factors that could explain the extent of warming besides CO2 and (iii) what stopped it.
I’m really looking for links to technical articles along these lines. I do feel that the CO2-lag link (in this site) is a bit disappointing because (i) it sounds speculative and (ii) it never actually states on what basis the **majority** of the subsequent warming (after initiation) can be attributed to CO2. For example, how do we know that those warming events weren’t say 90% “other factors” (e.g., whatever got the ball rolling) and only 10% CO2. So I’m interested in how well this has been addressed.
Of course, it’s a bit like arguing with creationists ….
which everyone keps pointing me back to – it’s sort of where I started – does a decent job of summarising the case but doesn’t really point to the evidence (specific studies, models, simulations etc.) underlying that summary. The latter is what I’m really looking for, i.e., a slighlty more detailed discussion of the potted version available on this site at the above link.
You wrote “Of course, it’s a bit like arguing with creationists …. “. My point is that it is exactly like arguing with creationists. They don’t respond to common sense, and even less to logic, so there is no way you can win!
Mankind seems to have a blind faith that because they are only enjoying themselves, then they cannot be destroying the planet. The only way you can change such an emotional attitude is with emotion. They won’t change until a disaster happens, and even then they may stay in denial just as has happened with New Orleans.
Bob, here you go, although this may be a bit more detail than you wanted:
There are a couple of interesting parallel lines lf research going on. First is by Wunsch and Huybers, who have been investigating the influence of the Milankovitch cycles on the Pleistocene glaciations. The upshot is that it appears the glaciations are driven by the @40ky obliquity (axial tilt) cycle. See this and this. While it seems clear that the obliquity changes are the trigger, the resulting direct insolation changes are only a fraction of what’s needed to drive the glaciations, and so some other mechanism must be involved.
The David Lea group is advancing the hypothesis that the needed mechanism is greenhouse forcing of the tropical seas. See the discussion on Lea’s research page here and in particular this key paper (viewing the full paper requires a Science subscription, unfortunately).
These two research threads may be headed in the direction of producing an overall explanation for the glaciations. While this makes sense to me, it’s not clear that the authors think so. There’s also very little recent activity from other scientists with regard to either area of research, although I notice that RC co-author Thibault de Garidel had a previous paper that criticized the conclusions of a prior related Lea paper. I don’t know whether that remains a live issue.
All of this seems like a good topic for a post IMHO.
I would also like a post on the glacial cycles as a whole rather than just the existing lag vs lead article.
I am worried that I went out on a limb here. Specifically, I am pressed in the comments and I say the climate behaviour over the Milankovich cycles is “fairly well understood” and it is orbital forcing amplified by ice albedo and GHG feedbacks. Is that reasonable? Also at issue is my statement “The rate of warming is on the order of 10 times faster today than seen in the ice cores”.
(sorry, is off topic for this post)
[Response: I would say that the astromonical forcing of the 100 hyr cycle is pretty well agreed on (though there are suggestions its the plane of the orbit). And everyone seems to agree that you need amplification from CO2 and stuff to explain turning a weak signal into a strong one. But to say that the details of the mechanism are well understood, no - William]
William, back on topic, I wanted to congratulate you on the graphic at the top — it took me til now to study it. You’ve put a whole lot of information into it.
Are you finding more datasets on a continuing basis? I went to Google just to figure out what “600 hPa” meant — I see it’s a barometric pressure, assume it’s the standard for measuring temperature using balloons because recording temperature and air pressure as the balloon rises is straightforward (and no other kind of altimeter has been available until electronic ranging devices came along recently). Could you give us — or point us to — more background for the lay reader on the data collection generally?
I just picked up Kim Stanley Robinson’s novel “Antarctica” and was reminded that when the first explorers reached Antarctica, they were collecting information without much idea how it would be used. The sudden change from a 2000 year old technology, wooden ships and sail, to steel ships and steam, was just happening — and science was just starting to happen. They were collecting for us, whoever we turned out to be, figuring we’d be able to use the info.
Are there datasets you believe exist somewhere that you’re still looking for?
RE 41: Someone on this site said earlier that a
new geological epoch may be starting (sorry, cannot retrieve the post any more). Reviewing the EPICA and Vostok ice core data gave me that impression some time ago. I even coined a name for it: “Technocene”. Dr. Hansen also states in recent presentations his view that the ice ages will not come back for several millions of years.
“Geological epochs” are mainly defined by the kinds of deposits that are found in rocks and soils. These deposits are commonly of biological origin and the term “biological epochs” could be used instead. Ending the period of regular ice ages may indeed cause a biology disruption qualifying as the start of a new epoch.
Warmer and cooler cycles will of course continue, but both the average level and the “waveform” will change. There is a strong asymmetry in the recent record. Currently, cold part (ice age) of the cycle is strongly limited (and lengthened) by some part of the process, assuming that the orbital forcings have an approximately sinusoidal shape. The reason may be geographic. There are a number of major continental boundaries that run in an East-West direction. When a climatological zone meets such a boundary, unlinear response can be expected. Examples are the regular movements of the ITCZâ��s crossing the southern shore of West-Africa and the northern shores of South America and Australia, or the snowline (or permafrost boundary) moving across the coasts of Siberia and Northern Canada.
A source of (unpleasant) surprises is also the carbon cycle. There are several major storage bins of carbon. For obvious reasons, our focus now is very strongly on the deeply buried and very slowly turning carbon deposits of oil and coal, and transferring them into the short cycle surface/atmosphere process. There are other storage bins of similar or higher volume: soil and permafrost, clathrates in the deep seas and ocean water itself. Inadvertently activating carbon from these relatively long term storage cycles generates major positive feedbacks. These are currently seen as the extreme disaster scenarios of low probability.
As to the timing of temperature and CO2 cycles. It makes little difference. In the “natural cycle” temperature may be the prime mover (input or forcing), CO2 a feedback. In the “artificial cycle” CO2 is the forcing, temperature is part of the feedback. In a control equation you may change the input or you may change the feedback, and still get the same output.
[Response: The suggestion (from Paul Crutzen) is that we are moving into the 'anthropocene' epoch. It appears to be catching on.... - gavin]
But Epochs are just the sections of larger Periods which in turn are parts of Eras. The current era is the Cenozoic (modern life) and the previous Eras were Mesozoic (middle life) and Paleozoic (old life.) That was preceded by the Proterozoic. If a new Era is about to begin it would seem to me that the most natural name to follow on from modern life would be postmodern life, ie Postzoic :-(
I am no expert, but I had thought that little change in Antarctica was anticipated at this stage.
I recognise that Bitz Fig 2 is based on deg C/Century, whereas Turner Fig 2 is decadal. Furthermore it’s tricky to try to compare the 2 different projections. And I don’t know whether I am comparing apples and oranges in the datasets.
Stephen Berg, the blogging software used here has bugs which prevent it from understanding links containing commas.
Use < a href="http://service.spiegel.de/cache/international/0,1518,405320,00.html" > this < /a > which results in a link like this
We know Christy et al. aren’t happy with your results. Have you any further news to relay about the food fight? Also, I sent you 2 e-mails, but have not seen any reply. If you sent anything, then we must assume it(they) was (were) lost in some “hole” in the net….
[Response: Hi Eric. Sorry, I've been busy - I got the mails. C et al - don't know; we shall see - William]
As for a reply from Christy, et al., I think they will just ignore the paper and hope it goes away. After all, they just went thru a review that took more than 2 years. Maybe William will summarize the feedback he’s heard so far.
Re: http://www.nsf.gov/news/news_summ.jsp?cntn_id=100385&org=NSF&from=news has the cause of the Larsen B Ice Shelf detachment been determined? Are there any local tropospheric warming contributions attributable to this as well (either thermal direct, or by sub-surface GHG release becoming aerosols)? And please comment on the distribution of temp sampling w.r.t. the troposphere proximity to above, Mt Erebus and others — I know geothermal factors are characteristically low, and are typically not factored into GCMs (unless cataclysmic); however some comment on such local factors is of interest?
[Response: The Larsen B collapse is within the area of surface warming, though the exact reasons for the collapse aren't clear. Erebus, etc, don't matter as far as I know - their heat may be significant very very locally, but no more (probably not even locally, since they are ice covered) - William]
“[Response: I would say that the astromonical forcing of the 100 hyr cycle is pretty well agreed on (though there are suggestions its the plane of the orbit). And everyone seems to agree that you need amplification from CO2 and stuff to explain turning a weak signal into a strong one. But to say that the details of the mechanism are well understood, no - William]”
This is not proven since over the long haul the heat deficit/surplus from the Malinkovitch cycles register as a reduction/increase in ice cover on a virtual one to one basis. Now it might be us putting abiotic carbon into the atmosphere will change this. But so far you would have to be going out on a limb here.
Re 54 True. The big amplification is from the major greenhouse gas water vapour, but those professional scientists like William, don’t appreciate being told simple truths by amateur scientists like me!
If there is more precipitation off the ocean due to CO2-based warming you might be getting more snowfall . The snowfall would tend to release a lot of latent heat into the mid-Troposphere. But the extra snow and cloud cover might leave the temperature at ground level lower.
Or it could be a sort of competition between the Malinkovitch cycles turning bad on us(in the Southern Winter, Northern Summer) and extra warming making its way down from the top of the Troposphere.
Why is it a big mystery. You make a few hypotheses in parallel and then you go about developing, testing them and altering their ranking in accordance with what you find.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 1:41 AM
Since the effect of Greenhouse gasses is not additive but Logarithmic, and since water vapour overwhelms all else the effect of CO2 will only be significant where the air is dry.
Dry air tends to be cold air on this planet. It is THIS small but cumulative addition to the energy retained by the weather system that CO2 is likely to make.
And a good thing too. At least for the forseable future since the natural tendency is towards glaciation which would be an unmitigated disaster.
The most important text for understanding the current goings-on is not any text on science. But a book written in the 1840′s by a fellow called Charles Mackay.
Its called: “Memoirs Of Extraordinary Popular Delusions And The Madness Of Crowds”
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 1:43 AM
Re 55, 56, 57
We are all aware of the prime importance of water vapor (radiative impact, latent heat, etc..)
However, regarding the importance of CO2 vs H2O:
It turns out that, in essence the GHGs with longer residence times (CO2) ends up controling the mean amount of water vapor presnt in the atmosphere. This has been covered on this site before. Please see Water vapor: forcing or feedback http://www.realclimate.org/index.php?p=142 . It can also be reached via the highlights side bar.
Oh…Re 57. There is alrady way more than enough CO2 around to stave off any possible glaciation !
The point is that because of the Logarithmic nature of the greenhouse effect CO2 will only tend to be significant where the air is dry. That is why when you look at the stats you cannot clearly divine the CO2 effect. Because its not some powerful one-off effect. Its a tiny cumulative effect. Tiny cumulative effects are more to be feared then one-off shocks. Its a minute-in minute-out relentless accumulation of extra Joules. But really taking it one year at a time it has to be pretty miniscule.
Still to be fair. Tiny cumulative effects are GOING TO ACCUMULATE and could be very serious over the long haul. Its just that in the next few thousand years there are greater risks to worry about.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 7:23 AM
“Oh…Re 57. There is already way more than enough CO2 around to stave off any possible glaciation !
Prove it. Eveyones just taken this Mantra up arbitrarily. You don’t know this. And neither does Steve Bloom not Gavin nor Stefan. You are making it up and ten of you saying it ten times won’t make the spell.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 8:04 AM
Trolls don’t footnote. Give us your references, please. With no cite and no name, it’s impossible to tell if one person posted the first idea then two more came along, copied the false name and posted other ideas trying to make fun of the first one — or if this is one person who thinks it makes sense in three different ways.
What is your source for your ideas, where did you read them, who are you quoting? Can I find your ideas in sci.environment? I admit I use a killfile there regularly, it’s possible I never saw your ideas there.
Re: 60. “Prove it.” “You are making it up…” ad nauseum.
This appears to indicate a fundamental misunderstanding or lack of knowledge about the basic scientific process. Science is about hypotheses, theories, and gathering/testing/modeling evidence to support theories. “Proof” is a *mathematical* concept. Those are very important differences that ought to be clear before the words “prove it” are toss around haphazardly.
Theories for glaciation are not supported. Theories for global warming are well-supported by data gathering, testing and modeling. Which is not “making it up”. Furthermore, science requires that modeling or experimentation be repeatable. So ten people “saying” it ten times is good science if the experiment is repeated with similar results.
Well “prove” that we are due for an ice age anytime soon…
I’ll be a bit lazy and cut and pase from a Wikipedia article: Note the last line.
“We are in an interglacial period now, the last retreat ending about 10,000 years ago. There appears to be a folk wisdom that “the typical interglacial period lasts ~12,000 years” but this is hard to substantiate from the evidence of ice core records. For example, an article in Nature  argues that the current interglacial might be most analogous to a previous interglacial that lasted 28,000 years. Nonetheless, fear of a new glacial period starting soon does exist (See: global cooling). However, many now believe that anthropogenic (manmade) forcing from increased “greenhouse gases” would outweigh any Milankovitch (orbital) forcing; and some recent considerations of the orbital forcing have even argued that in the absence of human perturbations the present interglacial could potentially last 50,000 years.”
Furthermore, if there was ever ever any “imminent danger” of sliping into an ice age (for instance an observed sustained high-latitude cooling trend or something like observed wide-spread glacier growth for a change !). Then a suitable deliberate injection of GHGs could be called for and would be well within our power to pull off. That is, unless you think ice ages descend overnight or something.
Right so no evidence from the campaign against warmer winters for the Siberians. Wiki is no evidence. Since the global warming fraudsters have their section locked down. And have even gone so far as to confuse ice ages with glaciations to mislead the public.
Now for this science article:
An Exceptionally Long Interglacial Ahead?
A. Berger and M. F. Loutre
Today’s comparatively warm climate has been the exception more than the rule during the last 500,000 years or more. If recent warm periods (or interglacials) are a guide, then we may soon slip into another glacial period. But Berger and Loutre argue in their Perspective that with or without human perturbations, the current warm climate may last another 50,000 years. The reason is a minimum in the eccentricity of Earth’s orbit around the Sun.”
Notice that there is a question mark in the very title of the article!!!!. So this glib confidence is competely without merit. The article itself implies the following.
The article assumes that glaciation MAY NOT occur with or without human-produced CO2. Right there we have something entirely implausible. One imagines the writer has miquoted the researchers. I’d accept the ….may not occur WITH human CO2 but the idea that we wouldn’t start icing over without it is foolish. Since the ice always oscillates back and forward and the fact that this cycle is milder would only make the ice grow more slowly.
In summary the level of certitude that this new Mantra is conveying is without merit. The burden of proof is on you guys not me since we know the norms of the climate over the last 3 million years and the norm is for us to be in catastrophic iced over conditions. If something has changed you would have to prove it. Mostly its the irrational level of certitude that I object to here. As if a single article written in the last few years is completely decisive.
Over the long haul the heat deficits/surpluses conveyed by the Makinkovitch cycles sooner or later registered as an increase/decrease in the amount of ice. If that’s changed then the evidence for the change is something that’s been a little hard to track down.
There is another very strange focus going on and that is the focus on average ground air temperatures. We have Buckleys chance of putting that together for thousands of years ago. Its hard enough to sort such a thing out today. We ought to be thinking in terms of the total energy retained by the system. The level of ice being a pretty good if delayed barometer for this.
If this is the focus then it may add an argument for the other side. Though air temperatures have increased only marginally this does not mean there hasn’t been a lot of “global warming”. Since the melting of ice implies a massive retention of extra Joules. Either right now or as a delayed reaction to extra Joules retained in the past.
So how about cutting out the absurd statments of certitude and try and gather evidence and let the chips fall as they may. As things stand we have to assume that the ice could start moving the other way on us at any time. The slightly less severe nature of the cycles this time round does not alter that unless it can be shown that the CO2 will (mercifully) overide.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 6:01 PM
Your position is a bit like sitting in your house on a warm day in July (in the NH)
knowing that winter will eventualy come so we should have the heat turned up now.
Within 100 GHF levels have the potential to cause us alot of nastiness. On the other hand, within the next 100 yrs you can not seriously argue for the glaciers starting to march forward. Just what type of mechanism would be behind such a thing ?
re: 66. Once again you talk about “proof” after it has been clearly explained to you what the scientific method is about. To repeat, “proof” is mathematical. Simply repeating your statement does not lend itself to any valid “proof” that it is true. The overwhelming evidence, data and modeling, in fact, show that the scientific conclusions that have been reached are valid with a very high degree of likelihood. That is how the scientific process works. And has always worked.
You are in no position to lecture me on the scientific method. I want evidence not proof. You have not brought any forward.
“Within 100 GHF levels have the potential to cause us alot of nastiness.”
No that’s incorrect. CO2-based warming can only be benign (at the very least until all the ice is melted). We would expect to have more arable land, more rainfall, less extreme weather events, greater access to untapped resources and greater crop yields.
” On the other hand, within the next 100 yrs you can not seriously argue for the glaciers starting to march forward. Just what type of mechanism would be behind such a thing ?”
Wrong again. This is the default position until we know that CO2 will overide. I think it probably will overide but I don’t know and your lack of evidence suggests that neither do you. The mechanism would be the same as for all ice build-ups and declines. The Malinkovitch cycles of course.
Supposing we had a thirty year drop-off in solar activity. This could easily combine with the cycles to kick the march of glaciers off. This is a serious risk whereas overheating is not a serious risk at all. Can you think of any time that you know for sure the planet was too warm? Not for sure and not in the last 100 million years right? Its a bit like being too rich.
People are acting like economic forecasters who have the habit of merely extrapolating what’s going on now into the future. But things can turn bad for us at any time. A few very cool Northern Summers and freezing Southern Winters and you guys will be predicting doom on the glacial side and demanding money.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 7:04 PM
re: 69. Excuse me? Yes, apparently I am in the position to “lecture” you on the scientific method since you are clearly not aware of what it means or what the process is. Either learn about it or stop repeating the same mantra with nothing to support it. Furthermore, you specifically asked twice for proof and now say you did not? Let’s see, from your post 60: “Prove it.” From your post 66: “The burden of proof is on you guys…”. Gee, there’s that “proof” word again.
Again, for the third time (sigh!), 1. “proof” is mathematical, case close. And 2. the scientific evidence is absolutely overwhelming. For starters, read the IPCC reports for evidence. Goodness, there are probably thousands of studies by climate scientists that are readily available for your persusal. Studies that are based on hypotheses, evidence gathering, testing, and repeatability. In other words, the scientific method. You now change your tune and ask for “evidence” as opposed to “proof”? Well, there it is. You can easily find the links on the internet. All those studies are based on evidence.
“Excuse me? Yes, apparently I am in the position to “lecture” you on the scientific method since you are clearly not aware of what it means or what the process is.”
You are not excused since you are repeating the unfounded allegation as if you have the power of second site or mind-reading. I know what the scientific process involves. And no global warming fanatic is guilty of it. Let us see some evidence.
The question is “What will win out”. Since the natural tendency is toward glaciation and the extra CO2 is going the other way then this is a quantitative matter. The articles written by global alarmists seldom seem to do no more then state opinions. We want to see which competing force wins out. Which means estimates of Joules added by CO2 and Joules subtracted by the cycles turning South on us.
The other thing is if CO2 wins that is a good thing indeed. And still no cause to waste money on your petty fears.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 7:51 PM
“No that’s incorrect. CO2-based warming can only be benign (at the very least until all the ice is melted). We would expect to have more arable land, more rainfall, less extreme weather events, greater access to untapped resources and greater crop yields.”
Ya want to present some “proof” of this ? There will be winners and losers as things change…But note: Unthawed Tundra does not become useful land overnight. More extreme events are forcasted…not less ! Greater crop yields ? Not in any of the papers I have seen. Unfortunately inceased CO2 levels do not autimaticaly mean more plant growth. Also, do not forget about sea level rise.
Here in the Netherlands our own reginal climate model work shows we will have problems with sea level rise, wetter winters but dryer summers. Its going to make water level managment here tougher than it already is ! On the plus side we will likely have more good beach days along the North Sea…if the beaches can be maintained against possible increased erosion.
“Supposing we had a thirty year drop-off in solar activity. This could easily combine with the cycles to kick the march of glaciers off. This is a serious risk whereas overheating is not a serious risk at all. Can you think of any time that you know for sure the planet was too warm? Not for sure and not in the last 100 million years right? Its a bit like being too rich.”
The paleoclimate records do not support anything like you are saying. Take a look at some of the links that can be accessed through this site.
“People are acting like economic forecasters who have the habit of merely extrapolating what’s going on now into the future. But things can turn bad for us at any time. A few very cool Northern Summers and freezing Southern Winters and you guys will be predicting doom on the glacial side and demanding money.”
1) Unlike economic forecasters we have valid physical theories to base our models on and better and better observations to test them with.
2) The rest is a bit much seeing as you are the one seeming to hold the alarmist view that if we ever stop pumping up the GHG levels that we are all gonna freeze without warning !
“Unfortunately inceased CO2 levels do not autimaticaly mean more plant growth.”
Dead wrong. How could you be so wrong. Amazing!
” Also, do not forget about sea level rise.”
A small problem in the wider scheme of things.
These studies that you refer to. They pretty much amount to an internet assertions tsunami. Where is added Joules from CO2 contrasted against reduced Joules from Milankovitch?
Nowhere. Which shows how political and unscientific the subject has become.
This very thread shows the war of Joules. The warming in the Mid-Troposphere is almost definitely a CO2 based phenomenon. And its right where you would expect it to be. Mid-Tropsophere. Because the extra Joules accumulate all over the globe at the top of the Troposphere (or at the bottom of the Stratosphere) and so you would expect the extra warmth, by the time it reached the Antarctic to be where it is. Alternatively it might be the result of extra snow due to extra precipitation off the warmer oceans, indirectly itself a result of global warming.
But there is a war of Joules going on. Because what this threads article did not emphasise is that the radiation in this area is reducing in the Winters. So more warmth from one source. Less warmth from another.
Show me the study where the maths is done to see which force will dominate the war of Joules.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 8:13 PM
Based on every post you have made in this thread, you have not shown any evidence whatsoever that you know the scientific process at all. In fact, quite the contrary. I find that quite sad since you have the opportunity to learn more through your own research on the web of peer-reviewed science.
To continue to repeat your mantra, after you have been given specific references (e.g. the IPCC report) in response to your request, is nothing less than intellectual dishonesty. For the last time, the studies are based on gathered data, i.e. evidence. They are repeatable. Thus they follow the scientific method. The apparent fact that you do not understand the scientific method does not mean that they do not follow it.
Finally, talk about “mind reading”: “my petty fears”? After investigating the “scientific method”, please check out “hypocrisy”.
“Joules subtracted by the cycles turning South on us”
are zero, global average. That is why this forcing doesn’t appear on such charts.
The Milankovic cycles only redistribute where the solar energy hits the earth. The consensus is that glacial cycles are driven by continental glacial growth which is kicked off by weaker summer insolation due to changes in fine details of the earth’s orbit.
The forcing numbers LOCALLY are large in the high latitudes, ten or twenty watts per square meter, so LOCALLY the glacial forcing would be cancelled out, if we were in a period where an ice age would be likely. However, even then the high latitudes would be in a context where the rest of the world was substantially warmer than normal. So even with an orbital configuration VERY favorable for ice sheet growth, which would win, which amounts to whether new glaciers would form on the North American landmass, is not a slam dunk.
But the orbital configuration, it turns out, is not favorable, as the Czech astronomer explains.
Anyway, the empirical evidence is pretty overwhelmingly against your suggestion at this point. Since ice is retreating everywhere except possibly the deep interiors of the two great ice caps, glaciation is clearly not in any danger of kicking in right now, purely on observational evidence. And global warming is just starting. We have decades of increase in greenhouse gas and decades of ocean thermal lag ahead of us.
1) it isn’t time for a glaciation
2) ice is retreating everywhere already
3) there’s plenty more greenhouse warming in the pipeline
so your point is decidedly moot. If we were going into a period of very low high-latitude summer insolation it might be a practical question.
“These studies that you refer to. They pretty much amount to an internet assertions tsunami. Where is added Joules from CO2 contrasted against reduced Joules from Milankovitch?”
The orbital parameters are well understood enough to know that within the next few 1000′s of years no orbital induced forcing is going to bring about an ice age. Go to your local university lib and look at a copy of something like “An introduction to Atmospheric Radiation”, 2nd Ed. K.N. Liou, Int. Geophys. Series Vol 84 for a start. Check out the IPCC material also.
You miss (or resuse to accept) the key point that. The rate of change of the Milankovitch type forcings just does not occur at anything like the anthro GHG forcing we are now applying.
you certainly have a lot to offer on the next glaciation and the wonders of accumulating CO2; good for plants (to a point, then not) curbing the glaciation habit (way too fast for my way of thinking and particularly for the farmers in Northern India and Bangladesh.
I came upon a few interesting contributions to the Mises Economics Blog of April 2, 2006..about the time the Lord showed up at RealClimate. Do you recognize the following exerpts?
It read in part,
So in the interim the ice oscillates back and forth. So if we could have magically melted the ice by 70 000 years ago we likely wouldn’t have had much in the way of catastrophic glaciation in the interim.
And likewise if capitalism does this for us and we get through the next 10 000 years we should be home free.
There is a limit to this BANK OF COLD model. The ice isn’t ever going to get near the equator. And if it was all melted and the oceans warmed one would expect the amount of heat radiated off to increase. So such a model can only go so far and be relevant to some degree.
But it ought to be good enough to say that if one is coming up to the danger time period then its helpful to get all the ice melted off in advance.
Posted by Graeme Bird at April 2, 2006 01:12 PM
Sound familiar? Then, a next post on Mises Economics Blog at the link below…copy it to the address box. It worked for me.
Forget proofs Tom. Evidence would be nice. And its evidence that CO2 release will overmatch glaciation that we are after. Lets not change the subject.
Yep. Industry funded sites that publish opinion/PR. See instead the peer reviewed journals recommended to you above.
As Mr. Reagan said — trust, but verify. Always read the footnotes and look for new science on the subject. Google Scholar and PubMed will help; any good reference librarian will help much more. The Internet is not your best source for reliable info.
Yep. Industry funded sites that publish opinion/PR. See instead the peer reviewed journals recommended to you above.”
Right. I asked the question and right there you show us just how indeed this level of ignorance is maintained. Its anti-capitalist bigotry ehanced ignorance. The fact is it doesn’t matter who finances the site. CO2 has always and will always improve plant yields. It is afterall what plants breathe.
Michael Tobis. That study from Jans Holland looks like what I was after. But don’t you suspect some sleight of hand here?!!!. I mean we get this regular cycle of glaciation and now he’s saying that all of a sudden they’ve stopped for 620,000 years. Lets not be too gullible here. What we really want to find is where he’s put the trickery into it. Why is he for example mixing up data from actual bases with estimates of how the Malinkovitch cycle will go.
But yes that is the kind of thing I’m after. Have you got any more?
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 10:27 PM
Michael Tobis sez:
“1) it isn’t time for a glaciation
2) ice is retreating everywhere already
3) there’s plenty more greenhouse warming in the pipeline”
Excellent news if true. One hopes then that you and your crowd won’t be holding your hand out for government money given such a favourable outlook. One hopes you won’t be burdening business with regulations or taxation and scaring the small children given such a fortuitous outlook.
But to tell you the truth I’m unconvinced on number 1. As you can see above. Its a pretty hard ask to imagine that we go 20 plus cycles nearly all of them at 60 000 to 100 000 years for glaciations and nearly all of them 6000 to 10 000 years for interglacials and just as this scientific freakshow develops then someone finds out that we are suddenly due a 620 000 year interglacial..
20 cycles of 6 000 to 10 000
Then out of a clear blue sky a sudden 620 000 year break.
Michael there is a few bridges I can sell you are cut price rates.
Comment by CO2-Lord Of Creation — 14 Apr 2006 @ 10:40 PM
Planetary orbits are well understood. If you would like to find fault with the graphs, do the calculations, or at least find someone else who has done them. Those are the rules. They’ve worked well enough in the past. Why should they fail now?
You are asking for a much bigger exception than that the glacial forcing is small. You are asking for the right to disbelieve any scientific evidence that doesn’t suit your purposes, without doing the work to refute it. And you are anticipating unlimited use of a scarce resource (a moderated discussion list) to promote your untested ideas.
You also say things like “our side” and “you guys” which constitutes prima facie evidence that you are taking some approach other than a scientific one.
This is not a high school debating club; this is the actual, real fate of the world we are talking about. Please get serious or go away.
There’s ample room for your sort of noise on usenet and numerous other open discussion lists. I don’t think the realclimate editors are under any obligation to let your postings through indefinitely.
The votes are coming in. Please dump Lord Graeme into the Bozo Bin. Enough pollution.
We’ll recognize his spew when he tries to sneak in under the radar. Then, we can appeal to you to dump his next a.k.a.
Keep the conversation on track. Time and space are important.
Comment by John L. McCormick — 15 Apr 2006 @ 3:48 PM
re: 83. Absolutely. There is no excuse for beligerence, subsequent lack of apologies, and gross intellectual dishonestly from anyone who will not make an effort to learn the basics about the scientific process. Or who will not follow up on specific scientific references when they are provided to him.
As there is no question global temperatures change over time, as does precipitation, the current change (increase) in temperature is not unprecented except in speed. Considering a term often used is ‘interglacial’ and we are in an interglacial period, if we attempted to completely negate the influence of man on global climate, when would we return to an ice age in the northern hemisphere? Is an ice age, by natural causes to be preferred to global warming? Or do those who prefer to think man is the enemy also believe man can completely control the climate?
[Response: I'm not at all sure you're right to say "the current change (increase) in temperature is not unprecented except in speed" (and even if true it wouldn't be very reassuring). Current T's are the highest we have good measurements for; its not at all clear that T has been higher, globally, any time during the current interglacial. As to the return of ice ages... without us, it would probably be 30kyr off (from astronomical considerations). "completely control the climate" is a strawman; and we have already emitted enough CO2 - William]
Even without anthro GHG emissions an ice age is a long way off…
The text below has been cut and pasted from http://www.aip.org/history/climate/cycles.htm (aip == Americian Institute of Physics, the well-respected Americian professional society for Physicists). It’s quite a good discussion looking at the history of the scientific undestanding of climate. I would recommend reading the whole thing.
“After 1988 =>after88
Looking at the rhythmic curves of past cycles, one could hardly resist the temptation to extrapolate into the future. By the late 1980s, most calculations had converged on the familiar prediction that the natural Milankovitch cycle should bring a mild but steady cooling over the next few thousand years. As climate models and studies of past ice ages improved, however, worries about a swift descent into the next great glaciation â�� what many in the 1970s had tentatively expected â�� died away. Not all ice ages were the same length, for the orbital elements differed in each. Improved calculations said that the next ice age would probably not reach its maximum for a few tens of thousands of years. [Ice core studies published in 2004 gave further evidence that a cycle like ours was likely to stay warm for many thousands of years].(53*)
The scientists who published these calculations always added a caveat. In the Antarctic record, CO2 levels over the past 400,000 years had cycled between about 180 and 280 parts per million. The level in the late 20th century had now climbed to 350 and was rising still. Greenhouse warming and other human influences seemed strong enough to overwhelm any natural trend. We might not only cancel the next ice age, but launch our planet into an altogether new climate regime. …..”
53. E.g., Berger (1988), p. 649; see Falkowski et al. (2000); Berger and Loutre (2002) discusses a long interglacial. The new Antarctic record of climate went back more than 700,000 years, through a previous cycle where the orbital elements had been similar to those in our own cycle. EPICA community members (2004). BACK