A new popular sport in some media these days is “climate scientist bashing”. Instead of dealing soberly with the climate problem they prefer to attack climate scientists, i.e. the bearers of bad news. The German magazine DER SPIEGEL has played this game last week under the suggestive heading “Die Wolkenschieber” – which literally translated can mean both “the cloud movers” and “the cloud traffickers” (available in English here ). The article continues on this level, alleging “sloppy work, falsifications and exaggerations”. By doing so DER SPIEGEL digs deeply into the old relic box of “climate skeptics” and freely helps itself on their websites instead of critically researching the issues at hand.
As a scientist I do not have the time to dedicate a whole day to one article and to do much research on it, which is why I here discuss only a few of the most obvious flaws and distortions of facts in this story.
Temperature data
Cynically and inhumanely the article sets off with remarks on our British colleague Phil Jones. The authors extensively revel in sentences like this:
He feels a constant tightness in his chest. He takes beta-blockers to help him get through the day. He is gaunt and his skin is pallid.
Jones is finished: emotionally, physically and professionally. He has contemplated suicide several times recently.
And this is the result of a media campaign consisting of precisely such poorly researched and fact-twisting articles as this one, for which Marco Evers, Olaf Stampf and Gerald Traufetter are responsible.
What is first greatly hyped is then gleefully destroyed. According to DER SPIEGEL “the entire profession” of climate science “based much of its work on his [Jones’] research” and “almost every internal debate among the climate popes passed through his computer”. Now it happens that I, most likely not an untypical example, have never worked with Jones’ data and have only exchanged a handful of emails (out of tens of thousands every year) with him, although I do probably count as part of the “profession”. There is a whole set of other data of global temperature, e.g. the data from NASA which is based on weather stations (and which I prefer for various reasons) or data from NOAA or the satellite data from RSS or the UAH. As is always scientifically useful, important conclusions are based not on one single set of data but on the fact that a whole range of competing scientific groups find consistent results, using different methods (see Figure).
Global mean temperature (annual means) according to the 5 most often used data sets. The graph shows the deviation from the mean of the last 30 years, as well as the linear trend over the last 30 years. The data from the Hadley Center, NASA and NOAA use measurements from surface weather stations, each with its specific method of quality control (e.g. correction for heat island effects) and interpolation and spatial integration. Independently, the satellite data from RSS and UAH (available from 1979 onwards) provide two different analyses based on the same microwave raw data. These measure the temperature of the middle troposphere, the variations of which can differ from those of the surface temperatures on short time scales. The record El Niño year of 1998 is an example. It has caused a greater temperature anomaly in the troposphere, presumably as warm air rising in the tropics spread in middle altitudes. The climatic trends, however, do not differ significantly since on longer time scales the surface and tropospheric temperatures are closely coupled due to turbulent mixing processes.
The quality of raw data from worldwide weather stations and vessels is indeed often unsatisfactory, especially if one goes further back in time – after all they were gathered to help forecast the weather and not to determine long-term climate trends. However, the error margin has been carefully analyzed – as is standard in science – and is shown in the temperature graphs on the Hadley Center´s website as well as in the IPCC report, and to date there is no reason to assume that the actual temperature evolution lies outside these error margins – the more so as the satellite data correspond well with the ground data. Whether the global warming trend was 0,15 or 0,17°C per decade in the past decades is of no relevance to any practical concerns.
IPCC-Figure of global mean temperature 1850-2005 (Fig. TS6).
According to DER SPIEGEL Jones has erased raw data and is “an activist or missionary who views ‘his’ data as his personal shrine” who “is intent on protecting it from the critical eyes of his detractors”. However, Jones is neither the producer and owner nor the archivist of these data – it is simply data from the national weather agencies, who also are responsible for its archiving or for the question to whom and under what circumstances they may be passed on. The majority of these data is freely accessible online. However, some weather services do not allow their data to be passed on because they sell such data. Other scientists have compared the CRU-data with freely available raw data from weather stations. And at NASA one can find the computer algorithms which are used to calculate the global mean temperature, publicly available for everybody. There is hardly any other scientific field in which more data and computer codes are freely accessible than in climate science (e.g. also codes and data of my current papers on sea level rise in Science 2007 and PNAS 2009). Do for example economists, on whose advice many political decisions depend, disclose their raw data and the computer codes of their models?
The British House of Commons has just published the report by the committee which has been appointed to examine the accusations made against Phil Jones. The report concludes:
The focus on Professor Jones and CRU has been largely misplaced. […] The scientific reputation of Professor Jones and CRU remains intact.
The fact that Jones has been rehabilitated will be welcomed by all those who know this decent, always helpful and universally well-liked scientist. For the general public the conclusions on his scientific findings will be even more important:
Even if the data that CRU used were not publicly available-which they mostly are-or the methods not published-which they have been-its published results would still be credible: the results from CRU agree with those drawn from other international data sets; in other words, the analyses have been repeated and the conclusions have been verified.
The ever-popular “hockey stick” discussion
DER SPIEGEL resurrects one of the oldest shelf-warmers of the “climate skeptics”: the hockey stick debate and a series of flawed accusations with it. The so-called “hockey stick” is a temperature construction for the Northern Hemisphere for the last millennium published by Michael Mann, Ray Bradley and Malcolm Hughes in 1999, of which DER SPIEGEL writes that the Canadian Steve McIntyre unmasked it as “a sham”. (And this is the only clue within the whole article pointing to the alleged “falsifications”). This is not true. Even a committee of the National Academy of Sciences looked in 2006 at the accusations made by McIntyre and has cleared the authors of all suspicions.
Raw data and computer codes of the “hockey stick” are online and publicly available, and independent scientists have recalculated everything years ago using their own codes (also available). The current IPCC report from 2007 shows in Fig. 6.10 these reconstructions together with a dozen more which have meanwhile been added; the Copenhagen Diagnosis published in 2009 shows some even more recent ones in Fig. 19 (page 43). All show consistent results, not in detail but in their fundamental aspects. This is why the conclusions drawn in the IPCC report of 2007 were stronger than back in 2001, when the “hockey stick” had been shown for the first time. The IPCC report 2007 concludes:
Palaeoclimatic information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1,300 years. [Summary for Policy Makers, S. 9]
In the third report from 2001 such a statement had been made only for he last 1000 years.
All reconstructions – with or without using tree-ring data – agree that the temperature in the Northern Hemisphere (for the Southern Hemisphere insufficient data existed until recently) is higher today than in medieval times. DER SPIEGEL simply claims the opposite:
There are many indications that in medieval times, between 900 and 1,300 A.D., when the Vikings raised livestock in Greenland and grape vines were cultivated in Scotland, it was in fact warmer than it is today.
No scientific evidence in support of this claim is mentioned. Locally – in the North Atlantic region – climate reconstructions do indeed show higher temperatures than today (see Fig.); hence there is no contradiction to the anecdotal evidence about Greenland and Scotland.
Temperature difference between the middle ages (years 950 to 1250) and the modern period (years 1961 to 1990) according to a reconstruction by Mann et al. 2009. The grey shadinghatching shows regions with statistically significant results.
Incidentally, looking at the forcings, it would be surprising if it had been warmer in medieval times than now. Forcings are the factors which affect the global radiation budget of the Earth, such as variation of solar activity, volcanic eruptions or changes of the amount of greenhouse gases in the atmosphere. If we compute the temperature evolution from the known forcings over the last thousand years, the result is consistent with the temperature reconstructions mentioned above. Merely one (in the meantime corrected) model simulation by Zorita and von Storch is an exception. These model calculations (18 in total) are compiled and compared with data in the IPCC report in figures 6.13 and 6.14 .
Only by looking at the forcings can one draw conclusions about the causes of global warming – the fact that currently it is unusually warm does not by itself tell us anything about the causes. If only natural and no anthropogenic forcing existed it would be much colder now than in medieval times.
The hockey stick debate exemplifies how the „climate skeptics“-lobby has tried to discredit an inconvenient scientific finding over the course of many years, without success. The scientific conclusions have proven to be robust.
Tropical storms
Under the subheading “The Myth of the Monster Storm” the SPIEGEL article reports on a “hurricane war” amongst US climate scientists:
The alarmists, using the rhetoric of fiery sermons, warned that Katrina was only the beginning, and that we would soon see the advent of superstorms of unprecedented fury. Members of the more levelheaded camp were vehemently opposed to such predictions and insisted that there was no justification for such fears.
Sadly, no example for the “rhetoric of fiery sermons” is quoted. “Levelheaded” is the well-worn SPIEGEL-parlance for describing anyone who downplays climate change, regardless of whether their claims are scientifically well-founded.
Then a recent study from Nature Geoscience is cited which allegedly announces “the all-clear signal on the hurricane front” and which signifies “another setback for the IPCC”. This is because “the IPCC report warned that there would be more hurricanes in a greenhouse climate”. Let us simply quote from the abstract of the new study:
Future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2-11% by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6-34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre.
Long story short, fewer but heavier tropical storms can be expected. By the way, the potential destructiveness of storms increases more steeply than the wind velocities; a 2-11% higher speed means a 6-37% higher destructiveness. (Emanuel 2005).
And what did the IPCC report have to say on this topic?
Based on a range of models, it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical sea surface temperatures. There is less confidence in projections of a global decrease in numbers of tropical cyclones. [Summary for Policy Makers, page 15.]
Long story short, fewer but heavier tropical storms can be expected, even if there was still less confidence about the first aspect at the time. The WMO, whose expert group has published this study, consequently describes the result as follows:
Substantial scientific progress has led the Expert Team to raise their confidence levels on several aspects of how tropical cyclone activity may change under projected climate scenarios.
This means: there is no reason for speaking of a “setback” in a “war”; rather the early findings of the IPCC report have been given a higher confidence level. The SPIEGEL story on this issue falls into a category of false allegations against IPCC mentioned by us already in February, namely those which can be falsified by simply reading the report (in this case even a quick look at the Summary for Policy Makers would have sufficed).
IPCC mistakes
According to DER SPIEGEL “more and more mistakes, evidence of sloppy work and exaggerations in the current IPCC report are appearing”. We already investigated this and came to the conclusion that of the mistakes discussed excitedly in the media, nothing much remains except for the Himalaya mistake. The SPIEGEL does not have anything else to offer either – it counts “Jones’ disputed temperature curve” as one of them; apart from that “the supposed increase in natural disasters” – wrongly so as we have already showed (in German) reacting to an article published in Die Welt which claimed the same.
DER SPIEGEL elaborates on the story of the alleged “phantom graph” by Robert Muir-Wood which we have explained there as well. According to DER SPIEGEL, Roger Pielke “tried to find out where the graph had come from” and “traced it” to Robert Muir-Wood. This must have been hard indeed, given that Muir-Wood, who provided the graph, is named by the IPCC in the figure caption. The only difficult thing is to find this graph (which incidentally is correct but not very informative) at all: other than DER SPIEGEL claims, it is not in the IPCC report itself but only provided as “supplementary material” on its website, where the IPCC publishes such background material. Although on the 3,000 pages of the report there was no space for it, the graph now seems to be important to SPIEGEL readers for reasons unknown.
What is it all about?
SPIEGEL defames some of the best scientists worldwide, who not least for this reason have become prime targets for the “climate skeptics”. If you look at publications in the three scientific top journals (Nature, Science, PNAS), the just 44-year-old Mike Mann has already published 9 studies there, Phil Jones 24 (comments, letters and book reviews not included). In contrast, DER SPIEGEL always calls upon the same witness, the mathematician Hans von Storch, who has published only a single article in the prime journals mentioned (and that was faulty). But he says the politically wanted thing, even if without any supporting evidence from the scientific literature: in his view we can easily adapt to climate change. He also publicly accuses the vast majority of his colleagues who disagree with him of alarmism, calls them “prophets of doom” or “eco-activists” who indoctrinate the public. He also insinuates political or financial motives for disseminating horror scenarios. In this article he says things like “unfortunately, some of my colleagues behave like pastors, who present their results in precisely such a way that they’ll fit to their sermons”. This quote matches the article´s inflationary usage of the words “guru” “popes” “fiery sermons” “missionaries” and so forth. And he goes on: “It’s certainly no coincidence that all the mistakes that became public always tended in the direction of exaggeration and alarmism.” The following statement would have probably been more correct: it is certainly no coincidence that all the alleged errors scandalized in the media always tended in the direction of exaggeration and alarmism.
It is obvious that DER SPIEGEL does not care about science. This really is about politics. This year will decide about the future of the German climate policy: in the fall the government will announce its new energy strategy. This will decide whether the energy transformation towards a sustainable electricity supply, increasingly based on renewables, will be pushed forward or thwarted. In a global context the issue is whether global warming can be limited to a maximum of 2 ºC, as the Copenhagen Accord calls for, or whether this opportunity will be lost. The power struggle on this issue is in full gear. The energy transformation can best be prevented by creating doubts about its urgency. The fact that scandal stories about climate science have to be invented to this end just proves one thing: good, honest arguments against a forceful climate policy apparently do not exist.
p.s. (26 April): It’s just a curiosity, but telling: DER SPIEGEL calls Pachauri’s novel “Return to Almora” an “erotic novel”. The novel follows the life story of Sanjay Nath, from a childhood in the 1950s in the Himalayas through decades spent in the US building up a chain of meditation centers, until his final return to the Himalayas at age 60. The 400-page book contains a handful of love scenes, only gently hinted at in a few sentences. Calling this an “erotic novel” is devious; it can only serve the purpose of letting Pachauri appear in a dubious light.
Correction: As Roger Pielke has pointed out to us, the Supplementary Material to the IPCC reports is not only available on the IPCC website, but also on a CD-ROM distributed with the printed books.
[This piece is a translation of an article that originally appeared in German on the KlimaLounge weblog.]
References
Emanuel, K., 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, 686-688.
Knutson, T. R., J. L. McBride, J. Chan, K. Emanuel, G. Holland, C. Landsea, I. Held, J. P. Kossin, A. K. Srivastava, and M. Sugi, 2010: Tropical cyclones and climate change. Nature Geoscience, 3, 157-163.
Mann, M. E., R. S. Bradley, and M. K. Hughes, 1999: Northern hemisphere temperatures during the past millennium: inferences, uncertainties and limitations. Geophysical Research Letters, 26, 759-762.
Mann, M. E., Z. Zhang, S. Rutherford, R. S. Bradley, M. Hughes, D. Shindell, C. Ammann, G. Faluvegi, and F. Ni, 2009: Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly. Science, 326, 1256-1260.
RC regulars…
Walter posted the 2009 Paltridge paper on trends in tropospheric humidity as an argument for a negative feedback that would limit climate sensitivity. I am still researching it and reading the paper. I’ve found the obvious arguments for and against (like constant comments from all quarters that the data itself is very suspect)… I’m afraid researching this one is coming up somewhat thin, with little more than shrill WUWT style pseudo-science praise, and other minor comments.
The only RC reference I found to it is in a separate piece that contains the following quote:
Can anyone direct me to those other, contradicting data sources? I’ve found references to Dessler 2008 and Soden 2005, but nothing more.
I have to just comment, after looking at Paltridge’s paper (and Lindzen and Choi 2009, and any number of others)…
I am struck by the fact that when I read most scientific papers, they are just that. They have a narrow focus, they discuss a specific issue, and without understanding the subject matter and how it fits into the scheme of things, one cannot tell whether or not the paper provides an argument for or against AGW in the larger picture, or what the author’s position in that debate my be. This is, of course, how it should be.
When I read a paper by someone who is “against AGW” — even without knowing what their position is — I can smell it in the abstract and opening paragraphs. It doesn’t read like an abstract, it reads like a lawyer’s opening arguments. A quick visit to SourceWatch or other research quickly affirms the suspicion.
I just think that it’s telling that some scientists appear to be doing science, while other scientists blatantly appear to be trying to support an agenda (i.e. are predisposed to a particular position in a larger debate) with scientific papers. I know lots of scientists will have leanings one way or another on controversial theories, but it is striking that in something as complex and varied as climate change, any real scientists could take a hard and fast “pro” or “con” position, and look only for data and arguments that support that position… and simultaneously be utterly transparent about their holding of that predefined position.
Ray @346
Actually Ray, more simply, it’s all greed.
When the CEO saw the risk of a meltdown, or had it pointed out to him by his “risk manager” – s/he had two choices. Do nothing, or cutback – to a reasonable risk, or get out of the market altogether didn’t matter.
Do nothing was good because the traders continued making money for the firm.
Cutback, or get out entirely, was bad because the best traders would go elsewhere and make money for another firm. With only low risk traders, the firm would not make enough money to satisfy the stakeholders and the CEO was out of a job.
“Useless, it’s useless, even when you’re playing rough. Take it from me it’s useless, you’re never rough – enough”
294 (Wilt),
On the Solomon paper, please see Real Climate. The bottom line is that while it is an interesting study, it provides no clear evidence for a long term, negative feedback, particularly not one that will overwhelm other positive feedbacks and keep climate sensitivity low. It is based on one occurrence in a very short time frame. It provides no physical mechanism to describe the observed effect. If anything, it points to something that should be studied, and may have had an influence in holding temperatures down in the 2000-2009 time period, but it can’t currently be taken as an “argument” one way or the other for anything. To do so would be vastly over-reaching.
Really? You’re sure they deleted your posts because they couldn’t dismiss them?
Interesting how we’re not supposed to speculate regarding Jim Steele’s motives, but it’s OK for Jim Steele to speculate about the motives of those who run this site who don’t bother responding to some of his “unanswerable” questions … it’s because the questions can’t be dismissed … those who run RC are hiding that fact … because … because … why are they doing this, Jim Steele?
Moderator Jim, you’re not applying your moderation powers evenly here …
[Response: Just can’t let it go can you? My tolerance for this crap is now zero, in Kelvins. Discuss the science of climate change ONLY, or see your posts deleted. Those are your choices–Jim]
> RodB
> I have no proof … neither do you
RodB is an oldtimer here. He certainly knows science doesn’t provide proof.
He’s also perhaps our foremost goat collector, and he asks “proof” as bait.
Hang onto your goats when he gets that gleam in his eye and asks for proof.
Bob (332), I have no problem with the myriad of studies that “point to” the 3K per doubling, and scientists drawing reasonable conclusions from that. I do have a problem with turning that into dogma never to be questioned.
Bob, indeed I did:
http://agwobserver.wordpress.com/2009/11/05/papers-on-climate-sensitivity-estimates/
Ray (347), No, I think you have claimed other statements of mine to be just as ignorant!
One teeny factoid: there has never been a scientific observation or measurement of global temperatures as (mostly) anthropogenic generated CO2 goes from, say, 400 to 800ppm. Also see an earlier post of mine.
“So the simplest question I am asking is “Without any additional loss of solar forcing on the down stroke, what causes CO2 to be sequestered any further, if according to RC’s explanation that at the same temperature on the upstroke CO2 was being released.” 11 April 2010 @ 11:43 AM
The short answer is ocean circulation.
The long answer has to take into account the mechanisms for exchange of CO2 from the atmosphere to the deep ocean, especially the dynamics of CO2 release into the atmosphere by warming and absorption of CO2 by cooling, the transport of water plus CO2 by the AMOC, and the growth and melting of (mostly NH) glaciers.
As a simplified qualitative thought experiment, assume a slab ocean bounded by South and North America, with a notch in the boundary which is the Straight of Magellan; the Antarctic Circumpolar vortex pushes surface flow from west to east through the notch, and coriolis forces couple this into a northbound surface flow and southbound deep flow in the slab ocean. The absorption of heat near the equator and loss of heat near the north pole, as well as evaporation near the equator increasing the salinity of water being transported north, cause a density gradient which enhances the AMOC by thermohaline circulation.
During the last glacial maximum, from -28k to -18k ybp, long enough for several ocean overturnings, the atmospheric CO2 concentration and global average temperature were relatively constant. Milankovic forcing was a little more complicated, but was changing slowly, sin functions of the periodic orbital parameters – see http://upload.wikimedia.org/wikipedia/commons/5/53/MilankovitchCyclesOrbitandCores.png.
The upwelling deep water of our slab ocean model, as it flows north toward the equator, warms and outgasses CO2; as it cools in the North Atlantic, it reabsorbs CO2, and when it gets cold and salty enough, returns to the deep water. If everything is at equilibrium, the outgassing and absorption balance; in the real world, ENSO, PDO, sunspot/TSI cycles, Arctic Oscillation, etc disturb the balance, but by small amounts and for comparatively short periods.
If we apply a slowly increasing Milankivic forcing to our simplified slab ocean model, at equilibrium with CO2 at ~190 ppm and avg global T equal to that of ~20k years ago, the upwelling deep water outgasses more CO2 as the temperature rises and the average SST increases; the increased CO2 adds to the temperature, and the rise in temperature starts melting glaciers, increasing freshwater flux into the North Atlantic; the fresh water slows the thermohaline circulation (decreasing salinity and density), which decreases the removal of CO2 to the deep ocean. The double whammy of more outgassing and lower removal by a slowed AMOC brings a rapid (8k year) end to the ice age. The details of how much ice is available, and glacial floods, and how fast the temperature rises cause real world nonlinearities, changes and overshoots in AMOC, and complications such as Dansgaard-Oeschger events, Bølling-Allerød transitions, and transition from Heinrich Event 1 conditions to the Bølling-Allerød. For more details see http://www.sciencemag.org/cgi/content/full/325/5938/310 and http://sciencemag.org/cgi/content/full/325/5938/273#R1
The dynamics are different with a decreasing forcing. The cooling created allows increased snow cover and decreased outgassing of CO2 from upwelling deep water, but the creation of glaciers requires the evaporation of water, transport, condensation, and precipitation of snow. The energy flux involved is much larger than with melting and runoff, so the accumulation of glacial cover is a slower process than its loss. This limits the rate of change of albedo feedback. Also, there isn’t a mechanism to increase the AMOC during cooling converse to the slowing caused by fresh water influx from glacial melting – there’s no evaporation threshold temperature corresponding to the melting threshold at zero degrees C – not to mention that temperatures are falling, not rising. This asymmetry in physical processes leads to the asymmetry between descent into and recovery from ice ages.
Mike ” dT/dt = S(t) where T is global mean temperature anomaly of a pure mixed layer ocean, CP is its effective heat capacity, and S(t) is some cyclical forcing S(t)=S0cos(wt) with period tau=2pi/w.”
Mike, I agree that with this simple model model, there is a constant 90° phase lag. But this is a “purely inductive” model in an electrical analogy. However the amplitude of the response is also (by simple integration) So/w or So.tau/2π. Meaning, as I said, that high frequency are simply cut-off and the response to rapid variations vanishes as 1/w.
This discussion is very reminiscent of that I had on sea level rise. Your equation dT/dt = Cp S(t) is necessarily approximate, since it would predict an infinite rise for a constant forcing. Physically, it holds only as long as the retroaction limiting the temperature rise is negligible – which can generally be expressed by a condition like t << tr where tr is a characteristic relaxation time. With a more correct expression including this tr (with a -T/tr additional term). This is equivalent to add a "resistive" term -Ri in an electrical analogy. The introduction of such a term introduces a characteristic relaxation time tr (=L/R) AND at the same time a break frequency 1/tr. For variations long with respect to tr, the phase vanishes, the signal is more or less instantaneous and in close equilibrium with the forcing. For variations more rapid, the phase is 90° but the amplitude decreases with frequency. I don't think you can avoid the association of the two, that's a general feature of low-pass filters. So if the relaxation time for temperature is larger than 1000 years, we shouldn't see anything after 30 years (the same for sea level, or more exactly the asymptotic state would be huge with respect to what we are currently seeing).
[Response: Of course the phase lag is not 90 degrees in general. This was a simple derivation to make a more general point (that phase lags tend to scale with the periodicity of the forcing). Please read the paper I linked to, which provides a more general derivation. Further comments on this are O.T. –mike]
I’m thinking Jim Steele’s difficulty re the CO2 lag might be because in his simple model, he ties the CO2 response solely to temperature and to a point in time.
As I understand it, the positive feedback also involves the biological and chemical interactions in the oceans, which can take up to 1000 years to fully work through and reach equilibrium in the ocean (and therefore the atmosphere). Atmospheric CO2 is not only or solely driven by atmospheric temperature changes, but is also affected by changes in the ocean itself (as well as land, volcanoes etc).
If the energy absorbed from the sun drops from orbital or similar changes, it precipitates physical, biological and chemical changes in the atmosphere/ocean/land involving CO2, which can take a very long time to stabilise. So when the orbital changes put downward pressure on temperature, it starts a chain of events involving CO2, ocean flora, ocean chemistry etc that continue well beyond the time that the orbital influences themselves cease operating; and continue to reduce the amount of CO2 in the atmosphere, thus continue to lower the temperature. (Articles on the carbon cycle can shed light on this.)
And although obvious to most people here, when I was (re)discovering global warming it took a little while for the meaning of positive and negative feedback to sink in. Positive feedback amplifies any change, both up and down changes. Negative feedback has a stabilising effect, moderating both the up and down effects. From what I read elsewhere the terms are sometimes misunderstood.
(I’m no climate scientist, and I expect someone better qualified will correct or clarify the above.)
Jim Steele (286),
NONE of the extra carbon is coming from natural sources. The ocean is a net SINK for CO2, not a net SOURCE. When temperature rise precedes CO2 increase, the average lag time is 800 YEARS. I demonstrated a close correlation IN THE SAME YEAR. That the source is fossil fuels is confirmed by the isotope signature, a point tentatively noticed by Suess in 1955 and confirmed by Revelle and Suess in 1957. And Sergeant’s partial-F tests for Granger causality show it running unequivocally from CO2 to temperature and not the other way around.
I’ve been doing regression-correlation analysis for a long, long time, and know my way around it. I wrote the old shareware MULTI program, and I’m working on a statistical analysis program for Windows.
Don’t know if that got through, since I got an “internal server error,” so I’ll repeat. Please remove any redundant posts.
JS (286),
I performed Cochrane-Orcutt iteration on that regression to compensate for the autocorrelation in the residuals, and still got 60% of variance accounted for when rho had dropped to an insignificant level.
We know from the radioisotope signature that the new CO2 is coming from fossil fuels, not the climate system. This was first noticed by Suess in 1955 and confirmed by Revelle and Suess in 1957. Here are the citations, please look them up:
Revelle, R. and H.E. Suess 1957. “Carbon Dioxide Exchange between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO2 During the Past Decades.” Tellus 9, 18-27.
Suess, H.E. 1955. “Radiocarbon Concentration in Modern Wood.” Sci. 122, 415-417.
Furthermore, when warming precedes CO2 rise, as in a natural deglaciation, there is an average time lag of 800 YEARS. The correlation I demonstrated was IN THE SAME YEAR.
I was a statistics minor at Pitt (’83). I have been doing regression-correlation analysis for a long, long time. I wrote the old shareware MULTI program, and am now working on a statistical analysis package for Windows.
Rod (324),
No. The emissivity and opacity of the atmosphere depends on its load of greenhouse gases. If the Earth’s atmosphere were entirely nitrogen and oxygen, the atmosphere’s IR emissivity/absorptivity would be near-zero and the Earth’s surface temperature would be 254 K, not 288 K as it is.
356 (Rod B),
This makes no sense to me.
On the one hand you say that you recognize that there are multiple lines of evidence that support a 3K/doubling climate sensitivity (which directly contradicts your statement in 322, that “I have no proof of what the actual climate sensitivity is, but then again, despite your assertions, neither do you.”) Of course, you qualify that by using quotations around “points to”, which suggests that somehow there’s some “trick” involved in actually applying evidence and logic to a problem, and so you don’t really accept the evidence at all.
But on the other hand you say that despite this body of evidence you have a problem with people turning evidence and conclusions into “dogma.” What exactly does that mean? How did that even enter in to the discussion? The question was what proof is there, you’ve been shown it, and you state (with subtle equivocation) that you accept it. Where and how does “dogma” enter into this discussion?
[This is where I have a problem with many skeptics. This was exactly something that was pointed out in my Catholic Pre-Cana classes before I got married. Beware of the argument where one person changes the subject the moment they are shown to be incorrect. Rather than admit to the truth and move forward, they instead attempt to jump tracks and shift the debate to some other area where they can try to score points. It’s unproductive, and demonstrative of someone who is both close minded and trying to “win” rather than trying to get to the truth.]
The German original of the article is now available online:
http://wissen.spiegel.de/wissen/image/show.html?did=69744066&aref=image042/2010/03/27/CO-SP-2010-013-0140-0149.PDF&thumb=false (PDF)
http://www.spiegel.de/spiegel/print/d-69744066.html (HTML)
Bob, thank you for your comment (#351). Due to circumstances there were some interruptions in our discussion (my first response ended up in a queue for many hours yesterday, and when it was published you were no longer on line). You write that you “can smell it in the abstract” when somenone is “against AGW” (I suppose that in the end we all are against AGW, but I understand what you mean). I then started re-reading Paltridge’s abstract because I thought I had missed something there. But I must conclude that apparently your nose is better than mine. In the abstract, the author states his method, honestly admits that some of his data require great caution, mentions his results (decreasing trends in specific humidity during several decades) and concludes that if this is confirmed upon more detailed examination it would imply negative water vapor feedback whereas in climate models one supposes a constant relative humidity (and therefore increasing specific humidity upon warming). I think I should leave the final judgment to the readers, here is the complete abstract:
“The National Centers for Environmental Prediction (NCEP) reanalysis data on tropospheric humidity are examined for the period 1973 to 2007. It is accepted that radiosonde-derived humidity data must be treated with great caution, particularly at altitudes above the 500 hPa pressure level. With that caveat, the face-value 35-year trend in zonal-average annual-average specific humidity q is significantly negative at all altitudes above 850 hPa (roughly the top of the convective boundary layer) in the tropics and southern midlatitudes and at altitudes above 600 hPa in the northern midlatitudes. It is significantly positive below 850 hPa in all three zones, as might be expected in a mixed layer with rising temperatures over a moist surface. The results are qualitatively consistent with trends in NCEP atmospheric temperatures (which must also be treated with great caution) that show an increase in the stability of the convective boundary layer as the global temperature has risen over the period. The upper-level negative trends in q are inconsistent with climate-model calculations and are largely (but not completely) inconsistent with satellite data. Water vapor feedback in climate models is positive mainly because of their roughly constant relative humidity (i.e., increasing q) in the mid-to-upper troposphere as the planet warms. Negative trends in q as found in the NCEP data would imply that long-term water vapor feedback is negative – that it would reduce rather than amplify the response of the climate system to external forcing such as that from increasing atmospheric CO2. In this context, it is important to establish what (if any) aspects of the observed trends survive detailed examination of the impact of past changes of radiosonde instrumentation and protocol within the various international networks.” http://www.springerlink.com/content/m2054qq6126802g8
I should also stress that the article is about the TREND in specific humidity, not about absolute values.
Bob @351
How about Hansen et al 2008?
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf
Or Rockstrom et al 2009?
http://www.ecologyandsociety.org/vol14/iss2/art32/main.html
Bob (#353), I agree that Solomon’s observations still lack a physical explanation. But I have confidence in her scientific integrity and in the quality of the review process of the journal Science, so let us focus on the reported observations. These cover a period of about 3 decades, I would not call that ‘a very short time frame’. The authors not only draw a conclusion about the 2000-2009 period but also suggest that during 1980-2000 the temperature increase was significantly higher (about 30%) than it would have been without the increase in stratospheric water vapor during those years. Since most of the temperature increase in that period is usually attributed to the increase of CO2 (at least by the proponents of the AGW theory), the most logical explanation seems to me that climate sensitivity with respect to CO2 increase is lower than thought before Solomon’s findings were published. Unless of course it would be proven that the changes in stratospheric water vapor are related to changes in CO2, but this seems unlikely in view of the 2000-2009 data.
Of course I realize that we have not been reading the final word in the debate on stratosperic water vapor, and on water vapor feedback in general.
366 (Walt),
My problem begins at the following sentence, which wanders away from his point of evaluating humidity observations in the troposphere into attacking climate models and thus guaranteeing that the study has the spin he intends.
I am only just getting to his discussions of models in his paper, but this is exactly the problem that I personally see. I feel that other authors would discuss the humidity in the troposphere and leave further inferences unspoken, for others to draw conclusions from the plainly stated scientific facts. The inferences are fairly obvious even to a layman. Paltridge, however, doesn’t let that sit. He has to make sure that he gets his argument in, too.
Beyond this, his argument isn’t entirely complete, either, because it is not merely the models but also our understanding of the underlying physics and our interpretation of paleoclimatology which support an increase in atmospheric water vapor, so to focus on models seems rather “trendy” and myopic — a good way to approach an argument, but not the science.
Maybe I’m wrong (I’m not a scientist… maybe this is very much how things often work in all scientific fields — scientists are human, and opinionated, after all), but it just doesn’t sit well with me, and I feel like I’ve really only seen that approach in other papers that offer evidence against AGW, but not vice versa.
Sorry, I labeled my previous comment 366 (Walt), when I meant 366 (wilt).
dhogaza: you got some blind anger. you say “Really? You’re sure they deleted your posts because they couldn’t dismiss them?
Interesting how we’re not supposed to speculate regarding Jim Steele’s motives, but it’s OK for Jim Steele to speculate about the motives of those who run this site who don’t bother responding to some of his “unanswerable” questions … it’s because the questions can’t be dismissed … those who run RC are hiding that fact … because … because … why are they doing this, Jim Steele?
Moderator Jim, you’re not applying your moderation powers evenly here …”
That quote is something I made months ago on a different blog after the insults of several deletions, whatever the motives. I didn’t insert that comment here. Here I applauded the new fairness. I don’t understand why you wouldn’t think respect and fairness to skeptical ideas wouldn’t make this a more educational blog. You can speak your truth, then like any kid, we usually do not learn just because some one told us. Right or wrong we learn by challenging ideas,applying them, and seeing where and when they work. Maybe it is a longer road than if we just accepted your truth at first go around. But probably why such childish skepticism persists,is new truths are also discovered.
But if that quote really bothered you and shouldn’t be allowed here, blame HankR, Maple. I have tried to keep my discussion on the substance of climate science. Why do you refuse to do likewise?
[Response: Jim, I appreciate your applauding our ‘fairness’, but it isn’t ‘new’. If we don’t respond to your queries, it is either because we a) don’t have time, and don’t read each and every comment — there are just two many or b) because we’ve responded many many times to the same arguments, and it gets tiresome. If you come up with something brilliant, that really does stump us, we will let you know and encourage you to publish it. No one gets deleted here for brining up ‘inconvenient truths.’–eric]
Also, wilt pointed to the Paltridge paper, not me.
BPL (363), I appreciate your help. But I can’t get through it entirely. In your basic model atmosphere composition is nowhere to be found. Or are you saying the simple assumption of 1.0 emissivity is misleading and that the assumed emissivity of the atmosphere (0.0 for visual) is either 1.0 or 0.0 for infrared depending on the wavelength — I assume in accordance with GHG energy levels (is this correct?). If so, I have some disagreement with it, but will accept it for now without prejudice for the sake of discussion. I still can’t see how the concentration of GHGs effect your model results. Or why the emission/absorption can still be described by S-B law, viz P = εσ[(epsilon)(sigma)]T^4 when internal GHG energy emission does not depend on temperature. (Whether emission occurs or not is indirectly related to temperature, but the energy of emission is not.)
Dave Benson. I accept that temperature will lag orbital forcing. And I see that as useful for aligning the Milankovitch forcings with historic temperature reconstructions. However, not being very familiar with the mathematical variables you used and how they totally relate to physical processes, I am not sure if I missed something, but I don’t see how your answer would explain the crux of my perceived problem. Given that the ocean temperatures were lowered by the orbital forcing and that is said to only account for half of the temperature drop, I am then concerned with the dynamic that sequesters the CO2 and accounts for the remaining temperature decline.
Dave Miller #335 Thanks for the thoughtful reply. You said The “insulating” effect of the CO2 doesn’t change – the GHG’s will reflect about the same percentage of outbound IR. But you answered your own question. Orbital and albedo changes change the temperature. Over a sufficient length of time this cools the oceans. Cooler oceans absorb more CO2 from the air. This is exactly the same mechanism as the positive feed back when coming out of the glacial, just running backwards.
Dave when you say “Over a sufficient length of time this cools the oceans” that is where I asked next “Without any additional loss of solar forcing on the down stroke, what causes CO2 to be sequestered any further over that time period?” meaning what mechanism/process/forcing is cooling the oceans further or sequestering CO2 and thus lessening the CO2 forcing and causing the oceans to cool?
In the context of the RC explanation that the non-CO2 forcing accounts for half of the temperature change, and in the context of the lag where the higher CO2 is still contributing most of its full weight of radiative forcing, in this example the orbital forcing has more or less completed its half of the temperature change. I understand albedo plays a role in changes of the balance, but then how would you characterize the difference in albedo at 1 degree both in the upstroke and downstroke? If not equal albedo for equal temperatures, I would expect more albedo on the upstroke, due to a likely greater extent of residual glaciers.
Brian Dodge #358 Thank you for this reply, I believe your answer correctly focuses on what I am trying to understand. My initial conclusions from my simple model were based on the assumptions that I expect the net rate of CO2 exchange with the ocean to be approximately the same at 1 degree (given there is no additional significant changes in solar forcings or albedo), and thus expect the same processes whether or not the temperature is intersected on the upstroke or down stroke.
I also had assumed that ocean circulation to be that same regards CO2, but your answer, points to a mechanism that I could see would make a difference and perhaps resolve my perceived paradox, but it also raises many more questions that I need to explore to better my understanding. I will definitely peruse your links and then I would like to pursue a more detailed examination and dialogue of your proposed mechanism, if the moderators and others do not think we are straying too far off topic? Moderators?
Bob (364) It’s a matter of degree (and not semantics). There are a number of assessments that you say “point to” (your words) the conclusion. This leaves a material doubt or uncertainty. You probably hedged enough (and appropriately) in #281 that you don’t cross the dogma threshold, so I was a bit off base here as far as you are concerned (though on another question you talk about, “….all….other arguments are all dead and buried” which sounds pretty dogmatic to me.) On the other hand there is a clear movement by many on this question (and others) from being indicative to dogma. It becomes dogma when there is absolutely no allowance for any sort of questioning. When anyone does so question, the response, to an outside observer, sounds strikingly similar to the Church ferreting out heretics. Though even in this example they try to buy an out by saying ‘we don’t know if it is 3.0K exactly — it might be only 2.9K’ But let someone suggest that the science is so uncertain that it might be a 0.05K sensitivity, and watch him not get rebutted but get crucified.
I’m not saying the 3.0K sensitivity is wrong. But I am saying that the observations and physics theory is sufficiently ambiguous to warrant serious questioning — given the seriousness of its consequences. It doesn’t matter if 1000 studies are made that point to 3.0K, though that certainty tends to somewhat mitigate — though not eliminate — the ambiguity. Those studies all use the same assumptions and suppositions of the physics. And, as I said earlier, none have measured or observed even by proxy the global temperature increase as CO2 goes from 400 to 800 ppmv. (And don’t parry with the ‘I’m slandering good scientists’ strawman. Those scientists are doing learned work and drawing reasonable conclusions based on what they know. They’re just not eliminating the uncertainty.)
Incidentally, I agree that some skeptics exercise what you were taught in your Pre-Cana classes. But in case you missed it some warmists do the same — right on this thread — some by you. You changed the MWP argument to one about climate sensitivity. There’s been a ton of guys here refuting stuff that Jim Steele never said.
[Response: Something that seems to always be missed in discussion of uncertainty is that it works in both directions (and indeed is heavily skewed in one direction. As the Economist put it in a recent article, “The fact that the uncertainties allow to you construct [that is, imagine] a relatively benign future does not allow you to ignore futures in which climate change is large.”–eric]
Re: glacial cycles
> too far off topic?
Can’t speak for others, but I’m following the replies to this with interest. And really, what needed saying “on topic” was said by Stefan in the OP already, so why not go off on an educational tangent…
Jim Steele
After the peak there is less incoming energy, the energy of the system falls and the planet cools. Because the oceans have cooled they absorb some CO2, lowering the CO2 forcing. Again with this lowered forcing the planet cools a little bit more, so more CO2 is absorbed, repeat in ever decreasing magnitude until you reach a new equilibrium.
Jim Steele, all I am saying you were easier to understand, would you only use shorter sentences. Can I try to paraphrase, what I think is your biggest concern:
1) Raise in atmospheric CO2 is known feedback to raising temperatures.
2) Source of this feedback CO2 are known: oceans, arctic bogs, methane clathrates.
3) Then, is drop in atmospheric CO2 known feedback to the dropping temperatures?
4) If so, what is the mechanism of this drop of atmospheric CO2?
Have I understood your problem correctly?
Bob (#368, #369), I can understand that you would prefer that authors refrain completely from writing ‘political’ conclusions in their abstracts. About Paltridge you write: “He has to make sure that he gets his argument in, too.” I have been a scientist all my life (not in the climate field, however) so I know a few things about getting your articles published. I think in virtually every field of science, the abstract is probably the most important part of a paper because that’s where a reviewer starts in his evaluation. So the abstract aims at summarizing the article but also tries to win ‘the hearts and minds’ of the reviewers by formulating some type of conclusion with respect to the relevancy. There seems to be even more pressure to extrapolate from the scientific findings to a ‘statement’ in climate science, where there is hardly any ‘neutral’ science left since everything is immediately somehow translated into pro or contra AGW.
PS Briefly after submitting my comment #366, I have also submitted an answer to your #353 comment on Solomon. This answer, however, still awaits moderation. Sorry about that (although it’s not my fault).
Jim Steele (371) — The excursion into linear systems theory demonstrates that even with the maximum possible positive feedback, the temperatures cycle up and down following the orbital forcing with a phase lag and a large amplification both on the upswing and the downswing.
I used H(s) = k/(s+1) with k=1 to represent a reservior; the deep oceans are a reservior of CO2. This reservior then gives up its contents to the surface on the upswing and replenishes the supply on the downswing. If k is greater than 1 the linear system is unstable but that implies an additional source of energy to drive it into ever wider swings; for the climate no such source is available. To obtain an amplification of exactly 2 of the orbital forcing, so that the response is
2cos(a(t-l))
it turns out that k = 0.516 and then the lag is l = 7.9894 ky, less than at full amplification.
This linear model certainly oversimplifies climate as it has no cryosphere. I don’t know what models are used for orbital tuning of bethnic and ice cores.
I guess I don’t understand your difficulty, I fear. Colder water holds more CO2 so during the cooling phase CO2 is removed from the atmosphere into the reservior of the ocean and providing the positive feedback on the downstroke.
Correction #381, answer to Bob: Bob’s initial comment can now be found under #371 and #372. This is because some older comments have now been inserted, including my response to Bob on Solomon (see #370)
“, with some cop-outs about going to the “Start here” section thrown in.–Jim]”
[Response: I knew I could count on you to chime in eventually with something you’d searched for to get yourself upset about. Everything I said to Dhogaza applies to you, times 2.–Jim]
So when JS yibbers on about a 800 year lag, we should instead get Jim to go off to skepticalscience?
Or does the Start Here actually go to a link about that subject?
[Response: The 800-year lag gibberish was discussed in the first week or RealClimate’s existence, so “start here” would be a an appropriate response. For the specific discussion, see: https://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/ –eric]
Rod B says: 12 April 2010 at 12:47 PM
Those studies all use the same assumptions and suppositions of the physics.
Rod, of a hypothetical N number of studies all pointing to 3.0K increase of temperature per doubling, you imply too much ambiguity will remain because all those studies rely on the same physics.
In order to drive conversation forward, it seems as though focusing on what assumptions and more particularly suppositions are at fault from your perspective would be a good thing. Otherwise it seems at first glance as though you’ll never be in position to be able to form a conclusion with regard to this matter of C02’s potential for forcing.
Not to pick on you particularly, but if the same line of reasoning is in the minds of others with responsibility for formulating policy, that’s not good.
Perhaps I’m looking too hard at that word “supposition”, but it’s got serious connotations if you mean it according to its definition. The fundamentals of this matter of forcing are not built on supposition. Knock-on effects perhaps are. Where in general terms do you believe we slide from demonstration to supposition with regard to forcing by C02?
#375 Rod B
It can’t and shouldn’t (common error). The emission is determined by the Planck distribution for black body radiation. The total radiation which is obtained by adding (integrating) the contributions from all wavelengths satisfies the S-B law if and only if the emissivity is independent of wavelength , i.e for black and grey bodies. Greenhouse gases are neither grey nor black so the S-B law is not even approximately valid for them.
[Response: That’s a bit of an overstatement of course — Stefan-Boltzmann is the starting point for any such calculation; one has to account for the wavelength emissivity though.-eric]
377 (Rod B),
Where to begin…
Well it is dogmatic, yes, if you want to take the approach that nothing is ever sufficiently settled, and everything must be debated over and over and over ad infinatum, then I lose patience. There are a lot of silly arguments out there that just aren’t worth discussing, no matter how much some deniers want to cling to them as open. To me, those people quickly expose themselves to be willfully ignorant, and so I have no time for them. One can’t teach someone who refuses to learn, no matter how much they proclaim their status as a “skeptic.” If they don’t understand the simple and obvious facts by now, I can’t make them.
This, by the way, is a purposeful or accidental Internet debate technique used by deniers, to constantly bring up long dismissed points as if they are new and fresh and must be given fair consideration. You can perhaps demand fair consideration for them from other people, but not from me as an individual. It’s not worth my own personal time to discuss nonsense (unless I feel that the other party actually has a chance of listening and learning and putting the silliness to rest).
This is more skeptic “owe, woe is me, they are religious in their warmist fanaticism and I’m just trying to get to the truth.” I don’t buy it. Discuss science with me, not debate tactics or how the evil warmist scientists are bullying the poor, freedom fighting skeptical underdogs.
I think that you are the one casting this as settled. This line of conversation began when I said that the only aspect of the science that I really considered open to debate was this.
I said that multiple lines of evidence support a 3˚C/doubling warming, but if something were to turn out to be different than we expect, this is it. But I also said that while alternative theories have been proposed, supporting evidence and specific mechanisms have yet to materialize, despite seemingly concerted efforts by skeptical scientists to prove otherwise. Perhaps if they put their time into something other than complaining about the “dogma” of the other scientists.
The fact that they have not yet is in fact circumstantial evidence that it is unlikely to happen.
My position is that the preponderance of evidence is on 3˚C, that I am open to other possibilities, but as yet there is no serious evidence otherwise (I’m looking at the Paltridge paper now, which for now shows merit, but by itself hardly stacks up to the list of other studies in favor of 3˚C).
You are the one that began the debate by saying that I did not have evidence. Now you say I do, but it’s no where near enough to end the debate. I agree. More evidence is needed. But with dozens of studies pointing to 3C being right, and one or zero pointing to 3C being wrong, I’m sorry, I’ll go with being worried about my future and wanting to take action.
Okay, now you’re rewriting history…
From comment 281 (mine, in response to Walter, after the sequence 235, 240, 272):
From comment 322 (yours, in response to 281):
I ignored the bait, sticking to my original statement in 281 that I won’t waste time discussing the MWP.
Now you bring it up again. But no, I did not redirect the debate away from the MWP, but rather you keep trying to redirect the debate to the MWP.
I’m not exactly sure why deniers are so hot on the MWP. If it did exist, it would simply be further evidence that climate sensitivity is high (i.e. 3˚C or greater). Deniers want it to mean “we don’t have to worry now, because it was warm then, too.” Except in truth we’d have to come up with a mechanism for the earth having warmed that much back then, without CO2, to contrast and compare with the effects of GHG in the present, and until we did, we’d still have to work from the logic that “GHG is warming the planet, climate sensitivity is high (as supported by the MWP), therefore we had better take action now.”
In particular, the causes of any MWP warming would have been naturally reversed, while we know that CO2 will stay in the atmosphere for a very long time, so it’s unlikely we can count on the same thing happening in the present.
Arguments I’ve seen for a MWP are down right weak, but even if they were true, they reinforce current logic rather than refute it.
Definitely my bad, and I apologize to Jim Steele, for looking that name up elsewhere, copying something in, right off. I should’ve waited a couple of days and learned by watching.
There was a real experience — the “disappearing” post — that led to the suspicions posted elsewhere that I found.
It’s a misfeature: after you post, the ‘pending moderation’ note appears, but only you and the moderators see it. If it ‘disappears’ for you, none of the moderators let it in (any one of them can).
Your post didn’t appear (to us) then get removed, as you thought it had.
As Eric notes inline above, a post may not appear because none of the moderators recognized it as new material. But as you showed us, it can be all new to a new person coming in and posting.
A hew person’s post mixing familiar skepticism and old science also makes people think, oh, this isn’t new. But your post was new for you.
Recently added moderator Jim (who knows you as a fellow biologist) spoke up this time when you cama back, and firmly. We amateur readers need to recognize that kind of professional courtesy and defer to it.
Lesson: scientists coming in here new, who haven’t studied climate, may be _very_ skeptical and say so very bluntly, just as many nonscientists do. We can’t tell, for a while, and new readers don’t know who we are either.
So, I reacted like a jerk, and I apologize.
People like me–amateur readers–often reply to new people who post FAQs, that don’t need attention from the real scientists.
We can and do get overexcited. I did. I trust the moderators to calm me down when needed: http://www.cartoonstock.com/cartoonview.asp?catref=amcn39
370 (Wilt),
I’m not disparaging Dr. Solomon in the least. That paper is a perfect example of sticking to the subject at hand, treating it as one more important piece of knowledge to add to the pile, and letting others make inferences.
Unfortunately, I haven’t paid to read that paper, so I am primarily speaking from the abstract and other’s commentaries, however my understanding is that it only discusses a drop in water vapor in the past decade. This is the “short period” I referred to and I stand by that.
I understand that it also estimates increases in stratospheric water vapor contributing to warming from 1980-2000, and attributes as much as 30% of warming to that. But your statement that “Since most of the temperature increase in that period is usually attributed to the increase of CO2” is, I suspect, inaccurate and overly simplistic. I know of no method of attributing warming to various individual factors and feedbacks, either positive or negative. I have never seen anyone “claim” that a certain amount of warming to date is the result of CO2, only that the end result per doubling will be anywhere from 2 to 5 C.
I would caution against any train of thought that sounds like hearsay (“at least by the proponents of the AGW theory” were your words).
The paper says what it says, that stratospheric water vapor increased for two decades and contributed to warming, and decreased for one decade which slowed warming. This is evidence that water vapor does in fact have a role in warming, and that unexpected effects in the stratosphere exist. It is not evidence, to me, in either direction for or against any particular climate sensitivity or any negative feedback which will limit sensitivity to CO2 below 3˚C per doubling.
Enough is enough. I think IPCC should sue the newspapers when they run such [edit] articles. Don’t you think ?
It seems everyone is trying to explain the same thing to Jim Steele. Since no one seems to have suceeded, I’ll give it a try:
In a simplistic thought experiment, we are gods playing with a planet covered by a huge H2O ocean. There’s a bit of CO2 in the water and in the atmosphere and the atmospheric fraction of the CO2 is in equilibrium with the oceanic fraction so that the net CO2 flux between the two is zero. The planet is also in radiative equilibrium with its sun and space. But then we turn up the sun a bit (+1K worth of forcing). Temperatures increase because the radiative equilibrium is perturbed and, as a result, the equilibrium amount of atmospheric CO2 rises (by an amount equivalent to +0.5K worth of forcing) which in turn causes the actual amount of CO2 in the atmosphere to rise. The planet will end up warming to +2K because the CO2 forcing feeds back on itself (it doesn’t warm a full 2K because each additional unit of CO2 causes a slightly smaller forcing). So far so good?
Now the planet is at a new hotter equilibrium and we dial the sun back down (-1K worth of forcing). As a result, the planet leaks more radiation than it receives and therefore it cools. The extra CO2 that we put in the atmosphere during our experiment would keep the planet near +1K (warmer than it was orginally) except that this -1K cooling causes the equilibrium amount of CO2 in the atmosphere to fall somewhat (by -0.5 K worth of forcing) and a CO2 flux from the atmosphere to the ocean is therefore initiated. The CO2 positive feeback works exactly as it did when we warmed up the planet so that the flux is sustained until the system gets back to its original equilibrium with the original amount of airborne CO2.
I hope this helps. I wouldn’t bet on it but you never know…
Jim Steele @376: “Without any additional loss of solar forcing on the down stroke, what causes CO2 to be sequestered any further over that time period?”
But there is an indirect additional loss of solar forcing due to a lowering of albedo as permanent snow cover expands at high latitudes, which progressively decreases insolation (energy in).
However, the main and relatively fast amplifying feedback that I haven’t seen you acknowledge yet is decreased water vapour in a cooler atmosphere, and thus a relatively rapid reduction in the greenhouse effect, which allows more radiated energy to escape.
Lower water vapour and albedo will cool surface and ocean temperatures further, which then promotes the absorption of still more CO2 (and the retention of soil and bog carbon), which then cools surface temperature still further. And so on in a diminishing series feedback until energy out once again more or less equals the orbitally reduced energy in.
While it is true that the cryosphere’s response to focings is nonlinear, on the scale of 100 ky this matters less than might be supposed. In
Climatic conditions for modelling the Northern Hemisphere ice sheets throughout the ice age cycle
A. Abe-Ouchi, T. Segawa, F. Saito
Clim. Past Discuss., 3, 301-336, 2007
SRef-ID: 1814-9359/cpd/2007-3-301
http://www.cosis.net/members/journals/df/article.php?a_id=5292
we discover that on of the problems with the modeling of a full cycle from interglacial 2 (the Eemian) to interglacial 1 (the Holocene) was the rapid decline in temperature after the Eemian in the descent into the first following stade.
RC Regulars,
Forgive me for repeating myself, but I only saw one response to my query (351), and that response gave papers on climate sensitivity, while I’m looking for papers that relate to relative and specific humidity in the troposphere, as it pertains to a positive water vapor feedback.
To repeat, I’m looking for the data that fills out the following quote from an RC post that itself references the Paltridge 2009 paper:
Can anyone direct me to those other, contradicting data sources? I’ve found references to Dessler 2008 and Soden 2005, but nothing more.
At the moment, I am left with only my own (amateur) observations and criticisms of the Platridge study which, while covered with caveats, may make a decent case that actual water vapor feedbacks may not be as strong as proposed.
S. Matthew — I beleive I insuficiently answered your question regarding the time for temperatures to respond to CO2 forcing.
First and foremost, the temperature responds to all fordings the same way; it doesn’t matter whether it is volcano forcings, CO2 forcing, solar forcing, …
The response has components on land which I ignore. The response has components in the cryosphere which I ignore. So I’m left with but three compenents:
(1a) atmosphere and the upper few meters of ocean well mixed by wave action;
(1b) the shallow ocean below that small bit;
(2) the deep ocean.
Component (1a) responds in about a year; component (1b) in about 30 years. Putting those two together, the early response is in “about a decade”. Component (2) responds on a millennial scale; adding excess CO2 to a state of equilibrium will result in a new equilibrium, with elevated temperatures and CO2 in both the atmosphere and the ocean in 100 decades or maybe 130 decades.
re Eric’s response to 377:
You make a perfectly valid point. I’m not arguing that the uncertainty of the “accepted” sensitivity value is as big of the uncertainty of my suggested value. Any reasonable analysis would suggest that the accepted value is highly favored to be much more likely than not. That’s not my point. My point is that since the ramifications of the accepted theory could be massive even the smallest uncertainty ought to given focused, serious and diligent due. At the least the skeptics should not be drummed out of existence carte blanche. And throwing out the accepted value because of a reasonable but small skepticism until we figured it out with more precision would be abominably stupid. A little like the uncertainty of Iraq having WMDs at the onset of our invasion despite the virtually 100% consensus world wide that they did.
Jim Steel @377,
You say ” I have tried to keep my discussion on the substance of climate science. Why do you refuse to do likewise?”
Yes, “climate science”, but not about material pertaining directly to Stefan’s piece on Der Spiegel. I’m sorry but the fact that posts go off topic is not an excuse for this kind of departure. Jim, if you re-read the thread, my comments have mostly been on topic (see #86, 105, 107, 280 and 348); with the first four of those related to the DS article or comments made about it. I, and others, began to get frustrated (e.g., me at #258) when the discussion became horribly side tracked and instead of focussing on the awful DS article, and almost everyone was distracted trying to explain the science of climate change you. Additionally, regardless of the reasons yo made for that infamous quote, you made that statement in a public forum, and you cannot take that back. To be frank, that is your fault and your fault alone.
RC is an excellent pedagogical tool/resource, and I hope that you are now willing to retract that statement you made in view of the candid, informative, patient and lengthy discussion that you have had with experts here.
Yes, some of us got frustrated with you, and some were rude (including myself and for that I apologize) but I hope that you can understand that based on the information we had access to, we had good reason for reacting that way. That and the fact that rehashing the same talking points put forth by skeptics gets incredibly tiresome.
Anyhow, best of luck.
Re Vincent @390, I agree, to a point. IMHO, legal action is probably not warranted in this case (maybe taking them to a German press council is though). The IPCC does need a dedicated PR team (incl. a spokesperson with experience in climate science) to pounce on such matters and to promptly and firmly set the record straight. Right now they are not equipped to deal with the DS debacle and other the misinformation oftentimes disseminated by the media on AGW. I really hope that they hire a strong and experienced PR team as well as some full-time research scientists to assist the PR team for AR5.
IPCC could also emulate what MetEd and COMET have done in terms of graphical representations of the science which is suitable for scientists and lay people (i.e., different tiers of detail). In fact, a series of COMET modules on climate science is long overdue, and would be an incredibly useful outreach tool for the IPCC. If the public is educated then then media outlets will have to smarten up very quickly to avoid becoming the laughing stock. If they public is educated, then misleading articles such as the Der Spiegel piece discussed here will become much harder to sell, and rightly so.
Re #386 Inline response by Eric
I don’t see it, at least not yet. I am not sure what ‘any such calculation’ refers to, since #375 linked back to a vague remark rather than a calculation.
Starting from first principles, can you obtain a T^4 approximation by integrating a Planck distribution over a finite and fairly narrow range of wavelengths, assuming a constant emissivity, for the sake of simplicity?
I can see how T^4 might apply to a gas at highish pressures when all the absorption lines are smeared out, but not when there a few distinct lines. Of course you can use any approximation as a starting point if you are prepared to iterate.
I feel some people are being deliberatly obtuse when dealing with Jim Steele’s question.
These responses saying, ‘of course atmospheric CO2 reduces in the cooling phase of the glaciation cycles’, are obfuscation. Jim has already said numerous times that he recognises this. His question relates as to how this cooling phase gets started at all now that we have a large upward forcing factor that was not present at the same stage of the warming phase? Simples!
It is not him that has given the hypothesis that CO2 changes from an initial feedback stage to a forcing stage and then back to a feedback stage. If CO2 was just tracking temperature change, which is one explanation after all, then this problem would not arise.
It is not Jim who has assigned such a large value to CO2 forcing that it is tricky to see how cooling can start at all.
It would be useful, seeing as this is a science site, if the calculated and measurable changes that the Milankovitch cycles introduce to total TSI reaching the Earth are stated.
Unfortunately we know that these calculations do not appear to produce a sufficient reduction in forcing effect to cause the glacial cycles. Something else seems to be involved as the correlation of the glacial cycles to the Milankovitch Cycles is so strong that it appears they are definitely connected.
So unless someone can give the actual measurements which can cause the glacial phases on their own then we are left with ‘other factors’. However, you are still left with the same problem ‘why is the strength of these factors different in the cooling phase’?
Alan
[Response: This is all nonsense (sorry). There is no ‘flipping’ back and forth between forcings and feedbacks, and there is little mystery about why Milankovitch forcings affect the ice sheets. Over the whole ice age cycle – warming and cooling and warming and cooling – CO2 is behaving in exactly the same way – responding to the shifts in the carbon cycle driven by temperatures, circulation, sea ice expansion, sea level change etc. The analysis by Gerard Roe (2009), shows very clearly that the growth of the ice sheets is related to the summer insolation at 60 N and that this is the driver of all subsequent changes (including CO2). Once the orbital forcing switches towards a warming, the ice sheet growth will start to slow, and then reverse, temperatures and carbon follow, leading to further warming. When the orbital forcing flips again, the ice sheet retreat will slow, then stop and then reverse, and everything goes the other way. It really isn’t that difficult. – gavin]
> Rod B says: 12 April 2010 at 5:26 PM
> … even the smallest uncertainty ought to given
> focused, serious and diligent due.
Zero uncertainty is unavailable in science, as Rod knows, so this
requirement would delay any action for approximately forever.