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.
re : #398 (continued).
Integral of Planck function over narrow range of frequencies (sketch):
(a) a factor T^4. This looks promising but
(b) there is another factor i.e the integral of (x^3)dx/[(exp(x)-1] ; still promising until you consider the limits x(0),x(1) of the integral which contain the absolute temperature T again as follows:
(c) x(0)= hf(0)/kT , x(1) = =hf(1)/kT
where h = Planck’s constant and f(0), f(1) are the frequencies defining the limits of the absorption band.
Conclusion: Result no longer looks like T^4.
“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”
I am sorry Gavin but this is far too simplistic an explanation for Ice Ages and the Glacial Cycles.
What you say has not been proven. It is one hypothesis to try and understand why the Glacial Cycles correlate with the Milankovitch Cycles but the actual changes due to the changes in TSI are far to0 small to cause the effects we observe.
Why, if that is the definitive explanation, does Orbital Eccentricity seem to be the most strongly correlated ‘Milankovitch’ effect, stronger than Obliqiuty which you refer to, yet has a much smaller calculated solar forcing effect?
If this is a science site you cannot just use some hypothesis just because it is conveniant to the current arguement, or your position, whilst ignoring serious issues with such a statement.
You have ignored Jim’s question that, clearly, at the same stage of the cooling phase as compared to the warming phase there is now an additional strong upward forcing factor.
How do these ice sheets start to advance? We are, for instance, told that the current trend in atmospheric CO2 will see the elimination of the Arctic ice sheet within a generation or two.
What is the strength of this purported reduction in temperature forcing due to Axial Tilt and how does it compare to some of the top end estimates of CO2 forcing and climate sensitivity?
Alan
[Response: Sorry, but I have to concur with Gavin here. He’s not ducking the question; he’s just telling you what well established literature says. If you have a better idea, articulate it, but don’t tell us we’re ‘avoiding’ something. As for the question of eccentricity, yes, that remains intruiging, but the fact is there is little evidence it matters very much. That is, the forcing is small, and the response is small, so there is no mystery. There is no so-called ‘eccentricity band’ signal prior to 1 Ma, and the 100 kyr cycle that it is sometimes attributed to isn’t stationary and probably has more to do with ice sheet dynamics. To answer your question: CO2 forcing is around 2 W/m^2, annually averaged, while annual insolation change due to axial tilt is zero! But seasonal insolation (which is what matters to ice sheets) is 40 W/m^2 or so, so completely dominates.–eric]
> Milankovich …. calculations
http://www.nature.com/nature/journal/v448/n7156/abs/nature06015.html
http://jgs.lyellcollection.org/cgi/content/abstract/142/3/417
http://adsabs.harvard.edu/full/1993A&A…270..522L
http://dx.doi.org/10.1016/S0012-8252(01)00061-7
It’s not _only_ Milankovich. Continents drift; biology increasingly participates.
http://geology.geoscienceworld.org/cgi/content/abstract/22/5/463
“… between 1 and 1.2 Ma … reflect a major shift in climate. … Major anomalies arise within the transitional regime (1.2 to 1 Ma). The origin of the cycles is unknown; we propose productivity variations in the western equatorial Pacific.”
Bob (387), me thinks you have “learning” confused with agreeing with you.
I have no problem with you accepting and running with the evidence as you see it (so long as it is not fanciful, which in this case it isn’t). But that doesn’t mean that those who might not are stupid, silly, can’t see “simple and obvious” facts (dogma??), and unworthy of any discourse. You are personally free to not enter into such discourse, and that is perfectly acceptable, might easily be a waste of your time, and your choice.
>> “… [don’t] debate how the evil warmist scientists are bullying the poor, freedom fighting skeptical underdogs.”
You really ought to read some of the posts.
I never said you have no evidence — you clearly do. I claimed your evidence does not rise to dogma.
To show you weren’t changing the debate from MWP (et al) to climate sensitivity you cited and quoted a paragraph in your #281. ‘cept oddly you left off your first sentence, “I think most educated people agree that the only real debate is in the actual value for climate sensitivity, low or high.”
You say, “Arguments I’ve seen for a MWP are down right weak,” to which I assume you meant to add ‘other than of course for the preponderance of temperature readings available for that period.’ I don’t wish to resurrect the MWP/hockey stick debate either (which is why I called it a pro forma comment.) Its interest to me is simply the ease with which it was thrown under the bus in preparing the hockey stick — didn’t take much rationale to discard that funny-looking inconvenience. Whether it means anything in the overall AGW scheme of things, as some have suggested, I don’t know, though I doubt that it does in any big significant way.
[Response: The MWP is discussed in the original hockey stick paper, and is shown to be largely a regional phenomenon. It might be wrong of course, but no one has credibly shown otherwise. That’s not a suprrise, because there never was good evidence for a global warm period at this time, though definitely many people — notably Wally Broecker — assumed it was global. The only thing Mike Mann’s work overturned in this respect was a popular conception, based on very little evidence. The idea that the hockey stick “through the MWP under the bus” is a nice story, and it helps support denialist myths, but it is historically inaccurate. Many of us have been criticizing the simplistic ‘global MWP’ long before we’d even heard of Mike Mann.–eric]
The reason Jones talked to the BBC and spilled the beans on global warming is that he was hung out to dry.
Hank, your concern is well taken. But I never said zero uncertainty. How much uncertainty is a judgement call — and a very difficult one IMO.
FE Smith says: 12 April 2010 at 8:44 PM
Would it be too rude of me to gently point out the bats escaping from FE’s belfry?
FE Smith: despite the two clichés, I have no idea what you mean.
404: Content not found.
Gavin, In the excellent book “Climate Change: Picturing the Science” which you edited and co-authored you wrote on page 200, concerning global temperature projections,:
” This should not be taken as implying that climate change doesn’t continue after 2100-it certainly will!-but detailed projections out that far become very problematic.”
Why do the projections become very problematic after 2100 ? Is it partially related to numerical dispersion ? Also, where could I find projections beyond 2100 ? What maximum temperatures are reached for the three CO2 emission scenarios ?
Bob (#389), you wrote: ‘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.’
If your suggestion that I am just following hearsay would be right, I would admit so and even feel ashamed, because I am always trying to formulate a view that is supported by evidence that everyone can evaluate. The statement about the probable cause of temperature increase in recent decades comes directly from the IPCC report: “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.”
As you probably know, the formulation ‘very likely’ in this context means over 90 % probability.
IPCC, Summary for Policymakers, Causes of Change
http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_spm.pdf
With respect to Solomon, the conclusion about the 1980-2000 period can also be found in her abstract (http://www.sciencemag.org/cgi/content/abstract/science.1182488). Now if Solomon is right, and a significant part of the recent temperature increase is linked to a change in stratospheric water vapor (and this change apparently is not related to increasing CO2), then my conclusion remains that presumably a smaller part of the observed increase in global average temperatures since the mid-20th century can be attributed to increase of CO2 than was thought before Solomon’s findings were published. If so, then it is even harder to reconcile the temperature data from recent decades with a suggested climate sensitivity of 3 degrees Celsius for a doubling of CO2.
Gavin at #399: “The analysis by Gerard Roe (2009)” — which one is that? (I found one from 2006, “In defense of Milankovich”, that seems to fit the bill.)
Bob (351),
Discussions of theoretical and, more importantly, empirical evidence for positive water vapor feedback can be found here:
Brown, S., Desai, S., Keihm, S., and C. Ruf, 2007. “Ocean water vapor and cloud burden trends derived from the topex microwave radiometer.” Geoscience and Remote Sensing Symposium. Barcelona, Spain: IGARSS 2007, pp. 886-889.
Dessler AE, Zhang Z, Yang P 2008. “Water-Vapor Climate Feedback Inferred from Climate Variations.” Geophys. Res. Lett. 35, L20704.
Held, I.M. and B. J. Soden, 2000. “Water vapor feedback and global warming.” Annu. Rev. Energy Environ., 25, 441–475.
Minschwaner, K., and A. E. Dessler, 2004. “Water vapor feedback in the tropical upper troposphere: Model results and observations.” J. Climate, 17, 1272–1282.
Oltmans, S.J. and D.J. Hoffman, “Increase in Lower-Stratospheric Water Vapor at Mid-Latitude Northern Hemisphere Site from 1981-1994,” Nature, 374 (1995): 146-149.
Philipona, R., B. Dürr, A. Ohmura, and C. Ruckstuhl 2005. “Anthropogenic greenhouse forcing and strong water vapor feedback increase temperature in Europe.” Geophys. Res. Lett., 32, L19809.
Santer, B. D, C. Mears, F. J. Wentz, K. E. Taylor, P. J. Gleckler, T. M. L. Wigley, T. P. Barnett, J. S. Boyle, W. Bruggemann, N. P. Gillett, S. A. Klein, G. A. Meehl, T. Nozawa, D. W. Pierce, P. A. Stott, W. M. Washington, M. F. Wehner, 2007. “Identification of human-induced changes in atmospheric moisture content.” Proc. Natl. Acad. Sci., 104, 15248-15253.
Soden, B.J., D. L. Jackson, V. Ramaswamy, M. D. Schwarzkopf, and X. Huang, 2005. “The radiative signature of upper tropospheric moistening.” Science, 310, 841–844.
http://www.gfy.ku.dk/~kaas/forc&feedb2008/Articles/Soden.pdf
Rod (375),
When I assumed 100% emissivity/absorptivity for the atmosphere, I was implying that it was loaded with greenhouse gases. The more GHGs, the higher ε/α. Is this really hard to understand?
Rod (377): 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.
BPL: Maybe that has something to do with the fact that it’s like suggesting the actual speed of light might be only 15 miles per hour? Or that human core body temperature is 12 degrees Fahrenheit in a normal person? Or that a typical aircraft carrier weighs 30 pounds?
GW (401),
Try Fλ = aλ σ T4
where the λ subscript refers to a particular wavelength.
Re :#401,398, 386,375 continued [I really hope this is the final one]
As you will see from #401 , in the limit of a narrow frequency range (small f(1)-f(0))
the radiation emitted by a sharp spectral line is proportional to
1/[exp(hf/kt)-1]
which you will recognise as the Bose function. All trace of the original Stefan- Boltzmann T^4 has vanished. To quote Realclimate on Monckton
https://www.realclimate.org/index.php/archives/2006/11/cuckoo-science/
It is also not, in my opinion, a mixture of black (or grey) bodies at different temperatures but a mixture of that kind together with a radiating gas.
410 (BPL),
Thanks! No idea where I’ll find the time, but thanks…
MWP under the bus? Would it be fair to say that the existence or non-existence of a global MWP is actually a point of debate rather than certainty one way or the other? The EAU e-mails are full of contention on this point, but are they perhaps out of date?
A lay reader such as me bouncing around from Jones to Broecker to Mann to Cook to Overpeck to Diaz to Esper to Briffa etc. etc. would certainly be left with that impression. Is there in anyone’s opinion anything close to a consensus on this issue?
[Response: My own take on this is that Mike’s ‘hockey stick’ paper was the first to bring any clarity to this question, which is why we all thought is was so important (and still do). That said, there remain insufficient data in the Southern Hemisphere. Borehole temperatures at Siple Dome (West Antarctica) appear to indicate a warm period around 1000 year ago; the same type of measurements at Taylor Dome (East Antarctica) suggest the opposite. They are probably both right, which proves the regional nature of these sorts of climate variations. However, neither of these are published. I do think it is pretty defininitive that the “little ice age” was not global, insofar as “ice age” implies “glacier expansion”. See this paper by Schafer et al., and the excellent commentary by Greg Balco, who writes something like: “The answer to the question of whether glaciers in the northern and southern hemispheres were outof phase during the little ice age is… “no.”–eric]
404 (Rod B.),
I’m not sure I see your point. My position was always that I will discuss climate sensitivity, and I see virtually every other denialist talking point to be a waste of time (especially MWP). Your quotation of what I said is part of that statement. I never switched the debate “from MWP” to climate sensitivity. I set the ground rules to exclude the MWP from the very beginning, and have been very up front about it.
I’m also sorry if my opinion that some denialist talking points are silly is offensive to you, or my opinion that the people that accept and repeat them are uneducated, but it’s how I feel. I’ve studied them in depth, and I have no interest in revisiting them with people who can’t be bothered to study things more closely themselves before they go trumpeting them as proof of anything.
Meanwhile, here we are for the zillionth post, not actually discussing the science, but instead discussing debate tactics and people’s attitudes and how denier’s feelings are hurt because they aren’t taken seriously. Because they won’t actually discuss the science!
I’ll bend my rules a little, though. You seem to think there’s all of this evidence for the MWP. I will tell you that I’ve looked at it thoroughly. I particularly like the sites that have maps that purport to show all of the studies around the globe that support the MWP, but when you look at the actual studies, it all falls apart.
The periods labeled as the MWP can vary by as much as a half a millennium from one study to the next. Imagine what it would look like if we computed the current global temperature by averaging in the temperatures in Africa from 2005, North America from 1998, Europe from 2009, and Siberia from 2008… and those would all be temperatures from the same 15 year span, instead of the 500 year window that is quietly used to support the MWP.
At the same time, many of those studies that supposedly demonstrate the MWP often themselves include other regional analysis that directly refute it, or error ranges that basically make the data inadmissible, but you don’t see that unless you go into the actual papers and read it. Sometimes the papers that have been cited were later rebutted or withdrawn for flawed techniques, or were never accepted by peer reviewed journals in the first place, and were ultimately published elsewhere because they were patently flawed from the start.
It looks wonderful on the surface where they only show the evidence that says what they want it to say, but it’s really just a trick. Unless you are skeptical and dig into it, if you accept it blindly because it supports your preconceptions, then you are going to be fooled. You have to look past that by yourself, or you are in danger of being manipulated.
#415
BPL
Your comment crossed with mine. Fine, it would be interesting to know its accuracy in various cases. Have you ever compared the T^4 dependence against the more exact answer for a highly ‘coloured’ gas with discrete spectral lines?
> 389 Bob
seems to be talking about 1980-2000, the Susan Solomon paper
> 410 Wilt
cites the IPCC talking about the 1950-2000 attribution
These are different time spans; the Solomon paper refers to a measured change in water vapor specifically during the time span.
Yes, measuring changes in the various greenhouse gases (including water vapor) is useful for attribution during that period for that measured gas.
Hank Roberts (#421) is in my view building up a rather artificial discrepancy when he writes that Bob (#389) and wilt (#410) are talking about different time spans. No doubt he knows (as I know and presumably almost everyone here will know) that temperatures were flat between 1950 and about 1975. The crucial part of the discussion that Bob an I were having is whether IPCC attributes most of the temperature increase in recent decades to increasing CO2 (answer: yes it does) and whether the conclusions of the Solomon article in Science are relevant with respect to the attribution (in my view they do.
MapleLeaf, Hank Roberts thank you. I understand the difficulty. RC is both an advocacy website and an educational website. Wearing the advocacy hat you cut the opposition no slack. But wearing the educational hat you need meet the student half way to understand where they are coming from. Which hat to wear won’t always be clear. The full connotation of climate jargon may be evident those in the field, but not to those outside. When my mother told me not put the knife in the electric outlet or I would get a shock, I did it anyways not out of disrespect to her knowledge, but because the word shock had no meaning other than it worried my mother. Only by seeing for myself did I get the full meaning of shock. (And I wonder how did my mother knew what a shock was) . And as an educator, unless you quit after the first class, you will be repeating the same story to all the next classes, but as you learn about the students, you find better ways to deliver the message .
It was unfortunate that past deletions led to large misunderstandings. I said it before, but it is indeed worth repeating. My experience in this thread has been educational, and I applaud and greatly appreciate RC’s efforts to allow and maintain respectful debate.
But I still come as a skeptic, because it still doesn’t all add up for me. I still need to check the accounting and probe the jargon. I realize the rehashing may be annoying, but good educators do want students to be critical thinkers. Best I can do as a good student is promise to be respectful in my journey and support my topic questions with evidence.
As for my question on the table, perhaps why I feel we keep talking past each other maybe a function of jargon. When I read the RC article stating CO2 was responsible for half of the warming, I see that as overstated because I interpret that statement to mean the radiative forcing by CO2 all by itself contributed 50% of the temperature rise. Would it be better said that the RC article believes that 50% of the warming is due to radiative forcing of CO2 PLUS all the positive feedbacks attributed to be directly linked to CO2’s forcing?
If that’s true I will still be probing how and why CO2 gets all the credit for all the positive feedback.
395, David B. Benson, thank you.
How accurately is it known how much energy the surface of the earth actually re-radiates outward? I have seen diverse energy budgets and calculations of uncertainty (one of which I linked to a few days ago), and I have the idea that knowledge is not very precise. What is the best and most up-to-date quantitative exposition? Which parts of the earth are the most like black bodies, and in which parts of the earth are the various approximations most accurate?
@ Walter Manny:
You still haven’t answered question I asked you, Walter – here it is again:
Please explain how, in your mind, statements in the Landsea-coauthored study including the following:
“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.”
can in any HONEST way be translated, as the Der Spiegel article did, into meaning that the link between global warming and hurricanes has been “finally disproven”?
Please finally answer the question, Walter, – ironic condescension and repeat evasion are fun but not particularly illuminating.
“No doubt he knows (as I know and presumably almost everyone here will know) that temperatures were flat between 1950 and about 1975.”
This line:
http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif
Looks NOTHING like a flat line.
wilt says: 13 April 2010 at 2:59 AM
[First, as an aside, I’ve taken to using the date/time, because the numbers keep changing when things that were stuck in the queue are added, or posts deleted.]
I think the problem here is one of semantics and language interpretation.>
When the IPCC says “most… is very likely due to … anthropogenic GHG concentrations,” I think that they do not mean “directly due specifically to CO2 and CO2 only” (as you seem to interpret it), but rather “due to CO2 as a forcing, and any accompanying feedbacks that have resulted from that forcing.” To put it another way, they are saying that most of the warming is explicitly not due to natural climate variability, but rather to the combination of effects that result from tipping the system out of balance by having added large amounts of CO2.
So any change in temperature that is also due to stratospheric water vapor can’t be viewed as separate from CO2 until you first ascertain that the change in stratospheric water vapor was itself independent of CO2 (as opposed to itself being a feedback caused by the increase in CO2). You must also confirm that any such change in stratospheric water vapor is/will be long standing, and not merely a transient event that is manifesting itself while the system is out of balance and undergoing rapid change.
Since no one yet knows the mechanisms (or do they?), I’m not sure that we can say anything, but I’d be very surprised if someone came up with a mechanism whereby stratospheric water vapor varies naturally and causes climate swings all by itself.
With that said… what really caused the stratospheric increase in water vapor, natural variability, or a feedback resulting from CO2? What can we expect in the future? Will the long term impact be positive, or negative, given that we’ve seen both in the last thirty years? What is the mechanism involved?
My point stands… the Solomon paper brings up a very important and interesting pair of observations, but says nothing about climate sensitivity. It does not stand as an example that water vapor feedback will or will not be either less than or greater than proposed. Either or neither is possible, given the two distinct effects studied. In particular, it brings up a separate area (stratospheric water vapor, as opposed to tropospheric) to be considered.
I am still researching the Paltridge paper, and I fear it will take me quite a while.
CFU @426, I suspect that what Jim Steele meant by “flat” is that there was no significant long term trend up or down between ~1950 and ~1975, which is exactly what the linked GISS line shows for that period. And in fact, the reasons why have been discussed here on RC many times.
Oops, sorry, it was Wilt who made the “flat” comment, but I’ll still give him the benefit of the doubt on this one.
Septic Matthew (424) — I’m not sure your question is properly formulated. If my “outward radaition” you mean escapes the atmosphere then such is called TOA radiation for top of atmosphere radiation. The budget of course is
EnergyIn = EnergyOut + EnergyRetained
and just now the EnergyRetained is increasing, primarily (I think) ocean heat content. But I don’t know the details.
Re: Septic Matthew
The following needs to be checked, but when I last looked up some data on this, I got the impression that most solids and liquids are fairly black in the infra-red, this includes e.g snow and ice. Greenhouse gases , of course, are quite different because they have a very spikey absorption spectrum especially at low pressures. Other gases are transparent.
Jim Steele: “I interpret that statement to mean the radiative forcing by CO2 all by itself contributed 50% of the temperature rise.”
Ah, right, so that explains why you did the correlation between glacier melt and CO2 concentration. I was trying to work out if you thought that CO2 had some direct effect on glaciers that would make them melt, but I see now that you were testing the proposition that CO2 concentration is a proxy for global temperature – which it isn’t.
That probably explains a lot of the hostility you received, because regulars here are well aware that it is not as simple as that, so to them it seemed like a very silly thing to do.
BPL (413), continued thanks. Similar analyses never mention the assumption that the atmosphere is mostly GHGs. Maybe they presume that we all should assume that, though that seems strange. I need to mull that over. I’m still bothered with the fact that GHG emission is not Planck-function type and not (directly) under the T^4 law used in the models. Nor, even with massive pressure broadening, would you get far from the discrete emission frequencies of CO2. ???
“428
Jim Eager says:
13 April 2010 at 2:04 PM
CFU @426, I suspect that what Jim Steele meant by “flat” is that there was no significant long term trend up or down”
Still not flat, is it.
No determined trend is not flat, as we’ve seen with the recent P Jones/no trend since 95 debacle.
Sepitc, #282, sorry if you didn’t understand that my post was tongue-in-cheek and to be taken as a metaphor.
For heaven’s sake, I’m certainly not going to let those denialists say “The devil made me do it” and get off the hook of responsibility, not just for their climate denialism (and dissuading people from turning off lights not in use, etc), but for their vicious and horrendous attacks on climate scientists — including job and death threats and actual loss of jobs, their attacking the messenger because they don’t like the message.
They have to take blame for their atrocities, which reveal more eloquently than all the scientists’ reasoned responses and debunking that these denialists are not on the side of truth. They are not the good guys in this drama.
Okay, I was even thinking my Twilight Zone/devil post might not pass moderation, unless its metaphorical aspects were grasped.
Perhaps I should talk more directly about science, or rather meta-science, and “what is truth?”
Well, scientific truths are admittedly changeable, based on the best data and theory to date. I don’t see the denialists striving after that type of truth, but only into deconstructing science and confusing everyone.
There is the truth that scientists are indeed human and are only doing the best they can under difficult circumstances. Their findings/theories are what we have to work with, and we shouldn’t just say “Oh, they can’t be true, because that will be inconvenient; the cures may cost and hurt somewhat.”
There are the denialists’ agenda-driven “truths” (falsehoods), as opposed to the truth-driven agenda of sincere environmentalists and those wishing to mitigate harm to people and the earth’s biota. Who knows, totally outside chance, maybe a huge meteorite (or something) will send us into a nuclear winter and the warming we have caused may help us a bit. Or, maybe scientists will find all this global warming stuff is untrue. But for now, we have to work with the truths with which they have presented us.
There is the decision-maker’s truth of striving to avoiding the FALSE NEGATIVE (failing to mitigate true problems), as opposed to the scientist’s truth of striving to avoid the FALSE POSITVE (making untrue claims). In the “Boy Who Called Wolf” story scientists learn the moral not to make untrue claims, but there is another moral for the villagers who got eaten up — not to stop heeding the boy when he calls wolf (even if you think the wolf might not be there).
The point is, when you take away that (as tenuous as it is) metaphorical “staff of truth” that is bolting the door, preventing all sorts of falsehoods that arise from people’s social-cultural-psychological-economic-political fears and foibles loose into the world like some opening a Pandora’s box (of course that is always happening to some extent), the very harms those fearful people fear and think they are keeping at bay with their falsehoods & heel-dragging, may come back like a boom-a-rang to harm them for failing to mitigate. Reality has a way of biting back. Like the man who feared Death, and ran off to another village, where he met Death.
(Note, I’m trying to developing a way of teaching science through folklore, so common people can understand it.)
Bob — 13 April 2010 @ 1:18 PM (#427?): I am not proposing that changing stratospheric water vapor causes climate swings all by itself. But it is unlikely that it’s a feedback resulting from CO2, since CO2 kept on increasing during 2000-2009 whereas stratospheric water vapor decreased. So changing stratospheric water vapor must probably be looked upon as an independent effect (at least independent from CO2). And according to Solomon the effect of the changing water vapor was considerable during 1980-2000, enhancing the warming “by about 30% as compared to estimates neglecting this change.” This implies in my view that from the total temperature increase in recent decades (about 0.6 degrees Celsius, in a period that CO2 rise was about 30%) even less than previously thought can be ascribed to CO2 increase. For me that leads to the conclusion that at least the temperature observations in recent decades do not support the hypothesis that the climate sensitivity is as high as 3 degrees Celsius for a doubling of CO2. But of course I leave it to you to draw your own conclusions.
Another example system with an amplifying feedback is
http://en.wikipedia.org/wiki/Bay_of_Fundy#Tides
which are around 17 meters in comparison to the approximately 2 meters at Bridgeport, Conn.:
http://en.wikipedia.org/wiki/Tide#Example_calculation
CFU @426, I suspect that what Jim Steele meant by “flat” is that there was no significant long term trend up or down”
I missed this conversation. Where did I use the word flat? Then maybe I could explain what I meant.
CTG #432 Jim Steele: “I interpret that statement to mean the radiative forcing by CO2 all by itself contributed 50% of the temperature rise.”
Ah, right, so that explains why you did the correlation between glacier melt and CO2 concentration. I was trying to work out if you thought that CO2 had some direct effect on glaciers that would make them melt, but I see now that you were testing the proposition that CO2 concentration is a proxy for global temperature – which it isn’t.
That probably explains a lot of the hostility you received, because regulars here are well aware that it is not as simple as that, so to them it seemed like a very silly thing to do.
Perhaps you can see why the wording would confuse me. And it still does. So why in the article on CO2 lag is CO2 given credit for 50% of the temperature change? If glacial albedo changes is part of that 50% of CO2’s contribution? I also assumed that when giving the Milankovitch cycles credit it was just for those immediate changes in solar forcing. I am still not clear how the accounting in that article was done? Any help?
Jim Steel, read the very next comment where I corrected the attribution.
No CFU, it was not truly “flat,” but there was in fact a negative slope from ~1945 to ~1951, commonly known as cooling, and a subsequent ~24 year period with no sustained positive trend, a long enough period to have true significance, and a fairly well accepted causation of aerosol loading.
Comparing that period to the spurious assertions that there has been no significant warming since 1995 is silly.
#433
Sorry to intrude in a private argument, but I think that you Rod are misunderstanding BPL. If someone is worried about e.g. the fact that the downward flux of energy at the surface is greater than at the top of the atmosphere then it is legitimate to use a highly simplifed ‘model’ to help explain that this does not violate the conservation of energy.
Such simplified models are akin to thought experiments. They use the same physics in most respects but they are designed for easy solution. To point out that such a model is unrealistic in some way does not invalidate the argument unless the simplification obviously reverses the conclusions.
430, David B. Benson, I expect you are right that my question was ill-posed. I was thinking of the radiation from the earth’s surface (at various place like the poles, the oceans, the forests, the plains) and the radiation from TOA. I should probably just wait to read the book that BPL recommended and then Raymond Pierrehumbert’s book. I have schematic diagrams of the heat budgets, but I was curious about how accurately the components are known.
431, Geoff Wexler, I was guessing that the frozen ice at the poles in winter would probably be most like black-body radiation, but then in the summer the ice melts instead of radiating heat — or does the ice/water combination continue to radiate the heat in the same fashion? Does the ocean surface (rippling, vaporizing, etc) actually radiate like a black body? The law was derived (IIRC) for radiation from a cavity of a black body.
Septic Matthew (443) — Read those and you’ll be able to tell me.
BPL (414), I exaggerated for effect. None-the-less we can and have measured the speed of light, the weight of carriers and the temperature of a body’s core, but, for the 3rd time now, NO ONE has EVER measured (or even observed) the global temp increase caused by CO2 going from 400 to 800ppmv.
Bob (419), you say, “It looks wonderful on the surface where they only show the evidence that says what they want it to say, but it’s really just a trick. Unless you are skeptical and dig into it, if you accept it blindly because it supports your preconceptions, then you are going to be fooled. You have to look past that by yourself, or you are in danger of being manipulated.”
That I can buy.
And, no, my feelings are not hurt.
Geoff Wexler (442), feel free to jump right in the pool!
I’m not concerned with the conservation of energy, but can not figure out where all the downwelling comes from — physically, not mathematically. Barton’s model, a simplified (but realistic and true to) version of the detailed models used to teach the basics of GHG warming, shows the math pretty well. But I’m questioning some of the physics assumptions.
“Comparing that period to the spurious assertions that there has been no significant warming since 1995 is silly.”
A good deal less silly than saying there’s been no warming since 1995.
And flat is still not flat. And you can cherry pick times more than 20 years apart and get “no warming” too.
So let’s stop with the “flat” moniker, hmm?
Septic Matthew (443), just a quicky: ice is not a very good black body radiator. Water is much better. An easy rule — the better it reflects, the less it radiates ala Planck function.
On a slightly different topic, I just ran across Mark Fiore’s prize-winning animated cartoon that looks at quote-mining and taking quotes from scientific works out of context.
http://www.markfiore.com/pulitzer/