Recently, I received multiple requests to discuss a paper, due to appear in Journal of Geophysical Research (JGR-atmosphere), that has been presented in the media just before the Bali conference and the Nobel Peace prize ceremony here in Oslo, Norway. The paper concludes that the warming measured over land is most likely exaggerated due to non-climatic effects, and it presents a regression analysis suggesting that the real (climatic) global mean temperature trend should be ~50% lower over land.
So, are the surface temperature trends inflated? This new paper by McKitrick & Michaels (henceforth ‘M&M2007‘) is a followup of an earlier paper they wrote in 2004 in Climate Research (MM2004a), which I discussed in my first RC post (Are Temperature Trends Affected by Economic Activity?) and in a commentary in Climate Research (Benestad, 2004).
So what’s new? Let’s backtrack a little and recount some of the previous arguments.
One of my main concerns then was that their analysis had not taken into consideration the dependency between the data points, as the temperature exhibits non-negligible spatial correlations. Furthermore, data from the same country were compared with the same national value in terms of economic indices. It was a bit like doing a poll by asking 10 people the same question 100 times and then claiming that it’s a survey with a sample size of 1000.
In 2004, M&M2004b said they were unaware of any paper in the refereed applied climatology literature that had performed a test where half the data was excluded when doing the model calibration and the rest was left for model validation. I guess that they were not really up-to-date then, because that has been a standard approach for a long time.
But this time they have split the data sample and used a part for validation, which I suggested in my comment in Climate Research. But they have not done it properly this time, and they still do not eliminate the effect of dependency. They split the data by randomly picking points which were either used for training the data or validating the model, thus data from adjacent sites which are related will end up in the different batches for training or validation.
The map above shows a simple estimate of the temperature change over the 1979-2002 period (here taken as the differences in the mean over two sub-periods and the National Centers for Environmental Prediction (NCEP) re-analysis have been used instead of the CRU data), and it’s easy to see that the warming varies smoothly from location to location. In other words, the trend estimates have significant spatial correlation.
The fact that they used sea-level pressure (SLP) data from (1974) because they could not find more recent data, suggest that they still are not up-to-date. Updated data, such as the National Center for Environmental Prediction SLP, have long been available from NOAA Climate Diagnostics Center. Furthermore, a wealth of up-to-date climate data are available from the KNMI (Dutch Meteorological Institute) ClimateExplorer.
Their regression analysis appears to suffer from over-fitting, since they have thrown in a lot of variables (both ‘meteorological’ and ‘economical’) for various vague reasons.
Not surprisingly, their analysis produces some strange results as a result of this shortcoming. They find that the greatest differences between measured and adjusted trends at Svalbard and other places in the Arctic and Antarctic (See marked sites in Figure below). This is not convincing. Thus, the results themselves provide examples of spurious values obtained by their analysis. Even if they were identified as ‘outliers’ (Svalbard was apparently not one), the fact that their analysis produced highest corrections for economic activity at these places suggest that their analysis is not very reliable.
The graphic below shows a Google Earth image of Svalbard, which is one of the sites marked in the map above with a large trend correction due to economic activities.
I have not examined the economic data, but it appears that M&M2007 maybe cannot win – either (i) the spatial distribution of the economic indices are equally smooth and M&M2007’s attempt to account for dependencies within each country fails to resolve the problem of dependency between the countries, or (ii) the economic indices vary abruptly from country to country and thus have very different spatial scales and structures to those seen in the warming trends. Either option suggest that their analysis may lead to spurious results, over-fit, or suffer from inter-dependencies.
I also think that M&M2007 is biased and gives an incorrect picture, as they do not discuss the fact that also the world oceans are warming up, and whether any economic activity can take the blame for that. I think it is difficult to argue that factors such as the urban heat island effect plays an important role here.
They do not mention my criticisms raised in Benestad (2004) either, which discussed a number serious concerns about their previous study; They merely state, as if it were a matter of fact, that urbanisation and economic activity has been shown to affect local and regional temperature measurements – citing their old criticised paper.
Their analysis relies on University of Alabama-Huntsville (UAH) satellite data (Microwave Sounding Unit, MSU) with a weaker global trend than others, and neglect to examine or even mention other products such as the Remote Sensing System (RSS) data. The difference between these data sets are discussed in previous RC posts (here). They reckoned that any of their results would not be contingent on the choice of MSU product, but did not test this hypothesis.
It should also be kept in mind that their analysis involved too short time series (24 years) for a proper local trend estimation, as local circulation variations (e.g. the North Atlantic Oscillation), the annual cycle, and inter-annual variations, most likely will make the analysis more difficult. Climatic time series from single locations tend to be very noisy, but a clear signal emerges when taking the global mean (by taking the mean, random noise tends to cancel to some degree).
I find it a bit ironic when people use satellite data measurements to argue that GHG is unimportant. They rely on the fact that these measurements are derived using the very same type of physical laws as those predicting an enhanced greenhouse effect due to increased GHG levels (neglecting feedback processes).
I think it’s good that M&M2007 put a focus on the problem with data paucity and quality. There may very well be some non-climatic effects contaminating the measurements, but I am not convinced by their analysis.
So in summary, I think the results of M&M2007 analysis and conclusions are invalid because
– They do not properly account for dependencies.
– They over-fit the regression.
– Their results look unreasonable.
– They “cherry pick” the MSU data that gives the lowest trend
168 Responses to "Are Temperature Trends affected by Economic Activity (II)?"
Dan Wentworth says
AEBanner, assuming your “ice actually melted” refers to arctic ice in 2007 (correct me if I am wrong). I have 2 questions about the significant relevance of your observation.
– Why didn’t the (arctic) ice melt as dramatically in 2003, since world energy consumption has not increased by 20% since then?
– What percentage of anthropogenic energy production goes towards melting (arctic) ice, as opposed to the percentage that is radiated off (at one wavelength or another)?
I have often wondered why anthropogenic heat production (beyond basic metabolism) is not considered in climate models. I have always assumed that it is insufficient to account for the observed climate changes, but I would like to see someone do the math.
Ian McLeod says
“How is saying “The science in Al Gore’s movie is largely consistent with the consensus view of climate scientists” an example of “partisanship editorializing”?”
Aside from a fragmented sentence, if ones political persuasion is more in tune with Al Gore and his brand of politics than the alternatives, then by default you have consciously or unconsciously made a choice and taken a partisan view, even if that view is the right one. This was the point I attempted to make. To defend Al Gore after legitimate criticisms were made of his movie, albeit some criticisms were more legitimate than others, in particular his exaggeration of sea level rise to name only one example that seems to stick in everyone’s head, where the defense boiled down to parsing words by nuance and subtly, rather than stating the difference between an effective message and a true one, is partisan, or worse, spin doctoring. If you disagree, then we agree to disagree.
#76 Timothy Chase:
I suggest you be watchful of libeling individuals like Patrick Michaels, Ross McKitrick, John Christy and Stephen McIntyre with the unconscionable Exxon-funded George C. Marshall Institute link. You have made many fine suggestions, comments and several good insights. However, that comment is not one of them. You have now directly implicated RealClimate since it appears on their blog. Gavin and Rasmus know that Exxon does not fund these individuals and so do you. Retract and apologize.
As I said, climate science is a partisan endeavor, real or faux. Politicians make movies, the UN—a political organization—writes scientific policy summaries, scientists create blogs and write partisan books and then the media sensationalize the worst part of the doom and gloom message for all to witness. This is, as I understand it, to shock us from our siesta in order to re-educate us to the so-called new reality—so much for the wisdom of crowds.
The euphemism “consensus science” is rife with worldview belief systems, which has more to do with faith than science. Science cannot progress in this manner. Not ever.
I do not think Gavin consulted Al Gore about the state of climatic science. That was a goof on your part, no doubt, so I will let it go.
As for bias, we all have them. This makes us human. To be completely open-minded means never governing ones actions on principle. We are by nature partisan and base our dialectics on our prejudice, right or wrong. Ross argues from his position and Gavin argues from his position. I hope that after arguing for some time a residue of progress can prevail, especially when each brings something to the table. The equivalency that you speak of comes from ones starting position on the ephemeral political spectrum. To suggest it does not exist, or that by arguing this point somehow short circuits discourse is intellectually dishonest.
“Anyone attempting to short circuit a judgment about the relative validity of work produced by ‘partisan’ or ‘biased’ authors by inane citation of the corresponding existence of a point of view is doing everyone involved a disservice, not to mention playing their part in the stunting of human discourse.”
Curiously, I partially agree with your statement, partially. So why do we do it? We do it because we are human. In the world of climate science, when facts are not on our side, it is easier to discredit the purveyor of partisan pomp rather than their multifaceted theoretical constructs. Have a look at the end of comment #76 as an example.
Rather than arguing what is not in a paper, why did they not do this and why did they not do that, and so forth, which I think is the worst form of argumentation; why not disprove their conclusions by using their own source material, which is freely available and easily accessible on the internet. Then, you have validated your suspicions with experimental proof. Now with real evidence of false conclusions, you can stand on the mountaintops and shout, “This paper is deeply flawed!”, otherwise you are just whining.
Harold Pierce Jr says
Do you know how much of this heat was released in the Northern Hemisphere? Actually, the amount of energy released from electrical power generation is much larger if you include waste heat. Nuclear power plant have thermal efficiencies of 30-35% whereas conventional power plants using fossil fuels have thermal efficiencies of 35-40%. France gets about 80% of electrical power from nuclear power plants. I did rough calculation and found all energy released these plants results in regional climate forcing of about 0.25 watts per square meter.
Climate science is no more a partisan endeavor than quantum mechanics. If you need it be for your own belief system, that is your problem. The UN does not write ‘scientific policy summaries’, whatever that is, although the climate scientists that make up the IPCC do summarize their efforts to comprehensively survey the existing peer reviewed literature, if that is what you mean. Such summaries are an exercise in pragmatism, not science, given that the survey is commissioned with the express purpose of informing policy.
I fail to see how scientists creating blogs substantiates your religious belief that climate science is uniquely or especially partisan, so I should be little surprised it sits so neatly amongst your list of innuendo cum non sequitur. As for the media, in the field of climate science the media has given more credence to the views of the tiny fraction of climate scientists that deny the existence of anthropogenic global warming, (I say views because even in this tiny fraction there is next to no coherence in their scattershot criticism of the mainstream science), than they would in other fields. How often do we get to hear from scientists that don’t believe that HIV causes AIDS, or that the link between that virus and the disease is ‘controversial’?
“Consensus science” is not a term I’m familiar with. If you mean to say “consensus amongst scientists” or “scientific consensus”, then I suggest you pick up a history book because that is indeed how science progresses (and that almost never means uniform consensus). It would be somewhat cumbersome to make all scientific discovery start from first principles, to make the understatement of the millennium. This is what is meant by ‘standing on the shoulders of giants’, in case you’ve come across that phrase before.
I was referring to Gavin’s comment somewhere in the nether region of this blog where he indicated he had spoken to Al Gore- in particular, corrected him if I remember right- about the way he was conveying the science, (he also indicated that the former VP had taken his comments aboard). I suppose you can quibble with the term ‘informal consultation’ if you’re into semantics. In any case, no doubt you’ll want to take up that offhand assertion with me now.
This next point of yours is curious. I think what I had expressly written is that citing the existence of an opinion in a given researcher about the veracity of the mainstream science, (I don’t know why you’ve chosen to introduce ‘position on the ephemeral political spectrum’ or perhaps I do, but in any case it is utterly irrelevant), i.e. ‘bias’, goes without saying. That because bias- for want of a word that isn’t totally misunderstood and abused, most notably by people of a certain position on the ephemeral political spectrum- is ubiquitous and to be expected, it is also immaterial. And that citing the immaterial, in this case an opinion about the science espoused in Al Gore’s movie, in order to supplant/short circuit the material- namely meaningful examination of the influence of bias on a second researcher’s scientific work- is fallacious, counterproductive and, yes, intellectually dishonest. As such, I would say that while what you’ve written resembles a rebuttal in tone, it isn’t in context.
As to what has been argued on this blog thread about M&M 2007, I see nothing wrong with it. Is it your position that making the observation that M&M’s conclusions are nonsensical and hence a red flag- e.g. an urban heat island in the satellite record, biggest differences between measured and adjusted record at places like Svalbard, greater warming of land than oceans, etc.- is the worst form of argumentation? That figures. Were sanity checks a part of the denialist routine, there would be no denialist routine. And were M&M’s primary interest in the scientific value of their work, rather than implications for policy advocacy of their conclusions, you think it might occur to them to solicit scientific feedback before grabbing the first public-at-large microphone they could find, (just as it might have occurred to them to consider the scientific criticisms of their source literature, e.g. Benestad (2004), before rushing to publish). By their behavior, M&M have made it clear that science is not chief amongst their ends, if it is one at all, and hence this blog thread is precisely the appropriate response.
Ray Ladbury says
Ian McLeod, It is clear from your post that you have not been involved much with science. For one thing, you don’t seem to understand scientific consensus. It isn’t some sort of vote or popularity contest. It is an agreement about what the evidence will support, and it is almost always conservative–as in the case of projections of sea-level rise by the IPCC. Scientists do have opinions and biases. Scientific consensus forces them to put those aside as much as possible and look at what the evidence says.
Ralph Smythe says
John Cross, you should have highlighted a bit more of your quote. “the estimated 1980-2002 global average
temperature trend over land ” Sure there’s an estimated trend. What you’re more asking is if there’s such a thing as “a” global average temperature. Depends on how you think about it. There’s the anomaly trend of what the GHCN and ERSST are sampling, which I suppose I would say is acting as a proxy for energy levels in the climate system. (although in this case, the topic is just land of course). It seems intuitive that areas around a factory would do something to the surroundings differently than a forest would. The consensus is that human activity is the primary cause of the anomaly trending up, or man-made variability as the cause. That it is so frequently stated in terms of CO2 is that CO2’s one of the few things we can directly control. But there’s actually 2 things here. Land use changes. Burning fossil fuels. What does burning fossil fuels do? Creates air and ground particulates and creates greenhouse gases.
So if the goal is to reduce the heating that our activities are creating, we have to understand all these things. Then we can consider:
What can we do with land to remove as many heating influences as we can.
What can we do related to burning fossil fuels to remove as many heating influences as we can.
This leads to such questions as if cut fuel usage in half, what is the net effect, since we would be removing a whole bunch of things (versus sequestering carbon dioxide and/or methane etc). See figure SPM.2
The range for human caused net forcing is given there as an additional .6 to 2.4 W-M2 although there are a couple things they don’t consider.
We could say CO2 equivalent after taking various feedbacks and forcings. Something like that.
Ralph Smythe says
I should say; that the anomaly trend is rising, and that it’s due to people is not really under dispute. How could buring fossil fuels and building cities/farms/roads not create more heat? That the system is mostly handling it, or not, that’s the question.
The discussion (debate, whatever) is not on the science, really. It’s about policy implementation and risk management. Degrees of issues.
The only questions now are:
What can we do with land to remove as many heating influences as we can.
What can we do related to burning fossil fuels to remove as many heating influences as we can.
How can we best do the above in terms of time, money, and possible lost opportunities.
Ian McLeod says
“Climate science is no more a partisan endeavor than quantum mechanics.” You say this with a straight face and without apology. You are right, this has do with how one sees the world or ones worldview, and yours and mine are different. We see the world differently. Enough said about that.
You said, “The UN does not write ’scientific policy summaries’”. Yes is does. Scientists write the main body of the report, but a small group of carefully chosen scientists and bureaucrats writes the Summary for Policymakers. This is the summary prepared for the media and world governments. The media and world governments do not wade through a 900 plus page report and another 300 pages of appendices of physics and chemistry. It is difficult going even for fellow scientists. The media and governmental policy makers expect a condensed version so they can quickly report what information is important and get on with making governmental policy. I could say a great deal more about bias here, but it is off topic.
You say, “… [I]n the field of climate science the media has given more credence to the views of the tiny fraction of climate scientists that deny the existence of anthropogenic global warming, (I say views because even in this tiny fraction there is next to no coherence in their scattershot criticism of the mainstream science), than they would in other fields.”
Okay, I agree that there is no coherence or alleged conspiracy, and I agree that the criticism is scattershot, but, what you have given me here is a description how science progresses, and not a critique of the media. By the way, I hold up “falsifiability” as science’s gold standard al la Karl Popper (Ray Ladbury #105). I would not be surprised if your picture of science is a collective enterprise beholden to paradigms, al la Thomas Kuhn. Perhaps this is our problem. It is a technical point in epistemology—the theory of knowledge.
This leads to the theory of scientific consensus we hear all the time, the science is settled, there is a wide consensus amongst scientists, and so forth. Science progresses in incremental steps as small improvements are made to refine uncertainty and by large leaps when scientists falsify conventional wisdom. Here is a very recent example of the latter. Researchers from the Max Planck institute for Nuclear Physics published a paper in the journal Nature for the January 2006 edition entitled Methane Emissions from Terrestrial Plants under Aerobic Conditions. This ostensibly impossible result, which seemingly defies the second law of thermodynamics—something difficult justifying to the review board while applying for grant money—is I think, a good example of conventional wisdom being falsified. There is a biochemical mechanism going on here humans’ have yet to explain. This new discovery not only turns conventional wisdom on its head, requiring all biochemical textbooks to be rewritten, but has a profound effect on our understanding and modeling of past, current, and future global warming and cooling.
We are off topic so let us finish with an on topic argument. The M&M.JGR07 paper takes the 1972-2002 warming trend an applies the grid cell technique and regresses a multiplicity of climatic and economic variables. M&M.JGR07 shows a strong correlation with the warming trend when statistically examining economic and climatic variables. The authors also show that the results are not some fluke by spurious correlation. Here is what they did (see link for remarks and further info) http://www.uoguelph.ca/~rmckitri/research/jgr07/M&M.JGR07-background.pdf
1. Tests for the influence of outliers and nonlinearity did not show any effects.
2. Multicollinearity diagnostics show that we do have sufficient explanatory power in the data to identify the effects.
3. A Hausman consistency test shows that we are not picking up biases effects due to reverse causality.
4. In 500 repetitions, we found that if we hold back 30% of the data set and estimate the model on the remaining 70%, the model then successfully predicts what the withheld 30% looks like.
5. The correlations with surface processes and inhomogeneities that are significant in the surface data disappear when compared to data from the lower troposphere.
6. Differences in effects arise when the sample is divided into economically growing and stagnating regions. The growing regions exhibit much stronger contamination patterns.
There is no such thing as perfect paper, particularly in the field of climate science. This is a fascinating paper despite its defects. It should be taken seriously and I think will be taken seriously by many scientists and economists. The link of UHI and economics is gathering momentum.
It does not account for all the warming. The authors are careful to point this out, it accounts for some of it. Thus, we should account for it.
[Response: Hmm… sorry to disappoint but I predict that this paper will neither gather momentum nor be taken seriously. It is much more likely that this result is statistical fluke than it is that the oceans are not warming, that the glaciers are not melting and that ecosystems are not moving upward and poleward. I’ll even suggest a test – take the IPCC AR4 model runs and use their simulations of the surface and atmospheric temperatures. Since there is no possibility of extraneous contamination within the model system, following M&M’s logic, one would expect that all of the economic correlations would be non-significant – implying indeed, that the alledgedly significant changes seen in this paper are indeed significant. However, should there be model runs which show similar levels of correlation with economic variables, that would indicate that the correlations are actually spurious and linked to some other third variable (such as the correlation of economic development and the mid-latitudes). Care to make a wager which one it will be? – gavin]
Ian McLeod says
Gavin, Response #108
Thank you for your response. You asked for a wager, so here it is. The statistical analysis presented in M&M.JGR07 is robust. Nevertheless, I grant that you may be correct in your supposition. It is possible that some other variable(s) will account for warming not indicated in their analysis. Conversely, the same thing could be said for climate sensitivity: 0.75 +/- 0.25 C/(W/m2) that represents approximately 3°C increase for doubling of CO2 based on models. I will wager that the climate sensitivity is smaller, by how much I do not know. I think the models have great value, but are incomplete describing reality.
I will also wager that the UHI affect has not been fully accounted for by mainstream climatic scientists. If I’m wrong, then the current majority view wins the day and everyone can sigh a collective, phew. If I’m right, well then, “Lucy, you got some splaining to do.”
A great deal of progress has shaped the landscape of climatology this past year and I for one suspect 2008 will be another seminal year in the field. I look forward to RealClimate’s continued success including your many excellent contributors.
Lastly, will we be any closer to answering my wager by the end of next year, probably not?
Hank Roberts says
Ian, Gavin offered a specific wager, that’s testable:
— model runs show all of the economic correlations would be non-significant, or
— model runs show similar levels of correlation with economic variables.
That’s a test that a third party can make using the available data.
And it makes sense, it would answer a valid question. Why not?
Nick Gotts says
Re #109 [Ian McLeod] “Lastly, will we be any closer to answering my wager by the end of next year, probably not?”
So Ian, when would you expect answers to your “wagers”, and what form could they possibly take?
What is your hypothesis for how the UHI effect pollutes the satellite temperature record?
What is your hypothesis for how the UHI effect accounts for polar amplification?
For cooling of the stratosphere?
For melting glaciers?
For the well-documented northward move of ranges for a wide variety of plants and animals?
For earlier spring and later fall migrations for a number of species of birds?
Jeffrey Davis says
Blaming the UHI vs. GHG for global warming is an odd thing for skeptics of anthropogenic global warming to pick up on. How exactly is that a win? “Well, we’re painted into the upper left hand corner rather than the upper right hand corner”?
Ray Ladbury says
Ian McLeod, so we can add the Second Law of Thermo to the list of things you don’t understand. Not every discovery–or even every surprising discovery–represents a paradigm shift. WRT scientific consensus, consider 2 incidents involving the premiere physicists of their day:
1)Newton’s advocacy of the corpuscular theory of light made it nearly impossible for scientists in Britain to pursue the wave theory of Huygens. This set optics in Britain decades behind the Continent.
2)In contrast, Einstein’s opposition to indeterminacy in quantum mechanics presented no such obstacles. Scientists found–collectively–that the evidence could not support Einstein’s viewpoint, and physics continued to progress AROUND Einstein.
The difference is that in Newton’s day, an international scientific community really did not exist, while in Einstein’s, science was inherently a collective enterprise that transcended not only international boundaries, but individual prestiege.
I am neither a disciple of Kuhn nor Popper. Both have strong points and weak points, but my views on science have been informed by my experience as a scientist and my study of the history of science.
WRT M&M2007, I suspect the correlations are spurious primarily because
1)their model is very complicated, and complicated models are prone to spurious correlations
2)there is no over-arching physics that guides the model.
3)we have plenty of evidence that warming is occurring in regions where human activity is minimal.
I look forward to the results of Gavin’s investigation.
Ralph Smythe says
“– model runs show all of the economic correlations would be non-significant, or
– model runs show similar levels of correlation with economic variables.”
Yes, I bet you could do both of those.
[Response: Indeed. And wouldn’t that simply show that the reported correlations were spurious? – gavin]
Steven mosher says
re 110. glad to see you get on board with auditing the results of papers.
I welcome third party tests of results.
I volunteer to be a third party.
Send me the most current source code. The most current data sets. a windows executable.
The IV&V report on the model. The unit test report on the model.
When the model doesnt match the “statistical fluke” in of M&M study. They we will have to choose.
Believe model A. Believe Model B.
[Response: Surely it would be better to do it with model results already generated to avoid any implication that they were somehow fixed, and of course, you would want to do it with a range of models since you wouldn’t want to rely on one particular one, and you’d want them to have used all the appropriate forcings for the exact same period, and lo! it is available: www-pcmdi.llnl.gov/ipcc/about_ipcc.php . Let us know how you get on. – gavin]
Ray Ladbury says
Steven Mosher #116–There is good reason to choose the simpler model. Overly complex models tend to lead to spurious results, and a good indicator of this is when they produce a spectacular result without yielding any real insight as to why–the paper here being a case in point.
If your quibble is with the summary for policy makers, I think that’s fair game (even as I wouldn’t at all agree with your characterization of it). But it sounds to me like you’re claiming somehow that bias accounts for the consensus view as represented in the IPCC chapters and the underlying literature. Frankly, I think you’ll find there is very little evidence to support that, and if there is any neither have you presented it nor I seen it. You have to ask yourself to imagine the perfect scientist, as objective as a human being can be, which is to say full of integrity and in strict observance of the policies and procedures that imbue his craft with meaning. Isn’t it the case that such an individual will have an opinion about, I don’t know, say, how fair a representation of the science was Al Gore’s movie? Isn’t it the case that this individual will have all sorts of opinions, just like you or I? Hell, isn’t it possible that he or she votes?!
You seem to imply that quantum mechanics is a world apart from climate research, and yet Einstein’s rejection of it could probably fairly be characterized as an artifact of his own bias: namely that he was invested in the problems he was trying to solve, and this somewhat upended the stature of what he was able to accomplish and where he thought the field was going. “God does not play dice”. I think it’s pretty clear you don’t have to dismiss the import of all manner of biases that abound to believe that scientific consensus- as can rightly be claimed regarding the broad outlines of the theory of AGW- is meaningful and hence actionable. Relatedly, the fact that a new discovery can overturn previously ‘known’ scientific explanation is a dead end. If you accept that as being a deal breaker, then no amount of scientific evidence, no matter how vast and compelling, could ever justify any conclusion. Does that strike you as being rational? I mean, for all we know, Einstein could end up being right about quantum mechanics given some distant understanding that more resembles his erstwhile problems with it than current answers- does that mean we shouldn’t pay any attention to any of the information generated by that field of science? That it shouldn’t effect technological progress/our capabilities and understanding? Do you follow me?
People that reject the current science should start confronting the fact that their problem is not the media, or the summary for policy makers, or Al Gore’s movie, and start appreciating the genuinely mammoth scientific case they should have to start building to bring the world around to their position. Either that or figure out a way to argue, for one, that individuals shouldn’t make decisions on physician determined diagnoses and treatments because they are uncertain, (and routinely far more so than our understanding of AGW). If they can’t do so, they should not feel aggrieved when society acts on what is essentially the same type of feedback. Partisanship has nothing to do with it.
Bottom line, society can, should and routinely does make decisions based upon effectively agreed conclusions of a particular scientific or social scientific community, (and often times less than such). Members of that community that disagree should focus their efforts on persuading more scientists to the merits of their claims, not on the public at large (where in this case, they have been to date). History has UNAMBIGUOUSLY shown that the former works where there is a case to be made, while very recent history shows that the latter certainly will not.
Re #101 and #103
Thank you for your comments. I did the calculations a couple of years ago and I’m afraid I’ve lost the reference to the practical figure for the amount of ice actually melted. However, the year for which this applied was around 2003. This was the latest for which energy data was available at the time from the Energy Information Administration of the US Department of Energy (1).
The problem of the proportion of the anthropogenic energy which is lost to space before it can reach the polar regions and melt ice is one for which I should really appreciate some professional help. For now, though, I have assumed no losses in order to make some sort of estimate of the maximum value of the effect.
Mr Pierce, thank you for your point about the thermal efficiencies of the power plants. This, of course, significantly enhances the ice melt.
Again from the EIA data (2), and for 2000, the proportion of the world primary energy actually produced in the Northern hemisphere is 0.867, and so leaving 0.133 for the South.
Greenland Ice Cap
A study by W. Krabill et al (3) of the changes in the Greenland ice cap between two series of measurements, one from 1993 to 1994, and the other from 1998 to 1999, gave a conservative estimate of 51 Km^3 for the average annual amount of ice lost for that period, which is equivalent to a mass of 46.8 Gigatons per year. (Unfortunately, it is not clear how much was actually melted and how much was lost by ice going into the sea.)
From the EIA (1), for 1997, the total world primary energy production was 4.017 × 10^20 Joules. Again assuming no losses as before, the Northern hemisphere energy was 3.48 × 10^20 Joules.
Suppose that this is shared out amongst the ice covered areas in the North.
Greenland ice cap 1.8 × 10^6 Km^2.
Small glaciers 0.58 × 10^6 Km^2.
Arctic sea ice 11.0 × 10^6 Km^2.
Total ice area 13.38 × 10^6 Km^2.
Then the Greenland ice cap share of Northern energy = ((1.8 ×3.48)/13.38) × 10^20 Joules
= 4.68 × 10^19 Joules
This amount of energy can melt a mass of ice of 140 Gt, for 1997 figures, which is about 3× the practical estimate provided by Krabill et al.
(3) Krabill, W., et al, Science 289(5478): 428-430
Ian McLeod says
Hank Roberts #110
Future modeling may well show that M&M.JGR07 results are spurious but it is unlikely. Dutch meteorologists, Jos de Laat and Ahilleas Maurellis, in a pair of papers published in 2004 and 2006 have shown quite independently from McKitrick and Michaels (M&M) that using different data and a different methodology came to the same conclusions. In their papers, de Laat and Maurellis showed that there is indeed a correlation between urbanization and warming and that their results were statistically significant. The IPCC has dismissed this by claiming it is Artic Oscillation. The problem of two independent and mutually exclusive research teams coming to the same conclusion is not going to go away. The IPCC cannot ignore their work come next assessment report.
Nick Gotts #111
You asked two good questions, which I purposely left vague because truthfully I do not know. I think that CO2 forcing is less than the models predict. However, I acknowledge that in the future a revolutionary paper may show the reverse. I’d say the results will be known with high certainty by 2015, perhaps sooner. The form they would take is less CO2 forcing and more UHI than is currently recognized by the IPCC. Please note that I say this only to answer your question directly.
UHI has nothing to do with polar amplification, cooling in the stratosphere, or melting of glaciers, and so forth. The IPCC have stated that it is the Artic Oscillation coupled with CO2 forcing, which is to blame for the warming in the Northern Hemisphere. That land mass has greater sensitivity to warming than the ocean because it has less thermal capacity.
Jeffrey Davies #113
You are right what I said does not make any sense. I misspoke.
Ray Ladbury #114
Newton was his present day IPCC, the voice of authoritative reason, just ask Leibniz. In Newton’s day, the late 1600s and early 1700s, scientists did not have a proper description of reality, as we understand it today. They knew nothing of quanta or the particle-wave duality inherent in the crazy world of quantum mechanics. It was Einstein in 1905 that defined the quanta and then later Niels Bohr et al in Copenhagen that defined the rudimentary constructs of quantum mechanics in the 1920s. Einstein’s stubbornness towards the so-called incomplete description of reality should not distract from his groundbreaking leap describing gravity in his special and general theory. Einstein was wrong, Niels Bohr was right, or until someone comes along and disproves both.
I agree that science proceeds in fits and starts, but often boils down to intuition and some nebulous hunch by clever scientists, the learning and doing part of science. Science does not proceed by building a consensus, although it is an outcome once a theory is firmly established like F=ma or E=mc2, or can be shown to be true anywhere in the universe.
Regarding the M&M.JGR07 paper and your comments:
1. The model is very complicated but the high r2 and low t-stats suggest robustness.
2. You said that if a climatic model does not contain physics, this is reason to be suspicious of the results. It is not sufficient or necessary in my opinion.
3. As I mentioned above and as Rasmus rightly pointed out as well, the Artic and Antarctic bias is problematic. M&M should explain this.
We are going around in circles but I liked what you said about quantum mechanics and Einstein.
Steven mosher says
“[Response: Surely it would be better to do it with model results already generated to avoid any implication that they were somehow fixed, ”
Well, I would have to validate that the model results were in fact the results of model. That would
mean running the model. That is validition 101.
“and of course, you would want to do it with a range of models since you wouldn’t want to rely on one particular one, ”
Actually, I might want to select one randomly. I might also want to consider truely independent models
rather than several models from the same groups of scientists. Lot’s of issues here.
“and you’d want them to have used all the appropriate forcings for the exact same period, and lo! it is available: www-pcmdi.llnl.gov/ipcc/about_ipcc.php . Let us know how you get on. – gavin]”
first one has to independently verify that the models in question actually put out the data you pointed to. This requires the data sets, the test data, and operating code. The
nice thing about M&M is that I can actually go get the data, get the code, run it and see that there results match what they published. That’s 101. Now, sometimes people
screw up there input datasets ( like from ushcn) and sometimes they screw up latitudea and longitudes.
So step one is always, can you at least duplicate the published report. That’s a bare minimum check.
What data did they use? did the program actually read that data in, what did it output. does the published
output match the actual output. IV&V stuff. basic 101.
[Response: Well if the idea is to waste your time, go ahead and re-derive the Navier Stokes equations, quantum mechanics and run a check over the HITRAN database. If you seriously believe that the data in the IPCC archive has somehow been hand written in order to match the observations and didn’t actually come from the models they say it does, you are deluded. But the GISS GCM is online and so go ahead and run it. Those simulations took us about a year, so you should be done in a decade or so if you are working on your laptop. With respect to M&M07, they used STATA which is not open source, nor freely available. Thus I cannot check what exactly their ‘regress’ or ‘test’ routines do, or whether they do it correctly. I have no reason to doubt that they are correct, but that is a long way from knowing for certain – however, there are more interesting things to check – surely you’re not dodging the question? (PS. you forgot to mention mixing up degrees and radians – probably a little more apropos here). – gavin]
Ray Ladbury says
Ian Mcleod #120, Come on, did you really have a straight face as you were writing this? “Newton was his present day IPCC…” Please. Just where does the IPCC get such tremendous power that none would challenge it? And the thing is that it’s not just the IPCC. The American Physicsl Society, American Geophysical Union, National Academies… They’ve all endorsed the basic conclusions of the IPCC. In fact, there is not a single professional society of scientists or engineers that dissents from the basic fact of anthropogenic causation of climate change. Do you think that none of the scientists in fields outside of climate change has ever looked at the science to see whether it holds together? If so, then you don’t know many scientists.
A model without physics behind it is reduced to the likes of an epidemiological study in medicine telling you that oat bran will make you live forever–oops, no it won’t.
Ray Ladbury says
Steven Mosher #121, Your missive puts me in mind of a story I heard about a young man who found himself traveling by train across Wyoming with the Calvin Coolidge’s Secretary of the Interior. Desperate to find some way to start a discussion and impress the Secretary, the young man scanned the horizon for something, anything, to open the conversation. However, as they were traversing Wyoming, there was little remarkable to see. Finally, he spied a flock of sheep and thought he’d at least impress the secretary with his powers of observation. “Looks like those sheep have just been sheared,” he said in the direction of the Secretary.
The Secretary looked out and pondered a moment, “Yeah…yeah,” he said finally. “This side, anyway…”
Perhaps you would make more progress if you moved beyond wheel invention 101.
Hank Roberts says
Ian McLeod says
Ray Ladbury #122
You say, “Come on, did you really have a straight face as you were writing this?”
I didn’t, my tongue was planted firmly in my cheek. Nice rhetoric Ray.
Hank Roberts #124
De Laat, A.T.J., and A.N. Maurellis (2004), Industrial CO2 emissions as a proxy for anthropogenic influence on lower tropospheric temperature trends, Geophys. Res. Lett.Vol. 31, L05204, doi:10.1029/2003GL019024.
De Laat, A.T.J., and A.N. Maurellis (2006), Evidence for influence of anthropogenic surface processes on lower tropospheric and surface temperature trends, International Journal of Climatology 26:897—913.
Complete McKitrick and Michaels paper. See references for more information.
Ray Ladbury says
Ian, the point of my post–which you seem to have missed is that it is that the climate consensus is not a matter of politics distorting scientific opinion, but rather of science calling on politicians to act. Even if your contention of political bias by the IPCC were correct (and if there is a bias, it has been toward toning down the science), that would not explain why every scientific professional society that has independently investigated the claims has endorsed the IPCC conclusions. Now the reality of climate change runs counter to the interests of most of these societies. It means less funding will be spent on basic research in their fields and that more of their efforts will have to go into mitigation. Yet, because the scientific evidence is overwhelming and the threat is real, they have endorsed to reality of the threat. The only two sides in this debate are science and antiscience–and if you want to tell which is which, the science side is where all the scientists line up.
Barton Paul Levenson says
Ian McLeod posts:
[[Regarding the M&M.JGR07 paper and your comments:
1. The model is very complicated but the high r2 and low t-stats suggest robustness.]]
You mean “high t-stats?” Studen’ts t statistics of low magnitude indicate that a variable is not significant.
The spectacular p value of the M&M paper is itself suspicious. It looks like a spurious correlation. Did they test that their time series were stationary?
[[2. You said that if a climatic model does not contain physics, this is reason to be suspicious of the results. It is not sufficient or necessary in my opinion.]]
Your opinion is wrong. Otherwise it would valid to just feed the right answers into a model and then print them out.
I think your comment to Ray said it best:
“Science does not proceed by building a consensus, although it is an outcome once a theory is firmly established like F=ma or E=mc2, or can be shown to be true anywhere in the universe. ”
Precisely. Consensus is not science but an outcome of science that sign posts scientific progress throughout history, (as well understood by Oreskes and scientific historians in general). And once certain scientific findings have been accepted, scientists largely do not revisit them, they pursue questions that the ‘settled science’ point up. Occasionally, those questions are not answerable, or their answers place the settled science in crisis. You are familiar with this narrative I presume.
Bottom line, while science is not an exercise in consensus building, the existence of a broad consensus after the science is done is highly meaningful to policy makers. It means the information- in this case, the link between carbon emissions and future economic and environmental damages- is massively more reliable than it would be in the face of significant scientific controversy, and therefore it is far more prudent to act upon.
Note that policy action does not require unanimous consensus, or the absence of uncertainty. To test that assertion, ask yourself whether you would be concerned to work in a building that had elevated levels of asbestos in the air or whether you pay attention to how much salt or cholesterol you eat, or whether you would give your children triple jab immunizations, or follow a doctor’s advice on treating any ailment or disease. Because if you would do any of the above, you would have effectively acted on uncertain science, in some cases, highly so, not to mention science almost never agreed on by all medical researchers, (and in some cases controversial in that regard). Actually, you will have taken a position on uncertain science no matter what you do- the issue is inevitable.
Saying that, were it the case that persons or even scientists were attempting to stifle a scientific challenge of the consensus view by shouting “consensus, consensus!!!” or “the science is settled”, I would agree, that is not science. That is dangerous. However if they are attempting to challenge that mainstream scientific conclusion outside the realm of science– in Op-Eds and astroturf and advocacy organizations, etc., without first building any compelling scientific case, (as unambiguously describes the high public profile of self-proclaimed skeptics views), well, then, “consensus, consensus!!” is a meaningful retort, because in this instance it is the ‘skeptics’ that are attempting to drown out science; their actions that are dangerous.
Michaels & McKitrick’s method in publishing this paper and not soliciting feedback and dialogue but instead diving headlong for the public mic, is, frankly, par for that course. And while that bad form isn’t sufficient to debunk their manuscript, and neither even are all the large waving red flags that have been highlighted here, (although Gavin’s test seems promising in this regard), it certainly increases suspicions that they don’t have anything scientific to add at all. And I hate to be the bearer of bad news, but confirmation of such would not be newsworthy enough to merit more than a blog post.
Chuck Booth says
Re # 108 Ian McLeod: “This ostensibly impossible result, which seemingly defies the second law of thermodynamics… not only turns conventional wisdom on its head, requiring all biochemical textbooks to be rewritten, but has a profound effect on our understanding and modeling of past, current, and future global warming and cooling.”
Or maybe not:
Butenhoff CL, Khalil MA. 2007 Global methane emissions from terrestrial plants.
“…We conclude that methane release from the terrestrial plant community as presently understood does not require major innovations to the global methane budget.”
Environ Sci Technol. 2007 Jun 1;41(11):4032-7
And even if a novel pathway for methane synthesis is identified in terrestrial plants, I seriously doubt that “all biochemical textbooks” will need to be rewritten – in most introductory biochemistry textbooks, methanogenesis is covered only superficially (e.g., Nelson and Cox, 2000, Lehninger Principles of Biochemistry,3rd ed) or is not mentioned at all (e.g., Berg, Tymoczko, and Stryer, 2007, Biochemistry, 6th ed). I also doubt that the second law of thermodynamics is in danger of being overturned by a new metabolic pathway, should one be identified in this case.
Ian McLeod says
Ray Ladbury #126
Okay Ray, every scientific body on the planet agrees that the IPCC is the arbiter of truth. I get your point. I just disagree with it.
[Response: I’ll take your weighty and well-considered opinion into account along with that of just about every scientific body on the planet when I’m reading the IPCC report. Thanks for taking the time to make your opinion on this matter known. –raypierre]
On a lighter side, are you aware of James Gleick’s book Isaac Newton? It is excellent. Every time Newton’s name comes up, I hearken back to this book.
Barton Paul Levenson #127
The low t-stat test referred to the over fitting criticism. They also used it as a rejection of the null hypothesis indicating support for their linear model.
The time series is bounded between 1972 and 2002.
My comment about physics as a necessity referred to M&M’s model in particular and economic models generally. Obviously, if we are referring to global circulation models (GCMs) then one must utilize physics.
PS: Interesting web page.
We finally agree that consensus is not science, phew. It took almost 2000 words. I call that progress. Then you go and cite Oreskes as a basis for consensus.
Naomi Oreskes (December 3, 2004). “Beyond the Ivory Tower: The Scientific Consensus on Climate Change”. Science 306 (5702): 1686. doi:10.1126/science.1103618. (see also for an exchange of letters to Science
Her bad social science paper should never have seen the light of day. It was flawed and unscientific. The editors at Science must have an agenda to put out and then defend their decision to publish such tripe. Although they have not said it publicly, I suspect they regret publishing the Oreskes paper. http://www.staff.livjm.ac.uk/spsbpeis/Oreskes-abstracts.htm
[Response: You are putting words in peoples’ mouth regarding the conclusions people can draw from the existence of consensus. I am beginning to worry that you are just trolling. –raypierre]
Chuck Booth #129
The Butenhoff and Khalil paper is money blocked, pity. Their conclusions outlined in the abstract are curious, but perhaps scientists are refining the work done initially by Kepler et al. The following is off-topic, but related to your comment. It is something I wrote last year and chopped down so it not onerous.
Methane is important in the global warming debate because it can adsorb and emit infrared radiation approximately 23 times more efficiently than carbon dioxide (CO2) does (ref. 1). Scientists know that methane is produced naturally by three different methods. One, it is generated when conditions favour fermentation reactions in swamps, marshes, and rice paddies. Two, methane is produced “as a by-product of anaerobic microbial digestion” (ref.2) in the gut of termites, ruminant animals (especially cows), and some humans. Please, no fart jokes. And three, methane is produced in significant quantities by plants.
[Response: The question of where methane comes from and what it will do in the future is an important an interesting one. However, I don’t see what point you are trying to make, as we can measure the past concentrations of methane, and compute accurately its contribution to global warming vis a vis CO2. We can also say what difference it would make if we double CO2 but reduce the methane to zero (some difference, but it won’t save you). On the upside, though, given uncertainties in the dynamics of methane sources, there is very considerable risk of unpleasant surprises if warming should cause methane production to increase. –raypierre]
Keppler’s team (lead author of Nature article) calculated that plants pump between 60 and 240 million metric tons of methane per year into our atmosphere. This represents 10 to 40 percent of the current methane budget, which is roughly 600 million metric tons per year. What this means, of course, is that the IPCC have not accounted for hundreds of millions of tons of extra methane in the atmosphere due to planets; the IPCC’s budget is too small. This is big news.
The following list is a breakdown of methane emissions in million metric tons per year as reported in Scientific American: wetlands (225), ruminants (115), energy production (110), landfills (40), biomass burning (40), waste treatment (25), termites (20), ocean (15), and hydrates (10) (ref. 4). Given that plants produce an additional 60 to 240 million metric tons of methane per year—not accounted for in the IPCC budget—this fact has an explicit outcome on the accuracy of the global circulation models.
The discovery explained why concentrations of both methane and CO2 increased in the atmosphere during deglaciation periods. The explanation goes something like this. As ice and permafrost began melting, the retreating glaciers exposed more landmass for planet growth. Meanwhile, as the oceans warmed, dissolved CO2 became less soluble and outgassed to the atmosphere. More CO2 in the atmosphere created a natural fertilizer effect augmenting plant growth. Stimulated plant growth in turn produced more methane. With more methane and CO2 in the atmosphere, a small upshot in warming was produced. The important warming from the Sun, which started the entire process in the first place, increased the evaporation rate from the warming oceans and lakes, producing higher levels of water vapour in air. Higher levels of water vapour produced more clouds and precipitation and helped control Earth’s unique thermostat that exists today. What is vital to our new understanding here is the natural coupling between methane and CO2 in the atmosphere. Before 2006, this phenomenon was unknown.
[Response: Possibly (but see below). What implications is this supposed to have for anthropogenic climate change? –raypierre]
The paper clarified another mystery perplexing physicists because of suspected anomalous satellite observations. In 2005, Frankenburg et al measured huge plumes of methane emanating from evergreen forests all over the planet (ref. 6). Botanists and climatologists assessing this paper wrongly assumed that the methane was coming from dead vegetation biodegrading. No, it was coming from living plants.
Ref.1 Keppler, F., Röckmann, T. February 2007. Methane, Plants and Climate Change. Scientific American, Vol. 296, No. 2, 52—57 (pg. 53)
Ref. 2 Ibid, pg. 53
Ref. 3 See 2 pg 56
Ref. 4 See 2 pg 55
Ref. 5 Ibid, pg. 54
Ref. 6 Frankenburg, C., Meirink, J. F., van Weele, M., Platt, U. & Wagner, T. May 2005 Assessing methane emissions from global space-borne observations. Science Vol. 308, 1010—1014
[Response: You should be more cautious about basing too many conclusions on one relatively new result on methane production by living plants. We know many bacterial means of producing methane from decomposing organic material, but there is only limited data on production of methane from live plants, which is subject to considerable methodological uncertainties. Even if these live-plant methane results hold up, you are jumping to conclusions when you say that the plumes of methane from forests come from living plants. There is a lot of bacterial activity in the soil, which could well be playing the major role. Science is more than just a matter of spinning convenient stories. It’s about doing the hard work to test ideas. –raypierre]
You had me going. For a while there, I sincerely thought you were given to reason, but just now you’ve made it clear you are content to play semantic games. Bravo. To your second brief riposte, I would only say your segue onto Oreskes was a train wreck, (and not even the first of this blog thread- one marvels at what you could accomplish in a calendar year). Or do you think Science deeply regrets publishing Oreskes paper because of a critique that has been both exposed as a fraud, and, subsequent to that humiliation, publicly withdrawn?
Here we are, a few years on, and you’re still proudly trumpeting poor old Benny Peiser’s public shame. My how you denialists enjoy hoisting yourselves up on your own petard. Next thing you’re going to tell us is that the scientists are suppressing the evidence of causation by benthic bacteria. Thanks for the morning chuckle old boy.
Chuck Booth says
Re # 130 Ian McLeod
Thanks for the discourse on methane emissions and global warming. I don’t know where you came up with this: “Scientists know that methane is produced naturally by three different methods…” – as there really aren’t three methods: Aside from the report that some plants (I doubt the authors are claiming all plants, are they?) make methane, the only known biogenic source of methane is the group of Archaea (or Archaebacteria) known as the Methanogens – they make methane in anaerobic swamps, termite guts, and the foregut of cattle and other ruminants.
I haven’t yet read the Kepler et al paper in Nature, but look forward to doing so, along with any letters to the editor in response to that article, as well as the Butenhoff and Khalil paper. In the mean time, I will remain skeptical that the plant cells actually generate the methane – there are too many cases of plant-microbe (and animal-microbe) symbioses to presume this is anything but another example of symbiosis (albeit a potentially novel one).
However, I am still curious about your suggestion that methane production by plants “seemingly defies the second law of thermodynamics.” Surely Kepler et al didn’t state this? Could it be that you misread a statement such as this one from a Nature news item:
“The newly revealed methane emissions have taken plant physiologists by surprise, because far more energy is required to create methane than, say, carbon dioxide in an oxygenated environment”?
If you read this carefully you will realize it merely states that methane production is expensive, raising the question of why plants would waste energy producing methane that will be released to the atmosphere. One simple answer is that they do not – the plant itself is not producing the methane. But, I will withhold judgment on this until more work is done.
Chuck Booth says
Re #130 Ian McLeod
This news item in Scientific American (June 1, 2007) discusses the Kepler et al claim that tropical grasses produce methane and contradictory findings by Dueck and colleagues:
I think Kepler et al have a lot of explaining to do before their findings will be taken seriously.
Ray Ladbury says
Look, Ian, First, if you look at the history of science, you will find that consensus is central to the scientific process. It is, however, not what is meant by consensus in the political sense, but rather an agreement about what inferences the data will support and at what level of confidence. For simplified cases, this can even be expressed mathematically–though not for cases where support comes from many different lines of argument/evidence. Second, the IPCC does not establish consensus–rather, it reflects it. The endorsements of professional scientific societies are a measure of how well they have done of expressing the consensus as supported by physicists, by chemists,… and in the case of the National Academies, by the most prestiegious official body of scientists in the country. What they are saying is the physics is solid, the chemistry is solid… So it is absolutely pointless to attack this consensus on the basis of the science as we currently know it–you won’t succeed. If you have some new science, fine. But nothing new has been proposed for nearly a decade now, and the consensus just gets stronger.
So the question, Ian, is what we do about it–and that’s where the politics comes in. That is where your opinion is as valid as anyone else’s, but unless you learn about the science and express an educated opinion with a sound basis in the science, you views will likely be ignored. That is why the opposition by the political right is so counter to their interests. They are attacking the science–which they do not understand–and remaining mute on solutions that reflect their values and interests–which only they can represent.
John Mashey says
r: #130 Ian
As others have noted, Peiser withdrew his claims.
Maybe you want to try Monckton + Schulte’s (attempted, badly) refutation of Oreskes, but first, I suggest reading: Monckton+Schulte+SPPI vs Oreskes, which I wrote to capture the entire sequence of silliness in attacks on Oreskes. Are these people you really want to emulate?
Arch Stanton says
Nature 447, 11 (3 May 2007)
Missing gas saps plant theory
“A team of plant scientists has cast doubt on one of the most startling research results the field has seen in recent years — the finding that green plants emit methane. Tom Dueck of Plant Research International in Wageningen, the Netherlands, and his colleagues say that they can find no evidence that plants produce the potent greenhouse gas…”
Arch Stanton says
I should have mentioned in 136 that the Tom Dueck et al paper was published in:
New Phytol. doi:10.1111/j.1469-8137.2007.02103.x; 2007
Steven mosher says
Well, gavin since I have registered to get the data you suggested I get, we will see if they give me access.
I gave you as a reference.
Steven mosher says
Gavin and ray. More sheep.should I get the results from here:
Hank Roberts says
What kind of computer do you have, Steven?
Ian McLeod says
Chuck Booth #132, #133
It looks like raypierre was right to suggest caution when holding up one study as a paradigm shift until it is independently corroborated. By the way, when I said, “… seemingly defies the second law of thermodynamics” I used the adverb “seemingly” quite on purpose. Meaning of course, superficially evident but not true. I did not say, “It defies the second law of thermodynamics”, which is saying something very different. Semantics, I know.
I tried finding a free version of the Nature article, sorry, no luck thus far. I have presented below some information that I thought you might find interesting.
Here is a copy of the Scientific American article that is more or less a summary of Keppler et al’s Nature paper.
This is a short summary of the Nature paper.
Here is an article that narrows the uncertainties.
Here is an editorial that states plants are not to blame for global warming. I think raypierre would like this one.
Here is a major critique of the Keppler et al paper, which I think all RC pundits will like.
Here is another overview. It discusses the consequences and shortcomings of some of the mitigation recommendations in the Kyoto Protocol and further outlines pitfalls of the Nature paper (click on the bottom of this page for pdf file).
I read the linked paper from you and Arch Stanton #136. Tom Dueck’s team has not corroborated Keppler et al’s results. To the contrary, they used a different methodology to see whether the methane flux rate from plants (primarily grasses) produced the same concentrations discovered by Keppler’s team. As of June 1, 2007, the issue is still up for grabs as each research team is now claiming a lack of scientific rigor from one another. A scientific controversy has now ensued.
If the Keppler et al claims hold up, I think those biochemical textbooks you mentioned will require an addendum during the next scheduled reprint. In addition, with the caveat, “if true”, the mitigation schemes outlined by the IPCC will require a rewrite as well, including a new methane budget. If on the other hand it is discovered that Keppler et al claims are false, then I retract what I said with a big fat Roseanna Roseannadanna, NEVER MIND.
[edit – enough on Oreskes]
The Saturated Gassy Argument
Initially, I was sceptical about the enhanced greenhouse gas effect due to carbon dioxide, but then I read Real Climate’s piece entitled “The Saturated Gassy Argument”, and it made me think there might be something in it after all.
The SGA says that photons must escape into space in order to balance the Earth’s energy budget. They manage this escape mainly from high altitudes where the atmosphere is very thin and there is insufficient carbon dioxide to absorb all the photons in the relevant CO2 band. Therefore, so the SGA goes, additional CO2 enables more photons to be absorbed, so reducing the numbers escaping to space, and thereby increasing the temperature until energy balance is again attained.
This is the enhanced GHG effect.
However, after further thought, I am puzzled again, and I hope someone can resolve my difficulty.
When a photon is absorbed by a CO2 molecule as above, its energy equivalent no longer contributes to the kinetic energy of the atmosphere. The absorbed energy has now become internal energy of the CO2 molecule by raising it into an excited rotational state. So the photon has been taken out of play, just as if it had escaped to space, and so the energy loss required for equilibrium has still been achieved.
This process will occur for the other CO2 molecules. Therefore, if more CO2 is added to the atmosphere, extra energy loss from the atmosphere will occur. This is a cooling of the atmosphere, rather than the heating postulated by the SGA.
Count Iblis says
Eventually that extra rotational energy becomes “thermalized”. Note that according to the equipartition theorem of Statistical Physics, each degree of freedom contains an energy of 1/2 k T in thermal equilibrium. So, if you put extra energy in some dgrees of freedom, you get a nonequilibrium situation and eventually due to interactions this extra energy will be distributed equally over all the degrees of freedom of the system…
Ray Ladbury says
AEBanner, The vibrationally excited mode of CO2 is quite long-lived. Therefore, there ar many collisions of the CO2 molecule with surrounding gasses before a radiative relaxation. This means that the probability of collisional relaxation is greater than radiative relaxation. Remember that the vibrational state is just kinetic energy of the atoms in the molecule–it can easily share that energy with other gas molecules in its vicinity. Thus the absorbed photon mostly goes into kinetic energy, raising the temperature of all the gas molecules, not just the CO2.
Re #143 and #144
Many thanks for your replies.
Re #144, Ray Ladbury
“Thus the absorbed photon mostly goes into kinetic energy, raising the temperature of all the gas molecules, not just the CO2.”
Yes, but the kinetic energy of the atmosphere supplied the energy for the photon to be absorbed/created by the CO2 molecule in the first place, so cooling the atmosphere. So the process has simply gone full circle without any overall change of temperature.
Photon Absorption and Emission at High Altitudes
I think that there is no doubt that global warming is occurring, witness the melting of the ice, and that it may well be due to anthropogenic activity. But, I believe it is not due to increased concentrations of carbon dioxide.
I have recently been having a problem with understanding the “Saturated Gassy Argument”. Initially, I was convinced, but on further thought I came up with the following, which seems to show that there is no enhanced GHG effect which can be explained by the SGA. So I am presently a sceptic, but anxious to know the truth about what is happening in the atmosphere. If anyone can post helpful comments, I shall be grateful.
Please consider the following.
Let C = total number of CO2 molecules in the pre-industrial atmosphere at 280ppmv
k = the increase factor in CO2 concentration relative to pre-industrial conc. of 280ppmv.
s = proportion of emitted photons escaping to space
win = total number of photons escaping to space through the “window” per unit time
For CO2 increase factor k, let
b = proportion of CO2 molecules excited by absorption of photons, and
Then, number of CO2 molecules excited by absorption/collision = kbC
All these molecules emit photons.
Let the following expressions apply for unit time, where p is the appropriate constant of proportionality.
Then in general, we have:
Number of photons escaping to space = pskbC + win ………………….. (Eqn 1)
Now consider the case of the pre-industrial atmosphere.
We can put k = 1 and b = b1.
Then, number of photons escaping to space = psb1.C + win ……………..(Eqn 2)
Now in energy balance conditions, the number of photons escaping to space must be constant.
Therefore, from Eqn (1) and Eqn (2), we have pskbC + win = psb1.C + win
Hence, kb = b1
But b1 is a constant.
So as k increases, b must decrease for this relationship to be satisfied and energy balance to be maintained. That is, as the amount of carbon dioxide is increased, the proportion of the number of CO2 molecules participating in the process is reduced. This requirement can be accommodated either by a fall in temperature from the pre-industrial value at high altitudes, or alternatively by the emitting layer moving to higher, colder altitudes.
What happens in the atmosphere?
Number of photons returning to the atmosphere = p(1 – s )kbC ……….… (Eqn 3)
And for the case of the pre-industrial atmosphere, k = 1 and b = b1, as before.
So, the number of photons returning to the pre-industrial atmosphere = p(1 – s )b1.C …..(Eqn 4)
Therefore, the change in photons returning to the atmosphere = p(1 – s )kbC – p(1 – s )b1.C
= p(1 – s )C(kb – b1)
But, in energy equilibrium, kb = b1.
Therefore, the change in the number of photons returning to the atmosphere = 0
This means that there is no change in the temperature of the atmosphere due to increasing the amount of CO2 present.
Ray Ladbury says
AEBanner, You are neglecting the surface of the planet, where most of the IR photons originate. Since the temperature is warmer than the atmosphere, it will emit more IR. Moreover, as a solid, the radiation spectrum will look more like a blackbody to begin with.
There are a number of problems with your argument. To begin with, photon number is not conserved. Second, we have a continual source of photons from the ground. These get absorbed, and most of the energy from the excited molecule gets transferred by collision to other molecules in the atmosphere. It is only where gas densities are sufficiently low and where the number of ghg molecules is sufficiently low that the excited molecule will decay radiatively and that photon has a chance of escaping to space. As you add more CO2, that level is pushed to higher altitudes and colder temperatures. Colder temperature means less radiation in that energy band, so less radiation escapes, and the planet warms.
Please look at the argument again. Look at Ray Pierrehumbert’s book. You have not comprehended the physics.
Arch Stanton says
AEB, I am not a scientist and I too struggled with the problem you are having. I will try to explain it as I now believe I understand it:
You are right; once the system regains equilibrium there is no change in the net gain or loss of energy into space. It is 0. Until that point however there is a net change in the energy gained or lost by our planet’s system.
You are also right that GHGs also act to cool the atmosphere, however you are forgetting that that the atmosphere, besides being warmed by GHG absorbed photons is also warmed by convection from the surface and (likely even more important) latent heat of vaporization of water carried aloft. Heat that is recaptured by the upper troposphere when clouds condense. These 2 factors are constantly warming much of the troposphere.
Increasing the “gassy” concentration increases the warming in the troposphere, as the photons “seeking escape” bounce around like pinballs more off the infreased GHGs. Subsequently more of them bump into relatively “cool” areas and are not quickly reemitted. Tjhe GHGs also tends to cool the stratosphere because convection rarely extends beyond the troposphere to bring the latent heat of water vapor up there (yet the CO2 does make it up there).
Result: Troposphere tends to warm, stratosphere tends to cool. Once the level of the GHGs (and the temperature of the solid/liquid planet) stabilizes, this effect will stop and the planet will once again regain a 0 net energy balance, albeit at a slightly higher temperature.
Hank Roberts says
This frequently asked question in past threads always gets stuck at the point where “pure mathematicians enter the discussion with rather surprising claims …” — which is to say, we’ve been repeating the history of this area of science.
This may help:
“… Looking at various proofs of a general physical law over a period of more than 50 years, a period in which theoretical physics in Germany developed into a new discipline, the problem of a history of proof is addressed and it is asked what different ways of reasoning can be found and whether these can be distinguished as styles of reasoning or thinking.
The case chosen is Kirchhoff’s formulation of a general law that relates the emission of radiant bodies to their absorptive properties. It stands at an intersection of a number of developments and fields of physics in the 19th century. First, there is the development of spectroscopy and the beginning of astrophysics ….”
“… physicists like Kirchhoff and later Helmholtz, succeeded to make the appropriate abstractions and arrived at general mathematical descriptions and at least claimed to be able to derive the laws from theoretical principles. This line we will follow further in this paper up to the point w[h]ere pure mathematicians enter the discussion with rather surprising claims as we saw in the beginning. The way to Kirchhoff’s law and the changing way of providing a theoretical foundation for it is hence a discussion that takes place in a process of a disciplinary formation and transformation that finally leads to the emergence of a theoretical physics for which Max Planck generally serves as the model scientist….”