Open Mind

311 responses so far ↓

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  dhogaza // December 16, 2007 at 6:04 pm

  Just to make clear to readers that there’s no way that Wegman can be ignorant of the fact that cherry-picking a starting point like 1998 …

  As part of [Wegman's] duties at the Office of Naval Research, [he] coined the phrase, computational statistics, and developed a high profile research area around this concept. The idea was to focus on techniques and methodologies which could not be achieved without the capabilities of modern computing resources. This program led to a revolution in contemporary statistical graphics.

  There’s more from his CV but you get the idea…

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  dhogaza // December 16, 2007 at 6:05 pm

  should’ve said “the wrongness of cherry-picking” …

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  KenH // December 16, 2007 at 6:35 pm

  The 2007 Arctic ocean ice extent may present a new cherry picking opportunity for denialists. If the minimum ice extent doesn’t match the 2007 extent for several years, they’ll be able to claim (like 1998 temperature) that “the ice extent was a minimum in 2007 and has been increasing ever since”.

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  tonylee6032 // December 16, 2007 at 6:37 pm

  Great post, Tamino. Very accessible for us non-scientists. I have a question and a comment.

  The question: Which dataset is preferred: HadCRU or GISS? I know the GISS includes estimates for the polar regions, which HadCRU doesn’t, but media reports almost always refer to HadCRU. Why is that?

  The comment: While it’s clear to me from what you’ve laid out that the temperature is increasing despite short-term noise, surely a denialist can simply claim that the current trend is just as indicative of a plateau before a drop. After all, if you believe current warming is just a natural cycle and that there is no link between human-emitted CO2 and warming, then the entire warming period from 1975 is just a deviation from the baseline. Which of course, just proves your point about the hardiness of denialist dog whistles.

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  Timothy Chase // December 16, 2007 at 6:40 pm

  From the essay:

  But I’ve been sidetracked by the revival of one of the favorite false claims of denialists, one of those pieces of garbage than never dies.

  Typo? I presume “than” should be “that.”

  Still reading the essay.

  [Response: Fixed!]

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  EliRabett // December 16, 2007 at 7:16 pm

  How about writing to Wegman and asking him what he meant?

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  vixt // December 16, 2007 at 7:20 pm

  This blog seems to be less about science these days and more about attacking others. Me thinks you should change the name to “anti-denialist mind”.

  Your argument is hypocritical. Anybody could pick any starting point and find a different trend. You picked one yourself when you said “The “modern global warming era” is from about 1975 to the present. ”

  [Response: I didn't pick 1975 out of a hat, nor did I choose it because it makes my case look good. There are objective mathematical reasons to choose 1975 as the "turning point" at which the rapid upward trend begins. Look a the graph of 5-year averages; it gives a good visual impression of the change that happened at that time. Running the numbers, rather than choosing randomly or cherry-picking what you want, indicates 1975.

  And that's the *real* difference between denialists and not. Those who claim that global warming is real and caused by human activity, do so on the basis of what the numbers say. Those who claim the opposite, trumpet only the numbers that appear to support what they say.]

  Anybody could just as easily say “the modern cooling trend began in 1998″. The difference is, you don’t like that, so you rant about it.

  [Response: "Cooling since 1998" FAILS statistical significance tests, while "warming since 1975" PASSES. Temperature since 1998 is perfectly consistent with a continued warming signal plus random noise. In fact, because of the existence of noise it's impossible NOT to get periods of apparent cooling. That's the point of the post.

  Do you believe there's no noise in the data? Do you dispute the validity of statistical significance testing?]

  In another post you wrote “13 years isn’t long enough to establish a trend”.

  Ok agreed, but 30 years is? It seems just as arbitrary to me. Climate seems to have longer cycles than that.

  [Response: Again -- it's called "statistical significance." It's how we tell the difference between actual trends in the signal and apparent trends due to the noise.]

  So it’s getting warmer since 1975. You promote that. But when some other scientist says “cooling since 1998″ you say it can’t be so and accuse using the old tired “cherry picking” argument.

  [Response: When someone trained in statistics, like McKitrick or Wegman, claims cooling based a data which are *easily* shown to be too brief for a signal to rise above the noise, they should know better -- I think they *do* know better. In your case maybe it's just ignorance. But for McKitrick and Wegman, it's cherry-picking.]

  I see cherry picking on both sides. Nobody is innocent. It’s all getting tiring. It’s like watching arguments in congress.

  [Response: False. In fact you've given us another favorite denialist argument: everybody is wrong, so nobody is any more right than anybody else. The AGW side rarely engages in cherry-picking, and the leading scientists supporting it don't do it at all.]

  The way I see it, a little warmer is a good thing. We can manage that, if sea levels rise like Gore claims, we move inland, we adapt. Been there done that. Humans adapt well. But if the ice comes, there’s no way in hell you can get out of the way of a glacier. Everything north of about 40-45, including Toronto, Montreal, New York, Boston, Portland gets ground up to a coarse gravel.

  Then there’s the massive agricultural failures in colder climates and the famines that follow. Crops grow better in warm climates with extra CO2.

  Warm is easier to manage. I like to think of Co2 based global warming as terraforming to our advantage. An ice age would be a true disaster.

  I’m sure you’ll all tell me how stupid and wrongheaded my view is. Flail away.

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  Timothy Chase // December 16, 2007 at 7:28 pm

  I didn’t know that Ross McKitrick had signed the recent letter about the plateau, but judging from what I found by doing a little search on his history, it really doesn’t surprise me. What is difficult for me to understand is how he or anyone like him could expect to be treated in a civil manner by any competent climatologist after having signed such a document — let alone coauthored some of the papers which have borne his name. But if I spend too much time thinking about that, something inside me is likely to short-circuit.

  Out of curiosity, have you looked into the spectral density which is associated with temperature series? Is it roughly constant? I assume there are measurable differences era to era.

  Anyway, one of the points that I remember we have bumped into in the past is the detection of regime change in the presence of red noise. One example would of course be in the case of temperatures (the temperature trend of the stratosphere seems to be rather step-wise, particularly in comparison to surface temperatures) but another would be with respect to hurricanes. (Quick question: I assume that internal to a given regime, there may nevertheless be a linear trend?)

  With this in mind, I thought I might bring to your attention something I found a little while ago which might be of interest — assuming you hadn’t already seen it:

  The Problem of Red Noise in Climate Regime Shift Detection
  Sergei N. Rodionov
  http://www.beringclimate.noaa.gov/regimes/Red_noise_paper_v3_with_figures.pdf

  Regime shift detection (Excel-based software)
  http://www.beringclimate.noaa.gov/regimes/

  Both are a little beyond me at this point, but at least the physical location is convenient: Sergei is at the University of Washington.

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  Aaron Lewis // December 16, 2007 at 7:30 pm

  You illustrate the point that we do not teach our young people enough math so that they can intelligently consume statistics.

  It is a problem we have had since Mark Twain said, “Figures don’t lie, but liars figure.”

  Excellent!

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  Hank Roberts // December 16, 2007 at 7:31 pm

  > writing to Wegman

  He ought to be interested in the subject:
  # Statistical Graphics and Visualization
  Wegman, E. J. and Carr, D. B..in Rao (1993) Handbook of Statistics, Elsevier
  # Statistical Image Processing and Graphics
  Wegman, E. J. and DePriest, D. J.. Marcel Dekker; New York, NY. 1986.

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  Timothy Chase // December 16, 2007 at 7:50 pm

  tonylee6032 wrote:

  The question: Which dataset is preferred: HadCRU or GISS? I know the GISS includes estimates for the polar regions, which HadCRU doesn’t, but media reports almost always refer to HadCRU. Why is that?

  I suspect both are valuable — as long as you know what each is refering to. As to why media reports might be focusing on HadCRU, I suspect it is either because it isn’t showing as much of a trend at this point as GISS, or because what happens north of the Arctic Circle can’t possibly affect all that much given how remote it is. However, when people bring it up, it might be a good opening for discussing the differences and what is going on north of that circle, or perhaps even the good work that is coming out of Hadley. I mean if they like the temperature series, undoubtedly they will find some of the other data from Hadley of value as well.

  tonylee6032 wrote:

  After all, if you believe current warming is just a natural cycle and that there is no link between human-emitted CO2 and warming, then the entire warming period from 1975 is just a deviation from the baseline. Which of course, just proves your point about the hardiness of denialist dog whistles.

  Sounds more like metaphysics than climatology, but I suppose that at least in terms of popular perception, this is precisely what they are trying to make it out to be. A bit like the “infinitely recurring cosmic cycles.” Then again, they a great deal of what they are doing reminds me of a Humean approach to causality and epistemology, too.

• 

  dhogaza // December 16, 2007 at 9:48 pm

  The way I see it, a little warmer is a good thing. We can manage that, if sea levels rise like Gore claims, we move inland, we adapt. Been there done that.

  Ah, we have years of evolution of the denialist argument compressed into a single post. First, “it’s not true”, then “it’s a good thing”. Actually, you left out the interim step, “it won’t be so bad”.

  You claim “been there, done that”, as though it’s not big deal. The dislocation of a couple of hundred thousand people from New Orleans serves as an example countering your “not a big deal” hand-wave. Yes, adaptation won’t have to happen overnight as it did in New Orleans. However, the number of people living in coastal urban areas is huge, and that migration will be anything than “ho-hum” if it becomes necessary.

  And this is precious…

  if the ice comes, there’s no way in hell you can get out of the way of a glacier.

  So, ignore warming issues in the next century because the next ice age, which will kick off in thousands of years, might be a bummer.

  That’s sorta like saying “I’ll jump off this 50 story building today because I’ll die of old age anyway 50 years from now”.

  But it’s interesting, because the Carter letter says essentially the same thing. Not explicity, because it’s so bone-headedly stupid, but implicitly, with its talk of investing to adapt to future natural changes (by which they mean “worry about cooling as much as warming”).

  Looks like the talking points broadcast center is working effectively, with the high and the low picking up the message and spreading it through the blogosphere.

  Then there’s the massive agricultural failures in colder climates and the famines that follow. Crops grow better in warm climates with extra CO2.

  The great breadbaskets of the world are in the northern hemisphere’s temperate regions, the plains of the US, the Steppes of eastern Europe, etc.

  The “extra CO2″ canard assumes that crop growth is currently limited by the amount of CO2 in the atmosphere.

  Tell that to farmers who spend millions on fertilizer, who rotate crops like wheat with nitrogen-fixing legumes, etc.

  The “extra CO2 means more growth” argument comes from research done in enclosed environments (like greenhouses) where other plant needs were provided to the point where CO2 was the limiting factor. Not a real-world experiment.

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  John Mashey // December 16, 2007 at 10:27 pm

  1) Absent human effects, we would normally have expected the glaciers to have been slowly growing again. [See William Ruddiman's Plows, Plagues, Petroleum.]

  2) We didn’t use to have ice caps on Earth. We could return to that state, to all intents permanently [>further lifetime of human species is long enough.]
  After all, Milankovitch ice-cap cycles didn’t appear until CO2 got low enough, i.e., we are already overriding the usual orbital cycles.

  3) And, if in some faroff future, it’s starting to get cold, stepping up CFC production takes care of lower CO2. I.e., it’s a *lot* easier to keep the planet warm than it is to cool it…

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  Steve Bloom // December 16, 2007 at 10:54 pm

  vixt wries: “But if the ice comes, there’s no way in hell you can get out of the way of a glacier.”

  Actually intentionally spreading black soot on glaciers would be a very effective way of getting rid of them. Given the ease of application, I suspect a glaciation could be fought off to a significant degree using such a method.

  However, just now we have the opposite problem. As Tamino is in the process of detailing in his “Wobbles” posts, glaciations come and go based on orbital changes that happen to be predictable with great precision. Conveniently, it’s possible to validate the likely future relationship between those changes and the glaciations by looking at the traces left by the many past glacial cycles that have taken place over the last two million years. IIRC current thinking is that we are in a very long interglacial, probably on the order of 30-40,000 years; i.e. without any anthropogenic influences it would be at least another 20,000 years until the next glaciation starts. With anthropogenic influences added in, I think it’s fair to say that we have nothing to worry about.

  One other thing you might want to bear in mind is that the geologic record shows that ice sheets form very slowly and melt very quickly. Another is that the climate scientists who study the past tend to be the most worried of all about the near future. This is because the last time GHG levels were anything like they are now we had a much warmer climate with much-reduced ice sheets, sea levels at least 25 meters higher than present, different rainfall patterns, etc., etc.

  If you want to learn more about all of this, you could start with the Wikipedia paleoclimate article and follow the references.

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  Fielding Mellish // December 17, 2007 at 5:00 am

  Vixt wrote:
  “This blog seems to be less about science these days and more about attacking others.”

  Your post certainly provides a self-proving example.

  “We can manage that, if sea levels rise like Gore claims, we move inland, we adapt.”

  To focus on the purely human costs of that, never mind the tragic impact on other species, can you conceive of the widespread bankruptcies that coastal areas would experience? Let alone the incredible task of moving enough infrastructure to support 150 million people, including reconstructing the entire power and transportation grid (into the exact area where you hope food will be grown). Lest this be so America-centric, consider how the rest of the world would fare. By the way, it isn’t ‘Gore’s claim,’ but thanks anyway for the lame perjorative.

  “Been there done that.”

  Never before. Not with 150 million+ residents, plus refugees, in this country alone.

  “Crops grow better in warm climates with extra CO2.”

  This would be a good place for you to toss in some of that science you think there is not enough of here. A frank examination of the state of our current food production coupled with growing conditions under a fully engaged AGW scenario ought to sober you up straight away. Besides other things, such as the fact that sunlight and soil quality restrains the northward move of North American cropping areas, the prospect of the Ogallala aquifer’s running dry about the time AGW snicks into third gear should have an effect rivaling that of the best contraceptives that Not At All Naughty Chemists, Ltd. has to offer. The tenor of your post suggests that you don’t know much about food production, so it might be a good idea to gauge AGW’s impact on the developing countries from where a lot of what you likely now eat originates. As you consider that, remember to exclude seafood from the food supply budget, owing to a collapsed marine food chain. AGW is bad enough on its own, but we also have a nice array of co-morbidity factors to consider.

  “Warm is easier to manage.”

  What about bloody hot? And when did the “either too hot/or too cold” strawman enter the conversation? On the bright side, we do figure that tropical diseases will waltz into latitudes heretofore hostile to them, so you have going for your view.

  “I’m sure you’ll all tell me how stupid and wrongheaded my view is.”

  Your post leaves little to embellish on that point. In fairness, it’s obvious that you did not generate your post from serious research, but rather from the consumption of propaganda designed and purveyed to maintain the purveyors’ profit. In the AGW conversation as in baking, chaff makes for very poor crumpets and a downright evil legacy.

• 

  Fielding Mellish // December 17, 2007 at 5:02 am

  edit: “On the bright side, we do figure that tropical diseases will waltz into latitudes heretofore hostile to them, so you have THAT going for your view.”

• 

  vixt // December 17, 2007 at 5:03 am

  You folks are wonderfully predictable. Are you 100% sure of everything or just in denial of alternate ways of looking at things? There’s not a curious one in the lot.

  Tamino - Thank you but I don’t need a statistical test to see trend lines, from the temp graphs I’ve seen there there’s a slight downturn since 1998. Run tests all you want, but that won’t change that perception.

  [Response: You *really* don't get it! Yes you *do* need statistical tests, unless you want to keep seeing trend lines where there's just noise. That's how we tell the difference; the eye is not good enough.]

  “been there, done that” I was referring to the fact that I once lived on the eastern seaboard. We had a beach erosion (probably due to catastrophic sea level rise y’all keep talking about) that forced me to abandon a beach home.

  Yes, I’ve “been there, done that”. I didn’t “dismiss it with a wave of the hand” I got busy and worked my butt off to save what I could. I’m still alive, so is the town. The beachfront is now back further. The point is that these changes are slow motion compared to human adaptability. Ice will be just as slow motion, but crop failures from an ice age will reach in the Canadian wheat-lands and upper US breadbasket. And that’s not something you can fix with a snowblower. Then there’s the cities like Minneapolis that will be uninhabitable. People will pack up and move just like in the Grapes of Wrath. Comparing that which will happen over years to Katrina which was 2 days notice is just stupid.

  For Mr. Hogaza, thank you but here is a story about CO2 and tree growth patterns. It looks like there IS an effect outside of the greenhouse. It seems reasonably “real world” to me.

  http://www.breitbart.com/article.php?id=paLeaves_Tue_10_CO2_impact&show_article=1

  I like a warmer world, so does agriculture. It seems our existence is owed to it because if we were still in the last Ice Age we’d still be chasing caribou. A warming world helped our transition from hunter-gatherers to agrarians, so bring it on! Sorry but I just can’t get too worried over the claims of impending doom having personally survived a few of nature’s trials myself.

  I just started up a blog. It’s not much. This makes good practice. I’ll send an invite when I’m ready.

  Flail away, lads.

• 

  nanny_govt_sucks // December 17, 2007 at 5:04 am

  But doesn’t noise work both ways? If we had just entered a climate cooling phase, might not the noise in the data possibly give a false impression of warming?

• 

  bill // December 17, 2007 at 5:10 am

  Interesting post. Could you expand more on your choice of 1975? Mauna Loa goes back to 1959, and the annual CO2 increment is positive over that range. I ask because forecasts using an autoregression will depend on your starting point. For example, using the entire hadley annual series forecast a decrease over the next decade (big C.I. though), while the 1975+ series forecasts a nice steady increase. (forecasts using SAS’ Forecast procedure)

  Also, what does your change-point algorithm (SCUMSUM) say? The claim is about a change-point.

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  jonathan // December 17, 2007 at 5:27 am

  Your outrage about the cherry picking and outright exaggeration in a political process should be directed within your own scientific community. I dare you to have the same critical analysis on Mann’s infamous hockey stick. Take away the bristlecone proxies and the convoluted statistic manipulations which make white noise show a hockey stick and what do we have?

  I happen to believe that humanity should drastically lower its carbon footprint (esp coal!) but I am disgusted how scientists have gotten so sloppy once their “consensus” is determined

• 

  bill // December 17, 2007 at 5:34 am

  My change-point algorithm (Hawkins, D.M. (2001) Comp.Stat.Data.anal) insists on putting a change-point right on 1997, and none after. It only fits constants between the change-points, though. I haven’t coded up the regression-tree yet.

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  Marion Delgado // December 17, 2007 at 10:10 am

  I can’t speak for anyone else, but vixt is well below my response line. So no flailing. just killfile.

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  Petro // December 17, 2007 at 2:29 pm

  One aspect of denialism is certainly a failure to understand basic statistics. That is not suprising by itself, since many times much easier natural facts are not grasped there.

  Lack of scientific education can be corrected by curious mind. Lack of curiosity cannot be corrected.

• 

  bill // December 17, 2007 at 4:00 pm

  To your point on 1975, CART in regression mode puts its first break point at 1977 (and its third at 1997. ) Its still fitting means within the intervals.

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  Hank Roberts // December 17, 2007 at 4:41 pm

  vixt:
  >beach
  North Carolina?
  http://www.questia.com/library/book/the-beaches-are-moving-the-drowning-of-americas-shoreline-by-wallace-kaufman-orrin-h-pilkey-jr.jsp

  >’hockey stick’ …what do you have left?
  You might as well imagine you’re undercutting current stem cell research by referring to what we know that Darwin or Wallace or Mendel didn’t, or undercutting microbiology by pointing out that Leewenhoek thought there were six kinds of bacteria.

  You’re right. Without statistics, all you get is what you see. Thrash on.

• 

  george // December 17, 2007 at 5:22 pm

  Isn’t it possible to actually estimate the magnitude of the temperature change induced by “noise” (which includes the effect of El Nino) in 1998?

  Doesn’t a least squares line fit to the decades preceding and including 1998 (or over all of the past 3 decades, for that matter) actually give us a pretty good idea what the temperature increase would look like without the “noise” over that period?

  Isn’t that one of the primary points of doing a linear regression?

  If that is the case, isn’t the difference between the ordinate for 1998 for that (several decade) trend line and the actual 1998 temperature a gauge of the magnitude of the noise (including El Nino) for that year?

  If the “noise” over that entire period has a root-mean-square value of about 0.1 deg.C, as you indicate, that would mean that the actual temperature for 1998 lies more than a couple standard deviations above the trend line at that point in time, would it not?

  Which begs the question about the validity of using 1998 as a comparison for later years, of course.

• 

  luminous beauty // December 17, 2007 at 6:49 pm

  Statistics applied without an understanding of underlying physical constraints is just noise.

  GHGs do warm the planet. Tree ring growth is effected by temperature.

  The slowing down of global temperatures since 1998 (anomalous in it’s own right as being a strong El Niño year) is consistent with known internal variability in the climate system. What is different about this particular fluctuation is that there is no downward trend after the warming trend, but global temperatures have continued to trend upwards, in spite of lowering solar insolation over this period of approx 0.15Wm^-2.

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  Pat Trombly // December 17, 2007 at 11:01 pm

  Signal = data that supports your theory

  Noise = data that doesn’t….

  …..Besides, the point isn’t limited to the fact that there still hasn’t been a year warmer than 1998 - the point is also that you folks predicted that by now there would be years warmer than 1998. As early as December 2006 we heard that 2007 was going to be warmer than 1998. Then as the year has progressed the predictions have come down, to second, third, and as of late November, sixth - though it’s been a cold December so far so 2007 could fall out of the top 10 - - starting to look like BC football’s BCS ranking….

  Yeah, I know - El Nino stopped way earlier than expected.

  But that’s the point - - - if you cannot predict a regional phenomenon a few weeks in advance, how can we place value on your longer-term predictions?

  And predictions are all you have - there is no tangible evidence of causation; every time anyone asks for evidence, you start talking about models - which haven’t predicted squat.

  What if 2008, 2009, 2010 pass and 1998 is still the record - will you guys commit to a date after which, if 1998 is still the ‘warmest year on record’ you’ll admit you were wrong? Or will there be some excuse? Will you claim that solar radiation has dropped temporarily, that mother nature is “giving us a second chance?”

  [Response: I differentiate between signal and noise based on sound statistical analysis. Only. Denialists do the opposite. So I'll ask you the same questions I asked vixt:

  1. Do you believe that noise doesn't exist? Because if it does, then it's impossible NOT to get apparent cooling trends which don't reflect the signal, just the noise.

  2. Do you not accept the validity of statistical significance tests? Because if you do, then there's not only no basis to claim a cooling trend, there's no basis to deny a warming trend.

  When a cooling trend in global average temperature passes statistical significance tests, I'll readily admit that global warming isn't happening. What will it take for YOU to admit you're wrong?]

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  cce // December 18, 2007 at 12:31 am

  I suppose it’s inconsequential that NASA puts 2005 warmer than 1998, and 2007 will probably be warmer also. As long as the other temperature analyses don’t address the poles, they will under count the amount of warming that is really going on, especially compared to 1998 which wasn’t particularly warm at the poles (at least, not compared to recent years).

  Go to the GISTEMP website, click on the “Global Maps” link. Specify 1998-1998 as the base year, and 2005 or 2007 as the time interval (for 2007, you can specify the Dec-Nov mean period). Look at where the strongest anomalies are.

• 

  luminous beauty // December 18, 2007 at 2:25 am

  “…will you guys commit to a date after which, if 1998 is still the ‘warmest year on record’ you’ll admit you were wrong?”

  Yes. 2005.

  If you’ll spot 1998 -0.2C for being an exceptionally strong El Niño year, then 2001. Even according to Hadley.

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  Boris // December 18, 2007 at 3:22 am

  “And predictions are all you have - there is no tangible evidence of causation; every time anyone asks for evidence, you start talking about models - which haven’t predicted squat.”

  There is tangible evidence of causation, evidence from theory–CO2 DOES cause warming. The question of how much has been estimated by models, but also by observational evidence, which suggests a range similar to models, though a range that has a wider uncertainty.

  Also, keep in mind that models generally don’t make predictions. Models simulate the climate and give us a good idea of what happens when CO2 doubles.

  But it a myth and absolutely false that models are the only evidence for what will happen if CO2 continues to rise.

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  nanny_govt_sucks // December 18, 2007 at 4:33 am

  GHGs do warm the planet.

  Well, Water Vapor in the form of a cloud, by reflecting incoming solar radiation, can have a cooling effect on the climate, so your statement is not 100% true.

  Tree ring growth is effected by temperature.

  But is this relationship linear?

• 

  luminous beauty // December 18, 2007 at 5:07 am

  nags,

  The reflective component of a cloud is tiny droplets of liquid water, not water vapor.

• 

  nanny_govt_sucks // December 18, 2007 at 5:26 am

  If you’ll spot 1998 -0.2C for being an exceptionally strong El Niño year,

  Since when have El Ninos been considered to be less than an integral part of the climate?

• 

  nanny_govt_sucks // December 18, 2007 at 5:34 am

  The reflective component of a cloud is tiny droplets of liquid water, not water vapor.

  OK, point taken. But water vapor has other cooling properties. Ex. Transport of heat from the lower atmosphere to the upper atmosphere where some of it is released to space on condensation.

• 

  elspi // December 18, 2007 at 5:57 am

  Wow ngs, you really outdid yourself.

  So an El Nino, which is just a transfer of cold to the ocean depths rather than an actual increase in the average temp of the entire planet, should not be adjusted for when looking for global warming.

  Kind of like where Karl Rove said that it was the democrats who were pushing for a vote on the war resolution before the 2002 elections.

  You ngs have a future in politics (in the worst possible way).

• 

  Hank Roberts // December 18, 2007 at 6:00 am

  > Since when have El Ninos been
  > considered to be less than
  > an integral part of the climate

  Nan’s got that right. An El Nino year is part of the climate for long enough to do trend calculations:

  http://geology.geoscienceworld.org/cgi/content/abstract/28/11/1007

  “significant periodicities of 3.1 and 8.4 yr in the terrigenous series; these are indistinguishable, within the frequency resolution of the spectra, from significant periodicities of 3.5 and 7.6 yr in the diatomaceous series. The 3.1 and 3.5 yr periodicities record El Niño modulation of coastal runoff and marine production; the 8.4 and 7.6 yr periodicities are consistent with modulation by strong to very strong El Niño events. …. terrigenous and diatomaceous records …. reveal inverse or antiphase relationships at 3.5 and 7.6 yr. Our work adds to a body of evidence that suggests that El Niño has been a persistent feature of late Quaternary climate variability.”

  So that’s clear — don’t cherry pick an El Nino year, pick the long span of climate records of which it is an integral part to see what trend exists.

  To look at any trends that’s happened during recent human fossil fuel use, you can’t fixate on an El Nino year — it’s a persistent feature that comes and goes, and you have to take the longterm trend to avoid getting misled by focusing on one El Nino temperature.

  Good point, Nan. Thank you.

• 

  RB // December 18, 2007 at 7:18 am

  I would just like to thank you for this and the garbage-never-dies threads. I was able to download GISTEMP data and run the same analysis.

  Trust but verify.

  It shames me that Dr. Gray’s name is on that denialist letter. I am embarrassed for my alma mata.

• 

  fred // December 18, 2007 at 7:57 am

  Still working on the troposphere and the stratosphere, but in the meantime, Pielke offers as the key signature of AGW, ocean heating. The link is here:

  http://climatesci.colorado.edu/2007/04/04/a-litmus-test-for-global-warming-a-much-overdue-requirement/

  And the suggested parameters are half way down the page.

  No idea what this indicator shows at the moment, and I’m aware of the measurement deficiencies in Willis’ cited paper.

  However, do you agree this is what Pielke calls a litmus test?

  This is not, please, about what the test shows now, or about whether Pielke is an estimable fellow. Just about whether the cited measure really is fit for purpose as a litmus test of the occurence of AGW. Or GW at least.

• 

  firebird // December 18, 2007 at 8:36 am

  nags,

  The reflective component of a cloud is tiny droplets of liquid water, not water vapor.

• 

  firebird // December 18, 2007 at 8:36 am

  Well, Water Vapor in the form of a cloud, by reflecting incoming solar radiation, can have a cooling effect on the climate, so your statement is not 100% true.

• 

  dhogaza // December 18, 2007 at 9:14 am

  Nags, nags, nags …

  If you’ll spot 1998 -0.2C for being an exceptionally strong El Niño year,

  Since when have El Ninos been considered to be less than an integral part of the climate?

  As was pointed out in the post, 2005 is the warmest year on record if you don’t discount for El Niño. 2001 if you do.

  The point was that the post being responded to claims that 1998 is the warmest year on record, which is incorrect, if you look at global temps (my guess is that the poster making the claim is one of those who thinks the lower 48 is the world, something my european friends complain constantly about when talking about the American view of life).

  But it a myth and absolutely false that models are the only evidence for what will happen if CO2 continues to rise.

  Absolutely false, yes. Myth, no. The truth is less flattering.

• 

  Chris O'Neill // December 18, 2007 at 1:48 pm

  will you guys commit to a date after which, if 1998 is still the ‘warmest year on record’ you’ll admit you were wrong?

  Ignoring polar areas (yes I know it’s an ignorant thing to do) we could use the HadCRU figures which, I think, give 1998 as being about 0.25 deg C higher than the trend level for that year. The warming rate is under 0.2 deg C/decade (lower if you leave out the polar areas) so we should expect it to take something more than 12.5 years after 1998 for the HadCRU trend to reach the temperature of 1998. i.e. it’s probably unlikely for HadCRU to be cooler than 1998 in 2011 and beyond.

• 

  Hank Roberts // December 18, 2007 at 3:59 pm

  Fred, here’s some reading on Pielke’s “litmus” test — if he were talking about ocean pH, he’d be closer to the mark. The buoy system (Argo) is producing data now and should inform this sort of discussion within the next few years.

  http://www.google.com/search?q=%2Bstoat+%2B%22litmus+test%22+%2Bocean+%2Btemperature+%2Bprometheus

• 

  Hank Roberts // December 18, 2007 at 4:19 pm

  Fred, the first link in the search above (if Google hasn’t changed, hah) is to John Fleck’s page, for discussion of the Pielke “litmus” paper. For convenience, this link gets you the paper discussed there, among many others on the subject:
  http://www.gfdl.gov/reference/bibliography/authors/stouffer.html

• 

  Rob // December 19, 2007 at 12:15 pm

  A bit of topic…(but not noice)

  Why aren’t we talking about the real cause of the problem of our times; overpopulation? Why care about warming or cooling when in the end it’s a resource problem; land, food, etc.?

  If we blend some sci-fi into the mix one could argue that mother nature is trying to kill us off (warming, earthquakes, flooding, diseases etc.) to survive her self?

  /Br. Rob

• 

  HJ // December 19, 2007 at 1:47 pm

  Your trend graph stretching to 2035 is about 300% off the scale since you have not included the most recent findings re. climate sensitivity:
  http://www.agu.org/pubs/crossref/2007/2007JD008740.shtml

  Also when extrapolating trends, why not also use HadAT2, MSU or UAH for the lower troposphere, all of which show considerably less warming than GISS and HadCRU? Surely surface warming alone from potentially UHI-biased data will not yield an accurate trend estimation?

• 

  Hank Roberts // December 19, 2007 at 4:32 pm

  >Chylek

  Hmmm.
  http://tamino.wordpress.com/2007/08/29/polar-ice/#comment-4603
  and
  http://julesandjames.blogspot.com/2007/11/kooks-corner.html

  I’ll wait til someone who can read the full paper, not just the publicly available abstract, can comment.

• 

  dhogaza // December 19, 2007 at 7:52 pm

  Why aren’t we talking about the real cause of the problem of our times; overpopulation? Why care about warming or cooling when in the end it’s a resource problem; land, food, etc.?

  Even if we cut the world’s population by 50%, if the developing world were to adopt a first-world lifestyle complete with profligate burning of fossil fuels, we would still have a problem.

  Population is an issue and at some point humanity has to reach zero growth or perish (unless science fiction dreams of planetary-scale emigration comes true), but it’s certainly not the only issue, and we can slow global warming without addressing population growth.

• 

  Ian Rae // December 19, 2007 at 8:56 pm

  I’m a skeptic, but I ignore any statement that includes the phrase “since 1998″. It was a strange year. Besides, ten years is not a climate trend; both sides, in their zeal, keep forgetting that.

• 

  Michael Smith // December 19, 2007 at 8:59 pm

  The author of this post said:

  “But we know, without any doubt whatsoever, that the signal is still increasing, at a rate of exactly 0.018 deg.C/yr. It’s the noise that shows cooling — and for such a short time span, the cooling in the noise overwhelms the warming in the signal.”

  This is the logical fallacy of “begging the question”. It consists of assuming the truth of what you wish to prove and then using that assumption as a premise in that proof.

  The fact that you can create a data series that combines a signal with noise and evenually find a set of data points that contradicts the trend only proves that such a contradiction MAY be the sole result of the noise. It is a useful exercise to demonstrate a POSSIBILITY — but it is not a proof that this is what has happened since 1998.

  You may BELIEVE “without any doubt whatsoever” that the signal is increasing, but you have not proven such to be the case. The fact of the matter is that you do not know whether the signal continued or stopped in 1998. The data — particularly the tropospheric temperature data — are inconclusive at this point in time. (And this would apply to any claims of cooling since 1998 as well — such a claim is simply not supported by the data.)

  AGW theory says that tropospheric warming should exceed surface warming — and the data does not indicate that this is happening.

  [Response: Isn't it obvious -- even to you -- that what you quote refers to the artificial data? Since the artificial data are signal+noise, and the signal is *defined* as a steady increase at exactly 0.018 deg.C/yr, we do indeed know without doubt that the signal is still increasing.

  The point of this post is to show that given a signal plus noise, with the signal steadily increasing, it's not only *possible* to have intervals which seem to contradict the trend, it's impossible NOT to. The only way to have no episodes of inconclusive trends, some even having an *apparent* countertrend, is to have zero noise. But we know, without any doubt whatsoever, that there is noise.

  As for the *apparent* contradiction between tropospheric and surface data, read this.]

• 

  nanny_govt_sucks // December 19, 2007 at 9:08 pm

  Why care about warming or cooling when in the end it’s a resource problem; land, food, etc.?

  Well, cooling leads to crop failures and large areas of land covered by ice, so these exacerbate resource problems. Warming leads to more livable land area, and warmth+CO2 leads to increased food production which should ease population pressures. But even as the Earth is now it can handle a much larger population, the problem is distributing the food and that comes down to politics and international trade policies.

• 

  Hank Roberts // December 20, 2007 at 2:18 am

  Nan, each time I ask you for your sources you go to CO2science or something. Please, try Google Scholar for each of those statements, just copy and paste into the search box everything between commas, limit to recent, and read. It’s a boatload.

• 

  Dano // December 20, 2007 at 4:15 am

  Oh, look: na_gs is back with his increased food production BS. The interval between his latest assertion and the refutation and his return with the same old refuted line is 49 days.

  The last time was 56 days, the time before that was 46 days., before that 55 days.

  There’s been no warming since 1998!

  Best,

  D

• 

  nanny_govt_sucks // December 20, 2007 at 4:18 am

  Hank, when have I ever referenced CO2science?

  What kind of a reference do you need to show that crops don’t grow on ice, that warmth melts ice, or that warmth and CO2 are good for plants? I thought these ideas were pretty well known.

• 

  JesusChristHimself // December 20, 2007 at 6:26 am

  I don’t know if you have ever farmed, but the difference between a crop and a bunch of crispy stalks can be just a little warmth and dryness above normal. What a farmer needs is lots of normal. He’s used to that, and he knows what to do with it.

• 

  nanny_govt_sucks // December 20, 2007 at 7:18 am

  I don’t know if you have ever farmed, but the difference between a crop and a bunch of crispy stalks can be just a little warmth and dryness above normal.

  Well it’s a good thing then that we have higher CO2 concentrations nowadays to help crops deal with dryer conditions. But I thought that predictions wer for a warmer, wetter global climate overall? It would seem that would favor farming. Not to mention more arable land and higher CO2!

• 

  ErikS // December 20, 2007 at 8:01 am

  Hank Roberts, I´ve read the Chylek et al. paper. To me it seems that there is a fundamental flaw in the way they treat the ocean uptake of heat. They state that it should be propotional to the temperature increase (deltaT) during the last ten years, which is kinda odd. They refer to a Raper et al. paper where deltaT is the difference to the unpertubed state.

• 

  Gary // December 20, 2007 at 10:30 am

  The reason that so many “denialists” use 1998 as a starting point is because it was used by so many as proof that things were getting bad very quickly. The temperature of 1998 was not described as an outlier in 1999 but was used as proof that GW was speeding up and at the time a 25 year trend from an artificially chosen low point was fine for those claiming that the rate of global warming was was increasing. We were told that we had hit or passed a tipping point.

  Now there is a 10 year trend showing that these claims were premature. GW is happening at rates similar to what it was prior to significant human CO2 production and at constant rates not at accelerating rates.

  All of this talk is rather ridiculous because discussing any climate trend without looking at the trends within the last 10,000 or even 100,000 years silly. We are still within the normal bounds of an interglacial warming period.

  [Response: Warming per se is not a problem, even if the planet heats up 3 deg.C or more this century. But that much warming in ONLY ONE CENTURY is a HUGE problem. There's abolutely nothing even close to it in the last several million years at least.]

  But the point is that when GW alamists used 1998 to “prove” that things are getting bad very quickly, at an accelarating rate then they have to be willing to let the “deniers” throw it back at them when their predictions of rapidly increasing temperatures in the next few years don’t come true.

  [Response: Name names: who used 1998 to "prove that things are getting bad very quickly"? Either back up this claim with citations, or don't expect to be believed.]

  The trend since 1998 shows temperatures going up at about the same rate as they were since we have been recording temperatures and those trends fit within longer term patterns and trends over 1000’s, 10,000’s and 100,000’s of years.

  [Response: Not so.]

• 

  dhogaza // December 20, 2007 at 10:34 am

  What kind of a reference do you need to show that crops don’t grow on ice, that warmth melts ice, or that warmth and CO2 are good for plants? I thought these ideas were pretty well known.

  The great breadbaskets of the world, such as the north american plains and the eastern european steppes, aren’t covered in ice.

  Wheat doesn’t grow in the sea, either, melting the artic icecap isn’t going to cause farmers to move to the north pole.

  Wheat doesn’t grow well in poor soil, either. Warming isn’t going to lead to flourishing crops in what is now boreal forest, either.

  But, as was pointed out above, your assertion has been refuted many times, and you come back over and over with the same crap at an interval of about one and a half months, on average.

  Typical science denialist tactic. You’re shown that available science doesn’t back up your assertion, you disappear awhile, then you pop up again. Climate science denialists use this technique. Creationsists use this technique. HIV denialists do. On and on.

• 

  fred // December 20, 2007 at 3:25 pm

  Well, its delightful to find someone else (Michael Smith) who shares my confusion about the troposphere. Maybe he would help out in the struggle by telling us if he has references for the idea that AGW predicts a warming troposphere? Help wanted on this one.

  But now there seem to be two additional candidates for litmus tests. The first is the heat absorption of the oceans. Not whether its happening or not, but were it to happen. It seems to be a candidate. Don’t think the papers referenced tend to show that it is not a test. They reflect more on whether its happening, which for now is a different issue.

  Its hard to see that CO2 absorption would be a litmus test for global warming. Why would that be? Any references?

  The second new one can be found on Pielke’s site. That is, water vapour in the atmosphere should be rising if the feedback loop CO2 - water vapour - warming were to be happening. Not commenting on whether water vapour is rising or falling, but this is right, yes? If we were to find water vapour falling with rising CO2, this would blow a hole in AGW? By contrast, measured rising levels of water vapour correlating with CO2 rises would support AGW?

  [Response: The oceans do appear to be warming appreciably, and the temperature rise has been used to estimate the net planetary energy imbalance (Hansen et al. 2005, "Earth’s Energy Imbalance: Confirmation and Implications", Science, 308, 1431). Atmospheric water vapor also appears to be rising, so as to maintain reasonably stable *relative* humidity (i.e., it's rising in step with temperature, according to the Clausius-Clapeyron equation). For a much better perspective on predictions and observations of tropospheric warming, and the uncertainties associated with them, see this.

  I'd say it's important to appreciate that despite reliability of the conclusion that greenhouse-gas increases are primarily responsible for modern warming, there's still a lot we don't know about climate. So, it's actually quite difficult to point to a single phenomenon and say it's a sure-fire litmus test for AGW. However, it's a common denialist tactic to *claim* certain phenomena as a litmus test, so that if they don't come to pass they can then claim that AGW has been disproved. Don't believe every claim that "if such-and-such doesn't happen, then AGW is disproved."]

• 

  Dean P // December 20, 2007 at 3:37 pm

  To “name names” on who used 1998 as the crux of the AGW argument, look no further than the IPCC and their report: “Climate Change 2001 Synthesis Report, Summary for Policymakers”, Q2.7

  “Globally it is very likely that the 1990s was the warmest decade, and 1998 the
  warmest year, in the instrumental record (1861–2000) (see Box SPM-1). The increase
  in surface temperature over the 20th century for the Northern Hemisphere is likely to have been
  greater than that for any other century in the last thousand years (see Table SPM-1). Insufficient
  data are available prior to the year 1860 in the Southern Hemisphere to compare the recent warming with changes over the last 1,000 years. Temperature changes have not been uniform globally but have varied over regions and different parts of the lower atmosphere.”

  We now know that the 1990s were NOT the warmest decade, that was the 1930s. We also know that 1998 was not the warmest year, that was 1934. But the 2001 IPCC report made the case that things were getting worse and would only stop when the world cut CO2 emissions.

  [Response: You're being ridiculous; just because the IPCC 2001 report states that 1998 was the warmest year in the instrumental record, it doesn't follow that it's the "crux of the AGW argument." The claim that AGW advocates have trumpeted 1998 was, and is, just plain false.

  And for your information, the 1990s *are* the warmest decade in the instrumental record (as of 2001), and 1998 *was* the warmest year (as of 2001). You're just repeating denialist propaganda when you say it was 1934; that applies only to the lower 48 states of the U.S. (less than 1.5% of the globe), not the planet as a whole (see this post), but denialist propaganda repeatedly omits to mention that. As of now, the hottest year in the instrumental record is 1998 (according to HadCRU) or 2005 (according to GISS).

  Why is it that people who haven't even looked at the evidence enough to know that the "1934 is hottest" claim applies only to the lower-48 U.S. states, nonetheless feel qualified to discredit modern climate science? You need an IMMENSE amount of education before you'll even be qualified to comment on the issue without making yourself look like an idiot.]

• 

  Dean P // December 20, 2007 at 4:23 pm

  I may have misspoke about the warmest decade. I can’t remember whether the temperature adjustment made over the summer dropped the 90s below the 30s for the world or just for the US. Likewise 1998 being the warmest. Regardless, IPCC 2001 clearly uses the 90s and 1998 as the basis for their argument that something has to be done now…

  [Response: Repeating garbage doesn't make it true.]

• 

  dhogaza // December 20, 2007 at 4:40 pm

  I can’t remember whether the temperature adjustment made over the summer dropped the 90s below the 30s for the world or just for the US.

  Perhaps you don’t remember which it is, because both are false.

  Likewise 1998 being the warmest.

  It’s the old “I don’t know what I’m talking about, but I’m right anyway” argument.

  In other news, Fred makes another valiant try:

  The second new one can be found on Pielke’s site. That is, water vapour in the atmosphere should be rising if the feedback loop CO2 - water vapour - warming were to be happening. Not commenting on whether water vapour is rising or falling, but this is right, yes? If we were to find water vapour falling with rising CO2, this would blow a hole in AGW? By contrast, measured rising levels of water vapour correlating with CO2 rises would support AGW?

  Warmer temps mean more water vapor in the atmosphere. This helps explain why morning fogs “burn off”, and why afternoon thunderstorms are frequent in Arizona in the monsoon season (well, the latter is due to the inverse of warming).

  This has nothing to do with “correlation with CO2 concentrations”.

  I imagine Pielke’s trying to argue that this is a way to show that global warming isn’t happening, AGW or otherwise.

• 

  Dean P // December 20, 2007 at 4:59 pm

  You have to love “ad hominem” attacks.

  To go back to the point. IF the 1990s weren’t the warmest on record, then the IPCC summary from 2001 would be moot. IF there was no warming trend in the 90s, the AWG argument would die. That’s plain and simple. TO say that the IPCC doesn’t use the 90s and 1998 to show that something has to be done is simply blinding oneself to the entire purpose of the 2001 report. It’s a report to POLICYMAKERS so that POILICYMAKERS are informed enough to make POLICY.

  If the trends seen over the last 10 years were actually the trends seen over the last 20, would that then refute AWG? If not, at what point would that trend refute AWG? At some point, a lack of warming would actually indicate a lack of warming and not just noise obscuring the trend.

• 

  Chris O'Neill // December 20, 2007 at 5:34 pm

  “You have to love “ad hominem” attacks.”

  Pointing out the mistakes in an argument is not an ad hominem attack. Saying an argument is wrong because the arguer is an idiot is an ad hominem attack. Please try to understand the difference.

• 

  elspi // December 20, 2007 at 5:38 pm

  Dean P
  Not only don’t you know anything about global warming, but you don’t even know what “ad hominem” means.

  That at least I can teach you.

  1. “You are an idiot therefore you are wrong when you say that 2+2=4” is an ad hominem.

  2.“You just claimed that 2+2 =17 therefore you are an idiot” is a logical deduction.

  You see the difference right?

  In the first the argument is dismissed because of the source

  In the second the source is dismissed because of the argument.

• 

  Dean P // December 20, 2007 at 5:48 pm

  Ok, independent of my being a total idiot, no one has given me a clear reason why the IPCC 2001 report did not use the records from the 1990s and 1998 to indicate that something needed to be done now. It did.

  As for my being an idiot, it really is immaterial. The question was posed to supply a reference to someone that used 1998 as an indication that something had to be done. I did. The IPCC 2001 report.

  Assume that i am an idiot. Now, if i say that 2+2=4, does that then imply it doesn’t? No, it means that even an idiot can be right upon occasion.

  The problem is that there was no need in the first place to call names. Calling people names NEVER advances one’s argument.

  [Response: Of course IPCC 2001 mentions that the hottest year so far was 1998. What's false is Gary's implication that it "was used by so many as proof that things were getting bad very quickly." All you've been able to show is that it was mentioned, and you have furthered his implication by arguing that it is somehow a crucial talking point, which is foolish.]

• 

  Barton Paul Levenson // December 20, 2007 at 6:54 pm

  nanny posts:

  [[Water Vapor in the form of a cloud, by reflecting incoming solar radiation, can have a cooling effect on the climate, so your statement is not 100% true.]]

  nanny, water vapor can’t be in the form of a cloud. Clouds are collections of drops of liquid or solid water (or some other volatile material).

  The relationship between water vapor in the air and clouds is unknown. Lindzen proposed that greater cloud formation with higher temperatures would provide an “iris” to control global warming, but satellite observations shot that down. Apparently the relationship is not that strong in either direction. So clouds ain’t gonna save us.

• 

  Barton Paul Levenson // December 20, 2007 at 7:02 pm

  nanny writes:

  [[Warming leads to more livable land area, and warmth+CO2 leads to increased food production which should ease population pressures.]]

  CO2 can only lead to increased food production in an environment where CO2 is the limiting factor. Do you know of such a place? You might want to google “Liebig’s Law of the Minimum.”

  Also, as the world warms, agricultural growing belts shift toward the poles — which means they get smaller. Area decreases with latitude on a (1 - sin theta) curve, where theta is the latitude.

• 

  nanny_govt_sucks // December 20, 2007 at 7:38 pm

  CO2 can only lead to increased food production in an environment where CO2 is the limiting factor.

  Sounds good to me. The fewer limiting factors, the better, no?

  Also, CO2 increases a plant’s ability to deal with drought by causing stomate to close up, allowing the plant to retain precious moisture. Another plus.

  Also, as the world warms, agricultural growing belts shift toward the poles — which means they get smaller.

  The shapes of the continents also play a role. North America and Asia get wider as you go North and will have vast areas of land that will open up for farming as the climate warms.

• 

  dhogaza // December 20, 2007 at 8:08 pm

  Also, as the world warms, agricultural growing belts shift toward the poles — which means they get smaller. Area decreases with latitude on a (1 - sin theta) curve, where theta is the latitude.

  Oh, come on! Mercator disproved that myth centuries ago!!!!

  CO2 can only lead to increased food production in an environment where CO2 is the limiting factor.

  Sounds good to me. The fewer limiting factors, the better, no?

  If you’re joking, there’s hope for you. If not … I really don’t know what to say. You do realize that if growth is limited by nitrogen (”fertilizer”), more CO2 isn’t going to increase growth, right?

  North America and Asia get wider as you go North and will have vast areas of land that will open up for farming as the climate warms.

  Re-read what I wrote above about poor soils and today’s boreal forests.

• 

  fred // December 20, 2007 at 8:11 pm

  dhogaza, if I am making valiant efforts, it is to understand what exactly counts as evidence for and against the AGW proposition. Not whether there is such evidence. No, just what would count as evidence, should we find it. I will worry about finding it later.

  Pielke, well, you have to read the site, and its worthwhile, but no, he is not trying to argue that global warming is not happening. Pielke can speak for himself, but I think a quick and dirty summary might be, there are lots of ways in which humans affect climate and CO2 emissions are among them, but not the most important. He gives greater importance to land use changes and to particulates. I do not know what he thinks of how much warming there is, it doesn’t seem to be a particular focus of his. He is quite interested, like me, in litmus tests, feedback mechanisms, evidence for them. Pielke is worth reading even if you don’t agree at the end of reading him. Perhaps especially then.

  With some irritation, let me also point out that trying to find out what would confirm or falsify a theory is not being a ‘denialist’ in relation to it. It is being interested in its truth or falsity. The idea that we should stop trying to find what are the observations which would confirm or deny this particular theory, or any scientific theory, is anti-scientific and anti-rational. I am not going to be stopped from doing this by being called silly names, and doubt Pielke is either.

• 

  Michael Smith // December 20, 2007 at 8:27 pm

  You responded to my post yesterday with this:

  “The point of this post is to show that given a signal plus noise, with the signal steadily increasing, it’s not only *possible* to have intervals which seem to contradict the trend, it’s impossible NOT to. The only way to have no episodes of inconclusive trends, some even having an *apparent* countertrend, is to have zero noise. But we know, without any doubt whatsoever, that there is noise.”

  I believe the point of the post was to demonstrate why the claim of “no net global warming since 1998″ is “garbage”.

  [Response: No, that was the point of this post.]

  You have demonstrated that the data since 1998 MAY be the result of noise. You have raised that as a possibility. However, this does not prove that global warming has continued and it does not refute the claim in the letter of “no net global warming since 1998″.

  At this point, the claim, “it is just noise, and the warming has not stopped” and the claim, “no net global warming since 1998″ are BOTH possibilities. The temperature data does not allow us to rule either one in or out.

  [Response: In fact it does allow us to rule out the possibility that warming stopped in 1998; as the above-linked post shows, the data since 1998 do *not* show an ambiguous result which may be due to noise. It actually shows a significant warming trend.

  GISS data shows a statistically significant warming, even if you start from 1998, and even allowing for the red-noise character of the data. HadCRU shows a trend which appears to be significant, and again it's warming, but when one compensates for the red-noise character of the data the result is actually inconclusive (but still consistent with the long-term warming rate of 0.018 deg.C/yr). However, starting from 1999 rather than 1998 returns a statistically significant warming even for HadCRU data, even accounting for red noise. The data actually do contradict the "no warming since 1998" claim.

  So not only is there no evidence to support the "no global warming since 1998" claim, it really can be refuted. Nobody who is both trained in statistics, and honest, can support such a claim.]

  You also wrote:

  “As for the *apparent* contradiction between tropospheric and surface data, read this.”

  I have indeed read that article and noted the revised +/-2sigma bars around the model results. The new bars show that model outputs even include outputs showing as little as .01 -.02 degC/dec warming up to 200mb and actual COOLING above that.

  Thus, we have arrived at a situation in which the models are offered as proof of upcoming catastrophic AGW — while at the same time they are defended as being not inconsistent with little tropospheric heating or even cooling.

  With that range of possibilities coming from the models, I see no way to claim that “the science is settled”.

  [Response: The models are not offered as proof of upcoming catastrophic AGW, they are used to obtain the best possible numerical estimates of climate sensitivity and regional response. Basic physical arguments are sufficient to show that sensitivity is high enough that we can expect severe harm from continued warming unless greenhouse-gas emissions are reduced.]

• 

  nanny_govt_sucks // December 20, 2007 at 8:31 pm

  Also, as the world warms, agricultural growing belts shift toward the poles — which means they get smaller.

  Actually, growing experiences a poleward expansion which is different from a shift towards the poles. People are still farming at the equator, you know.

• 

  Michael Smith // December 20, 2007 at 8:37 pm

  Fred asked:

  “Well, its delightful to find someone else (Michael Smith) who shares my confusion about the troposphere. Maybe he would help out in the struggle by telling us if he has references for the idea that AGW predicts a warming troposphere? Help wanted on this one.”

  See the link that I was referred to here: http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends/#more-509

  Note that , according to that article, increased tropospheric heating, greater than surface heating, is considered intrinsic to any global warming, regardless of the source of the forcing.

• 

  elspi // December 20, 2007 at 9:16 pm

  “The shapes of the continents also play a role. North America and Asia get wider as you go North and will have vast areas of land that will open up for farming as the climate warms.”

  Nanny
  It turns out that the world is not flat, ie
  that flat map you are looking at is not actually the way the world is. The area that is improving in terms of agriculture is smaller than the area where it is getting worse. In the southern hemisphere this is catastrophic, while in the northern hemisphere it is merely disastrous. Add to this the fact that the areas improving are so far from the equator that the amount of sunlight becomes the real issue (Hint: not changing).

• 

  P. Lewis // December 20, 2007 at 9:47 pm

  nanny_govt_sucks says

  Sounds good to me. The fewer limiting factors, the better, no?

  Also, CO2 increases a plant’s ability to deal with drought by causing stomate to close up, allowing the plant to retain precious moisture. Another plus.

  …

  The shapes of the continents also play a role. North America and Asia get wider as you go North and will have vast areas of land that will open up for farming as the climate warms.

  Ah! Yes, just move the agricultural production!

  Agriculture occurs where it has over the last few hundred to a few thousand years because the climate and soils were/are suitable for growing the crops that were/are grown.

  I can’t imagine the permafrost wastes of Canada and Siberia being much good for agriculture when they’re no longer frozen (or no longer frozen all year).

  Also, the further north you go, the shorter the growing season is. And the greater the altitude, the shorter the growing season is. If there are suitable soils further north, then are they at acceptable latitudes and altitudes before spring/autumn frosts and light levels become a problem for achieving suitable yields?

  So, do you know whether the soils (other than the no-longer permafrost soils) further north are suitable? If perchance the US grain belt can theoretically and practicably move north (into Canada presumably), are you (I’m presuming a US citizen) prepared to become a net grain importer?

  IIRC, Australia might be in a bit of a pickle with regard to wheat (or was it corn?) and rice if continued global warming occurs for this very reason (though there it is presumably a progression further south that is an issue), i.e. that the soils and water are not available elsewhere (or not in sufficient quantities) on the continent to sustain the current levels of agricultural output.

  Are you prepared to foot the bill for modifying the soils as necessary by, say, increased irrigation, reducing possible aluminium toxicity, modifying cation-exchange capacity and modifying other deficiencies and fixation efficiencies? Are you prepared for the necessary land use changes required (perhaps conversion of pristine forests and wooded habitats to agriculture; or resettlement of coastal populations inland on possibly good agricultural land; …)?

  Since I know next to nothing about this particular subject (but perhaps someone can enlighten us all), the questions posed (without little thought, off the top of my head) may already have perfectly acceptable answers and there is consequently no reason to worry. But, I have the notion that thinking you can just shift agriculture to follow the climate is a pipedream, at least in the short term. Minor changes to chemistry and processing variables in my materials research days (let alone major changes to the same) took many months to years to work through into saleable products. I daresay the same/similar is true of any scientific endeavour and practical agricultural endeavours.

  I have the notion that anyone thinking agriculture/food production can just simply shift with the climate (which it must, of course, eventually do) has not engaged the requisite number of little grey cells.

  Food production can generally get through the odd year’s decimated or poor harvest without too much dislocation to normal life (at least in the first world), but real hardships occur when that may carry over into subsequent years. Are you prepared for that possible dislocation to the food supply?

  Do you expect to wait until global warming stabilises and then move your agriculture, or do you propose to move it every 5 years or so? Will the farmers just swap the no-longer-suitable agricultural land on their southern borders for suitable agricultural land on their northern borders? How would this be achieved (and what happens when you cross a national border)? Will governments have to nationalise the land and food production to ensure that food can be produced when and where it needs to be produced? (Jeez, I hope not. It didn’t work for the Soviets.)

  Just move the agriculture? In your dreams! Prepare for the nightmare more like.

  Past civilisations have fallen on past climate changes’ effects on agriculture. Just because we’re technologically and scientifically better off than past civilisations doesn’t make us immune to those effects. Thinking that we will be is just pure arrogant nonsense.

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  Hank Roberts // December 20, 2007 at 10:37 pm

  > The fewer limiting factors,
  > the better, no?

  Free market botany? Hmmmm…

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  erikv // December 21, 2007 at 2:17 am

  >1. Do you believe that noise doesn’t exist? Because if it does, then it’s impossible NOT to get apparent cooling trends which don’t reflect the signal, just the noise.

  What do you mean by noise? Those blips on the temp graph are weather, right? They represent the sweater I need to wear today or the A/C I had to run in July.

  To an engineer, “noise” is random fluctuations in a electrical signal, caused by the statistics of thermal processes. (That why you cool your sensor to reduce “noise”)

  Are you saying that the earth really has warmed, we just can’t see it because of measurement noise? Or are you saying that is has not warmed, but only because of short timescale processes which we have reason to believe will be reversed soon.

  Maybe if you define how you are using the word “noise” I can understand better.

  [Response: Noise is the part of the data that is random. It can be measurement error (so it's only an artifact of imperfect measurement) or it can be a physical process that is truly random (like the decay of a radioactive atomic nucleus, or the thermal fluctuations of an electrical signal). The terme "noise" is also used to refer to deterministic physical processes that are unpredictable either due to insufficient understanding of the system, or the chaotic nature of the dynamics. The essence of noise is that it can't be predicted and follows no pattern.

  Global average temperature exhibits noise, because there are fluctuations which are unpredictable and show no pattern. Perhaps someday we'll have such an advanced understanding of weather and climate that we'll be able to predict, or show the pattern of, part of the fluctuations that are now called noise -- just as someday we may have a sufficiently advanced understanding (and computing power) to predict, or show the pattern of, part of the fluctuations due to thermal processes in electrical signals.]

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  Chris O'Neill // December 21, 2007 at 3:58 am

  ngsucks:

  North America and Asia get wider as you go North and will have vast areas of land that will open up for farming as the climate warms.

  Try living on the south coast of Australia.

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  Heretic // December 21, 2007 at 7:35 am

  NGS is at it again relaying CO2Science “message.”
  Maybe you should look at a globe instead of a Mercator projection. Soil composition will not necessarily follow your wishes. It’s not because the polar circle regions will become warmer that they won’t get 6 months of night, NGS. Talk about limiting factors. I guess we could try mushrooms as alternate crops, they grow in the dark, don’t they? Could that be genetic memory from the time there was no light?

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  Andrew Dodds // December 21, 2007 at 8:34 am

  NGS -

  People may farm at the equator, but they don’t in the sahara.

  In any case, current farming is adapted to the current climate - and this is non trivial, since soil types vary strongly with latitude - most of our best farmland happens to be in the temperate zones where the outwash from the last glaciation was. This produced vast amounts of excellent and fertile soil; as you go north you go into the zones that were scraped clean of soil by the glaciation.

  At best this means that whole new varieties of crops will be required; at worst we’ll be finding that we can’t grow anything useful.

  But still, at least you seem to think that this will be happening now..

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  henry // December 21, 2007 at 8:39 am

  [As of now, the hottest year in the instrumental record is 1998 (according to HadCRU) or 2005 (according to GISS).]

  Have you done, or could you do a post on the reasons the two measurment systems are so far off?

  [Response: The only thing I know about the difference is that GISS attempts to estimate the temperature over the arctic region (by interpolation) while HadCRU doesn't. That's probably the reason GISS shows more warming over the last decade than HadCRU; the arctic region seems to be the fastest-warming part of the planet. That's the main reason I prefer to use GISS data, considering it more repr