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Argus at 18:04 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Some thoughts around the following argument: "The truth is unfortunately not that simple – plants don’t just need food, they need water too – something that will be in much shorter supply with the increased frequencies and lengths of drought that climate change will bring." If the temperatures of the oceans are rising, more water vapour will be transferred to the atmosphere (per day, or whatever). That is physics. The same goes for lakes, if land temperatures rise. Evaporated water has to come down again, hence more rain than today. Wet and warm ground evaporates even more water back to the air, and so on. Were is the proof that a warmer ocean will produce less rain, and more drought?Response: What has been observed over the last century is an intensification of the hydrological cycle. Wet areas are getting wetter and drier areas are getting drier. This is because with warmer temperatures, you get evaporation which leads to heavier rainfall but also drying out of drier soils. Doing a post about this has been on my to-do list for a while but I'll move it up the priority list, seeing how popular the 'CO2 is plant food' argument is becoming. -
tobyjoyce at 17:57 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
@Marty said "What seems to be lacking is a serious high level public debate on the arguments for and against man-made climate change so that non-experts such as myself can make informed judgements. " Unfortunately, scientific differences cannot be decided by public debate and a vote. Nature is not a democracy! Politicians have little choice but to follow the scientific consensus, and I hope that you can see what that is. Unfortunately, there are powerful vested interests (political and economic) who do not want the full implications of the scientific consensus to be carried through. The public have a right to reject the implications of the scientific consensus, but that leads us to a place where people are preferrring short-term comfort over long-term safety. A comprehensive picture of how doubt in the scientific consensus is a manufactured phenomenon can be found in Oreskes and Conway's book "Merchants of Doubt" -
David Horton at 17:37 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
The continuation of the "CO2 is plant food" line, first invented, if I remember correctly, by one of the oil companies, sums up the approach of people like Carter. He must know, surely, at some level of consciousness that this is meaningless. Has he never spoken to a botanist in his university about this? Has he read nothing about it? Every sentient being in the universe must be aware that CO2 is not limiting on plant growth in the real world, where limits are set by water, sunshine, temperature, soil nutrients, soil trace elements, competitors, pests and diseases, and so on. Except in the laboratory conditions of a greenhouse, where all these other factors are supplied in abundance, increasing CO2 can have little if any effect. Even in the greenhouse the effects are minimal and may have unforeseen consequences like increasing toxins. One point of "CO2 is plant food" is presumably to make people think that this is going to lead to a brave new world of giant pumpkins and waving fields of grain, but that is clearly not going to happen, even if other factors are kept constant. And Carter, being Australian, must know that the other factor are not constant as we see increasing crop failures due to record high temperatures and record low rains. And the other point, I guess, is that they are trying to subliminally suggest that it doesn't matter how much CO2 we pump out, it will all get taken up by increased plant growth. But we know, and they know, that this isn't happening because CO2 levels keep rising. Furthermore we know, and they know, that it didn't happen in the past because, wait for it, climate changed in the past. Finally, what on earth would make you think that plants adapted to the CO2 levels of up to a couple of hundred years ago, would have the potential to react to the burning of millions of years worth of previously locked up carbon in a matter of 200 years? So Mr Carter keeps saying "Co2 is a plant food" why? because he believes it adds substance to what he must know is an increasingly weak argument, and because he thinks it makes CO2 sound cuddly and friendly. Every one of the points that Megan records could be analysed in the same way. So why do they keep trotting them out in the absence of new data? It all feels a bit like a gospel meeting where the preacher repeats the same old biblical lines, knowing that his audience will feel comforted by the familiarity, and certainly won't ask questions. An impression, of substance and meaning, will have been created out of material which in real life has neither. -
Riccardo at 17:36 PM on 20 June 2010Astronomical cycles
shawnhet, I think you're missing the central point of what Scafetta did. His model model is about the cycles and does not include the trend. Indeed, Scafetta works with separately detrended data, he does not fit trend and cycles together. If, as I showed, his starting point (the detrended data) is biased, his conclusions are biased as well. Does one need to show a better model or measurement to prove that the one shown in a paper is biased? It could be desirable, but not required; if its very premises are untenable one can not add a few bits to correct it. And given that it is Scafetta that is trying to push an alternative view, it's up to him to prove it. We stand where we were if he fails. "your trend doesn't work, so even if both your and his choice of trends are both *completely* arbitrary, his is *still* better than yours." I'll never get tired to repeat it, I do not have a trend of mine. And yes, they're all unjustified. Being them the basis of the subsequent analysis, the latter stands on shaky grounds. -
marty at 17:34 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
I'm glad to see that you are engaging with the sceptical arguments. As someone who has tried to follow this issue I still find myself at a loss to decide which way to jump. What seems to be lacking is a serious high level public debate on the arguments for and against man-made climate change so that non-experts such as myself can make informed judgements. That said however I would still insist that a consensus in science is something that forms around an issue that is by its nature controversial. No consensus is required with respect to Newtonian science since it is about as uncontrovesial as anything in science can be. So even if we accept the theory of man-made global warming it is very much in the nature of a judgement and not a certainty. Science does not deal with certainties but with knowledge of overwhelming probabilities. The place of science in life also needs to be taken into cosideration. How we act in relation to advances in scientific knowledge is not a push-button affair. There is a somewhat Mathusian tone to the pronouncements of many proponents of man-made global warming that perhaps explains some of the resistance to their scientific case. 'The science says so' is not an acceptable argument for the complete re-allocation of society's resources. Firstly because even scientific othodoxy is not beyond question but also because we must take into consideration many other things such as ethical, economic, political, considerations alongside the scientific knowledge. Having said all that I do recommend your site to any sceptics that I come across and it has made me a bit more sceptical about the sceptical science. I still need that public debate though! -
tobyjoyce at 17:28 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Ove at Climate Shifts had a brush with Watts & Co. An unpleasant quarter of an hour I think attending sceptic meetings and asking questions is important. However, public debates like Tim Lambert vs. Monckton is not a good idea as it implies a false equivalence between scientists and deniers. -
barry1487 at 17:14 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
kdkd, for Poptech's benefit I added trend lines to the graph (and included 1979). -
kdkd at 16:52 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
John Cook #14 Broadly your post is correct. However, any difference in trend between the different data sets is not statistically significantly different. The easiest way to estimate this effect is to observe thatthe 95% confidence interval of the correlation coefficient of anomaly against time overlap for all three main data sets. However, as this approach does not correct for autocorrelation (time series property) it's insufficiently conservative. Either way, Poptech's position is silly. -
Doug Bostrom at 16:23 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Eschenbach (of WUWT) has just produced another article trying to bury signal in noise, this time having to do with temperature anomalies on the West Antarctic Peninsula. Although there is clearly an upward trend in temperatures as reflected by all datasets, Eschenbach is -extremely- concerned about variances between each set of temperature measurements. As is usual, we are supposed to conclude that nothing can be concluded: "All of which makes it very difficult to come to any conclusions at all … except one. My only real conclusion is that it would be nice if we could get some agreement about one of the most basic data operations in the climate science field, the calculation of area averages of temperatures from the station data, before we start disputing about the larger issues." The review article in Science (Science 328, 1520 (2010); Oscar Schofield, et al) attracting Eschenbach's scorn is concerned with impacts of warming on the ecosystem of the West Antarctic Peninsula. Here are the physical symptoms of warming, as summarized in the article: Changes in the WAP are profound (Fig. 1). Midwinter surface atmospheric temperatures have increased by 6°C (more than five times the global average) in the past 50 years (14, 15). Eighty seven percent of the WAP glaciers are in retreat (16), the ice season has shortened by nearly 90 days, and perennial sea ice is no longer a feature of this environment (17, 18). These changes are accelerating (19, 20). On careful reading, it turns out Eschenbach's quibble with this scenario is not that there is no trend in temperature, rather that he sees it as exaggerated. Doing his own numeric massaging, he finds not a 6 degree C increase but rather "only" 3 to 4 degrees C depending on how he treats his analysis. Note that Eschenbach's own conclusion is that WAP temperatures have risen far faster than the increase in global average. Eschenbach is in significant agreement with the summation of the paper he's criticizing, but you'd be hard pressed to notice the inconvenience by reading his own words because that conclusion is left buried between the lines. This is pretty much classic "How climate skeptics mislead" material. Zero in on whatever defects are available regardless of whether they have explanatory power, ignore the big picture, make sure readers end up lost in a myriad of details that are interesting but not really significant. -
barry1487 at 15:51 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
At the outermost, there is a 0.03C/decade difference in trend between satellite and surface temperature trends. On what grounds do you propose this is 'statistically significant', Poptech? -
snapple at 15:47 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
As luck would have it, John Costella's "Climategate" analysis is available as a reprint from SPPI (Monckton's group) and posted on Anthony Watts' site. http://wattsupwiththat.com/2010/01/21/climategate-analysis/ -
ginckgo at 15:44 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
oh dear, Poptech confuses difference in temperature with difference in trend. -
John Cook at 15:39 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
I think what Poptech is saying (correct me if I'm wrong) is both the satellite and surface data show a warming trend but that the satellite trend is not as strong. This is in large part due to the different ways the data is processed. The RSS satellite trend is warmer than the UAH satellite trend because RSS's adjustments for satellite bias add warming in the tropics while UAH's adjustments add cooling in the tropics. The HadCRUT surface temperature trend is not as strong as the GISS trend because it doesn't include the Arctic regions where warming is strongest. Nevertheless, all these records are broadly consistent and show a statistically significant warming trend over the last few decades. -
WheelsOC at 15:37 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Poptech, I'm not the handiest person with plotting but even I know what "trend" means. There is no way you can say that the satellite data to which you linked "trends cooler." It is in fact trending upwards, just as the surface-based measurements are. Even a simple line plotted between end-points shows an extraordinarily similar slope (trend) among the two data sets. What is different is the offset from the x axis, but that's not a trend. Words have meanings, please use yours carefully. -
Megan Evans at 14:52 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
NewYorkJ - no, Watts conveniently ignored Menne et al 2010 villabolo - For sure, I'd be more hesitant to follow my own advice it it were Chris Monckton :-) Of course, if he agreed to refrain from name calling it might not be an impossible task. -
Marcus at 14:49 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Poptech, you are aware that the anomalies measured by ground-based measurements are based off a 1961-1990 average, wheras the anomalies measured by satellite are based off of a 1979-2000 average? Given that average temperatures were warmer for 1979-2000 than for 1961-1990, then its perfectly reasonable that the size of the temp. anomaly measured by satellites would be smaller. That said, both ground based & satellite temperature measurements are showing a warming trend of +0.14 to +0.17 degrees per decade from 1979-2010 (with only UAH being below +0.16 due to failure to account for diurnal drift). That puts ground & satellite measurements in very close alignment, & utterly debunks Watts' weak arguments. Now, if you're not going to contribute anything *sensible* to this thread, then I might suggest its better to contribute nothing at all! -
kdkd at 14:31 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Poptech #9 You're repeating a false assertion. The satellite data shows exactly the same trend over time as the GISS, HADCrut etc. Statistically the trends are indistinguishable. Visually, the graph presented by NewYorkJ in #7 totally debunks your argument in any case. Here is is again:The absolute difference in measured temperature is of no importance, it's the change over time that's the feature of interest. More fodder for the "how climate sceptics mislead" thread here methinks.
Moderator Response: wonderful, thank you - jb -
shawnhet at 14:31 PM on 20 June 2010Astronomical cycles
Riccardo:"you assume that: 1) i'm supporting the n=4 versione of the trend; 2) i'm a competitor to Scafetta. Neither is true and nothing i said should let you think they are. I esplcitly stated (several times indeed) that the n=4 has no more value and I nowhere tryed an alternative hypothesis. Insisting on this point is, at best, specious. I'll said it again, maybe sooner or later you'll will accept it. I just showed the weakness of Scafetta paper through its arbitrary choice of the trend. Stop. I understand that it's hard to accept the fault one of the skeptics heros, but you know, sometimes even heros might be wrong." Sure he can be wrong and frankly I am quite skeptical of these sorts of linkages, but that doesn't mean that you have demonstrated what you think you have demonstrated. Whether or not Scafetta's choice of exponent is valid or not is dependent on how effective his *complete model* is at reconstructing all the observed temperatures. At this, his model beats your "model" hands down. I am pretty sure that there are many equally effective (to Scafetta's) ways of getting a decent reconstruction of temps. The way to deal with Scafetta's paper would be to show how an alternative reconstruction works just as well or better. Scafetta himself concedes that there are other possible trends to explain the data so I doubt that he considers your objection significant(he mentions it himself). Respectfully, your trend doesn't work, so even if both your and his choice of trends are both *completely* arbitrary, his is *still* better than yours. (I don't want to get into the semantics of the word arbitrary). BTW< just because a choice of parameters may be arbitrary, doesn't mean it won't turn out to be a good predictor of events. Cheers, :) -
Doug Bostrom at 14:09 PM on 20 June 2010How Jo Nova doesn't get the tropospheric hot spot
How are those papers "devastating," poptech? Here's the conclusion of John's post: Detecting the tropospheric hot spot is not a test of the greenhouse effect but of the moist adiabatic lapse rate. Data uncertainty and long-term biases mean detection of the hot spot has been difficult. Nevertheless, there is evidence that the hot spot exists. But if you cannot accept this evidence, to be strictly correct, what you are is a moist adiabatic lapse rate skeptic. You've seized an opportunity to highlight some material contradicting McLean and other climate researchers, but I don't see how your argument is "devastating" to John's summary. Can you explain? -
kdkd at 13:59 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Poptech #4 Your argument here is invalid and thoroughly discredited. We're not interested in the absolute measurement, but the trend over time. In fact the literature will tell you that you can't make absolute comparisons between different data sources, and have to rely on relative data. So given that, as trends assessable from the satellite and instrumental records are statistically indistinguishable from each other, your position has no merit. -
NewYorkJ at 13:58 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Megan, Did Watts make any reasonable attempt to address the peer-reviewed study that debunked his photo gallery? Poptech, You forgot the baseline adjustment described here. I included the data through 2010 YTD as well. GISS to RSS comparisonModerator Response: NO. he did not acknowledge that there was any criticism of his work and didnt even really synthesize it -
musubk at 13:38 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
"1) Temp record is unreliable, 2) CO2 effect is saturated, 3) CO2 is plant food, and 4) It’s the sun." So the argument is: 1) There's no warming. 2) There's can't be any warming. 3) The warming that isn't and can't happen is a good thing. 4) The warming that isn't happening is happening because of the sun. How is this not obviously contradictory to them? -
snapple at 13:31 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
The Climate Skeptics Party has a list of websites. One link is to John Costella's "Climategate Analysis." http://www.climatesceptics.com.au/websites.html It takes you to this. http://johncostella.webs.com/ But he still has it on his Assassination Science site. http://assassinationscience.com/climategate/ -
Marcus at 13:05 PM on 20 June 2010Astronomical cycles
Methinks that HumanityRules & John D both need to spend a little time hanging out with the Pastafarians, to see the dangers of the kind of unfounded correlations on which they choose to rely. After all, the Pastas can show a *really* strong inverse correlation between declining number of pirates in the world & the rise in global CO2-it's such a close fit that it *has* to be true! Right? Of course not-not unless you can back it up with (a) a physical explanation of *how* pirates were keeping CO2 levels down; (b) some empirical evidence that backs up this explanation (like showing pirates sucking the CO2 out of the atmosphere) & (c) making sure that the declining number of pirates was the *cause* of rising CO2 levels-instead of the other way around. This is where Scafetta's paper falls apart. With a little statistical gymnastics, he's able to show a correlation between a 60-year alignment of planets & a warming of the climate-what he doesn't give is an explanation of *how* this alignment might be causing the sun to make the Earth warmer or how we might expect these impacts to manifest themselves on the planet's surface. Nor does he try & show how his hypothesis compares to existing paleo-climate data from before 1850 (probably because it increasingly falls apart). The thing is that we already have a very *very* good idea what caused the warming between 1880-1940, & that is the significant rise in sunspot numbers over that period. Now I'm happy to accept the possibility that planetary alignments could be driving this increase in sunspot numbers but, if that were the case, then we should have seen a similar sunspot response during this current PUTATIVE 60-year cycle. Yet we don't see that response from the sun. Indeed, sunspot numbers have been trending downward. The fact is that Scafetta's 60-year "trend" is highly dependent on only focusing on the period from 1850 on, & then only if you rely on HadCRU data, rather than the more reliable GISStemp data (GISStemp shows no cooling trend between 1880 & 1910, the supposed "cooling" trend between 1940-1970 only works because of the relatively big drop off in temperatures around 1943-1945-without it it becomes a warming trend-& 2000-2009 shows a distinct warming of +0.12 degrees for the entire decade-not the cooling that we'd expect if Scafetta was correct). As to John D, a fall in average precipitation is *exactly* what we expect when temperatures warm excessively-the only thing is that you've got CAUSE & EFFECT the wrong way around-just like those who run around claiming that warming is generating the excess CO2 in our atmosphere! -
snapple at 12:57 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
John B--there is little consensus among denialists except that they all agree that the scientific consensus is wrong. I think that Watts must be down on his luck if the webmaster for the Australian Climate Skeptic political party is affiliated with something called "Assassination "Science." What kind of science is that? -
robert way at 12:49 PM on 20 June 2010How Jo Nova doesn't get the tropospheric hot spot
Poptech, notice the word "submitted" on two of those papers... notice how its not "accepted" -
John Bruno at 12:41 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
Wonderful post Megan and I think a great description of the event. Something that really struck me in Bob Carters summation was his argument that "we don't know" what is going on with temperature or glaciers. He said (to paraphrase) some are shrinking, some are growing, we don't measure enough to know what the mean trend is. Archibald made the old argument that there has been no warming over the past 10 years, then showed a graph that seemed to disprove his point, even though it only went through mid-2009. But wait, Archibald also argued that there is warming but it is caused by the sun. And in a recent paper, Bob argued there is warming, but it is caused by El Nino. Yet at the event he said there is no warming then a few minutes later said we don't know if there is any warming. Which contradicted Archibald's strong argument that the earth has been cooling for thousands of years and continues to so. Confused? Me too. But the contradictory nature of their arguments is a common trait of the skeptic case against AGW. All fodder for future posts. - JB -
robert way at 12:40 PM on 20 June 2010Watts it like at a climate skeptic speakers event?
I think this post is spot on. The only way to deal with skeptics is address them straight on. Engagement is key and sitting back to the protection of our own blogs is not the way that paradigms change. If only the boys at real climate would realize this. I think people like gavin and ray pierre should be stepping in and addressing issues at WUWT and Climate Audit as well as in person. -
Doug Bostrom at 12:38 PM on 20 June 2010How climate skeptics mislead
This paper Bayesian approaches to detection and attribution (J.D. Annan, 2010, in press, Wiley Interdisciplinary Reviews: Climate Change) provides some useful food for thought about how we might more reliably tease out a useful message from climate research. It addresses some of BP's concerns. Abstract: We consider the Bayesian alternative to the classical frequentist approach to detection and attribution of climate change. Some of the notable advantages of the Bayesian paradigm include a more consistent approach to competing hypotheses, a coherent interpretation of all available data, and an intuitively natural interpretation of the results. Well worth reading. -
Doug Bostrom at 12:22 PM on 20 June 2010How Jo Nova doesn't get the tropospheric hot spot
A more accurate way of phrasing poptech's synopsis might be "The failure of a warming trend that is entirely consistent with model results has been shown in various papers..." A minor quibble, based on other folks such as McLean et al attempting to explain measured temperature anomalies in the tropics via SOA and other means. My point being, if there's no noticeable warming trend in the tropics it's hard to say why McLean would need to be creating alternative explanations for why there's a multi-decadal anomaly in tropic temperatures. Incoherence. -
MattJ at 10:06 AM on 20 June 2010Astronomical cycles
When this kind of pseudo-statistical reasoning is applies to stock market prices, it is called 'chartism'. I guess it is not just in the stock market that chartism continues to fool many even today, years after it was soundly refuted... -
johnd at 09:16 AM on 20 June 2010Astronomical cycles
These notes apply to the chart posted above. Figure TS.9. (Top) Distribution of linear trends of annual land precipitation amounts over the period 1901 to 2005 (% per century) and (middle) 1979 to 2005 (% per decade). Areas in grey have insufficient data to produce reliable trends. The percentage is based on the 1961 to 1990 period. (Bottom) Time series of annual global land precipitation anomalies with respect to the 1961 to 1990 base period for 1900 to 2005. The smooth curves show decadal variations (see Appendix 3.A) for different data sets. {3.3, Figures 3.12 and 3.13} -
johnd at 09:12 AM on 20 June 2010Astronomical cycles
HumanityRules at 03:41 AM, in addition to the various factors illustrated, perhaps the annual precipitation cycle has a place. Whilst it may be indirectly represented, perhaps by ENSO(?), precipitation is a direct indication of a cooling influence both immediate and longer term as it replenishes and maintains a reservoir of soil moisture that are only significantly depleted by drought. This IPCC chart at the bottom gives an indication of the cycle as observed in the 20th century.
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Riccardo at 08:28 AM on 20 June 2010Astronomical cycles
HumanityRules, "what she seems to do is develop a model which has reasonable match to HADCRUT then derive the anthropogenic signal from that model." This claim is compleately unfounded. Please stick to what she said in the paper and do not try to make people say what you'd like them say. shawnhet, you assume that: 1) i'm supporting the n=4 versione of the trend; 2) i'm a competitor to Scafetta. Neither is true and nothing i said should let you think they are. I esplcitly stated (several times indeed) that the n=4 has no more value and I nowhere tryed an alternative hypothesis. Insisting on this point is, at best, specious. I'll said it again, maybe sooner or later you'll will accept it. I just showed the weakness of Scafetta paper through its arbitrary choice of the trend. Stop. I understand that it's hard to accept the fault one of the skeptics heros, but you know, sometimes even heros might be wrong. As for the "competitors", aka currently accepted hypothesis, again as said countless time now, there are plenty of papers, one of them quoted before. I'm sure you know many more. There's still something missing? Sure, hardly a breaking news, you will hardly find someone claiming the opposite. It's still a topic of active research for a reason. For sure what is missing is an "alternative" hypothesis and the astronomical cycles theory is not (yet?) up to the task. -
Alexandre at 07:32 AM on 20 June 2010How Jo Nova doesn't get the tropospheric hot spot
Chris Colose #15 Thank you very much for your response. Now I think I understood it: without a lapse rate, you cannot "see" other temperatures from the top of the atmosphere, so there would be no GHG "bite" in the OLR spctrum. So if the hotspot were not there, then the lapse rate would be probably greater (greater temperature drop with altitude), and hence the intuitive conclusion that the climate sensitiviy would also be greater. Thanks. -
shawnhet at 06:48 AM on 20 June 2010Astronomical cycles
Riccardo, I guess I don't really understand what you're up to here. Scafetta is attempting to reconstruct the observed temperature record by combining a cyclical component (initiated by changes in the SSCM) and a given trend. I don't really know if he does a good job of this or not. You, OTOH, seem to be claiming that because your n=4 trend more closely matches the recent temp trend, then apparently it is superior (or at least equal to) Scafetta's, but really this is apples to oranges. Scafetta, purportedly has an explanation for warming for the entire record, you, at best can only explain the last 30-40 years. For periods prior to that you still have essentially the same fluctuations(Fig. 3) in temp that Scafetta tries to explain by referring to SSCM. An effective competitor to Scafetta's hypothesis would need to explain the same data that he did, not simply choose one portion of the data, and calculate a trend on that basis. Cheers, :) -
Doug Bostrom at 05:58 AM on 20 June 2010Astronomical cycles
Something that bothers me about Scafetta's paper is the seemingly combative or biased attitude he drags into the conclusion section of his paper. He makes some statements that are plainly exaggerated or at least factually erroneous as well as citing other, unrelated research in an apparent attempt to bolster his findings with circumstantial evidence that he cannot show as related to his core thesis. For instance, Scafetta claims "...the AGWT promoted by the IPCC [2007], which claims that 100% of the global warming observed since 1970 is anthropogenic, is erroneous." Nowhere in the IPCC 2007 report can such an assertion be found; the remarks on attribution in the IPCC synthesis are heavily nuanced and qualified. Scafetta departs from a straight discussion of the relationship of his research to the IPCC summary to make an unfounded allegation. This harms his credibility for any reasonably informed layperson reading his paper, leading readers to conclude he's pursuing an agenda beyond scientific inquiry. Elsewhere in the discussion Scafetta mentions Solomon's work on stratospheric water vapor. By his own words, we can conclude that he's attempting to establish a conceptual space for unidentified climate forcings: "[Solomon 2010] reinforces that climate change is more complex than just a response to added CO2 and a few other anthropogenic GHGs." That's a plainly obvious fact and adds nothing to his thesis, but it certainly will help lead readers in the "correct" direction. He also makes a curious choice of words to describe Solomon's findings, saying "...stratospheric water vapor has largely contributed both to the warming observed from 1980-2000 (by 30%) and to the slight cooling observed after 2000 (by 25%)." We could agree that Solomon's work describes a significant influence, but largely? That word suggests that water vapor is a dominant effect but it's apparently not. Again, there's a clear tone audible here that goes beyond a simple spirit of curiosity. Further to Solomon, Scafetta goes on to say "Perhaps, stratospheric water vapor is driven by UV solar irradiance variations through ozone modulation, and works as a climate feedback to solar variation [Stuber et al., 2001]. Thus, Solomon’s finding would partially support the findings of this paper..." But Scafetta cannot describe how this might work; he can't establish any factual basis for a relationship between Solomon's findings and his thesis. In fact, he struggles to establish any physical mechanism for how the solar system vibrations might act: "Alternatively, the planets are directly influencing the Earth’s climate by modulating the orbital parameters of the Earth-Moon system and of the Earth. Orbital parameters can modulate the Earth’s angular momentum via gravitational tides and magnetic forces. Then, these orbital oscillations are amplified by the climate system through synchronization of its natural oscillators." Reading that part of Scafetta's discussion makes me better able to understand this notion of "handwaving" scientists speak of. Scafetta presents us finally with this conclusion: "...climate models are missing fundamental mechanisms that have their physical origin and ultimate justification in astronomical phenomena, and in interplanetary and solar-planetary interaction physics." A bold claim based on what appear preliminary results and an incomplete investigation, and when I consider that Scafetta tries to shore up this assertion with incorrect summaries of the IPCC thesis and what appear to be rhetorical artifices I'm left to wonder, is this research, or axe-grinding? I would have thought that before making such a claim Scafetta would have extended this work by further investigating the specific nature of the physical mechanisms that might exert the influences on climate he alludes to but cannot actually identify. Scafetta's leapfrogging of open and unexplored investigative alleys to jump to conclusions about the validity of GCM projections leaves me with the solid impression he's not concerned so much with research but instead is pursuing an agenda not primarily concerned with scientific investigation. -
HumanityRules at 04:19 AM on 20 June 2010Astronomical cycles
#66 Marcus Riccardo's article suggests Scaffetta links this analysis to the motions of the planets. It isn't just some free floating "statistical gymnastics" it does try to base things in a real universe. -
owl905 at 04:14 AM on 20 June 2010Astronomical cycles
Ken Lambert wrote:- "this “nice AGW trend” is not looking so nice when the purported energy flux imbalances are not showing up in OHC for the last 6 years and probably not much in the last 16 years." Well, they have been and they are showing up. The Scaffetti paper is similar to the 'cooling trend' distraction - statistical construction artifacts. Mathmagic, if you like. http://www.noaanews.noaa.gov/stories2010/20100615_globalstats.html 1. May 2010 - warmest May in the records, 1st on land, 2nd for SST 2. April 2010 - warmest April in the records, 3rd on land, 1st for SST 3. March 2010 - 2nd warmest March in the records, 1st on land, 13th for SST 4. March-May qtr - warmest in the records, 1st on land, 2nd for SST The cooling 'trend' only lasted as long as the latest La Nina 'event'. -
HumanityRules at 04:03 AM on 20 June 2010Astronomical cycles
60 Marcus I know the human eye likes to see patterns in things but do you not see phases of warming/cooling/warming/cooling/warming with an approximate length of 30years? We can argue about the exact length or whether that pattern in 'dirtied' by other phenomenon but if I see it and you don't then I guess there is no possibility for us to come to any sort of understanding. My comments here don't come from any sort of position other than I see that pattern superimposed on a general warming trend and I'm curious about it. I can accept that pattern may be circumstantial but I've yet to see anything that proves that. I wonder if you'd like to expand on what "people like yourself" are? Or maybe apologize for the unnecessary language in your post. Finally I don't understand who humanity should be seeking absolution from, who's judging us? -
Marcus at 03:48 AM on 20 June 2010Astronomical cycles
HR @ 63. There's a very simple test you can do-plot the temperature anomaly for 1950-2010 vs CO2 concentration for 1950-2010. Guess what you get? A linear correlation with an R-squared value of around 0.79. That effectively means that 79% of all climate variability since 1950 can be attributed *solely* to the change in CO2 concentration. In science, that's considered an extremely good fit-good enough for the statement that "CO2 is driving climate variability post-1950" to be valid. Of course correlation alone doesn't prove anything, it's also backed up by things like our knowledge of the IR-absorbtion properties of the various GHG's, the reduction in outgoing IR radiation reaching the outer atmosphere & the cooling of the stratosphere-all of which are consistent with a GHG-induced, not solar induced, warming trend. -
HumanityRules at 03:41 AM on 20 June 2010Astronomical cycles
Ooops you provide a possibly example of what I'm asking for from Lean
except what she seems to do is develop a model which has reasonable match to HADCRUT then derive the anthropogenic signal from that model. Unfortunately graph a) isn't the clearest but her model does seem to flatten out the 20th century data. The magnitude of the 1910 low and the 1940 high are reduced. We seem to have a similar problem to Scaffetta. In the case of Lean a model that seems to remove the cyclical nature of the 20th century temperature ends up 'proving' there is no room in the data for a 60year cycle.
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Marcus at 03:38 AM on 20 June 2010Astronomical cycles
HumanityRules, why are you choosing such arbitrary dates to prove your point about temperature trends? It sounds to me that, like Scafetta, you're desperate to shoehorn the data to fit your extremely weak hypothesis-yet your dates don't even fit his 60 year cycle hypothesis-they're more like 70 years here & 50 years there-hardly very scientific. Also, if you look at the HadCrut3 data, the period from 2000-2009 showed a *warming* of +0.003 degrees per year, not much lower than the warming of 1850-1880, that you're trying to attribute to this magic 60-year cycle (which isn't *really* 60 years at all). So already your hypothesis is looking extremely shaky. Also, if you look at the GISStemp data, your hypothesis takes another battering, because the cooling from 1880-1920 is missing-temperatures remained effectively *flat* during that time period. As I said above, if you look at a *real* set of 60-year cycles (1890-1950 vs 1950-2010), you see that you have half the warming in the first 60 years that you have in the 2nd 60 years-even though the first 60 years is dominated by rising sunspot numbers, wheras the 2nd 60 years is dominated by falling sunspot numbers. This does really shot some massive holes in the 60-year cycle hypothesis, as does the lack of stratospheric warming-which we'd definitely see if the sun was to blame for post 1970's warming. Lastly, the Hue & Cry of the Denialosphere has always been that correlation doesn't equal causation, yet people like yourself, HR, are pretty desperate to cling to correlations based entirely around statistical gymnastics-without any firm rationale with which to back it up. That's not the action of a SKEPTIC, its much more of a FAITH BASED position. I guess though, HR, that you'll cling to any hypothesis, no matter how far fetched, if it will absolve humanity of responsibility for global warming! -
HumanityRules at 03:12 AM on 20 June 2010Astronomical cycles
60 Riccardo But you seem to be finding a solution. The solution being there is no 60yr cycle? From yours and others post on this subject there seems a very simple solution to all this. You take the HADCUT temp record and you subtract the solar cycle effect the enso signals the volcano signals any other signals you think acceptable and you're left with a nice curve that has some simple relationship to the increases in GHG emissions. You then get the equation for your 20th century trend. Why haven't I seen this curve? It seems the consensus around climate science would tell us we know everything necessary to have a reasonably good attempt at this. In fact it doesn't seem too much to demand this of the science. -
Riccardo at 03:05 AM on 20 June 2010Astronomical cycles
shawnhet, apparently my point was not made clear enough if commenters keep repeating the same criticism: "It's not to say that the n=4 trend has more value than the n=2, but in the end we can say that the nice cyclic behaviour seen in fig. 1 depends on the choice of the trend function." The point here is that being the presence of the cycle dependent on the (arbitrary) choice of the trend, no conclusions can be drawn "at least until we can make a proper choice of the underlying trend.". That's it. If you drop the last cycle, e.g. like with the n=4 trend, i can't see what cycle need to be explained. Would you call for a connection with the 60 years sun cycle when you have less than 2 periods that does not repeat? I think the really hard part would be to explain why the supposed cycle has disappeared. -
shawnhet at 02:40 AM on 20 June 2010Astronomical cycles
Riccardo, I agree with BP on this one. Simply because Scafetta doesn't discuss physical mechanisms doesn't mean that a sixty-year cycle in temperatures(induced by variations in the position of the SSCM) is equally physically plausible to a quartic trend in temperatures. Practically everything we know about physics would say that it would not be possible (for example) for each doubling of the forcing to produce 16 times the temperature increase as the last doubling. Further, even if you accept the quartic trend, you still have the same basic patterns of the last 150 years(that match up reasonably well with changes in the SSCM) as shown by Fig. 3, except that they break down on the most recent timescales for an exponent of n=4. You are then in a position of still having to explain the apparently cyclical changes in temps. Cheers, :) -
Riccardo at 02:03 AM on 20 June 2010Astronomical cycles
HumanityRules, I'm not a scientist, you can not ask me to find the solution to a problem that professionals didn't solve yet ;). I agree that pointing to the weakness of Scafetta paper does not move anything forward; this means we have to rely on previous scientific litterature which tells us that other effects influence decadal variability more than the sun's 60 year cycle. You may find more on this, for example, in the Lean 2009 quoted in my previous reply to johnd. -
HumanityRules at 01:43 AM on 20 June 2010Astronomical cycles
>0.1oC should be <0.1oC -
HumanityRules at 01:37 AM on 20 June 2010Astronomical cycles
55 Riccardo You may answer this question as you did a similar question with something like "it's not my job to identify cycles" but how would one go about identifying a cycle in the 20th century temperature record in a credible way? Because simply saying Scaffetta's assumption could easily be wrong really doesn't move things forward. Given the complex,chaotic, poorly measured and poorly understood nature of climate I imagine most analyses of data in this field rely on one or two untested or unproven assumptions. We end up with an arguement that you can use statistics to prove anything, not the most enlightening idea. You're still avoiding specifically describing what is going on in the ~30year up and down phases of the HADCRUT3 data. I'm not convinced ENSO, Volcano and solar really address this. 56 johnd From memory earlier articles here about solar cycles, whatever the index, have tended to downplay the potential amplitude of warming that can be caused by these solar changes. Again from memory this was in the region of >0.1oC. Also this website has argued there is no long term trend in ENSO, I think you'll have to look elsewhere for an explanation. -
Riccardo at 01:24 AM on 20 June 2010Astronomical cycles
johnd, actually the ENSO periodogram is a bit messy (part B on the right taken from Lean 2009), but it does not show any dominant 60 year cycle. The large peaks beyond beyond 1000 months are spurious, being too similar to the time range of the data. Interestingly, although in Lean 2010 she also finds a peak around 60 years in the temperature periodogram, she is able to reconstruct temperature as a combination of various effects (sun, ENSO, volcanoes and anthropogenic) with no dominant 60 years cycle. Including the known sources of variability and calculating the residuals could be a good way to isolate what's left.
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