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RSVP at 16:34 PM on 4 May 2011Why 450 ppm is not a safe target
From the article, it sounds like ensuant drought, famine and flooding should take care of all these problems quite effectively. -
Marcus at 16:17 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
"Other than say - well done John, one could suggest that disagreement is not denial, and that there are valid reasons to doubt some of the supporting evidence for the AGW case." Hmmm, I'd say the only *valid* reasons to doubt the supporting evidence would be if (a) the evidence was obviously flawed or (b) if the Contrarian Camp were able to come up with a better hypothesis to explain the observed warming trend of the past 60 years, in general, & the last 30 years in particular. Neither seems to be the case-the evidence is as strong as it was over 100 years ago & the Contrarians have yet to come up with an opposing hypothesis which is able to stand up to scrutiny. What I see from Contrarians, most often, are attempts to discredit the scientific community, wacky conspiracy theories, attempts to downplay the future seriousness of the problem and attempts to overstate the possible economic consequences of taking action. None of which I'd define as *valid* reasons for doubting scientific *fact*-just a desperate bid to muddy the waters & delay action for as long as possible. -
owl905 at 15:59 PM on 4 May 2011Why 450 ppm is not a safe target
Why have you written an article about 450ppm CO2 when the issue is 450ppm CO2e? Off the cuff, CO2 is into 'the red zone' at about 425ppm with the rest coming primarily from increases in CH4. Pre-Ind 2009 Increase Forcing wm2 C02 280 ppm 388 ppm 108 ppm 1.46 CO4 700 ppb 1745 ppb 1045 ppb 0.48 With CO2 concentrations growing at about 2ppm per year, it's less than 20 years to be 'in the red zone'. But even the 2 ppm growth rate will be surpassed once the current global recession gives way to new global growth. -
Jason at 15:57 PM on 4 May 2011Video and podcast about confusing the hockey stick with the 'decline'
"Baseload power" is a concept that exists only because certain technologies are inflexible, not because it reflects what is actually required. The demand for power fluctuates through a range of about 2.5:1. In other words, the peak power requirement during a hot sunny day in a place like California is 2.5 times greater than in the middle of the night in winter. Coal-fired power stations and nuclear powerplants really like a constant output, both for technical reasons (it's difficult to change the output for both plant types) and economic reasons (coal and nuclear powerplants have relatively high capital costs, relatively low fuel costs, and finite lifetimes, so getting a good cost per kWh generated depends on generating as much as possible during the lifetime of the plant). Because of this mismatch between supply and demand we have "peaking power generators", like gas, that follow the load and produce more power when the demand is high and less when it is low. Peak power generators have much higher fuel costs compared to capital costs and they pay for themselves by only selling power when the price is right. This is why many utilities offer pricing schemes where they charge more for power during peak periods and much less for power during off-peak. The forecast expansion of nuclear was also the driving force behind expanding pumped hydro capacity a few decades ago (see Dinorwig power station for an example) so it's a mistake to think that energy storage is an issue for renewables only. In fact, with solar power, because the generating behaviour more closely correlates with demand, the gap between what is being generated and what is being demanded is less, and peaking power generators are actually required less often when using solar than when using so-called "baseload power generators" like coal and nuclear. Nevertheless, there is no reason why solar and wind can't displace a large percentage of "baseload power" generators with load-following generators filling the gap in exactly the same way they do now, and as storage is added to the system (molten salt, pumped hydro, etc.) peaking power will be used less and less often. Of couse, we have a long way to go before this becomes an issue -- until solar and wind penetration exceeds 20% of the grid, we can just use "grid storage" (i.e., use them to displace other sources of power), which is extremely efficient because you're not really "storing" energy at all, you're simply avoiding the generation of energy you don't need. Here is a report from Germany on the reduction in the cost of electricity that wind power resulted in that more than compensated for the subsidy paid to have that wind power added: Merit Order Effect The reason for the cost reduction was that although wind power wasn't the cheapest energy source available, wind power providers will dump all the power they can generate onto the market whenever they can -- there's no benefit to them in turning off turbines when the price gets too low because there's no "fuel" to save in doing so. The availability of wind power electricity at whatever-price-was-going meant that customers avoided buying power from peak power generators using more expensive technology when there was enough wind for them to do so. -
Philippe Chantreau at 15:33 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
I find the paper of seriously limited interest. Since it does not consider calving, it does not address mass balance, which is the really important metric. The main focus appears to be on statistics, while ice sheet dynamics hold many areas of inquiry that are far more interesting than the mere descriptive numbers. It is not very useful for much of anything. As with most statistical approaches, the lack of the most recent data in the analysis makes it even less useful. I'm sure Pat Michaels can throw around a lot of sound bites from it that are technically true within the frame of the paper, and that satisfies him. After all, his main line of work seems to be PR. However, for those who really study ice, like Dr Box or Mauri Pelto, it offers next to nothing toward an improved understanding of the physical reality. Much ado about nothing, really. -
Ken Lambert at 15:21 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Albatross #72 I invited all to the Flanner thread at #64. Tom Curtis has not responded to my posts there since 30th April. He then places a post here at #65 which should have been on the Flanner thread. Direct your criticism to Tom Curtis. If this thread has a clearly defined topic, it is about the personal musings of our host John Cook on what motivated him to start up the site. Other than say - well done John, one could suggest that disagreement is not denial, and that there are valid reasons to doubt some of the supporting evidence for the AGW case. -
Albatross at 15:00 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Marcus @77, You can add Pat Michaels and Christy to that list. -
Albatross at 14:58 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hello Chip, Thanks for your post @119. You did not refer me to #95 before, you referred me to #112. Regardless, I'm afraid that you insist on continuing to evade the point. Quite frankly your "strong belief" that including the 2010 data would not make a difference to your conclusions is irrelevant, and unscientific to boot. What it boils down to is this. The validity of your argument now rests on you demonstrating qualitatively to everyone that the melt stats for 2007 exceeded those for 2010. While what you believe may be correct (albeit unlikely, given other people's findings on 2010 melt versus other years), you have not demonstrated that despite having ample opportunity to do so. Rather, you admit that you are making a claim without having done the analysis and choose to cite "belief" instead. Not a compelling argument, so thank you for confirming that. -
KR at 14:55 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Marcus, johnd - Here in the States, we don't read the Australian at all. Washington Post? CNN? The Guardian? Yep. But not the Australian. That's "local" news for a locality far from here. That said, Monckton has shown up in front of Congress for the Kabuki theater that is the US Congress (which I state as someone for whom Congress is local news). When he does, we in the States make appropriate noises in response. Usually gagging. --- For me, looking at the world through the clearest glass I can find is important for my personal integrity. Logical fallacies, rhetoric contrary to facts, and lying for self-interest are maddening to me. I have the greatest respect for John Cook for putting so much effort into this website. I believe that it has had an effect - clearly delineating the science, and hopefully killing off some of the counterfactual rhetoric. I hope, in my own small way, to help contribute to this effort for some time to come. -
Marcus at 14:53 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
I will say this much, though. Its true that Plimer & Monckton have become slightly *less* important, in the eyes of the Denialist Community, since the start of this year-maybe because their comments are so blatantly embarrassing that even their fellow travelers are beginning to want nothing to do with them. That certainly shouldn't allow the Denialist Movement to try & rewrite history, & pretend like Monckton & Plimer weren't ever their "star performers". As I said, though, some elements of the Denial community *still* view Monckton & Plimer as heroes of their movement. Last point, John, I personally *rarely* mention Plimer or Monckton unless they're first mentioned by one of the Denialists. Given that it was *you* & Ken who brought them up in this thread, then that surely suggests its *you*-& not us-who are fixated on them. -
pbjamm at 14:53 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
By the way Ken Lambert, Your last comment on the Flanner thread was May 2nd while your last Flanner based comment here was May 4th. If you really intended to invite people over there you would post something to the effect of "please see my comments here" with a link to your latest comment. And so I don't add to your feelings of persecution, Tom Curtis should be doing the same. -
scaddenp at 14:46 PM on 4 May 2011Models are unreliable
Slight difference. We can't predict ENSO, PDO,AMO in models. These internal variabilities exist in models. You can certainly run a model and get PDO index out of it. However, you cant initialise a model to predict them. I don't of any paper which puts a case for DO being internally driven. Do you? Everything has physical causes. -
Marcus at 14:45 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
"Is Monckton that important a figure to you that you are now actively recommending others should read certain sections of certain newspapers just to keep up with the latest news about him?" The point, John, is that whether you choose to accept it or not, the majority of your fellow Denialists clearly see him as an important figure-to the extent of viewing him as an "expert" in the field-otherwise, why would they give him so much air-time? Talk-back radio, Right Wing Newspapers (like The Australian), Fox News & the US Republican Party *all* give him & his ilk plenty of lime-light, hardly something they'd do for someone they considered inconsequential. This, of course, speaks volumes about the dearth of *real* experts that exist within the Denialist Camp. JMurphy's link was simply to show that, in spite of your rampant denial, The Australian still views him as a very newsworthy figure. That point, like most others, appears to be completely lost on you however. -
KR at 14:44 PM on 4 May 2011Models are unreliable
trunkmonkey - So, a little uncertainty, and we know nothing? That's not a reasonable statement, trunkmonkey. I don't think that's been established anywhere. Tamino has demonstrated how to look at ENSO and other local variations, and remove their influence. The results? The warming we expect from the CO2 we've added, at the trends we expect from the physics. A wee uncertainty is reason for resolving how much we know despite the uncertainty, not reason for throwing up our hands and giving up. That said, an overturning of the thermohaline circulation due to increased fresh water would be a large change in climate state. But that hasn't happened for a long time, and won't happen unless due to our influence, barring major changes in natural forcings which are well out of what we've seen in millenia. -
pbjamm at 14:42 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Ken Lambert@71 Your comment @2 was an off topic complaint about moderation and a claim of victory on the Flanner thread. Nothing at all to do with the creation of SkS or why you come here. This was a fairly successful redirected of this thread into a subset of Flanner. Quite frankly I think the moderators should delete *ALL* the Flanner based comments (including my own) as they are 100% off topic. -
Marcus at 14:37 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
"Marcus at 18:24 PM, you are confirming my point." How so? I don't exactly seek out mentions of Monckton, Plimer or any of those other hard-core Denialists in The Australian, they're there in Black & White in every single Op Ed piece that is devoted to the issue of Climate Change. The Editorials also frequently make mention of these "stars" of the denial movement, as do many of the journalists who work for The Australian. If you've missed these frequent mentions, then I can only suggest that its because you're trying to read the *braille* version of the newspaper. -
Chip Knappenberger at 14:32 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Albetross, Since you think that repeating things seems to help clarify things, I'll go ahead and repeat what I wrote in comment 95 concerning the melt extent in 2007 and 2010...Granted, incorporating the melt extent for the summer of 2010 into the methodology as described in our paper may have required a few minor tweaks to some of the wording (and a few specific numbers). But, by and large, as I have said many times, I strongly believe (although I have not done the analysis) that the changes would not have altered the general nature of our conclusions (as we explained to the JGR editor).
and in comment 112 concerning the same thingAs far as 2010 having a greater melt index value when processed through the methodology described in our paper, I have not done the calculation, so I don’t know. I have reasons to believe it is not as cut and dry a situation that many of you all tend to want to make it.
So I guess now that we've both repeated ourselves, the topic should be about as settled as it is ever going to get until (when/if) our analysis gets updated. Agreed? -Chip -
trunkmonkey at 14:32 PM on 4 May 2011Models are unreliable
363. We established a while back that we know nothing at a decadal scale because the models can't resolve the irregular and powerful influenses of the ocean sloshings; ENSO, PDO, AMO, IOD (It's almost like Lake Tahoe must have a dipole as well). These influences are stronger than the expected warming so we could concievably have a decade of cooling or a decade of warming much greater than the models predict and it would mean nothing (except politically). The implication of DO/meltwater is profound, because if it is internally driven, we might not know anytinig at a centennial or millenial scale either. -
Albatross at 12:33 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Ken @71, "I have already done that at #64" And yet before your comment #71 and after #64 you managed to make two more off topic posts at #68 and #70 :) Now, please either speak to the content of John's post/article, or move on. Thank you so very much. -
Albatross at 12:13 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hello Chip, Regarding your claim that "My [Chip's] command of English must be slipping,". Perhaps it is. Let me help if I may. And for the record you never have provided an explanation or specific reply to my comment original comment @61, so it is not possible for me to not "like" your explanation. Below is my post at 61 repeated here for everyone's convenience. I spelled out the problem with your claim very clearly: "You claimed in your response that: "We would like to note that waiting for one more year of data is not going to materially affect our analysis or conclusions." We know that claim in demonstrably false, because the melt data for 2010 surpassed those for 2007, which renders the following from your abstract obsolete (i.e., including those 2010 would have very much have affected your conclusions): "The melt extent observed in 2007 in particular was the greatest on record according to several satellite-derived records of total Greenland melt extent." Including those 2010 data also renders the first part of this conclusion in your abstract obsolete, while also calling into question the validity of the second part of the following: "The greatest melt extent over the last 2 1/4 centuries occurred in 2007; however, this value is not statistically significantly different from the reconstructed melt extent during 20 other melt seasons, primarily during 1923–1961" So contrary to your claims made here and elsewhere, the 2010 do very much affect your conclusions and desired narrative. " To summarize (again), the greatest melt over the last 2 1/4 centuries was in fact in 2010, not 2007. You claim that excluding those 2010 data "is not going to materially affect our analysis or conclusions" is demonstrably false, unless you are trying to argue that the 2010 figure was not higher than that observed in 2007. Thank you. -
Chip Knappenberger at 11:56 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Albatross, My command of English must be slipping, because upon re-reading your comment 61 I see nothing that I haven't already addressed. Just because you, perhaps, didn't like my explanation doesn't mean that I haven't offered one. -Chip -
Albatross at 11:44 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hi Chip, No, #112 does not address the issue, and your post @115 simply evaded the issue. Please read my comment @61 again-- I provided a link to that comment for your convenience in my post at @114 above. I was very specific in that post, concerning the claim that you made @ 58 and why is was demonstrably false. Thank you. -
muoncounter at 11:38 AM on 4 May 2011Why 450 ppm is not a safe target
dorlomin#2: "methane in the atmosphere exceeds 2ppm." Shakova and Semiletov 2007 reports: the surface layer of shelf water was supersaturated up to 2500% relative to the present average atmospheric methane content of 1.85 ppm, pointing to the rivers as a strong source of dissolved methane -- emphasis added That's consistent with the graph shown below: source
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Chip Knappenberger at 11:30 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hi Albatross, I think I discussed the general topic you were interested in at #61 regarding the impact of 2010 (which remains unknown), in my comments posted above at #112. If not, maybe you can ask them again. Thanks, -Chip -
Marcus at 11:10 AM on 4 May 2011Lindzen Illusion #3 and Christy Crock #5: Opposing Climate Solutions
"And in a competitive economy what measures would those be? Bankruptcy??" Of course, this is a text book argument from the Contrarian Movement. As has already been pointed out, the additional cost of carbon-rich energy, when taxed, will be applied to the *unit* cost of the energy (in MJ or kw-h), not to the total bill. In the last 10 years, I've seen my electricity tariffs rise by 8c/kw-h (due almost entirely to privatization & inflation), yet I'm currently paying about $40 per month *less*-on my total electricity bill-than what I was 10 years ago, simply by halving my daily use (purchasing energy efficient appliances & light globes, less reliance on stand-by modes & swapping my electric hot water system for a continuous flow gas hot water system). Now it's true that I spend about $20/month for my gas hot water, but that still leaves me $20/month better off than 10 years ago-& I can probably improve my position further by getting insulation installed to reduce my energy use for heating & cooling-so claims that reducing our CO2 emissions will send us *bankrupt* are just complete nonsense. Businesses & Industry also have plenty of room for reducing their CO2 emissions *and* reducing their total energy use. For example, the cement industry generates about 1t of CO2 for every tonne of cement made. Now I've seen evidence to suggest that this can be significantly reduced by measures like (a) recycling of old cement, (b) use of aluminium silicate instead of Calcium Carbonate, (c) capturing the CO2 from baking Calcium Carbonate & converting it to algal biomass, (d) using bio-gas, rather than natural gas, to bake the calcium carbonate. Of course, if the industry also captured its waste heat & converted it to electricity, then they could offset the costs of a carbon tax via the sale of electricity (co-generation). So we see that, yet again, a Carbon Tax represents an *opportunity*, more than it does a *burden*. -
Albatross at 11:09 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hello Chip, Back at #61, I showed that you made a demonstrably false statement/claim in you post @58. I was wondering whether or not you have any thoughts on that matter? I also have some other comments/questions, but have to take care of some other matters right now. -
Bern at 10:47 AM on 4 May 2011Why 450 ppm is not a safe target
mandas: Aim high and underachieve, rather than aim low and underachieve by even more. -
mandas at 10:30 AM on 4 May 2011Why 450 ppm is not a safe target
I both agree and disagree with your position re the target of 450 ppm. I agree that it is dangerous, and that the effect on the environment are likely to be significant. However, I disagree that it should not be an aspirational target, because given the current state of politics and the pitiful efforts to reduce current emissions, 450 ppm is likely to be at the low end of what we can realistically achieve. I am very concerned by this, and I despair about what the state of the environment is going to be at the end of this century because of it. But what can you do? -
Chip Knappenberger at 09:40 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Tom@111, Thanks for the questions. Our ice melt index is an average of the ice melt extent reported by three different research teams (using different methodologies) studying ice melt across Greenland. We didn’t feel that we were in a position to pass judgment on which of the methods was better, so we took the data provided us by the researchers, standardized it, and averaged the three standardized values together for each year. That is why we refer to our value as an ice melt extent “index” (it is unitless). So, the zero value of our index is really just close to the average of the index for the period 1979-2009. Regarding calving, see my comment @112, I think it will answer your question. And regarding the relationship between our reconstructed ice melt index and Greenland temperatures, remember that we also incorporate winter NAO along with summer temperatures into our reconstruction model. NAO doesn’t have a large effect, but it does has some effect, and its influence likely explains the situation that you describe. I hope this helps! -Chip -
Ken Lambert at 09:39 AM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
pbjamm #66 "Ken Lambert@everywhere Please stop trying to derail this thread and take the discussion back where it belongs." I have already done that at #64 - come on over to the Flanner thread yourself. -
RW1 at 09:37 AM on 4 May 2011An Even Cloudier Outlook for Low Climate Sensitivity
KR, "RW1 - Looks like both SW and LW; see the bottom of column 1, page 1524, where Dessler 2010 discusses combining the uncertainties of SW and LW measurements to determine total uncertainties." Yes, I know about that. That would seem to indicate it is the net SW and LW flux, but I should probably clarify this with Dessler himself just to be sure. -
Ken Lambert at 09:37 AM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
#69 Tom Curtis Dr Trenberth is estimating the 'annual' contribution of Sea Ice loss in the Arctic to the global energy imbalance budget. If you want to look at the Sea Ice loss relative to 1979, you need to look at the 'cumulative' loss over 32 years. -
Chip Knappenberger at 09:28 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
skywatcher@110, Thanks for the good questions. Let me try to answer them. You are correct that our uncertainty bounds represent statistical uncertainty in our model (which has some contribution from measurement error in that the model was built from likely non-perfect observations). So, the better the model performs, the tighter the error bounds. Or another way, if you prefer, the worse our model is, the wider the error bars and voila, nothing is statistically different than anything else (I would imagine that this is a property shared by most statistical models). All I can say, is that we tried to produce the best model that we could and reported the statistics associated with it. I believe this is the same thing as was done in the study I referred to that the IPCC highlighted. We did not report the error bars associated with our observed melt index, nor did we consider them in our determination of whether 2007 was or was not statistically different from any of our reconstructed values (including error bars). If we had considered errors in our observed melt index, I imagine that the number of reconstructed values which were not found to be statistically different from 2007 would have increased. And, just as in the example I pointed out from the IPCC, our error bars do indeed increase as predictor variables drop out as we go back in time. This is clearly stated in our paper, where we stated “It should be noted that the confidence of the reconstruction, as indicated by the error bars in Figure 2, degrades in the period prior to 1840 as the amount of independent data is reduced.” As far as 2010 having a greater melt index value when processed through the methodology described in our paper, I have not done the calculation, so I don’t know. I have reasons to believe it is not as cut and dry a situation that many of you all tend to want to make it. Further, I don’t see it as a factual error. If the sentence that everyone has the most concerns about is placed back into its proper context of the abstract, it should be plainly clear that our period of record, and thus the sentence in question, only goes through 2009. Heck, the title of our paper is “A reconstruction of annual Greenland ice melt extent, 1784–2009.” So I don’t think that anyone who reads the title and/or the abstract thinks that we have secretly left out 2010. If you picked our paper up in the year 2025 and started reading it, I don’t think you would be under the impression that this sentence in the abstract “The greatest melt extent over the last 2 1/4 centuries occurred in 2007; however, this value is not statistically significantly different from the reconstructed melt extent during 20 other melt seasons, primarily during 1923–1961” was referring to the period 1800-2025. So there is not a factual error in that sentence as written in context, nor has it been established that 2010 has a greater melt index (using our methodology) than 2007. But, like we said in our paper, “…preliminary estimates place the ice melt of 2010 at their highest level since at least 1958” so the possibility exists that 2010 may exceed 2007 (but even so, it doesn’t effect the correctness of that sentence in our abstract in context). Regarding calving…our paper was about surface ice melt, so our comments on other dynamic changes were mere speculation under the assumption that surface melt and other dynamic processes were correlated. As we stated in the paper “The forces acting in concert with ice melt across Greenland to produce higher global sea levels currently, should also have been acting during the extended high‐melt conditions from the mid‐1920s to the early 1960s.” If this assumption is invalid, or is becoming invalid, then our suppositions following there from may need reassessment. I hope this helps explain where we were coming from. -Chip -
dorlomin at 09:22 AM on 4 May 2011Why 450 ppm is not a safe target
Are you sure about this? "In parts of the East Siberian Arctic, methane in the atmosphere exceeds 2ppm. This is partly responsible for temperatures in the Arctic rising 2-3 times faster than in the tropics" The Zepplin station in Svalbard shows a slight decline in YOY methane concentrations. http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=ZEP&program=ccgg&type=ts I would have thought Arctic amplification is far more likely to be down to factors such as increased water vapor in the air, changes in ice albedo than methane. -
Tom Curtis at 09:10 AM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Ken Lambert @68, so you don't see using the previous lowest year to 2007 as the benchmark when the discussion regards net increase in incoming flux relative to 1979 as an error? -
Tom Curtis at 09:07 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip Knappenberger, I am having difficulty coming to grips with your paper, in large part because I am unable to access the original (given my limited means). I would appreciate it if you would answer some questions for me. With regard to the Ice Melt Extent Index in your paper, does the zero value represent total ice melt equaling total snow accumulation such that for negative values, the GIS gains mass if we ignore glacial calving, and positive values a mass loss? If not, what value does represent an equality of mass gain and loss (ignoring calving)? Further, although your paper does not deal with glacial calving, do you think it is reasonable to treat the Ice Melt Index as a proxy for total mass loss from the GIS as Michaels is doing, and as you appear to to do here. Finally, your Ice Melt Index shows similar values in the periods 1840-1920 and 1960-1990 even though Greenland temperatures where apparently half a degree colder in the former period. Is there any particular reason for this? -
Ken Lambert at 09:01 AM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Tom Curtis #65 I have already invited everyone to the Flanner thread, where Tom Curtis has not responded to my latest piece, even though he has quoted numbers in detail above in #65. This gross bit I cannot let go elsewhere: "To cap the later of you then divided the result by two again apparently because the measured 2 million square kilometer reduction in sea ice did not fit your prejudice. Again, you have refused to acknowledge that that mistake was a mistake." I got that 'prejudice' from Dr Trenberth, Tom - Dr Trenberth says in his "Tracking the Earth's Energy" Aug09 paper: Quote "Sea ice is important where it forms. Record losses of Arctic sea ice of about 10^6 km2 occurred in summer of 2007 relative to the previous lowest year [25], although the thickness and volume of the ice is quite uncertain. To melt 10^6 km2 of ice 1 m thick and raise the temperature of the water by 10 degC requires 3.4 x 10^20 J, or globally 0.02 W/m2. For 2004–2008 this is about 0.9 x 10^20 J/yr." Endquote Am I to be allowed to answer the rest of Tom Curtis' post at #65? -
skywatcher at 08:16 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
So far as I can see though Chip, your calculation of error is a purely statistical construct from the modelled timeseries values (the RMSE of the series), rather than a physically-based estimation of the uncertainty, which might be generated in this case, say by comparing observed melt values with modelled melt values where the series overlap? I'm not saying it's necessarily an incorrect way of estimating uncertainty, but it is not similar to the IPCC example you refer to - as seen by the fact that your uncertainties appear constant, while in the example, they change (increase with age in that case). Please correct me if I am wrong! Your conclusion fundamentally depends on the uncertainties being large enough to encompass the recent values in 2007 (and of course should have included 2010). Your factual error, surely, is of course that 2010 is the greatest melt season, not 2007, which also means that the two largest melts occurred in the past four years. Any further thoughts on my comments regarding melt values in comparison to mass loss (calving, recently accelerated flow rates)? I feel your paper inadequately deals with that and this largely leads to the erroneous statements on sea level. And why would sea level rise have had to have jumped to 3mm p.a. in the 1960s to confirm an accelerated contribution from Greenland alone? You never talk of all the relative contributions to sea level (thermal expansion etc) so this statement is made without context and is seriously in error. -
Bibliovermis at 08:14 AM on 4 May 2011Why 450 ppm is not a safe target
For comparison, the global mean passed 350 ppm in 1988 and is currently at 391 ppm. NOAA/Earth System Research Laboratory: Global CO2 Data -
scaddenp at 08:03 AM on 4 May 2011Models are unreliable
"Isn't meltwater, meltwater," Volume matters. At end of glacial, you have large amount of ice to melt below the arctic circle. The issue of interest for now wrt to sealevel rates, is that rate of warming is far higher than exiting a glacial but amount of ice available to melt is far less. As to BP, look at the data yourself. As to role of meltwater - this is unsettled science. There is good evidence of disturbance to thermahaline cycle and ditto for solar forcing. What causes the disturbance, relationships and timing is not settled. If you are really interested, read Wally Broecker on the subject. Relevance to now? Well no solar forcing and no disturbance to thermahaline cycle detected as possible causes of warming. -
johnd at 07:08 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip Knappenberger at 05:39 AM, fear not being seen as dense. Far from it, your contributions have provided an unusual degree of clarity and logic. -
Chip Knappenberger at 06:30 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chris@107, If I may join your conversation… I am not following your assertion that we are somehow unique in comparing an observed data value with reconstructed data values, and assessing whether or not they differ from one another by examining the error range that we determined about the reconstructed values. As a prominent example, I direct you to page 2 and 3 of the IPCC Third Assessment Report, particularly Figure 1b (I hope I am not falling for some sort of bait here). It shows a 1,000 year reconstruction of northern hemisphere temperatures along with the observed temperatures since 1861 and includes, among other statements, “The 95% confidence range in the annual data is represented by the grey region. These uncertainties increase in more distant times and are always much larger than in the instrumental record due to the use of relatively sparse proxy data. Nevertheless the rate and duration of the warming of the 20th century has been much greater than in any of the previous nine centuries. Similarly, it is likely that the 1990s have been the warmest decade and 1998 the warmest year of the millennium.” This figure, procedure and conclusion are similar in nature to ours. And as to our offending sentence in the abstract, I don’t think any portion of it has been firmly established to be factually in error. -Chip -
chris at 05:43 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Dikran Marsupial at 23:07 PM on 3 May, 2011 apols again Dikran - I seem to have failed in conveying I was being tongue in cheek! You said my response was a little pedantic in an early post and I was using the theme of pedantry in my conversation with you. Absolutely no offence intended. These issues can become over-serious, and it helps (me anyway) occasionally to relax by being a little light-hearted in these discussions however serious some of the dimensions are. In my opinion the sentence: ”The greatest melt extent over the last 2 1/4 centuries occurred in 2007; however, this value is not statistically significantly different from the reconstructed melt extent during 20 other melt seasons, primarily during 1923–1961.” shouldn't have been included in the abstract, since first it's factually erroneous, and second because it gives a spurious impression of a precision. The meaning of statistical significance in this case needs to be qualified, since it refers not to the question of whether Greenland melts now are different from melt rates then, but to whether Greenland melt rates now are different from a reconstructed model of melt rates then. So it’s got little meaning without consideration of the accuracy of the model of historical rates and the variance in the data in the reconstruction. These aren't well specified with respect to reality even if they are specified within the model. If this was a study in a medical journal (say) in which there are clear conventions in the description of statistical significance, then a single sentence statement in an abstract is appropriate. Maybe I haven't read enough papers but I've never seen a paleoreconstruction assess statistical signficance between contemporary empirical data and paleproxy data. I would insist that this sentence be either removed or made to better represent the findings; e.g.: “”The greatest melt extent over the last 2 1/4 centuries within our study period occurred in 2007, although the very recent 2010 melt exceeds that of 2007; these value are not statistically significantly different from the reconstructed melt extent during 20 other melt seasons, primarily during 1923–1961. However we emphasize that this analysis relates to a comparison of contemporary melt with a historical reconstruction having considerable uncertainty” But if there are good reasons not to assess statistical significance in differences between contemporary empirical data and historical reconstructions, then I don't see that FKM should be the groundbreakers here. But that's for an appropriate expert to assess... -
Chip Knappenberger at 05:39 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
logicman, Despite your handle, I am have trouble following you :^) Pat authored his own article at Cato, do you think I am serving as propagandist to spin it other than in a way he meant it? Perhaps I am not understanding your question. And, back to your comment #70, question 1. Comments have never been activated at World Climate Report, the latest piece is no exception. However, we’d be happy to entertain funding offers to hire someone to oversee that feature! And as to your second question, I am not sure I fully understand it. Wasn’t that topic covered in subsequent discussions in comments with Dikran, skywatcher, et al.? Sorry to be so dense. -Chip -
logicman at 05:25 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip "It should be clear from Pat's recent Cato piece that he is not particularly concerned that a sustained rapid acceleration in the rate of sea level rise is imminent." The ambiguity in that statement might allow a propagandist to write with some truth that Michaels, aware that a sustained rapid acceleration in the rate of sea level rise is imminent, is not concerned. Since I am not a propagandist, I will merely observe that in my opinion he should be concerned! Perhaps you did not see my comment #70? Can you respond please? -
KR at 05:15 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip Knappenberger - Thanks for coming by! -
Chip Knappenberger at 04:50 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
citizenschallenge, While I appreciate the courtesy, I am not a professor, so there is no need to address me as such, "Chip" works just fine! It should be clear from Pat's recent Cato piece that he is not particularly concerned that a sustained rapid acceleration in the rate of sea level rise is imminent. In that piece, and in several others in his 'Current Wisdom' series (some of which we link to here), he explains why, citing recent papers from the scientific literature. You are quite free to reach a different conclusion! -Chip -
citizenschallenge at 04:37 AM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Professor Knappenberger, I apology if that came across a bit strong ~ insulting wasn't my intention. I had just finished reading Pat Michaels’ take: "Sell Me Your Beach House, Please!" and was feeling a bit feisty. Also, I did not mean to imply I thought your study had no value. But it seems a small piece. Perhaps destined to become a historic benchmark as the trends blast free of the background noise. ... it just seems wrong to present a study such as KFM as though it were in a vacuum, as Michaels and others are clearly doing. -
johnd at 04:31 AM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
JMurphy at 22:30 PM, I don't know what more I can say except, courtesy of your post, I read it here first. Is Monckton that important a figure to you that you are now actively recommending others should read certain sections of certain newspapers just to keep up with the latest news about him? I remain fascinated/bewildered by the close attention being paid to him by the regulars here. -
johnd at 04:17 AM on 4 May 2011Could global warming be caused by natural cycles?
JMurphy at 22:06 PM, I follow the JPN-FRCGC model predictions which is included amongst the range of predictions on page 27 of your linked site. Just remain aware that I referred specifically to the El-Nino Index value, not whether that value was moving in or out of the range considered neutral or not. I note that NOAA confirm on page 3 and elsewhere that as at May 2nd, La-Nina conditions are still in place.
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