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malamuddy at 10:56 AM on 5 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Given that William O'Brien was talking to Americans for Prosperity when he made these comments, it is not hard to imagine where the pressure to repeal cap and trade in his state came from. If so, then the story has another significance for Australia. If the current government manages to introduce a carbon tax scheme, some businesses will pressure any subsequent conservative government to repeal it. The conservative side is already promising to do so. -
dana1981 at 10:53 AM on 5 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Thanks Alexandre. I agree, there are definite benefits to a carbon tax, especially in terms of simplicity. The benefit of cap and trade is the control that the cap gives you. The major problem with a carbon tax is the word "tax". It's why Republicans called US cap and trade proposals "cap and tax". Americans are deathly afraid of taxes, so a carbon tax is a non-starter here. -
Alexandre at 10:29 AM on 5 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Personally, I like the carbon tax better. It sounds simpler to execute, monitor and enforce. But it's great to know about these success stories with cap-and-trade schemes. About the export of emissions pointed out by ranyl above: AFAIK, the US (and many others) also buy loads of Chinese goods and have rising emissions all the same. The European success should not be so easily dismissed. Great post, Dana. It would be great to have more of these. -
ranyl at 10:12 AM on 5 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Not convinced there ahs been a drop in carbon emissions and European drops are false promise due to outsourcing of industry to China and the East and the resessional dip in power hungry activities. Carbon trading is claimed by many to be fundamentally flawed concept that will not cause CO2 to fall, read the Hartwell report http://eprints.lse.ac.uk/27939/ and watch the story of cap and trade http://www.storyofstuff.com/capandtrade/. All systems are supported by offsetting and loop holes and how can carbon honestly be accounted for considering the complexity of the fluctuations involved. Don't get me wrong we need to sequester billions of tonnes of CO2 and get back to 350ppm to even to be able to adapt but creating money spinning trading scheme markets and marketers to heighten the inequality gap (wait until it gets expensive to buy fuel to see who has it), and produce little or no actual CO2 savings. Not sure how on earth fossil fuel use will ever possibly stop but prohibition through money, tax or law won't work, like they don't with drugs and humans are totally addicted to the benefits of fossil fuels. How on earth are 40ppm of CO2 (20 years or emissions) going to be removed from the atmosphere especially considering the current state of the eco-systems and tendency towards CO2 release as the earth heats up? -
Climate Sensitivity: The Skeptic Endgame
Gilles> the average value of the "1/1-f" (and hence sensitivity) factor will be larger than the 1/(1-f0)) When providing a probabilistic estimate of sensitivity, we are looking for the most likely value (the peak in the distribution), not the mean of the distribution. This value is not at all biased in the way you suggest. -
Rob Painting at 09:46 AM on 5 March 2011Icing the Medieval Warm Period
Williambaskerville - that's nuthin. The Franz Joesph glacier (a tourist spot) info centre has a number of photos of the glacier dating back over a hundred years. Despite periods of advance the long-term retreat of the glacier is spectacular. When you walk to the glacier face, there are pegs marking where the face/front used to be at a particular time in the past. I can't find copies online but here's an indication:
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KR at 09:35 AM on 5 March 20112nd law of thermodynamics contradicts greenhouse theory
Fred Staples - My apologies, I'm mixing two examples in my last post. The isothermal atmosphere example you posit will increase in temperature due to increased GHG absorption, and will remain stable at that higher temperature unless the emissivity increases. That's a requirement of the S-B law. Temperature and emissivity are the two flexible values if emitted power is fixed - as one goes up, the other goes down. And in this case temperature is the dependent variable; emissivity is the driving variable. The actual Earth system includes both band widening/deepening as well as lapse rate driven cooling of the emissive layer. But both are part of the radiative greenhouse effect. Rock salt convective greenhouses are irrelevant to this - and the Woods experiments have been repeatedly debunked over time. -
KR at 09:28 AM on 5 March 20112nd law of thermodynamics contradicts greenhouse theory
Fred Staples - Even in the toy case of an isothermal atmosphere, absorbing/emitting greenhouse gases will increase the stable temperature. Power emitted must equal power received at equilibrium. Greenhouse gases do not affect power received (visible light window), while they decrease planetary emissivity in IR by radiating part of the energy back to the surface. Given the Stefan-Boltzmann relationship, if emissivity decreases power radiated decreases, causing an imbalance. An increase in greenhouse gases directly decreases emissivity by absorption band deepening and widening. This drops emitted energy to space. Power = emissivity * SB constant * Area * T^4 That imbalance will persist (accumulating energy, increasing temperatures) until radiated power rises to the level of incoming power again, at a higher stable surface temperature. The temperature will not drop again under those circumstances, because the emissivity of the planet remains lower. The only way to reduce the stable temperature of the planet would be to increase emissivity, by (for example) decreasing GHG's. Emissivity does not magically drop when the imbalance zeros out, which seems to be what you are asserting. Current Earth effective planetary emissivity is ~0.612, with ~240 W/m^2 entering and then going to space. Doubling CO2 creates an imbalance of 3.7 W/m^2, which is equivalent to reducing emissivity to 0.6026 by simple power scaling. Earth surface temperature is ~14C, or 287.15K. Calculating: ( 287.15^4 / ( 0.6026/0.612 ) ) ^ 0.25 = 288.27K The surface temperature under those conditions rises to 288.27K, or 15.1C, matching the 1.1C rise predicted for doubling CO2 with no feedbacks. -
williambaskerville at 09:01 AM on 5 March 2011Icing the Medieval Warm Period
@ Robert Painting Very interesting picture - especially the periods 1979-1981, 1982-1987, 1988-1989, 1990-1997, 2000-2001, 2002-2005 and 2006-2007. -
Fred Staples at 08:54 AM on 5 March 20112nd law of thermodynamics contradicts greenhouse theory
I do not claim, KR, 337, that all AGW theories contradict the second law. It is just that many of them do. Most of them confuse heat and energy, which is where entropy comes in. One such explanation, which you can still find in modern text-books, (Houghton for example) is the original greenhouse radiative effect. Consider a greenhouse made of non-absorbing material, such as rock salt. It will absorb heat from the sun, the interior will heat up, and, with convective cooling eliminated, the internal temperature will be higher than the surroundings (G and T’s car interiors, for example). The greenhouse will radiate W watts per square meter, proportional to the fourth power of its temperature. Now replace the rock salt cover with glass, which absorbs infra-red radiation. Half of the outgoing radiation will return to the interior, which, so the story goes, will heat up until it radiates 2W. The original W will then be radiated to the atmosphere, and W will be returned to the interior. The ratio of the glass interior temperature to the rock salt interior temperature will be the fourth root of 2, or 1.19. An increase of 19% of the rock-salt interior absolute temperature, or about 60 degrees C. Does that argument sound familiar? You will find it in part 1 of the Rabett paper to which SOD contributed. It is, of course, wrong. Back radiation from the cooler glass cannot heat the warmer interior. It would breach the second law if it did. To check this R W Woods built two greenhouses – one rock salt, one glass – so that their convective warming would be identical. Any back-radiative effect would heat the glass green-house preferentially. Their temperatures were the same. “Higher is Colder”, is not “part of the greenhouse effect”. It is the only plausible way of explaining how increasing atmospheric absorption and emission can increase the surface temperature. Incidentally, it is a mechanism which G and T did not discuss, although it was current from 1900 onwards. Think about an atmosphere without a lapse rate – an isothermal atmosphere where higher is not colder. Add greenhouse gasses, increase absorption, and you suggest that the atmospheric temperature will increase. What would happen if it did? Apply the Stefan-Bolzmann equation to the radiation to space, and energy emission will also increase (proportional to the fourth power of the atmospheric temperature). But the incoming energy, from the sun, will not change. So the atmospheric temperature will fall back to its original value. With a lapse rate, you can suggest that the effective emission level moves up to a colder region, reducing energy emission. All the temperatures must then increase to restore the balance. The only snag with that argument is that the evidence from the last 30 years shows that it does not happen to any detectable extent. -
Rob Painting at 08:38 AM on 5 March 2011Icing the Medieval Warm Period
scaddenp -Virtually all the rest of NZ glaciers are in retreat, mostly very rapid retreat. Picking one or items is Cherry Picking. Look at the overall picture. You mean like this overall picture Phil?.
See NIWA
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dana1981 at 08:32 AM on 5 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
Yes, the EU is another example, with a carbon cap and trade system in place since 2005. There have been some criticisms of the system though, that they started the carbon price too low so it hasn't been very effective. A good lesson for us to learn from in the USA, if we ever get a system of our own. -
scaddenp at 08:30 AM on 5 March 2011Icing the Medieval Warm Period
I would add further comment on glacier's as a climate proxy (though Mauri could say more). Glacier response varies depending on quite a number of variable. NZ West Coast valley glaciers in deep shaded valleys response to snowfall is marked. They have further complication that rock load from valley sides protect the ice from melting so may respond to earthquakes (increasing rock cover) as well. A better determination is done by looking at glacier system as a whole, or chosing glacier locations where response in highly dependent on terminal temperature. Either way, NZ is warming (as temperature records would also show), as is Argentina. Whether other glacier record in Asia support or defy a MWP cannot be taken in isolation without either surveys of larger system or data on response. -
Byron Smith at 08:30 AM on 5 March 2011SkS Housekeeping: navigation dropdowns, short URLs and monthly donations
I frequently link to the ten key indicators of a warming world post and the 10 key indicators of human fingerprints. -
Jesús Rosino at 08:13 AM on 5 March 2011A Real-World Example of Carbon Pricing Benefits Outweighing Costs
A real real-world example is the European Union, they have reduced their emissions 7% (EU15) or 11%(EU27) since 1990, mainly with their cap & trade system, and they don't seem impoverished. http://www.eea.europa.eu/pressroom/newsreleases/eu-greenhouse-gas-emissions-more http://www.eea.europa.eu/publications/eea_report_2009_9/ghg-trends-and-projections-2009-summary.pdf -
robert way at 07:55 AM on 5 March 2011Icing the Medieval Warm Period
Mcshane and Wyner had about 8 comments on their study by climatologists, many found substantial errors. Mann et al (2010) in their response found that Mcshane and Wyner should have concluded based upon proper analysis that there was an 86% probability that the 10-year period from 1997-2006 was the warmest on record. -
scaddenp at 07:54 AM on 5 March 2011Icing the Medieval Warm Period
What I argue is that you cannot take isolated pieces of data and draw conclusions. The paper I pointed to did that and all proxy data used in supplementary data. Can you explain why you think the methodology used for regional reconstruction of temperatures in that paper is flawed compared to yours? As to global - I agree that LIA appears to be global. However, it also appears to have been much stronger in NH than in SH based on the patterns of glaciations in both. (Unfortunately papers on this at work). -
Kevin C at 07:50 AM on 5 March 2011Roy Spencer’s Great Blunder, Part 3
Arthur@19: Oh yes, you are right. You could have a big transient due to 20 years of strongly negative PDO from 1880 (although it looks implausibly strong). So the MacDonald data is relevant after all. -
actually thoughtful at 07:45 AM on 5 March 2011Icing the Medieval Warm Period
I recall a controversy over the McShane/Wynter (sp?) paper trying to show the confidence for the 1990s being the warmest decade. Does Martín-Chivelet et al effectively refute their claim that there was a relatively low confidence that the 90s were the warmest of the last 2000 years (at least for Spain)? Please, I am not asking for a rehash, just to understand if we are more or less past McShane. -
Kevin C at 07:42 AM on 5 March 2011Roy Spencer’s Great Blunder, Part 3
Just done a quick confirmation. Here is a graph of the PDO (false scale), a 30 year exponential, and the convolution of the exponential with the PDO, which is Arthur's function Q(t):
Q(t) is simply the PDO with an asymmetric smoothing. To a good approximation we could say it has been smoothed and then lagged by about a decade.
If Arthur is right, then if we add the exponential (scaled by some factor) to Q(t), then we should be able to get Spencer's model. Or Barry's figure 8 by using different scales for the exponential term. Here goes:
That's pretty close. Looking back at Barry's figures, Spencer has applied an extra pre-smoothing to the PDO, which accounts for the remaining difference.
So what happens if we go to the future? Well, the exponential term is pretty near zero by 2000, so all that is left is the smoothed PDO. Hence Spencer is predicting cooling as the PDO goes negative.
What about the past? I think you can see where the exponential is going. Snowball earth in 1800, Pluto a little earlier.
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apsmith at 07:42 AM on 5 March 2011Roy Spencer’s Great Blunder, Part 3
Kevin C - good point on the transient bit blowing up into the past, I was trying to get to the bottom of that with Barry B. over email just now. In reality it is legitimate to have some transient value as a substitute for the missing forcing data before the starting point in the model (if you start just at T = T_e then you're saying there was no effect of forcing on temperature before the start). But to have such a large negative starting anomaly requires the forcing to have been large and negative in the prior period - and as we see from the MacDonald data it actually was quite close to zero for the few decades before 1900. -
robert way at 07:42 AM on 5 March 2011Icing the Medieval Warm Period
Another interesting paper using low resolution proxies is Viau et al (2006) which is based on pollen records and reconstructs temperatures similar to the MWP for up to 1950. http://www.skepticalscience.com/pics/1_Viauetal2006.png
Moderator Response: [DB] Enabled in-line graphic. -
robert way at 07:30 AM on 5 March 2011Icing the Medieval Warm Period
Fredrik Charpentier Ljungqvist at 02:14 AM on 5 March, 2011 Dr. Ljungqvist, would you not agree however that your reconstruction of the extra-tropical northern hemisphere demonstrated that the temperatures are currently above those during the warmest decades of the MWP. I have often wondered why your 1990s decade shows lower temperatures than the 1980s and correspondingly why the instrumental record for the 2000s was not plotted. Nevertheless I would wonder if perhaps results might differ if tree rings (33% of the reconstruction) were not included because they tend to have issues with low frequencies. Either way I do agree that proxy data from the southern hemisphere is too sparse for global reconstructions but examples of attempts such as from Huang et al (2008)
do demonstrate current global warmth exceeding the warmth during the MWP.
Furthermore when we think of the most sensitive of indicators of climate change ice caps are undoubtedly amongst the most sensitive. Evidence from Anderson et al (2008) demonstrate that ice cap recession on baffin island is beyond any period over the last 1700 years. Although the results of this study are of a low temporal resolution, conclusions such that ice cap recession is unprecedented over at least the last 1700 years are assured.
Each individual study obviously has their pitfalls but I do find it challenging that using annually to decadally resolved proxies for reconstructions are the only way of determining the magnitude of MWP to CWP comparisons. Perhaps Moberg's wavelet method is a plausible solution?
Moderator Response: [DB] Enabled in-line graphic. -
williambaskerville at 07:00 AM on 5 March 2011Icing the Medieval Warm Period
@ scaddemp "As for opinion on MWP - opinions are worthless unless based on data. For more complete picture of MWP globally, then try here." My opinions are based on data. Quite ignorant your post. Maybe you take a look on the reconstructions listed on the NOAA or my summary on mittelalterlichewarmperiode and then you get a better understanding :) @ muoncounter ".. it seems to be comparison of MWP vs. the current warm period." Yes, indeed. I don't know if medieval temperatures were warmer than the temperatures are today. I say, you can't count some glacier advances in the MWP against a MWP but on the other hand some glacier advances today not as an argument against a current Warm Period. To say: We have global warming now contra Northern Hemispheric Warming at medieval times is no argument in this case. If we had a global LIA we also had a global MWP with regional differences in warming, as we see them today. If there was no global LIA there was (at least) a bi-hemispheric MWP. Btw if the sun was the main factor in past, medieval warming, this would be an argument for a global MWP, as Dr. Büntgen stated: Gehen Sie von den möglichen Steuergrößen aus. Was bleibt übrig? Alles läuft auf dieser Skala auf die Sonne hinaus. Wenn dem so ist, müsste man sicher von einer globalen Anomalie ausgehen dürfen; natürlich durch interne Oszillationen modifiziert William -
thepoodlebites at 06:47 AM on 5 March 2011Ice age predicted in the 70s
#39 Your Barry et al. link is broken. Read just before the sentence you quoted, "the summer cooling is apparently widespread through the Canadian Arctic so that a larger scale control must be sought." A thorough scientist will recommend the need for further study when a cause for the observed trend can not be conclusively determined. -
muoncounter at 06:32 AM on 5 March 2011Icing the Medieval Warm Period
No, I got your argument entirely. I agree with your "LIA glaciers were increasing on a global basis," signifying a cold period. I took your earlier statement to suggest that the presence of a few 'increasing' glaciers today, along with a reference to warmer temps in the '30s and '40s, to mean that we are not in a global warm period. Most glaciers today are not increasing, as shown by the WGMP mass balance. The question is hardly a comparison of MWP vs. LIA; it seems to be comparison of MWP vs. the current warm period. -
scaddenp at 06:18 AM on 5 March 2011Icing the Medieval Warm Period
william - it is common to quote that two valley glaciers are advancing as evidence that its cold in NZ. In fact those two are in long term retreat but advance/retreat with ENSO-driven changes in snow. Virtually all the rest of NZ glaciers are in retreat, mostly very rapid retreat. Picking one or items is Cherry Picking. Look at the overall picture. As for opinion on MWP - opinions are worthless unless based on data. For more complete picture of MWP globally, then try here. Note the marked variations when you put it all together.Moderator Response: [DB] Good points, all. Alpine glacier advance is a function of temperature and precipitation in the accumulation zone, with terrain and slope a modifying variable. Thus, it is quite conceivable for a few NZ glaciers to be advancing in a warmer world even though the vast majority are receding. Saying otherwise is to simply be in denial. -
williambaskerville at 06:18 AM on 5 March 2011Icing the Medieval Warm Period
@ muoncounter "That statement holds little meaning on the global basis. Isolated increasing glacier references can indeed be found, but the entire picture is negative" So what? You did obviously not get my argument. We can turn your statement on the LIA and the MWP too. In the LIA glaciers were increasing on a global basis but some were decreasing and in the MWP the same vice versa. This does not mean that the LIA was not a global phenomenon and one of the coldest periods within the last several thousand years. This does also not contradict my opinion on the MWP as a bi-hemispheric phenomenon (for some the evidence for the Southern Hemisphere ist not "good" enough for this statement but ever since I've gone through papers of Lara, Villalba (1990a, b), Villalba (1994), Stine (1994), Thompson et al. (2000, 2006), Boninsegna et al. (2009), Ljungqvist (2009), von Gunten (2009 - Inauguraldissertation), von Gunten et al. (2009), Moy et al. (2009-Springer) and Neukom et al. (2010) on the (southern) South America and Huffman, Holmgren, Holmgren 2003, Holmgren and Öberg 2006, Robertshaw and Taylor 2000, Tierney et al, Lamb et al. 2007, Verschuren et al. 2000 and Ngomanda et al. 2007, for Africa, I am quite sure for this part too). Within the MWP - for South America more specific "the late Medieval Warmperiod" mean temperatures were warmer than in the LIA. Of course this does not mean that the mean temperatures in Europe in contrast to the temperatures of the subsequent LIA in Europe have to be the same in Africa. It depends on the region. -
scaddenp at 06:08 AM on 5 March 2011Ice age predicted in the 70s
thepoodlebites - the question is whether the scientific consensus was that planet was cooling. You can find papers noting long term negative turn in solar forcing, and plenty on aerosol cooling but also considerable concern about warming. Was there a consensus like there is on AGW now? Was there even a slim majority worried about cooling? You can only answer those questions of with systematic survey of scientific literature, not picking papers.(eg Peterson) As for Climate Depot - how many examples of misinformation would we have to show you before you abandoned it? 5, 10, 100, every post, - or never so long as it says things you want to hear. (ie is it worth our time trying?) -
Alexandre at 06:05 AM on 5 March 2011Icing the Medieval Warm Period
Pete Dunkelberg #24 Maybe this post about a Mann 2009 paper can be a partial answer to your second question. It's not really a time series, but two snapshots: one of the MWP temp averages over the world, and one of the Little Ice Age. You can see there many cold spots during the MWP. -
thepoodlebites at 05:53 AM on 5 March 2011It's Pacific Decadal Oscillation
#74 Response: Thanks for the link Daniel. [OT] The title kinda reminds me of the that character on Big Bang Theory, Eric Kripke, the university bully with a lisp and Sheldon's arch nemesis. [end OT] I'm open to the idea that the 0.5 C warming in the last 30 years is both natural and anthropogenic. My argument continues to be more from natural variability than man-made CO2 induced. If the UAH annual trend continues upward this decade, >0.8 C, then I think the AGW proponents have a stronger case. If the trend is flat to cooler, <0.3 C, then the AGW case will be weaker. Sorry to hear about the failed Glory launch. We need better satellite-based measurements. -
muoncounter at 04:56 AM on 5 March 2011Icing the Medieval Warm Period
William B: "there are glaciers increasing" That statement holds little meaning on the global basis. Isolated increasing glacier references can indeed be found, but the entire picture is negative:
Annual mass balance at World Glacier Monitoring Project
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williambaskerville at 04:50 AM on 5 March 2011Icing the Medieval Warm Period
@ JMurphy Don't be aggressive, Mr. Murphy. Infact it is maybe true that my statement is correct only for the norhern part of Scandinavia. Even if Dr. Büntgen in my interview told me: "Speziell sei noch darauf hingewiesen, dass gerade aus Skandinavien die vielleicht besten regional-scale summer, i.e. June-August temperature reconstructions based on annually measurements of conifer maximum latewood density kommen. Eine Divergenz zwischen ansteigenden Sommertemperaturen und geringerem Jahrringwachstum ist in Skandinavien eh kein Thema, da die höchsten Temperaturen in den 1930er Jahren lagen (der Sommer von 1937 war extrem warm)." http://mittelalterlichewarmperiode.blogspot.com/2010/08/menschen-im-gesprach-teil-vi.html Unless that, my argument is still correct. What do I want to proof? Nothing. I only add my opinion on the MWP and it's extend. @ Moderator Thank's I'll do so. -
invicta at 04:40 AM on 5 March 2011Icing the Medieval Warm Period
TIS & AS thanks for the links I'll get reading -
Fredrik Charpentier Ljungqvist at 04:34 AM on 5 March 2011Icing the Medieval Warm Period
Concerning Scandinavian temperature: It is only in the northern part of Scandinavia that temperatures were about as high in the 1930s and 1940s as in the post-1990 period. In southern Scandinavia the last two decades have been generally warmer than the 1930s and 1940s. -
JMurphy at 04:32 AM on 5 March 2011Ice age predicted in the 70s
thepoodlebites, it is difficult to know what argument you are trying to support, especially as the first paper you linked to (W.S.Harley) also stated : "Thirty years of data are found of insufficient length to determine whether the cooling constitutes a climatic change under the given criteria"; and the second one (Barry Et al) concludes the introduction with : "The evident sensitivity of this area to climatic fluctuations on both short and long time scales makes it a rewarding area for interdisciplinary environmental studies". Is any of that evidence of anything you are trying to prove ? -
Pete Dunkelberg at 04:32 AM on 5 March 2011Icing the Medieval Warm Period
Moderators: 1. Where did you get / how did you prepare the graphic in # 15? Could you also show the same but using, say, a 1959-1980 baseline vs 2000-2010? 2. Given the ability of Skeptical Science to present and clarify global climate, have you thought of a time series of the MWP? In other words, in a certain period of 50 to 100 years the MWP was in South America, then in the Caribbean, at another time in Europe, and at these times other regions were perhaps cool. Some newer temperature series (single spot 'hockey sticks') that have been mentioned here would be useful for this project.Moderator Response: [DB] That is a NASA graphic for which I lost the link (irritating, yes). However, I was able to quickly find that version on Treehugger.com (they added the obvious text, but the rest of the graphic matched my aging memory). I'll try & track down the exact NASA link. If you go to here you can create this output:
The rest of your suggestion, while intriguing, would amount to repudiating a Gish Gallop, in my opinion. -
JMurphy at 04:13 AM on 5 March 2011Icing the Medieval Warm Period
williambaskerville, a quick Google found this WIKIPEDIA page which states that, in Denmark, July 2006 was the warmest July ever and the second highest temperature ever recorded there - only beaten by August 1997. It also states that Sweden's highest daily average temperatures were in 1994 although, indeed, the highest individual temperature readings were in 1947 and 1933. It also states that many high temperature records were broken over many parts of Central and Southern Finland. What are you trying to prove ? -
Berényi Péter at 04:08 AM on 5 March 2011Climate Sensitivity: The Skeptic Endgame
#85 KR at 15:22 PM on 4 March, 2011 Berényi - I'll admit to having some trouble following that last posting. Try harder please and you'll find it makes sense after all. The last I heard you were claiming that the relaxation time was essentially zero, so that there was no heating left in the pipeline. Now you are arguing that relaxation times are long enough to slow warming to a manageable level??? You're contradicting yourself. No, I am not. The nice thing about linear systems is that they are additive. If there are several different processes in the climate system operating on different timescales, the overall response is simply the sum of individual responses. So the impulse response function can be written as the sum of λk/τke-t/τk (if t > 0, zero otherwise) for k=1,2,...,n. Guess why the full set of (λk;τk) pairs, along with their error bars is never specified in the mainstream climate science literature. Just play with the numbers and you'll see it is entirely possible to have a pretty high equilibrium climate sensitivity (sum of λk's) with extremely low short term climate sensitivity (sum of λk's for which τk is small) while rate of change in response to a quasi-realistic CO2 forcing scenario is never too steep. In fact this state of affairs is consistent with all the empirical data we have. Second, 1934 is not the start of anthropogenic carbon forcing - that's somewhere around the beginning of the industrial revolution, circa 1850 or so. Come on, the transition in the first half of 20th century was of course smooth, but the error in the response is the response to the difference between a smoothly changing excitation and this artificial one. As the difference between them is small and it was largest a long time ago (more than 70 years), the error in the climate response as of now is small. Third, relaxation times are relative to multiple time frames - from the several week H2O forcing to the multi-century ice response. Your simple formula is therefore inappropriate. And, since rate of change is dependent on scale of forcing, your 1.8C/century limit is, in my opinion, nonsense. As for the first part, see above. As for the latter part, please clarify what "rate of change is dependent on scale of forcing" is supposed to mean. Describe the dependence you think should hold in detail. -
williambaskerville at 03:48 AM on 5 March 2011Icing the Medieval Warm Period
@ DB "No one is suggesting that the warming of the global will be a uniform or linear process. But it is indeed a global process, as you can see here" If it is ok for the current warming not to be a uniform or linear process, why it is/was not ok for the so called MWP? I am convinced that the MWP was at least a bi-hemispheric event. Unfortunately we have not enough data to give information about the existence of a "MWP" in the equatorial areas of the world. I have listed some in my post: http://mittelalterlichewarmperiode.blogspot.com/2011/01/prima-klima-am-aquator.html For me there is no doubt at all that we have hundreds of pr-papers affirming the claim of H. Lamb for the Northern Hemisphere. Even scientists, sceptical towards the terminus "MWP" say that "mean temperatures during this interval were warmer than the subsequent Little Ice Age" (P.e. Crowley, Lowery: How Warm Was the Medieval Warm Period?, in: Ambio, Vol. 29 No 1, Feb. 2000, 54). We have also evidence for the existence of a MWP in Southern America, Africa, the Antarctica and New Zealand. On the other hand it looks like that there's a broad consent within scientific community that the LIA was a global event (p.e. Wanner 2008; the newest paper by Lane et al.: Oxygen isotope evidence of Little Ice Age aridity on the Caribbean slope of the Cordillera Central Dominican Republic. They write: "Climate change during the so-called Little Ice Age (LIA) of the 15th to 19th centuries was once thought to be limited to the high northern latitudes, but increasing evidence reflects significant climate change in the tropics"). If we accept that the LIA was a global event and, as Wanner wrote, one of the coldest periods within the last several thousand years, we have imho to accept that the temperatures at the foregoing time period were warmer than they were in the LIA too. Why don`t call it MWP like Lamb called it? For me one thing is clear. If you don`t accept the MWP as a warm period you can't accept the current warm period as a warm period either. As I said before, there are glaciers increasing in the Karakorum, in Norway and New Zealand even in Argentina. Don`t you know that the highest temperatures in Scandinavia were in the 30 and 40s of the 20th century? Best William http://mittelalterlichewarmperiode.blogspot.comModerator Response: [DB] Please read this post and then this post for background on the Medieval Warm Period. If you then still maintain the MWP was a global phenomenon, continue that conversation there. For posterity and context, current northern hemisphere temps greatly exceed those of the MWP:
Northern Hemisphere Temperature Reconstruction by Moberg et al. (2005) shown in blue, Instrumental Temperatures from NASA shown in Red -
dana1981 at 03:38 AM on 5 March 2011Climate Sensitivity: The Skeptic Endgame
HR #91:" how much of the 0.8oC would you attribute to anthropogenic GHGs?"
About 80%. -
thepoodlebites at 03:34 AM on 5 March 2011Ice age predicted in the 70s
#37 I find myself at a disadvantage here. If I answer your question my post most likely will be deleted, evaluated as an off-topic opinion. I'm finding the Climate Depot's link a valuable resource. I cited one peer-reviewed paper that supports my argument and I can cite many others, here. I will provide more links if this post is not deleted. Richard Feynman's first principle of scientific integrity states "you must not fool yourself, and you are the easiest person to fool. After you have not fooled yourself, it's easy not to fool other scientists." This first principle should be applied to everybody in equal proportion. -
les at 02:23 AM on 5 March 2011Climate Sensitivity: The Skeptic Endgame
Sorry Eruc; CERN doesn't just use them for QM - far from it. The fact is that such techniques are widely used and yield useful results -and probabilities, not "probabilities" - in all kinds of situations. Ofcourse they, like all techniques, can be used well or badly. That has to be argued, per application, on individual merits ... or, if you prefer on your POV -
Fredrik Charpentier Ljungqvist at 02:14 AM on 5 March 2011Icing the Medieval Warm Period
There have been a lot of discussions about the spatio-temporal pattern of the Medieval Warm Period in the last two decades. But the statements, often made, that the evidence for a Medieval Warm Period is most clear in Europe simply does not hold true. The evidences are in fact even better, and more numerous, from China. Also, the data from Greenland are quite good. I do not know why the Chinese scholarship, mostly published in English, so often are overlooked in the context of the Medieval Warm Period. This is a pity! The second half of the 10th century was pretty warm, well above the 1961–1990 mean, in most regions in the extra-tropical Northern Hemisphere where we have data (China, Europe, Greenland, Alaska, and Siberia). The data from the tropics and Southern Hemisphere still too spare to say anything certain still about the amplitude and extent of the Medieval Warm Period compare to the recent warming. What we do know is that it was synchronically warm in Greenland, Europe and China, and Siberia as well as, probably, over large parts of North America, c. AD 950–1050. Only this time interval shows evidence of coherent warm conditions in multiple regions. Later in medieval times (and earlier) the conditions were more geographically heterogeneous although quite similar still in Europe and China.Moderator Response: [Daniel Bailey] Thank you for taking the time to share your perspectives and expertise, Dr. Ljungqvist. An expert's presence is always welcome here. -
bbickmore at 02:03 AM on 5 March 2011Roy Spencer’s Great Blunder, Part 3
Alexandre, I have no idea how reliable it is, except that it is pretty accurate for the 20th century. I believe I linked to both data sets. -
Alexandre at 01:49 AM on 5 March 2011Roy Spencer’s Great Blunder, Part 3
Kevin C # 15 & 16 Thanks. Yes, I understood that too (even if more superficially and intuitively than your explanation). Spencer's model just yields absurd results as we get further from the calibration period. My question was not regarding the analysis of Spencer's work, but the certainty of the reconstruction itself. There's a quite popular meteorologist here in Brazil that uses the PDO argument now and then, and I'd like to know how much I can depend on that kind of long term reconstruction to make a counter-argument. -
Eric (skeptic) at 01:18 AM on 5 March 2011Climate Sensitivity: The Skeptic Endgame
les, being proper for quantum mechanics at CERN doesn't justify creating distributions for climate parameters that are completely described by classical mechanics. It impacts the policy debate only because the resulting "probabilities" are (from my POV) easy to unravel. E.g., someone links to a paleoclimate sensitivity argument and I simply point out the red boxes in Knutti, figure 3, that were left out of the figure 3 above (measurements for probabilityy distribution were not made with current climate) -
Arkadiusz Semczyszak at 01:11 AM on 5 March 2011Icing the Medieval Warm Period
... a propos Anasasi - generally: the drought in MWP. From the papers cited here: Land surface temperature changes in Northern Iberia since 4000 yr BP, based on δ13C of speleothems, Martín-Chivelet et al., 2011.: - “... 1350–750 yr BP warm period (Medieval Warm Period) punctuated by two cooler events at ~ 1250 [!] and ~ 850 yr BP ...” The same can be seen and here: Ababneh, 2006. Hence the declaration: “This drought marks the middle of the Medieval Warm Period - an interval of warmer temperatures between approximately AD 800-1300 characterized by greater drought duration and frequency in the Northern Great Plains compared to more modern times.” by Stambaugh et al., 2011.; does not give decisive argument to statements: drought = MWA - even regionally. -
Kevin C at 01:05 AM on 5 March 2011Roy Spencer’s Great Blunder, Part 3
One other thought: With Arthur's equation we can now run Spencer's model *backwards* through time using Spencer's parameters. The exponential decay of the transient becomes an exponential growth. The size of the transient at 1900 looks to be about -0.4C. An exponential with period of 30y multiplies by about 25 times every century. That means by 1800 it would be about -10C, by 1700 the temperature of the earth would have been approaching absolute zero. No matter how big the PDO, there's no way it can overcome an exponential. -
James Wight at 00:43 AM on 5 March 2011Putting a new finger on climate change
“10 fingerprints: Make room for Number 11 (gonna need a bigger glove).” Actually, make that number 12. Climatologists have recently found a human fingerprint in intense rainfall: Two seminal Nature papers join growing body of evidence that human emissions fuel extreme weather, flooding that harm humans and the environment
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