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Comments 97501 to 97550:
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krab at 09:01 AM on 24 January 2011A Flanner in the Works for Snow and Ice
I confess to being much confused by this post. How could W/m^2 for land be added to that for sea? Aren't they different areas? Going to the paper itself cleared this up. The total Watts are calculated and then divided by the total area of the whole northern hemisphere. This approach allows adding contributions together but still seems strange. Why not divide by the area of the whole earth? That way they could be directly compared with the other Global forcings. To make the comparison e.g. with the standard summary chart http://en.wikipedia.org/wiki/File:Radiative-forcings.svg, the northern contribution given above must be divided by 2. -
Bodo at 08:57 AM on 24 January 2011A Flanner in the Works for Snow and Ice
@kdfv: No, why should it? It means that climate sensitivity is a bit higher and therefore 2*CO2 warms the planet more than previous thought. -
kdfv at 08:52 AM on 24 January 2011A Flanner in the Works for Snow and Ice
Does this mean that the warming affect of carbon dioxide is less than thought? -
Ron Crouch at 08:46 AM on 24 January 2011A Flanner in the Works for Snow and Ice
To gain a little perspective on Arctic temperature and precipitation trends have a look at Climate Trends and Variations Bulletin - Annual 2010. Precipitation trends would tend to indicate that there should be no lack of snow cover in the immediate future. It's the extent depth/thickness and length of season that are changing subtly and amplifying the warming that is already taking place. If you look at the Annual Regional Temperature Departures we see a 63 year temperature record with the trends (relative to 1957). These temperature departures are well above global averages. The Mackenzie district experienced it's second largest departure while the rest of the Arctic districts experienced their largest. And if 2010 is any indication, then the Arctic will continue to get warmer. That's likely to have effects upon Arctic Ocean currents and atmospheric circulation patterns. -
Steve Bloom at 08:28 AM on 24 January 2011A Flanner in the Works for Snow and Ice calculations
I have yet to read the paper, but the press release quoted Flanner as saying that they found an ~+15% increase in TOA forcing. Is that consistent with your calculations? A ~20% sensitivity increase seems huge. Maybe run this by him? BTW, on a related topic I just happened to see this new paper (abstract), which got almost no attention when it came out a couple of weeks ago (I only saw it because of an article in a co-author's hometown newspaper) but sure seems like it deserves some. AFAICT (haven't read the paper) lack of prior data makes it a snapshot rather than a trend analysis, but even so the indicated change (~-25%!) to the land sink is not small potatoes. -
nealjking at 08:21 AM on 24 January 2011Oceans are cooling
Folks, The discussion #43 - #51 on the penetration of temperature variation as a function of frequency is a well-known result of the heat equation. As a quick sketch, if you impose a sinusoidal temperature variation at the top surface of an infinite block, the temperature variation within the brick will also be a sinusoidal variation in the time variable, but the amplitude will die exponentially as a function of depth. The characteristic length for the exponential fade is proportional to the square root of the period of variation: L ∝ √Period. So the longer the period of variation, the deeper the temperature of variation reaches, so the greater the effective heat capacity or"thermal inertia" of this situation. Some references: Brief general discussion of the heat equation: http://mathworld.wolfram.com/HeatConductionEquation.html Start with eqn.2 and read to eqn.5. Unfortunately, they don't discuss oscillatory solutions: However, if you assume a positive separation constant in eqn.5, it becomes: (1/κ)*(1/T(t))(dT/dt) = (1/X)(d^2 X/dx^2) = 1/λ^2 Assuming T(t) = exp(iωt), and X(x) = exp(-λx), iω/κ = 1/λ^2 λ = sqrt(iω/κ) = √(ω/κ) * √i = √(ω/2κ) * ( 1 + i) Therefore the solution is: T(t)*X(x) = exp(iωt) * exp(-ix√(ω/2κ)) * exp(-x√(ω/2κ)) Taking the real part of the solution, we get: cos(ωt - x√(ω/2κ)) * exp(-x√(ω/2κ)) So this is a wave traveling downward at speed v = √(2κω), with angular frequency ω, and fading out with characteristic length L = √(2κ/ω) So the slower the frequency, the longer the cycle period, and the greater the depth of penetration. This solution applies straightforwardly to the brick, or to the ground. It applies to the oceans as long as they are not disturbed, so the layers are not mingled. If the layers are mixed, then the depth of penetration is increased; and the longer the period of the driving temperature variation, the greater the likelihood of mixing. So the application to the ocean still makes sense: The liquidity still supports the point that the greater the period, the greater the depth of heat penetration and thus of the thermal inertia. -
Dikran Marsupial at 08:06 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
actually thoughtfull@37 I don't think the journals are feeling the pressure to publish papers that question AGW to the extent that bad papers are getting published because of it. Peer review is only a basic sanity check, so bad papers get published occasionally anyway. This is especially true when there is a heirarchy of journals and if your standards are low enough, your papers will get published regardless of how bad they are (the bottom end is little more than vanity publishing). However, even when they do get published, they don't generally attract many citations (other than in papers that point out the error), so looking at the citations is still a reasonable indication of whether a paper is of any value. There will undoubtedly be dodgy papers from mainstream climatologists as well, but you will be less likely to hear about them as they weren't preceded by a press release. -
Daniel Bailey at 07:58 AM on 24 January 2011Could global warming be caused by natural cycles?
For those inclined to favor the AMO (Atlantic Multidecadal Oscillation), Tamino has a nice summary opinion on it:"The increase in AMO from 1975 onward is because the detrending (an attempt to remove the global warming signal) is linear, but the global warming signal is nonlinear. Therefore the AMO increase since 1975 is because of global warming. Using it, without detrending the 1975-present segment separately, is exactly the problem previously described: using the effect of global warming as the cause of global warming."
and"the residue of the global warming signal in the AMO data gives the visual impression of a roughly 60-year cycle -- a mistaken idea for which there's no evidence other than wishful thinking on the part of denialists."
and finally"It really comes down to another lame attempt to claim that some "natural cycle" is responsible for global warming. The cycle doesn't exist, the one you think you see is the residue of global warming in N.Atlantic temperature data. If you want to remove the impact of N.Atlantic fluctuations on global temperature, detrending the post-1975 AMO is the only way to do it right.]"
I'd read a great deal lately on the AMO as a possible source for some of the observed warming in the NH, but this is (honestly) the best explanation of the AMO I've yet read. Or at least that I've understood. Good stuff. The Yooper -
Daniel Bailey at 07:41 AM on 24 January 2011A Flanner in the Works for Snow and Ice
Good writeup, Mark. If these results are subsequently confirmed the upcoming Arctic melt seasons will get very interesting... The Yooper -
muoncounter at 07:39 AM on 24 January 2011It's cosmic rays
#37: Eric, Thanks for the link to the Veizer 2005 paper; it certainly is unusual. He's mixed together what we've called GCRs with solar cosmic rays into a 'cosmic ray flux' (CRF). The CRF, in turn, is believed to correlate with the low altitude cloud cover. The postulated causation sequence is therefore: brighter sun ⇒ enhanced thermal flux + solar wind ⇒ muted CRF ⇒ less low-level clouds ⇒ lower albedo ⇒ warmer climate. Who among us will argue with the endpoints of that logical chain? Yes, brighter sun -> warmer climate. However, nothing in either Veizer or Rao substantiate the postulated mechanism of the steps in between. -
dhogaza at 07:23 AM on 24 January 2011Monckton Myth #6: Global Sea Ice
GC:Here is some information on Arctic ice in a region...
So your point is that the sea ice area in the sea of okhotsk is far below the 1979-2008 average, which ... disproves global warming?
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Eric (skeptic) at 07:18 AM on 24 January 2011It's cosmic rays
#36, I just read through that paper and I don't see a quantification of the low cloud changes. I don't think the author divided the TSI fluctuation by 4. His figure (2) comes from this paper http://www.sciencebits.com/files/articles/GACV32No1Veizer.pdf The Veizer paper references this paper http://www.agu.org/journals/ABS/2002/2002GL015474.shtml which states "Correlation of our total irradiance time series with T accounts statistically for 80% of the variance in global temperature over that period, although the irradiance variation amplitude is insufficient to influence global warming in present-day climate models." I'm skeptical about this last paper, correlations are suspect and I have not seen correlations of TSI and GAT. -
dana1981 at 06:59 AM on 24 January 2011A Flanner in the Works for Snow and Ice
Nice analysis, Mark. Interesting, and somewhat worrying study. -
Bob Lacatena at 06:51 AM on 24 January 2011Medieval Warm Period was warmer
Stefann, Oxford Kevin, Some time ago I went through as many of the co2science papers as I could bear. What I discovered was that: 1) Very many papers described a "medieval warm period", but differed from each other in actual dates by hundreds of years. Some would say 900, some, 1200, some 1400. Often there might be a period of some warmth for a few hundred years, but the period coming close to modern temperatures would be a peak covering a mere 20 span, and the peaks varied by hundreds of years from one study to the next. So the site will quote papers as seeing the MWP from 900 to 1250, and exceeding current temperatures by 1.5˚C, any yet the actual period where temps were that high were a mere couple of decades, and never the same couple decades from one study to the next. This would be the equivalent of taking the warmest annual temperatures from each country in the past three hundred years, and using each such maximum in concert to determine the temperature for the entire globe in that period. You couldn't even justify doing that in a single year, let alone ten, let alone hundreds. 2) I found several studies that were very selectively interpreted. For instance, one was based on a graph from a paper which showed warming in South American lake sediments. If you went to the paper, there were five other lakes in the study, all of which showed substantially cooler temperatures. They picked the one that showed extreme warmth and ignored the others. In another study, it was clearly stated by the authors that they were not studying climate and that their results could not be taken to reflect the climate in the region. But that didn't stop CO2science. In another case, the study only went back 500 years from the present (to 1500). That didn't stop them from including it in the MWP. In many cases, there were very wide error bars on the temperature and/or period range, or both, but these were always interpreted kindly in favor of the preferred conclusion. In other cases, the papers or graphics were so vague as to be worthless... they looked like they were scribbled on napkins. They either came from non-peer-reviewed articles and write ups (not studies), or else the subject of the study was not actual temperatures in the period in question, so any graphs included were worthless in that respect. After too much time wasted, it became quite obvious to me that there was neither rigor nor honesty in the effort. If there were, it would be published as a comprehensive, meaningful study, such as Mann et al (2009) (which reached the opposite conclusion, by combining all available proxies and systematically determining that while there was regional warming, such warming was not global... but it did so out in the open, in a peer reviewed study, not on a web site with no rigor or honesty). It says a lot, I think, when something is designed as a fun to use interactive map on a web site, yet can't make into the realm of peer reviewed science. -
jpvs at 06:19 AM on 24 January 2011It's cosmic rays
@35 (and others) I finally found the paper: http://moef.nic.in/downloads/public-information/Discussion-paper-INCCA-1-2.pdf It includes a reaction by prof Rawanathan (Scripps San Diego) -
ktam at 05:58 AM on 24 January 2011Medieval Warm Period was warmer
Re: @stefaan I don't know whether co2science had been selecting which bits of research to choose to include in their database or not but I know at least one instance where they misrepresented the results of the research. I'd felt for a while in their blog that they had been misrepresenting the results of published research, but I had no evidence so finally after I was pointed to another entry on the co2science website I decided to follow up and I read the original papers and contacted the lead author, I then wrote the results up on my own blog. You can read that here: http://oxfordkevin.carbonclimate.org/?p=469 Basically the lead author stated that "Our figure does not lead one to conclude that past sea surface temperatures were warmer than today as is suggested on these websites" My personal conclusion from this experience is that I cannot trust the work that they have done. Kevin -
actually thoughtful at 05:54 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
@Dikran: "(a good way of telling if a paper is any good is to look at its citations, if nobody cites it, it is generally because it is either uninteresting or incorrect). This advice is beginning to break down, as, due to the intense pressure to let the deniers have published papers (like letting your kid brother play ball even though he isn't coordinated enough but MOM said you had to let him play). Now we have these sub-par papers (McShane, Lindzen (according to commentary here), a recent paper that purports to show Antarctic warming at 1/2 of previous levels, etc.) and future denier papers will heavily cite these papers in order to run them up the credibility scale. It is the inevitable result of playing the "no peer reviewed papers" trump card. What is missing, quiet simply, is thet desire for honest results. The deniers are an entire industry that wants the answer to be "no warming; if warming, natural causes only" - and they will do anything to accomplish this, including perverting peer review. In fact they have already begun. In two years time deniers will be touting their "body of evidence" in peer reviewed journals. In 5 years time it will be true. Note - I use the term denier here quite intentionally. There are many skeptics who provide honest analysis of what we know we don't know (or think we know but don't). Trenberth being the Platonic ideal of a skeptic with his "travesty" comment. Even Pielke Sr. is using scientific method and the proven peer review process to establish (or see destroyed) his claims regarding ocean heat. -
JMurphy at 05:31 AM on 24 January 2011It's cosmic rays
pdt, I wouldn't get your information from sources like THE REGISTER. Having done a search for this 'paper', I have only found links to the usual sources of denial (like the one you found), most of them having copied a report from THE HINDU. In that original report, it states that Dr. Rao's findings were released "as a discussion paper" by the Indian Environment Minister. Another Indian source calls it a "scientific review...[of] recent studies..." There is also a report in the HINDUSTAN TIMES, with a reaction from V Ramanathan of the SCRIPPS Institute. None of the reports I found, actually had a link to the paper or, even, any information about the title or where it was to be published. Seems like they were just interested in copying and pasting something that sounded to them like an anti-AGW paper. Strange, eh ? Doesn't appear to be that hoped-for 'final nail in the coffin of AGW' that some are hoping for (yet again). -
Monckton Myth #4: Climate Sensitivity
RW1 - I've read the Lindzen and Choi 2010 paper as well. While submitted to JGR, it hasn't been published, hasn't made it through peer review yet, and I don't know if it will. They are still using a simple geometric extension of their tropical data to the rest of the globe (they refer to the well debunked method of L&C 2001), whereas Trenberth 2009 notes ENSO variations move an order of magnitude more energy between tropic and subtropic regions than their calculated imbalances. And Murphy and others have shown that using global data sets even with L&C's methods show much higher climate sensitivities. Having read each version of their paper, I don't believe they have addressed even a fraction of the serious issues pointed out to them. -
muoncounter at 05:19 AM on 24 January 2011Oceans are cooling
#50: "Can you direct me to a source" You could call your local HS physics teacher or look here. Low thermal conductivity translates to high thermal inertia, as 'inertia' is commonly understood to mean resistance to a change of state. I see the results of a very similar experiment every day in the summer because I live in a brick house in a hot climate. But this is not about bricks or shuttle tiles. It's about the response of the oceans, so please respond, in the context of KR's comment #46, to the discussion of the thermal inertia of the oceans presented in the linked NOAA paper in #49. -
stefaan at 05:17 AM on 24 January 2011Hurricanes aren't linked to global warming
Does anybody have a comment on this paper cited by post 20? (the Maue paper). Its a new 'hot item' among gw denialist sites... -
muoncounter at 05:09 AM on 24 January 2011It's cosmic rays
#33: "a recently published paper" Thanks for finding the appropriate thread. It appears that this is one from the 'here-we-go-again' department (I note that W^W# has already picked it up). I won't bother with snide editorialisms in the Register article or any of the other newspaper feeds that parrot it. Here is a link to the Rao paper (it's actually a 'research communication') to be published in the IAS publication 'Current Science'. I see several points in a quick look: a. No new data are presented b. The most recent reference is 2007 c. He relies on the 'well-established excellent correlation' between GCRs and low-level clouds. The CERN CLOUD experiment, designed specifically to test this, has yet to produce any such results d. He pulls a graph from a 2005 paper (Veizer) to show 'correlation' between surface neutron monitors and 'low-level cloud intensity'. Although this is supposed to be a heat-trapping mechanism and the conclusion of the 'paper' is that this is a significant part of global warming, he curiously omits any temperature data. e. He makes the usual hash of GCRs-> more high level clouds -> cooling due to increased albedo and GCRs->low level clouds -> warming due to heat trapping. Same old song, not even a new verse. -
pdt at 04:10 AM on 24 January 2011It's cosmic rays
This recent "The Register" article about a recently published paper on the influence of cosmic rays on climate presents a very different picture than the one shown here. I would be interested in seeing a assessment of the paper if anyone has time. -
RW1 at 03:54 AM on 24 January 2011Oceans are cooling
muoncounter, "That is a standard high school physics demonstration. I promise you the back side of the brick stays much cooler than the rapidly heated side." Can you direct me to a source that shows or documents this demonstration? I guess it would depend on the size and makeup of the brick, as well as the amount of and duration of heating/cooling, etc. -
Dikran Marsupial at 03:52 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
RW1@34 Yes, that is the one I found, and they use the AMIP models, so they haven't addressed the criticisms levelled at Lindzen and Choi (2009). The SSTs in the AMIP models are forced from the observations, which means that the system no longer conserves energy; hence any argument that is based on energy budget will be invalid. Lindzen argues that only the AMIP models have the same SSTs as the ERBE obeservations, but so what? The assumption of conservation of energy is broken so the argument is invalid. This error was pointed out to them. Also isn't this paper from the procedings of a symposium, and hence (a) it was lightly peer reviewed (if at all) and (b) there is no mechanism for formal comments papers like there would be for a journal paper (c) it is very recent, which means that it hasn't been scrutinised by the research community yet (a good way of telling if a paper is any good is to look at its citations, if nobody cites it, it is generally because it is either uninteresting or incorrect). -
muoncounter at 03:36 AM on 24 January 2011Oceans are cooling
#48: "the whole brick would warm and cool" That is a standard high school physics demonstration. I promise you the back side of the brick stays much cooler than the rapidly heated side. "What is the physical reason? If the whole ocean participated in the thermal mass, the short term seasonal warming could not occur." Let's lose the hypothetical nature of this question and start with the observation that seasonal warming and cooling does indeed occur. We certainly can agree that ocean surface layers therefore act as if they have low thermal inertia and participate in these relative rapid changes. As to the greater inertia question, do you agree with the analysis presented by NOAA here? The seasonal variations in heating penetrate into the ocean through a combination of radiation, convective overturning (in which cooled surface waters sink while warmer more buoyant waters below rise) and mechanical stirring by winds. There are your mechanisms. ... These processes mix heat through the mixed layer, which, on average, involves about the upper 90 m of ocean. The thermal inertia of a 90 m layer can add a delay of about 6 years to the temperature response to an instantaneous change ... As a result, actual changes in climate tend to be gradual. There is the reason why 'the tiny little increase from CO2' does not change the ocean temperature quickly. With its mean depth of about 3800 m, the total ocean would add a delay of 230 years to the response if rapidly mixed. However, mixing is not a rapid process for most of the ocean ... An overall estimate of the delay in surface temperature response caused by the oceans is 10–100 years. --emphasis added All of that inertia, without any discussion of the complicating roles of density layering and thermocline structure. Salinity effects on ocean density are also important but are poorly measured at present. It is essential to be able to attribute changes in ocean heat content and the mass of the ocean to causes (such as changing atmospheric composition), perhaps using models. Climate models suggest that the THC could slow down as global warming progresses, resulting in counter-intuitive relative regional cooling or, more likely, reduced warming on multi-decadal time-scales. -
Camburn at 03:29 AM on 24 January 2011The Climate Show #5: Green roofs and Brisbane floods
Albatross@14: My skepticism of the validity of SSM/I is a result of finding the on ground measurements verses the SSM/I indications. I am most interested in Argentina/Brazil as weather patterns in that area directly affect my business. I do not take a single rain guage as verification. It is quit easy to find various rain guages that verify or refute what the satillite is showing at a certain time. This indicates to me that the satillite measurements/data are not reliable metrics. Radar for sure is an unreliable metric of actual measured precipitation. I have read several papers concerning precipitation events/trends etc. One thing I have noted is the seemingly absense of error bars in the papers. It is very hard to draw conclusions without those present. My experience would indicate that the SSM/I error bars should be relatively large, but without the underlying data it is impossible for me to create them. This type of science is extremely important to me in making sound business decissions and I can only hope it becomes more precise in the future. Thank you for the links presented. -
RW1 at 03:13 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
Dikran (RE: 33), Lindzen2010 -
RW1 at 03:01 AM on 24 January 2011Oceans are cooling
KR, "The top of the brick will alternately be hot enough to burn your hand and cold enough for a nice iced drink." I wouldn't think so - I think the whole brick would warm and cool, but a pot of water would be more analogous to use. That's not going to work either though, I don't think. "Only the upper layer of the ocean gets seriously involved in short term seasonal temperture/insolation variations, and since it's a fairly small mass it changes quite a lot. But a constant offset? That has time to sink in, to change the deep ocean. And hence the average temperature of the oceans." Why? What is the physical reason? If the whole ocean participated in the thermal mass, the short term seasonal warming could not occur. There is no reason to believe the tiny little increase from CO2 wouldn't also change the ocean surface temperature just a quickly. The question is equilibrium time per incremental amount of forcing - not whether or not gradual changes in the upper ocean layers can eventually trickle to the deep ocean waters somewhat. There are also many reasons why the temps of deep ocean waters can change. -
Dikran Marsupial at 02:58 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
RW1@31 Can you give a specific reference for Lindzen 2010? The only one I could find appears to be still using AMIP models and hence does not address one of the key criticisms of Lindzen and Choi (2009). -
Eric (skeptic) at 02:55 AM on 24 January 2011Arctic sea ice has recovered
Riccardo, I will keep that in mind. The LIA was stuck in my mind because I wanted to caveat the record low in sea ice by saying post-LIA. But I actually do not have any evidence in hand that sea ice was lower before the LIA (e.g. MWP), so I should have left that out entirely. -
angliss at 02:51 AM on 24 January 2011Oceans are cooling
You can prove that there is heating in the pipeline, as it were, by using a simple capacitance relationship: I = C * dV/dt, where C is the heat capacity of a block of ocean, dV is the change in temperature, I is the amount of power injected into the block of ocean, and dt is the time it takes to heat up the amount dV. Note that I used electrical terminology because of my EE background, but the math is the same. Rearrange the terms to solve for dt and then do a little digging for the heat capacity of a block of seawater, and ta-da, you've got your first-order approximation of the answer. It neglects seasonal variations, convection, and radiation, and heat conductivity so it's hardly perfect, but it's a good starting point. Add heat conductivity and the time goes up. Add convection and radiation and the time drops. Add seasonal variation and the time shouldn't change much if at all. -
Eric (skeptic) at 02:49 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
Ken, considering that some models predict more positive AO http://www.cccma.ec.gc.ca/papers/jfyfe/PDF/FyfeBoerFlato1999a.pdf and some say more negative due to ice loss http://journals.ametsoc.org/doi/pdf/10.1175/1520-0442%282004%29017%3C0890%3ATARTRA%3E2.0.CO%3B2 the AO response is a prime example of a climate change paradox: http://www.agu.org/pubs/crossref/2005.../2004GL021752.shtml Natural variations in albedo are over 10% in summer in the Arctic alone https://www.cfa.harvard.edu/~wsoon/MattCronin-Mar21-07-d/WangKey03-ArcticClds+TfromAVHRR.pdf strongly correlated with AO. It is even more difficult to predict the cloud and albedo changes in the NH land masses without knowing the AO sign. I have to ask the question: what is the solution to this prediction problem? Assume the models are correct and AO will become positive? Assume it will become negative in early winter due to ice loss and add that feature to the models? Assume it varies randomly and add random variation to the models? -
RW1 at 02:39 AM on 24 January 2011Monckton Myth #4: Climate Sensitivity
People keep referencing Lindzen 2009, but they addressed the criticisms and largely re-did the whole thing in Lindzen 2010 and the end result was pretty much the same. -
michael sweet at 02:34 AM on 24 January 2011Monckton Myth #6: Global Sea Ice
Galloping Camel: Since the most recent IPCC report was issued BEFORE the sea ice low in 2007, it is impossible for them to be alarmist about the sea ice low that year. Denialists, on the other hand, frequently make alarmist statements. Your claim in 29 shows that you do not care about the facts of the situation. Please stop making such absurd claims. -
JMurphy at 00:42 AM on 24 January 2011Medieval Warm Period was warmer
hengistmcstone, there are a few studies here, here, and here, which go back to about 11000 years ago. -
hengistmcstone at 23:48 PM on 23 January 2011Medieval Warm Period was warmer
Hi, "the Medieval Warm Period occurred during a time which had higher than average solar radiation and less volcanic activity" I don't see how the first argument there 'a time which had higher than average solar radiation' can stand on it's own. What measurements do we have for solar irradiance 500 years ago? Can you please cite some papers in support. Thx Hengist -
Ken Lambert at 23:32 PM on 23 January 2011Monckton Myth #4: Climate Sensitivity
Eric #29 How about we try to put some numbers on cloud and direct albedo going forward. The TSI (divided by 4)is about 340W/sq.m at TOA and total reflection (cloud and direct albedo) is quoted as about 100W/sq.m (30%) leaving about 240W/sq.m energy flux to play in the biosphere. AGW theory says that there is an average 0.9W/sq.m positive warming imbalance which means that for a net 240W/sq.m incoming, 239.1W/sq.m goes out. How accuragely do we measure the roughly 100W/sq.m ie; 30% reflected? How do we project that measurement forward to cycle models? eg; let us assume that the 30% is measures to +/-1% accuracy; therfore it could be 30.3% or 29.7%. In real terms 101W/sq.m or 99W/sq.m. This example tolerance +/-1W/sq.m is higher than the imbalance (0.9W/sq.m) postulated. Are we measuring these numbers to that accuracy and how would these vary in a higher WV or higher CO2 environment for input to climate models?? -
Riccardo at 23:23 PM on 23 January 2011Arctic sea ice has recovered
Eric (skeptic) sorry for being OT and a bit pedantic. Given that your comments are usually scientifically well reasoned, I'd like to suggest to not use the term "recovery from LIA". This term implies a planet that for some reason was pushed out of a well defined equilibrium and is now going back toward the previous (or any other) equilibrium. In reality, as I'm sure you'll agree, the forcings has changed, and are still changing for whatever reason, and the planet is changing accordingly. -
Eric (skeptic) at 22:12 PM on 23 January 2011Arctic sea ice has recovered
Overland has a more recent paper http://onlinelibrary.wiley.com/doi/10.1002/joc.1973/abstract attributing the 1920-1940 Arctic warming as partly AGW: "Our findings indicate that early climatic fluctuation is best interpreted as a large but random climate excursion imposed on top of the steadily rising global mean temperature associated with anthropogenic forcing." -
Eric (skeptic) at 21:57 PM on 23 January 2011Arctic sea ice has recovered
Let me first answer the overt question of the thread: Has Arctic sea ice returned to normal? No, it is still near record lows for the post-Little-Ice-Age period. But there is also a covert question in this thread that came up in the thread linked by Muoncounter above. That question is: Has Arctic sea ice fluctuated in the past (i.e. what is normal)? The Walsh data that muoncounter provided is flat mainly because it is out of date. It doesn't include the Russian data http://nsidc.org/data/g02176.html) For example, the dip in the 30's is nonexistent. There are natural explanations for such dips, for example http://www.agu.org/pubs/crossref/2005/2005GL024254.shtml "The period from 1928–1935 also had a dipole structure in SLP, which contributed to the interdecadal arctic-wide warm temperature anomalies in the first half of the 20th century." Also as I pointed out in the other thread, the main cause of late 19th and early 20th century decline in both hemispheres was recovery from the LIA. The main cause of the current, abrupt decline is AGW plus local feedback from open ocean. I am not trying to hide anything. -
michael sweet at 20:49 PM on 23 January 2011Arctic sea ice has recovered
Responding to Galloping Camel on the Monckton thread who wants to throw away the data: The data set that Muoncounter cited says the data is reliable back to 1953. I figure that is 60 years, not 40. The additional data back to 1900 can be used carefully. Scientists use all the available data to reach the most comprehensive conclusions. It is typical of "skeptics" to deny data that has been carefully gathered because it shows that AGW is much worse. People live in the Arctic and they record the conditions where they live. Explorers kept careful records of ice conditions where they were. Fishermen record the ice edge (watch Deadliest Catch). These records enable comparisions to current data. Cite a reference that says the graphs I have copied are not usable or stop your unscientific comments. It was not my intention to suggest that the ice was flat in the past. The data shows that the ice has been in significant decline because of AGW for longer than the 30 year satelite record. Deniers want to limit the data used to hide the decline in Arctic sea ice. -
scaddenp at 20:45 PM on 23 January 2011Global Warming and Cold Winters
"Climate change can be very sudden" - yep. Broecker commented too that climate change that rapid would destroy temperature food production in NH as how would farmers know what to plant? However, these very rapid reversals only appear in the historical record when coming out of a glacial. If there was a risk of such an event due to current climate behaviour then we would be in a grave position indeed but there is little evidence for such a risk. There may be more than one cause for YD-type, Heinrich events and such like but none of theories suggest a risk that would operate now. -
gallopingcamel at 17:59 PM on 23 January 2011Monckton Myth #6: Global Sea Ice
Accurate measurement of sea ice extent has been available for less than 40 years so we don't yet know what the "normal" range of variations is. However this thread does at least admit that Antarctic ice cover has been increasing over that brief period while Arctic ice has trended downwards. Those folks (e.g. the IPCC and the NSIDC) who predicted a dramatic decrease in Arctic ice by assuming that the trend that gave us a record low ice coverage in 2007 would continue have been shown to be wrong (color them "Alarmists"). Here is some information on Arctic ice in a region that has some economic importance (at least to the Russians): http://diggingintheclay.wordpress.com/2011/01/09/ice-build-up-in-sea-of-okhotsk/Response: Actually, the IPCC grossly underestimated the decrease in Arctic sea ice:
In this case, the "alarmist" is nature itself which reacted more strongly than even the IPCC's worst case scenario. -
Oceans are cooling
RW1 - "Neither will the top of the brick." Really? The top of the brick will alternately be hot enough to burn your hand and cold enough for a nice iced drink. As to why a brick - I thought that a simpler case for discussing slow thermal transfer from top to bottom. Only the upper layer of the ocean gets seriously involved in short term seasonal temperture/insolation variations, and since it's a fairly small mass it changes quite a lot. But a constant offset? That has time to sink in, to change the deep ocean. And hence the average temperature of the oceans. I'm beginning to find your objections to this disingenuous... -
RW1 at 16:31 PM on 23 January 2011Oceans are cooling
KR, Also, why are you analogizing with a brick rather than a pot of water? -
dhogaza at 16:29 PM on 23 January 2011A Case Study in Climate Science Integrity
Ron Crouch:If governments would only face global warming with the same tenacity that they apply to terrorism.
Actually, the current leadership of the Republican Party in the US does ... Problem being they look at climate science as being equivalent to terrorism ... -
dhogaza at 16:27 PM on 23 January 2011Monckton Myth #6: Global Sea Ice
muoncounter: I responded to Eric before reading your request to move discussion to an earlier thread ... -
dhogaza at 16:25 PM on 23 January 2011Monckton Myth #6: Global Sea Ice
" I think flat linear is not a good fit at least for maximum ice extent (perhaps better for minimum) because of harsher winters up to the end of the Little Ice Age." So everybody take care that I explicitly mentioned the last two graphs of Eric's first post (June and August), and he responded by plotting April. We all know that the maximum winter extent tends to be geographically bounded in the Arctic, which is why the most attention is paid to the September minimums. "it is a smaller area and it is the max extent and it ends before 2000, so obviously a lot less of a drop. You are correct that the AGW variations show up in the min extent more. The point of the chart is to show the natural variation." Well, at least you admit to cherry-picking. Why on earth you think this will add to your credibility here is beyond me. -
RW1 at 16:09 PM on 23 January 2011Oceans are cooling
KR, "If I take a brick and repeatedly pass a hot torch and a block of ice over the top of it, the bottom of the brick will change temperature almost not at all." Neither will the top of the brick.
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