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HumanityRules at 14:11 PM on 6 May 2010Kung-fu Climate
11.CoalGeologist The Journal of Quaternary Science in Jan 2010 produced a special edition entitled "Special Issue: The 4th IPCC Report and Beyond: Palaeoclimate Perspectives" The introductory article makes good reading. IPCC and palaeoclimate - an evolving story? (p 1-4) Chris J. Caseldine, Chris Turney, Antony J. Long Published Online: Dec 4 2009 12:14PM DOI: 10.1002/jqs.1336 It nicely goes through the history of paleoclimate data in the IPCC. It would suggest that it's not just the "sceptics" that have increasingly seen the importance of this field of study. When you say "climate scientists have looked long and hard for contemporary natural drivers other than AGHGs" I'd suggest they look longer and harder. I'd like to know the role of clouds and water vapour, aerosols and given the 'missing energy' issue just what is the role of the oceans. -
Doug Bostrom at 14:01 PM on 6 May 2010Kung-fu Climate
Poptech, why should it matter if the current warm period is within the range of natural variations? The current warm period appears -not- to be a natural variation according to the best synthesis we can produce. The paper does not seem relevant to the topic, except maybe as a rhetorical lever. -
Doug Bostrom at 13:59 PM on 6 May 2010Kung-fu Climate
Poptech, Loehle apparently has no issue w/Hadley, he supplied it to Ron after all. Why should you? Are you aware of any problems w/Hadley data? If so, specifically what are they? -
Doug Bostrom at 13:55 PM on 6 May 2010Kung-fu Climate
Nice article, Rob, and thank you. But I guess I'm w/CoalGeologist on this-- what's the big deal? Strangely enough (or perhaps I'm not as strange as I think) I wasn't aware of this article prior to reading about it here. What I gather is, Dr. Loehle has teased out what he sees as better understanding of the MWP's magnitude although not its areal extent and he adds the further conclusion "The warmest tridecade of the MWP was warmer than the most recent tridecade, but not significantly so." What if anything about this paper speaks to current climate forcing theories, prognostications and observations? -
nautilus_mr at 13:47 PM on 6 May 2010Kung-fu Climate
The deniers' focus on discrediting the hockey stick is due to its political value, not because of its role in the science. It is the most easily recognisable symbol of AGW and, I would argue, did more to win broad public support than any other item of evidence. Like many of the contributors above, people who see global warming as a scientific matter tend to scratch their heads about the extreme emphasis on this one small part of a huge body of research. But we must remember: certain well organised and noisy organisations see data and scientific jargon as nothing but a political tool, not to achieve truth, but 'truthiness' (S. Colbert's contribution to modern english). Fox and the Heartland Institute couldn't care less about scientific accuracy. They are after the 'hearts and minds' and they understand the minds are easier to win with good old FUD, than with complicated analysis. -
Rob Honeycutt at 13:43 PM on 6 May 2010Kung-fu Climate
@Poptech... I have to disagree with you about the battle. I believe you maybe do not understand my broader point that there are a lot of versions of the paleo reconstructions, each vying to be the definitive chart. But I'm trying to say that is far less important than what we see today and how we respond to the challenges we face. Honestly, I am more concerned when I see charts like Loehle's with a large variation in temperature because that suggests much greater climate sensitivity and could spell a much worse situation for us going forward. We should all HOPE that it's Mann's chart that is the more accurate one. Then we may be able to respond in time to what could be a looming crisis. -
Rob Honeycutt at 13:37 PM on 6 May 2010Kung-fu Climate
@Poptech... You are correct. I misread Loehle's statement in his paper. But the data that I appended to his chart is the Hadley data that he provided to me. -
garythompson at 13:09 PM on 6 May 2010Kung-fu Climate
i enjoyed this piece Rob, thanks. a question i have always had was how accurate are tree ring proxies from many years past? can someone point me to a link or paper that describes this tree ring proxy procedure, how it was verified, etc.? without being familiar with the procedure, my question is as a tree ages for hundreds of years, those inner rings would come under pressure and perhaps shrink thus skewing the actual temperature of those older timeframes. i'm not a biologist nor do i have extensive experience doing this but i'm just mainly intersted in learning about the procedure. many thanks ahead of time for helping me out! -
scaddenp at 12:42 PM on 6 May 2010Kung-fu Climate
ubrew12 - I think comments about arctic methane really are alarmist. see arctic methane on the move. If continental shelf hydrates were lost, then that would be problematic but I think there is any serious science to suggest this is likely? Like coalgeologist (hey I spent a lot of my life as one too), I fail to understand the obsession with MWP. Though as Rob has pointed out, the instrumental data on the same graph gives one pause to think about the rate of warming compared to past periods. -
johnd at 12:37 PM on 6 May 2010Kung-fu Climate
Just to be certain, could the base period for each anomaly be attached to each graph so that we know, rather than having to assume, that they all refer to the same benchmark. -
carrot eater at 12:36 PM on 6 May 2010Kung-fu Climate
Credit to Loehle in that there were a number of sloppy errors in the original attempt; the corrected version is improved. Spencer Weart: I think only three of Loehle's proxies were Southern Hemisphere. From the nature of the proxies used, there's also going to be some dating error. If nothing else, Loehle's reconstruction is the people's reconstruction. The method may not be the best, but it's simple enough that anybody could do it. But beyond the issues with the amount of data and simplistic processing, is the question of exactly why these results support scepticism. Loehle's results show a bit more variability than others. Sceptics like to jump from that to various unsupported conclusions. -
CoalGeologist at 12:31 PM on 6 May 2010Kung-fu Climate
I’m flummoxed, as ever, by the obsessive fixation AGW “skeptics” have with the MWP and LIA. Even if one concedes that certain regions of the Earth may have been episodically cooler during the LIA, or warmer during the MWP, in what manner does this negate the warming effect of anthropogenic CO2? Geologists have an expression: “The present is the key to the past”, which suggests that if we are able to understand natural processes occurring on the Earth today, we will be in a better position to understand events that occurred in the geologic past. The implication, however, is that the same or similar processes have occurred in the past as are occurring today. This is only partly true. Geologists now recognize that rare, catastrophic events are disproportionately represented in the geologic record. Many AGW “skeptics” attempt to invert this principle by stating the something like: Climate change has occurred naturally in the past; Therefore contemporary climate change might be natural as well. So far, so good, and most climate scientists would agree. The problem arises when “skeptics” commit a perversion of logic in extending this to infer, “Climate change has occurred naturally in the past, therefore present climate change must be natural also.” (I might not have represented this fairly, as the logic eludes me.) The problem is that climate scientists have looked long and hard for contemporary natural drivers other than AGHGs, and can’t find any that can adequately explain the observed warming. One contribution geologists can make to present situation is that there is no precedent in the geologic record for the sudden release of such massive quantities of CO2 into Earth’s atmosphere—certainly not during the Middle Ages. CO2 levels have been higher in the distant past than they are today; however, the sun was cooler then, or the configuration of the continents was different, etc. We are dealing with a unique set of circumstances today. Therefore, the MWP does not illuminate our understanding of contemporary warming. In both the “hockey-stick” diagram of Mann et al. and the “camel-back” diagram of Loehle, we may be seeing the intrusion of bias into the representation of the proxy temperature data. On the one hand Mann et al. may have felt justified in emphasizing the uniqueness of contemporary warming. Loehle may have felt justified in showing that the “hockey stick” may have exaggerated the steadiness of temperature over the past 2000 years by decapitating his poor camel at the base of the neck, as nicely documented in the present analysis. The important conclusion for us—here and now—is that it doesn’t matter if both diagrams were simultaneously valid and invalid. Either way, the present is NOT the key to the past, nor vice versa. It would be nice if we could just move on, but “skeptics” will not allow the poor hockey stick to rest in peace. -
ubrew12 at 12:31 PM on 6 May 2010Kung-fu Climate
As many here already know, if the Kung Fu alarmists win incorrectly, they are chaining their children to an unnecessary 2% drop in global GDP (according to Krugman, citing other studies) this entire century. If the Kung Fu skeptics win incorrectly, they are chaining their children to a 5% drop in global GDP (again Krugman) this century. But, there's a small chance (Arctic methane) that they may actually be destroying any chance of their children's having a future. Admittedly, those odds are small, by why go there? -
HumanityRules at 12:16 PM on 6 May 2010Kung-fu Climate
Putting aside whether the MWP was warmer or not what is the importance of the level of natural variability suggested by these records because that appears to show some significant differences on fig 3. By eye, and just to illustrate, Loehle's reconstruction (dark blue) maybe shows 1oC between the highest and lowest points. Jones and Mann 2004 (orange) is maybe 0.5oC (for the non-industrial period). What does this natural variability tell us? And what difference in natural radiative forcing, if any, is suggested by the different estimates? -
Rob Honeycutt at 11:38 AM on 6 May 2010Kung-fu Climate
@HumanityRules... I did notify him about it. That's when he sent me the Hadley data. I'm sure he'll be here before to long with some comments. -
Rob Honeycutt at 11:37 AM on 6 May 2010Kung-fu Climate
Correction. Loehle says 0.07C warmer. But also 0.53C warmer than (I believe) the end of his 2008 chart. -
HumanityRules at 11:37 AM on 6 May 2010Kung-fu Climate
Rob, It does sound like dr Loehle was co-operative. Did you tell Dr Loehle you were going to post this? Or did you maybe mail him the the post and get any feedback on it? It would be great if you could encourage him to reply to this here. -
Rob Honeycutt at 11:36 AM on 6 May 2010Kung-fu Climate
@HumanityRules... I'm sure there are camps on both sides of this and Loehle stated to me that he falls into the camp of believing it's not right. But even he does comment on this at the end of his paper and states that current temps (being 1992 for the smoothed average) are 0.7C higher than his MWP temps. I personally don't see how you can NOT at least make the attempt to concatenate the data in some meaningful way because this is the very essence of the debate about climate change. @ nautilus_mr... I just emailed the information for John to post. -
HumanityRules at 11:27 AM on 6 May 2010Kung-fu Climate
Thanks for that Rob, Something that's been bugging me for a while is the way instrumental temperature records are pasted onto the end of these graphs. Can you just confirm that there is no issues with doing this? I don't mean your attempt just the general practice of doing this. I remember the recent post about the Mclean paper specifically critisised this sort of splicing of data sets.Response: The problem with the McLean paper was the way they spliced the data - they hid the splicing boundary by breaking the graph into different boxes, they used different Y-axes for the different boxes and the way the data overlapped, the splicing also hid the incline in temperature. This problematic graph was then cited by the authors as proof that humans weren't causing global warming.
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ProfMandia at 11:21 AM on 6 May 2010Kung-fu Climate
Rob, You have achieved what many fail to do: you have done science and you have done so with a story. Essentially, you have kept the novice interested which means your message was received. Kudos to you. Alan Alda would be proud of you. Scott A. Mandia, Professor of Physical Sciences Selden, NY Global Warming: Man or Myth? My Global Warming Blog Twitter: AGW_Prof "Global Warming Fact of the Day" Facebook Group -
Spencer Weart at 11:19 AM on 6 May 2010Kung-fu Climate
I don't have access to Loehle's paper, but I note from the abstract that he derives his result by averaging 18 series. Most such data comes from the Northern Hemisphere, so that's probably what he is mainly measuring. Fair enough, so did the original Mann hockey stick and many others. We should note, however, that there is considerable historical evidence of an ocean "see-saw" whereby when one hemisphere warms, the other one cools. The MWP may therefore not have been a global phenomenon, and indeed this is what Mann's most recent work tells us. Now here comes the kung fu move. The current situation is strikingly different, since for sure both hemispheres are warming together. The argument that we have seen something like this before, therefore, is mere speculation, since strong warmth in the S. Hemisphere in the Medieval period has not been demonstrated. -
nautilus_mr at 11:14 AM on 6 May 2010Kung-fu Climate
John, a quick suggestion: would you mind editing the paragraph before Fig 3. to indicate which colour lines relate to which studies?Response: All the other reconstructions come from this Wikipedia page which includes the sources along with each colour. -
scaddenp at 11:06 AM on 6 May 2010Where is global warming going?
"The boring thing is that G&T are just applying traditional thermodynamics and find that the CO2 AGW theory just does not stack up." They are misinterpreting classical thermodynamics. Consult a text book. ( eg Fundamentals of Heat and Mass Transfer). This was covered well at: The imaginary second law -
kdkd at 10:42 AM on 6 May 2010Where is global warming going?
suibhne #83 Please excuse my rusty chemistry, but I think you've made a fundamental error. Please correct the below if it's wrong. The IR absorption of CO2 has very little to do with the electron energy levels (except from the context of forming the bonds in the first place). The bond energy in the CO bonds in a co2 molecule is around 1500kj per mole of CO2. So in order to break the bonds of the co2 molecule you have to supply 1500kj of energy to 1 mole of co2 molecules before the bonds break, and the energy levels of the electrons come into play again. Again, my chemistry is very rusty, but this is my understanding. I really don't think that quantum effects are relevant at all in the way that you are claiming they are. -
Chris G at 08:34 AM on 6 May 2010A visual depiction of how much ice Greenland is losing
notcynical (#72), Applying localization and rainfall amounts, that's a neat 'trick'! I'm putting that in my bag for later use. -
Doug Bostrom at 08:13 AM on 6 May 2010Where is global warming going?
Suibhne, in order to say "they just don't", you must also say what they do. What do photons emitted from a cool body do when they encounter a warmer body? -
Riccardo at 07:30 AM on 6 May 2010Where is global warming going?
suibhne, nice reply: "they just don't". In fact they do, as already shown. P.S. review your quantum mechanics and in particular how bosons work. -
chris at 07:20 AM on 6 May 2010What causes Arctic amplification?
slightly off the point but possibly of general interest: The European Geosciences Union annual meeting currently underway in Vienna have put some of their summary "Press release" presentations on line as webcasts. There is an interesting presentation by Peter Wadhams entitled "Arctic sea ice is in terminal retreat" available from here. The question/answers session at the end is interesting..... -
suibhne at 06:53 AM on 6 May 2010Where is global warming going?
doug_bostrom In order for your assertion to be true, photons emitted from a lower temperature source must somehow be unable to interact with surfaces radiating at a higher temperature. Well they just don't. KR (78) puts it quite well. Here's my guess from Quantum Mechanics. The higher temperature energy levels will already be full from bottom up. Lower energy photons will not find any "slots" to fill and will be at something of a loose end. -
suibhne at 06:44 AM on 6 May 2010Where is global warming going?
KR This is what your link led me to! To ensure top quality, review articles are by invitation only and all research papers undergo stringent refereeing. We welcome you to submit your research papers to IJMPB for publication. You say further .....If you want to claim that the last 100 years of thermodynamics, radiation equilibrium ... are wrong. Who wants to claim such nonsense. The boring thing is that G&T are just applying traditional thermodynamics and find that the CO2 AGW theory just does not stack up. -
Philippe Chantreau at 03:29 AM on 6 May 2010Rain in the Canadian High Arctic in April?
Interesting facts Mauri. I won't hold my breath to see it reported on the "skeptic" web sites where the record February snow cover was trumpeted as some sort of proof of something or other... -
Doug Bostrom at 03:24 AM on 6 May 2010Are we too stupid?
What sort of philosophy produces the following behavior? It was hailed as a breakthrough in the fight to cut carbon emissions. In 2007, researchers found that heavy electricity users cut their consumption after being told that they used more energy than their neighbours. Almost a million US households have since received similar feedback and have cut electricity use by an average of 2.5 per cent. But a new study has identified a wrinkle in the plan: the feedback only seems to work with liberals. Conservatives tend to ignore it. Some even respond by using more energy. The findings come from a study of over 80,000 Californian households, just under half of which received feedback on energy use. Overall, the technique worked: households who got the feedback cut electricity by around 2 per cent, say Dora Costa and Matthew Kahn at the University of California, Los Angeles. But important difference emerged when Costa and Kahn looked at the political leanings of those in the survey. Homeowners who identified themselves as Republicans cut energy use by just 0.4 per cent on average. And those Republicans who showed no practical interest in environmental causes – people who did not donate to environmental groups and did not choose to pay extra for renewable energy – even increased electricity use by 0.75 per cent. Republicans won’t be nudged into cutting home energy Why would somebody behave like that? I can understand doing nothing, but actively increasing one's electric bill as well helping to erase efficiency gains? What's up with that? -
mspelto at 00:31 AM on 6 May 2010Rain in the Canadian High Arctic in April?
Sometimes an event such as the rain even here is spatially or temporally limited and of as such is an isolated weather event. If it coincides with other events spatially and temporally then it is just another measure of a broader event that is important. For example February had the 3rd highest mean snowcover extent of the last 44 years in North America according to the Rutgers Global Snow lab. The most extensive melt off of snowcover in the last 44 years has occurred in March and April. Leading to March mean snowcover extent being the 18th of 44 years, and April being the 41st highest of 44 years. That is correct going from third most to third least snowcover. This indicates a continent wide period of unusual melt conditions. -
michael sweet at 22:23 PM on 5 May 2010Rain in the Canadian High Arctic in April?
Westwell: Perhaps your reporter in the Hawaii story should have reported on ice in the great lakes last year, since they used data from last year. There was a lot of ice in the great lakes last year. It was a La Nina year. This year, in contrast, was record lows. Last year was high for recent years, but not record highs. It is easy to cherry pick data to try to influence people who are uninformed. You will have a lot more trouble on this site where people check what you say. -
Westwell at 21:54 PM on 5 May 2010Rain in the Canadian High Arctic in April?
Climate change? Global warming? Maybe it's just the weather, did anyone think of that? Lots of Ice—But No Media Coverage http://www.hawaiireporter.com/story.aspx?0b9e4b5f-5225-40c7-b775-03c822fbffc8 Catastrophic” retreat of glaciers in Spitsbergen http://wattsupwiththat.com/2010/05/02/catastrophic-retreat-of-glaciers-in-spitsbergen/ -
Juergen Wanninger at 21:41 PM on 5 May 2010Flowers blooming earlier now than any time in last 250 years
Hello Argus, thanks for your answer. However if you are looking only for short periods, the typical climate oscillations which happened always in the past independant of Co2, will show exaggerated tendences. But if we look at longer times and only 'normal' periods (not those being famous for their extraordinairy cold climate like Maunder or Dalton) we can suddenly see, that the nature is not as much 'alarmed' like lots of people or our politicians. Each month the press shows new temperature diagrams commented with messages of 'new temperature records'. But my personal daily experience in the last 30 years does not show a 'Michael Mann' - heating. And the above diagram confirms my experience. Obviously the short warm period between Maunder and Dalton minimum looks having been as warm as today - however there was a much smaller Co2-concentration in the atmosphere at that time. If wee can confirm the above work by further groups and examinations, what would that mean for the theory of Co2-driven global warming? I think this will mean at least, that the predicted amount of warming due to Co2 is estimated extremely too high! Doubling should give 0.5 degrees, like Lindzen says. And there should be other things beneath Co2 driving our climate! Maybe Svensmark is on the right way? -
Argus at 17:38 PM on 5 May 2010Flowers blooming earlier now than any time in last 250 years
Thank you Juergen for this sobering time perspective on the 'alarming' news of early blooming! To me it looks like spring has moved three to four days within the last 250 years, so it is exactly in line with your 25800 year period. No cooling. But let us not forget that between the first and the last period in the whole diagram there are also striking maxima and minima. What if a diagram-interested scientist 100 years ago had concentrated on the period 1840 to 1910? ''Alarming news! Flowers now blooming 12 days earlier than 70 years ago!'' Or take 1920 to 1970: '' New ice age imminent! Spring now comes five days later than just 50 years ago!'' -
KR at 15:41 PM on 5 May 2010Where is global warming going?
The IJMPB review paper policy is described here - Gerlich and Tscheuschner (2009), FALSIFICATION OF THE ATMOSPHERIC CO2 GREENHOUSE EFFECTS WITHIN THE FRAME OF PHYSICS, was definitely not peer-reviewed. And, sadly, it's junk... -
SoundOff at 14:13 PM on 5 May 2010Rain in the Canadian High Arctic in April?
#24 - Pete, It’s a regular pattern, at least in east central Canada. Each El Niño episode does give us very mild winters. And colder winters result when a La Niña episode is in effect (such as the prior two winters before this last one). So yes ENSO does have a long reach. Keep in mind that Toronto is slightly closer to the equator than to the North Pole, at the same latitude as southern France (but without the palm trees), so we get influenced by both ends. Perhaps in the far north, the Arctic Oscillation normally dominates. I did notice that Canadian Arctic surface temperatures were significantly above normal, while at the same time the Canadian prairies and US plains states were freezing under the deepest part of the negative AO. There’s much supporting science that says the stratosphere above the Arctic warms during the negative phase of an AO but little science making such claims for surface temperatures. So I’m not prepared to say that a negative AO typically results in warmer Arctic surface temperatures. Analyzing it logically, if the air pressure is high in the north and low in the mid latitudes (a negative AO), then what one should see is the surface air moving generally from north to south (from the high pressure area to the low pressure area). This in turn should pull down some upper atmosphere in the north to replace the exiting air, which in turn, pushes the higher level jet stream to move in the opposition direction to fill the high level void created in the north, and lifting air out of the south to complete the circle. These movements would all have a slight eastward slant due to planetary rotation. With colder high level air being pulled down in the north, one would expect things to be a bit cooler up north on the surface, and some minor ice extent recovery this past winter is evidence that this did happen overall. But how does one explain the warm surface temperatures I noticed in the north at the peak of the negative AO? I don’t know but perhaps, with an El Niño raging on top of the usual GW and a negative AO, just maybe a layer of warm Pacific air was being pulled in below the north and east moving jet stream during that same time and it was filling the surface viod in the far north instead of higher air. Weather is very chaotic so it’s hard to say. The early rainfalls reported in this article were well after the negative AO peak (but still within the ENSO influence), so we might have moved off topic by discussing AO here, but it was worth considering nonetheless. -
Doug Bostrom at 11:21 AM on 5 May 2010Where is global warming going?
Suibhne, what you said is that back radiation cannot do any work. In order for your assertion to be true, photons emitted from a lower temperature source must somehow be unable to interact with surfaces radiating at a higher temperature. Can you describe the mechanism that isolates and sorts photons in this way? -
actually thoughtful at 11:08 AM on 5 May 2010Rain in the Canadian High Arctic in April?
#24 - can you make your point differently? Are you saying warming arctic corresponds with negative AO? The opposite? Something different? A quick review shows that AO is not strongly correlated with temperature in 1999 and 2005 (notably hot years...). -
muoncounter at 10:26 AM on 5 May 2010It's cooling
And its been 90 here (on the coast of that great bowl of oil and vinegar we call the Gulf of Mexico) already - two days running. However, this new study suggests that we ain't seen nothing yet. "Researchers for the first time have calculated the highest tolerable "wet-bulb" temperature and found that this temperature could be exceeded for the first time in human history in future climate scenarios if greenhouse gas emissions continue at their current rate." -
KR at 10:21 AM on 5 May 2010Where is global warming going?
Incidentally, that's an abuse of IJMPB's own editorial system. A "review" paper should consist of describing the state of the art in a field, listing significant contributors, seminal papers, and directions for future research. If you want to claim that the last 100 years of thermodynamics, radiation equilibrium, and climate theory are WRONG, that's original research (certainly an original opinion), and deserves peer review - which G&T did not get. The editors of IJMPB simply published a long polemic - one that had been solidly refuted ages ago by people with actual knowledge in the field. -
KR at 10:14 AM on 5 May 2010Where is global warming going?
doug, Riccardo, folks, my apologies - I referred to an earlier topic without sufficient attribution/context. The 324W/m2 number comes from an earlier thread, Is CO2 a pollutant, where suibhne argued at length against GHG heating, using as a reason the G&T paper. My most recent (and sadly a little rough) posting was in response to seeing G&T arguments against greenhouse gas heating again; not the energy flows at Earth's surface. And yes, you can extract some energy using the photoelectric effect (which is how the detectors for IR work), but that energy isn't usable in a heat engine without a cold sink. suibhne, it turns out that the G&T paper was NOT PEER REVIEWED; it appeared in International Journal of Modern Physics B as a review paper, not a research paper - invited by the editor(s) on a topic of their interest, and very definitely not subject to a peer review process. No peer review, hence no checks by anyone actually knowledgeable in the field, hence I have even less reason to take any arguments from G&T seriously. -
Riccardo at 08:09 AM on 5 May 2010Where is global warming going?
suibhne, we're way offtopic here. The short answer is costs and efficiency. -
suibhne at 07:42 AM on 5 May 2010Where is global warming going?
doug_bostrom As I said to KR in post70 ............... the figure of 324W/m2 Back Radiation. Why is this huge magnitude of photons not put to some useful work? If this could be shown I would have to reconsider the whole issue. Yes and I stand by this statement. -
chris at 06:04 AM on 5 May 2010Tracking the energy from global warming
Ken Lambert at 11:55 AM on 3 May, 2010 O.K. fair enough Ken; we've pretty much come full circle and arrived back where we were a few days (and many posts!) ago. For a short period (largely 2006-2008) there was a brief reduction of sea level rise which has brought the trend down a tad when measured over a very short time period. However the sea level rise has now more or less caught up with the long term trend around 3-3.4 mm.yr-1. It is reported at the European Geoscience Union meeting this week that the recent ARGO ocean heat content meaurements are showing significant rises again (I've just heard this from a colleague; no doubt this will be discussed/published more widely in due course). Since glacial/polar ice melt is seemingly increasing (and as we have both pointed out on this thread, this seems to have contributed a larger proportion of sea level rise in the last 6-7 years than during the previous decade), and since measured upper ocean heat content may well be on the rise again, and the sun has grudgingly started its rise up the ascending limb of the solar cycle, it wouldn't be surprising if the rate of sea level rise made another acceleration. The point is that anomalies during very short time periods need to be interpreted with caution. It's possible that the apparent stutter in sea level rise/upper ocean heat content was due to some heat transfer to the deeper oceans which warm with a lesser contribution to thermal sea level rise than surface waters. Perhaps there was an anomalous period of atmospheric behaviour (clouds/aerosols). Perhaps some of the heat has just "disappeared".... We don't really know yet. That's actually the point of Trenberth's recent publications on this subject. My original post was to point out that Peter Berenyi's analysis (that the apparent energy budget "defecit" "bring(s) havoc to standard greenhouse theory" is unscientific. It really isn't helpful to unleash profound interpretations based on throwing numbers at very short time periods especially in the circumstance (Trenberth) that our measuring systems, though greatly improved during the last decade, aren't yet up to the task required for a full accounting of short term phenomena. -
Riccardo at 06:00 AM on 5 May 2010What causes Arctic amplification?
Arkadiusz Semczyszak, not sure I understand your point. The paper main focus is on the vertical structure of the temperature anomaly following the new ERA-interim reanalysis. The latter is in constrat with previous reanalysis datasets: "We diverge considerably from ref.8 [Graversen et al., Nature 451, 53–56(2008).] in finding that the maximum Arctic warming is at the surface and that warming lessens with height in all seasons except summer. This vertical structure suggests that changes at the surface, such as decreases in sea ice and snow cover, are the primary causes of recent Arctic amplification." So, they are not discussing the origin of the warming but the feedback that can be inferred from this new reanalysis. -
Doug Bostrom at 04:45 AM on 5 May 2010Where is global warming going?
Just to amplify Riccardo's remark, one could in principle arrange an array of photovoltaic IR detectors to liberate mechanical energy via an electric motor, aka "do work" in the most prosaic sense. With such an apparatus pointed skyward on a cloudy night, even if the detector array IR radiation temperature was higher than the cloud IR radiation temperature one would still be able to see a net increase of electrons flowing from the IR detectors and ultimately liberating their energy as heat at the motor, compared to the same arrangement pointed at a clear sky. Photons arriving at the detector array neither know nor care about the temperature of the array itself. They are not somehow driven back because the detector is warm, they plow into the surface regardless where they stand the usual probability of bouncing an electron. G&T's paper lacks perspective. -
Pete Dunkelberg at 04:42 AM on 5 May 2010Rain in the Canadian High Arctic in April?
That 1 or 2 degree warmer area in the tropical Pacific has a long reach! Or, from your link "This [the positive phase of the AO] keeps much of the United States east of the Rocky Mountains warmer than normal, but leaves Greenland and Newfoundland colder than usual. Weather patterns in the negative phase are in general "opposite" to those of the positive phase, as illustrated below." When the wind blows hard from the Arctic, the Arctic does not become a giant vacuum. Other, warmer air blows in from elsewhere. The slightly warmer air from the tropical Pacific, even if it gets there without cooling much, could not account for the very high arctic temperatures. What does it is the quantity of air from lower latitudes, which must match the quantity of air blowing out of the Arctic. I had hoped that mentioning the AO would make a light bulb go off. How does it correlate with warm Arctic years in the past?
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