sunny starry skies

Sounds like you're arguing from authority Y.S. I can assure you, authority is not on your (or Taylor's) side: http://www.logicalscience.com/consensus/consensusD1.htm I'm not concerned whether Peter Taylor has done good work in other fields, but I am concerned that as he is a self-confessed non-scientist, and with no evident expertise in climate science, he wishes to write a book full of disinformation on the subject. He's sold lots of copies of it, which is unfortunate, but the central point is that he's had to go through no scientific assessment of his claims in order to publish the book. He's in fact able to say any old thing, and he does. It's a pity you find it compelling, but the balance of evidence is not on his side. Your underlined, un-referenced quote does not show that he has any of the qualifications required to make him 'qualified' on climate science. He's done some complex computer modelling - so have many others, including myself. That doesn't make him an expert in the fundamentals of the theory, for example atmospheric physics, oceanic physics or palaeoclimate reconstruction. Climate science is a great deal more than just models, and the key evidence that supports the AGW consensus is not model-based. It's not a 'party line' either (the very idea in science is comical), it's a balance of evidence - and that is not in your favour either. sss

You mis-quoted NaDamantaSam, I merely corrected you on your data. Your data is correct, specifically for the month between ~21 June and 21 July, but NaDamantaSam was talking about July being a low melt, "on the back of" June's record high melt. Your data is mostly from July, and covers the period of low melt, but it was not what NDS was talking about. July's indeed mercifully low, but it's on the back of the fastest melts recorded for June and May, and the second-fastest recorded melt for April (behind 2003, another year with a late-season spurt). The total melt since April 1st is the highest in all IJIS years by a clear 0.6 of a standard deviation from 2007 (2010: 7698125sq km; 2007: 7311876sq km, all other years below 6.9m sq km). Without July's slowdown, this would have been an even more exceptional year.

Is this the same Peter Taylor that thinks plutonium has health benefits (Shiva's Rainbow), amongst other outlandish claims? It is. I'd rather get my scientifc understanding from someone with a more reliable grasp of science, and preferrably someone who has studied and published in climate science, specifically. As I've said a great many times, you can say almost whatever you like in a book, but it does not make it factual. Ask historians about the guy who wrote a best-seller claiming that the Chinese reaching America and circumnavigated the globe years before Columbus. Or Mike Baillie, who while being a decent dendrochronologist, wrote a book on a hypothesis that the Black death was caused by a comet. These things might make good stories, indeed they might even sell very well, but there is a key parallel through all of them. They are not supported by the evidence. They are essentially fiction. Or 'pseudoscience'. Peter Taylor in his own words: "In truth, in the scientific realms in which I worked, and gained by now, some standing, I was an imposter. I am not a scientist. Apart from my brief survey of tree-hole communities when I successfully correlated insect larvae diversity with circumference and aspect of the hole to the sun, which, in any case, had been done many times before, I have never `done' science." From Shiva's Rainbow http://www.amazon.co.uk/gp/cdp/member-reviews/A77M4UTAYXKO7/ref=cm_cr_pr_auth_rev?ie=UTF8&sort_by=MostRecentReview His claims are dogmatic and unsupported by the evidence, so why do you keep referring to him as if his is the silver bullet that demolishes the science. He does nothing of the sort. If he had, he would have done more than publish a popular work of fiction through a publishing house that does not deal properly with science Peter Taylor on global warming: "We fight so strongly against the global emissions of carbon dioxide, yet the quietest of questions surfaces: is Gaia, after all, a sentient mother protecting us from the next cooling?". Y.S., do you believe that the Earth is sentient, as Taylor does? Taylor has as much credibility as astrology or homeopathy, yet you say you believe in science? PDO - a measure of spatial pattern, not total heat content so irrelevant to Earth's total heat content - how can an ocean that is warmer now than all times before the mid-1990s, including all previous 'warm' episodes' be cyclically absorbing and releasing heat to/from the atmosphere? Arctic ice - bang on normal according to steven goddard at WUWT.... and pretty much nobody else. Currently at the second-lowest ever recorded extent, and at the lowest ever volume, not what I would call anywhere near a 30-year average. sss

July's melt was "On the back of an entire month of record fast melt, yeah?". "On the back of", as in "after", namely that July's slow melts have followed the entire month of June being a record fast melt: Total June melts from IJIS data, 2003-2010: 2003: 1689844 2004: 1254844 2005: 1672031 2006: 1845781 2007: 2032188 2008: 1816094 2009: 1727343 2010: 2245468 And corroborated by NSIDC's different data source: http://nsidc.org/arc...010/070610.html "In June, ice extent declined by 88,000 square kilometers (34,000 square miles) per day, more than 50% greater than the average rate of 53,000 square kilometers (20,000 square miles) per day. This rate of decline is the fastest measured for June." sss

2008: http://rapidfire.sci...230000.500m.jpg 2007: http://rapidfire.sci...233000.500m.jpg 2006: http://rapidfire.sci...000000.500m.jpg 2005: http://rapidfire.sci...211500.500m.jpg 2004: http://rapidfire.sci...233501.500m.jpg 2002: http://rapidfire.sci...220500.500m.jpg Yesteray's image: http://rapidfire.sci...211500.500m.jpg Note these are not all images of an identical region (approximately ice N of the Canadian Archipelago), and so I would not call it a 'scientific' assessment of previous years' ice cover. Additionally, they are raw images so there are the usual MODIS distortions - ie none down the vertical spine of the image, but large on either side. And of course there's cloud cover to contend with, but maybe someone more dilligent could try and find images with less cloud cover that are closer to these dates. What I see is that 2008 is the only year I can spot comparable areas of broken up ice within the central pack, and they are less extensive than this year. Where ice is visible from under the cloud in the other images, it tends to have the look of much more coherent pack, ie a solid mass with lines of fresh and old leads through it, and melt ponds. Today's pack has broken floes in brash ice with some patches of open water. Ice loss has indeed been remarkably slow in terms of extent but the record low volume shows up clearly when you look at what is supposedly the oldest and best ice of the pack. Extent and area will eventually decline rapidly when the ongoing volume decline renders it impossible for the ice to spread out over such a large area. Weather conditions may dictate that this is not going to be in 2010, but it's not going to be long if this rate of decline continues. A poster put on Neven's blog a comment about thicker pack and compression. This year the Arctic has a catch-22 situation. If the ice stays spread out and thin, the extent/area measures will not show a big loss this year. It will be desperately vulnerable to melting out next year as it will be very thin. If the ice is compressed against the Canadian Archipelago/N Greenland, where it is piled up to create thicker ice that has a chance of surviving multiple melts, the extent and area loss will be catastrophic. Check? Or is it checkmate? Can White pull a win out of the bag? sss

Part of the influence on Arctic summer temperatures is in the latent heat of melting of the ice, which holds down the surface temperatures in summer. I think it's the reason the summer temperatures never get very high above zero and the graph has an odd flattened shape to it, and also the reason you can't easily use them to infer 'hot' or 'cold' summers there. Maybe it has been cold up there, but I wouldn't base that assessment on the surface temperatures if there has also been a lot of melting going on (which there obviously has!). That melting is using up very large amounts of near-surface energy and holding the air temperatures down to just above freezing. Once the ice is gone, the pattern will change to one we're more familiar with - higher sea surface temperatures in warmer weather, lower in colder... and a corresponding jump up in global temperatures. sss EDIT: G-W: your lower map is rotated ~90deg clockwise from your upper one, so the drift is towards NE Siberia, not Alaska.

It doesn't take a mathematical formula to determine that a dark ocean absorbs much more incoming radiation than white ice. Or that a warmer atmosphere holds more water vapour (a powerful greenhouse gas) than a cold one. Or that warming Arctic permafrost will lead to methane release which leads to more warming, not less. Quantifying them, yes, you need to do your sums [see refs below]. The exact values are of course up for debate, which is why the climate sensitivity appears to be between 2 and 4.5C (best estimate ~3.1C) per CO2 doubling. Palaeoclimate supports this very well (Knutti and Hegerl, 2008). It might, however, take a bizarre mathematical formula to create a century-scale rising trend, the size and rate of which is unseen in the Late Holocene out of otherwise energy-neutral ocean oscillations. Surely if such heat-trapping processes operate now they would have operated before? Why is it that the PDO, supposedly in a neutral/negative phase since ~2000, occurs in a body of water that has been warmer since 1996 than at any other time, including the previous PDO positive stages? What's the total effect of this body of water on global temperatures? The PDO is a measure of the spatial redistribution of heat, not the total heat content, therefore contributing nothing much to the total global heat content anomaly. Rather like our cold and snowy winter this year compared to the globe, which was unusually warm between December and February. That was a similar, though atmospheric, spatial redistribution of heat/air masses between the Arctic and the mid-latitudes. ENSO also has wide-ranging temporary and spatial effects, but they are short-lived and ultimately energy neutral. There's no observational evidence for these effects to be cumulative. So we have a lot of evidence for not only the feedbacks themselves, but the fact that they must operate in order to reconstruct palaeoclimate. We do not have evidence for PDO, ENSO or any other ocean oscillation providing anything more than noise to the trend of global temperatures. http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf [Knutti and Hegerl] Warren and Eastman, 2007: A Survey of Changes in Cloud Cover and Cloud Types over Land from Surface Observations, 1971–96. Journal of Climate, 20, 717-738. http://www.atmos.washington.edu/~ignatius/CloudMap/Publications/WarrenEtal2007_CloudSurvey.pdf “The global average trend of total cloud cover over land is small, -0.7% decade-1, offsetting the small positive trend that had been found for the ocean, and resulting in no significant trend for the land–ocean average.†Trenberth et al 2005. Trends and variability in column-integrated atmospheric water vapor. Climate Dynamics, 24, 741-758. Soden et al, 2002. Global Cooling After the Eruption of Mount Pinatubo: A Test of Climate Feedback by Water Vapor. Science, 296, 727-730. Austin and Coleman, 2007: Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback. GRL, 34. http://tomix.homelinux.org/~thomas/eth/8_semester/master_seminar_atmosphere_and_climate_I_ss_2007/unterlagen/papers/augustin_colman__lake_superior.pdf Some other relevant refs on feedbacks here: http://agwobserver.wordpress.com/2009/09/10/papers-on-global-cloud-cover-trends/ http://agwobserver.wordpress.com/2010/03/09/papers-on-ice-albedo-feedback/ http://agwobserver.wordpress.com/2009/10/13/papers-on-water-vapor-feedback-observations/ Many of these papers rely on observations, therefore they are rather more than "supposed". sss

Difficult to read Polyakov's crucial slide where he suggests a 'peak', interesting if true, however I'd be awfully cautious about declaring a peak only two years after the event. His second-last slide is disingenuous if he spoke to it about a post-2007 cooling, as the data on the slide ends in 2002. But all that said, it would be good news if he's right. However, as Dev said, the physics is not in his favour, and are Atlantic SST anomalies not high at the moment - surely they'll feed more warm water into the Arctic, similar to the pulse post-1990? G-W, I think you're right about the nature of the PDO and other cyclicities in ocean temps. It seems that we're well into the latest PDO -ve phase now, but it's well worth noting that the SST anomalies that are used to calculate the PDO are higher now than at any time during the previous positive phase! Specifically, the North Pacific has been warmer than in the last PDO positive phase since 1996, during which time we've been led to believe in a PDO negative phase for much of the time. See the graph in the link below: http://bobtisdale.blogspot.com/2009/04/misunderstandings-about-pdo-revised.html PDO: index relating to the spatial pattern of North Pacific temperatures. It is not remotely related to total heat gained or lost by the North Pacific. [if I have referred to it before as detrended temperature anomalies, it isn't that either as I have learned, and as Bob Tisdale explains above]. So if you hope that -ve PDO means global cooling, you're hoping wrong. AMO: is a detrended temperature anomaly. Maybe this is more relevant on the ocean page, but the clear observation is that absolute overall ocean temperatures are rising. Oscillations about that rising trend don't mask the fact that the trend is a rising one, and that the oscillations favourable for more Arctic sea ice occur at higher temperatures (therefore less favourable for sea ice) than they did during previous manifestations of those oscillations. Interesting NSIDC post G-W! sss

"Less reliable" is fair enough, but don't conflate that term with "unreliable" - there is a reliability spectrum out there! My take would be that we have observations, maps, documentary sources including reports from various expeditions in the 19th Century and early 20th Century (for example Northwest Passage), as well as traditional knowledge. All point to an extensive thick pack, similar to the 1939 sea ice minimum map below: Taken from Patrick Lockerby's latest post - what is notable is that the map is for summer minimum extent, and there are gradations from 'permanent pack' through 'perennial pack' (what we now have only in the central basin). This is the largely sound mass of ice that remained coherent, throughout the year barring temporary leads and polynyas, and was many metres thick. The maximum extent was rather larger than that, and according to historical sources periodically, and quite often, reached Iceland during the previous centuries (see Astrid Ogilvie's work). Taken all together, we can see that while we don't have nice detailed annual maps of sea ice extent (certainly the maps would be 'less reliable'), we have absolutely no evidence for less than a substantial, coherent body of sea ice, similar to that mapped in the 1930s, in any of the past two centuries. http://www.science20...2010_update_3_0 [Lockerby's post] What we have now is nothing like that, and the late 20th Century observations of decline coherently fit the transition from a strong multi-metre thick cap down to the shattered brash of floes that now exists, and is wildly sensitive to large melts or ice exports, given favourable weather. Nothing to do with fabled ocean cycles (oceans are warming as recorded by rising heat content and by sea level rise from thermal expansion), but the pattern fits neatly with the observed rise in ocean temperatures and rise in Arctic air temperature. sss

lovely photos there! Pity it was cloudy in embra toon...

Hi CJWRC (and everyone else of course), try these for size: Thickness anomaly graphs don't so far as I am aware, exist in the way you suggest, though I think there are outputs from the PIPS (and PIOMAS?) models that suggest thicknesses? Good graphical resources of various kinds here: http://sites.google.com/site/arcticseaicegraphs/ The most important of which for your question is perhaps the PIOMAS volume graph: http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png It hasn't been updated since June, and it will be very interesting to see what the volume estimates for the past few weeks were. Obviously thickness is a function of area and volume! http://www.science20.com/chatter_box/arctic_ice_july_2010_update_2 Patrick Lockerby has some intriguing observations on the recent slowing of the extent curves. Basically the ice is thinning and spreading out in situ, and that has in the last few days become painfully obvious in the central Arctic basin with sizeable patches of open water appearing in an obviously highly degraded pack. Consequence: not much change in the extent figures (they've slowed down because there is no compression of the pack to produce large areas of open water), but ice melt and pack degradation has visibly continued apace. Once the wind blows, compression of the pack will quite likely produce a very rapid apparent decline in ice extent, as extent is defined as >15% concentration, so thin, spread out ice is not much different to thick ice, but thin ice compressed into thicker ice will produce a very large drop, the cost of producing some slightly thicker/more concentrated ice. Similar observations from NSIDC in this post by Neven: http://neven1.typepad.com/blog/2010/07/sea-ice-extent-update-16-back-to-the-30s-again.html sss

HI VP, I hope you didn't misinterpret my post - and as your description shows, many relevant problems are quite graspable by numerate non-specialists. But I think that in a way supports the point I was trying to make. It is not necessarily harder to teach a geoscientist sufficient mathematics than to teach a mathematician sufficiant geoscience. In the 'language' cotext, you can successfully buy your shopping in France with a far-from-complete knowledge of French (you can do your data analysis without a research-grade understanding of the full body of statistics)! But when dealing with problems in geoscience it is important to have a thorough understanding of the problem, the interrelated concepts and contexts, and how these systems operate in the real world. To publish research-grade science relevant to climate change I think you need to have a very good understanding of the processes relevant to your problem. That particular language is not always easy, and how easily it is picked up varies depending on the person. Some will do it well, others won't. I'll repeat my caveat - some, and maybe even many, will go both ways just as well, but it's not a given). A classic example of someone who doesn't get it is the poster by the pseudonym of stevengoddard on WUWT. Among his myriad misunderstanding of the cryosphere is that Antarctica can't lose mass except by surface melting (and air temps in Antarctica aren't of course going above freezing any time soon!). By utterly failing to understand the processes of ice flow, calving and mass balance, he doesn't get the problem, and doesn't admit it. But of course he's quite happy to spout off about it, and deny the research and obvious fundamental issues when they are pointed out to him. http://www.skeptical...to-Goddard.html {Robert Way has two previous relevant posts on glaciology too} It is why as a scientist you need to be skeptical of work that has not been replicated or verified by some independent means - problems can occur with numeracy or the understanding of concepts that are missed by reviewers. This happens to both pro- and anti- papers. If a piece of work is not peer-reviewed or supported by corroborating evidence (often books, including examples cited by some here, fall into this category), you need to be even more sceptical of the conclusions because there has been far less of a verification process. You can claim pretty much any old rubbish in a book so long as the non-specialist publisher thinks it will sell copies! Now goddard was an extreme example (McLean et al 2009 was another), and one who has shown with pretty much every posting that his grasp of numerical analysis is dreadful too, but hopefully it's a useful example to show how much difficulty someone can get into when they enter a complex subject with minimal training/skill in that subject. sss

I'd agree with that G-W - it's very important to consider the difference between a pack with a lot of thick ice and a pack with virtually no thick ice left. At the rate of volume decline, a seasonal pack is moving pretty rapidly towards the present, and 2020 would hardly be implausible. I think the accelerating trend seen in September minima is consistent with a progressively thinner pack, which is more and more prone to spectacular melts. They won't happen every year, as weather conditions dictate whether spectacular melts can occur, but the ice is now thoroughly preconditioned for big melts. It will be very interesting to see the rate of melt if favourable melt conditions return in the next 6-8 weeks. We can hope for the current (2 week) slowing of extent melt to continue, but that doesn't do anything much for the long-term decline in ice volume. sss

Indeed, the best scientists are genuinely sceptical! I actually agree with both Pete and to a lesser extent VP here. You would ideally have someone well-versed in both techniques, but the reality is that you can't easily have a fully qualified person (ie research-grade) in both. So which is better, the mathematician/physicist who turns their hand to a branch of environmental/climate science, or the reverse? I've seen both at first hand, and surprisingly it is not as simple as you make out VP. It turns out that the concepts, and the ways of thinking required to do detailed science in glaciology or palaeoenvironmental science are very different from the concepts and methods required by mathematicians, physicists or computer programmers. For example, I saw an otherwise excellent physicist doing a PhD utterly fail to grasp the concepts in their glaciological modelling project, much to the chagrin of the supervisor, who at least in part regretted going for the physicist rather than a numerically-capable Quaternary scientist/geographer/geologist. I think the issue is that while mathematics may be the language of glaciology or palaeo data analysis, I think the language of data analysis is easier to teach to the numerically-able Quaternary scientist than the more obscure language of palaeoenvironmental science is to the mathematician, who is bounded by different training, preconceptions and rule systems that don't always apply. There's also a preconception that somehow the maths is "harder" to learn, but I don't think that holds water at all. Of course that is not a universal observation and there will be excellent exceptions, but it is wrong to suggest that it is easy for a mathematician to get to grips with the complexities of spatial environmental/climatological problems, challenging data etc, especially if they have no specific training in the field. sss

P.P., that's why we have independent replication of datasets. Verification of the numbers is of course important, and goes on all the time, but the results are far more robust when they are replicated separately. YS: I didn't say they were 'settled', but quite what is wrong with 2,3 and 4? For (2) I think the figure is ~95-98% of publishing researchers in the field agree with that. (3) you ought to agree with, as it's required to produce a significant/distinguishable MWP from natural forcing! (4) high climate sensitivity is certainly a bad thing - given our forcing of climate with CO2, which you admit has some effect (*). The effect will be worse with high sensitivity compared to low sensitivity. (*) This is about 0.8-1.2C per doubling of CO2, not including feedbacks, which are dominantly positive for fast feedbacks. This is not in doubt at all. The magnitude of the feedbacks (water vapour, albedo etc) that take us to between 2-5C warming is of course in some doubt. http://www.pik-potsd...edillo_2008.pdf http://www.atmos.was...90_ice-core.pdf http://chriscolose.w...fect-revisited/ The relevance of the 'bent' or 'straight' hockey stick is slight though, and the only crucial thing it tells us is something about sensitivity. It's a simplistic, romantic notion to consider that our climate may be similar to the Vikings, the Romans or the Neolithic... or the dinosaurs (choose your favourite) and so we have nothing to worry about. The forcings are different now - we have set a different table on which the climate system operates. Consider riding a bike down a steep hill with a sharp corner at the bottom. Now consider riding down the same hill again, only this time halfway down you find your brakes are not working. Do you think as you reach the bottom of the hill "it's OK, I've done 35m.p.h. at this point before, nothing to worry about"?... The hockey stick tells us something about the steepness of the hill, CO2 is the grease on the brakes. Seeing as this thread is supposed to be 'in the news' here's a draft paper from NASA GISS (Hansen et al, presumably will be 2010), found at Climate Progress: http://data.giss.nas...0_draft0601.pdf http://climateprogre...d-hottest-year/ Now CP is full of rather a lot of bluster and considered biased by some, but read the paper itself and there's a really good discussion of the progression of global temperature and how that progression has continued through the last decade and we are now at an all-time 12-month running mean record, despite low solar, negative PDO and though an El Nino, hardly a super-El Nino. Also some interesting comment about public perceptions and last winter's remarkable -ve AO weather. Speaking of bias, Anthony Watts has sunk to a new utterly despiccable low, highlighting an aggressive comment on his blog that compares academics to cockroaches: http://rabett.blogsp...s.html#comments - scroll down to 15/7/10 12:21 PM where it's highlighted. I hope the original is removed promptly. This is particularly reprehensible because 'cockroaches' is how the Hutus described the Tutsis in radio broadcasts in 1994: http://news.bbc.co.u...ica/3257748.stm Watts and MacIntyre are both guilty of sending mobs after scientists they don't like (Watts on John Abraham, MacIntyre on CRU). It is disgusting and has no place in a debate on the science. To them, when the data, the physics and the enquiries don't support them, it is all they have left. I hope we can all agree that whatever our differences in opinion, and however deeply they run, there are certain lines that should not ever be crossed. The only consolation in all that is that the fantasist Monckton is hanging himself by his own petard in trying to threaten John Abraham for daring to engage in a scientific discussion whereby Monckton's failure to grasp facts is exposed . See the above Rabett run post, and the one below from Skeptical Science: http://www.skeptical...p=2&t=60&&n=277 He's been roundly rebuffed by lawyers for St Thomas University - you don't threaten legal action because you lost an academic debate Mr Monckton! I'll end a rather long post on a lighter note: . sss

P.P., nobody does their rounding like that... rounded, 2 + 2 = 4. If your input data supports it, 2.2 + 2.4 ~= 5. Though I see the point you're trying to make, it's irrelevant to generalise like this. The point was (it was one of the Muir Russell findings) that MacIntyre and his ilk could easily get the data if they wished and perform their own analysis. And also that the data in question, (CRU temperature series) has been independently verified by several other temperature series, and the CRU series itself replicated. What big problems do you see in a temperature series that has been verified several times over? If it was the only one in existense, you would have a point, but it's not, so your point is rendered irrelevant. The M&M's have no greater claim to be professional statisticians than Mann, or Tamino for that matter. But why don't you analyse the millennial-scale timeseries yourself? Simple averaging produces a bent 'hockey stick' (Medieval comparable to mid-late 20th Century), a Mann-type algorithm, where records have greater relevance if their correlation to 20th Century warming is greater, produces a straighter-shafted stick where the 20th Century is unprecedented. But the data is there for you to try! I suspect the truth lies between these two (unprecedented in some but not all is the message from other palaeo-records), but the significance is this: 1: nobody sensible debates the instrumental record seriously, ie the world is warming. 2: very few people debate that CO2 rise is contributing to that warming significantly. 3: a more bent stick = more climate sensitivity. 4: more climate sensitivity is a very bad thing. I hope Mann's closer to the truth because it implies a lower climate sensitivity and therefore warming closer to 2C than 5C in the coming century. Is the Hockey Stick relevant to anthropogenic climate change? Yes, but only for determining climate sensitivity - romantic notions of what our Viing ancestors put up with, or our Roman ancestors for that matter, are not terribly relevant as the forcing factors active in their climates were different to the forcing factors operating now. The graph doesn't tell you anything much about the physics operating in the atmosphere, or the other forcing factors at work. That's why Mann himself thinks the graph is overplayed, but unfortunately I imagine the politicians liked a pretty, simple and striking graph they could comprehend... sss

Hi G-W, I think this is an interesting post! Are you aware of any research into the extent of this effect on Antarctic sea ice extents? Could Bob Grumbine or someone else analyse this year's ice using a coastline from 20 years ago? I guess it's one of those things where we can talk of chunks of ice the size of small uninteresting countries , but have these chunks amassed to make a notable percentage (0.1%, 1%??) of the Antarctic total sea ice?. Nonetheless, as you and others have commented, there are a great number of reasons why Antarctic ice and Arctic ice have been behaving differently - not all are intuitive, including the one you mention. It's the thing that all other things being equal, GHGs should also warm the Antarctic, and we should see acceleration of glaciers (observed), retreats (observed in some places, not others), and ultimately retreat of sea ice. But at present, all other things are not equal, and so the sea ice has mechanisms to help it remain and expand. In the interests of fairness (lest people think I write one-sided), I should compliment 4wd on their prediction of sea ice from the other day. So far, spot on! Though I think there's unusual weather patterns in play and with the very low overall volume, that may subsequently change. I can only hope the weather patterns help maintain the ice, as we're much better off with it than without! I'm not yet going to revise my prediction - as 2008 showed, late melting of the already thin ice could easily put my prediction (~4.2-4.5m sq km) well within rage. Though I'm concerned with 4wd's 'exponental increase of Antarctic ice'? Any evidence more substantial than a Goddard junk post at WUWT? How long till a snowball earth :lol:? sss

The problem there is that there is so little real replication done by the community of people who would like not to be called 'deniers' by the rest. Replication of results means that you reproduce the same results using your own methodology, a different dataset, or even both. It does not mean fire off an FOI request or two, get exactly the same data and code and fiddle to find trivial errors. Meanwhile, massively irritate the people who did the hard work gathering and analysing the data in the first place, while nothing useful emerges. If I want to verify that the published global temperature data is correct, I'd download the raw data, apply necessary corrections, then lay the data out spatially and assess the result. I would not need to have the exact code for the data corrections, or for the spatial analysis, I would generate it myself (I have done similar jobs with smaller datasets - it's not that hard). DItto timeseries of proxies - which are a rather better data source than one poster suggested earlier. I don't even have to do complicated statistics to identify the trends! If MacIntyre, Watts and their ilk spent more time (actually, any time at all would do) doing real science, they would be taken seriously by real scientists. Verification is carried out all the time in science and especially in climate science (hence the myriad 'hockey sticks'!) - but it has to be done properly, After all, great fame does await someone who can show that we have nothing to worry about regarding global warming - if they can overturn one of the most verified theories their place in the pantheon of greats is assured. Genuine scientific replication and verification would be a place to start for the MacIntyres, Keenans and Watts of this world. I like your last post VP! THe thing is, I do believe that was where we were headed, only very sloooowly! Most 'hockey' sticks and their relatives do not have very steep pre-industrial gradients, and some of that can be accounted for by combined volcanicity and low solar conditions. You're also right to point out the refutation of the Lu paper. The same physics that works for the CFC molecule has to work for the CO2 molecule, and so if you argue for CFCs being a contributor, you're arguing for CO2 to be a major contributor - the links in the ever-excellent Skeptical Science article show that observations match modelled predictions for downward longwave radiation, of which CFCs only contribute a relatively small part. Someone else called Skeptical Science biased - well, I guess it is if you don't want your theories to stand solely on the evidence that supports or refutes them. sss

Just read an interesting article by Atmoz - it's a couple of years old but is well worth a read for those who still think that an oscillation, and in this case the PDO can cause global warming: http://atmoz.org/blog/2008/08/03/on-the-relationship-between-the-pacific-decadal-oscillation-pdo-and-the-global-average-mean-temperature/ Two stand-out quotes from the above link: "On Friday I was pointed to another Internet posting that purported to show that the recent warming is due to changes in the PDO. ... I’ve written before that the PDO cannot contribute to global warming for the simple reason that for the ‘classical’ definition of PDO, the trend is removed (eg, at the University of Washington). There will still be variations about the mean, and those variations may mask or enhance the global warming signal in the global mean surface temperature, but it cannot contribute to a trend." [emphasis mine] There follows a really informative discussion of the relationship between the region wher the PDO is defined, and the warming global oceans. The second stand-out comment: "This implies that the mode of variability known as the PDO has the same spatial and temporal characteristics as the mean global surface temperature anomaly. The PDO doesn’t cause global warming, the PDO is global warming. (Insert all the caveats of PCA; statistical relationship not causal, linear, etc.)" - See the article for the quote in the context of the analysis. What he's done is perform the analysis that extracts the PDO signal on the whole ocean dataset - you get exactly the temperature rise you expect (ie one that matches the observational global temperature timeseries) - the variations, with a warming trend, in the Pacific are merely the local expression of that. The local variations, like PDO or ENSO may tweak global temperature up or down a bit, and this is very noticeable with ENSO, but they fundamentally cannot cause global warming. sss

I see you're still keen on repeating MacIntyre's tired old arguments. If you're right, why is it I (and Peter Hogarth in the Skeptical Science link below) can reproduce the 20th Century 'uptick' from this data set: Ljungqvist 2009, TEMPERATURE PROXY RECORDS COVERING THE LAST TWO MILLENNIA: A TABULAR AND VISUAL OVERVIEW (capitals not mine!) http://www3.interscience.wiley.com/journal/122225084/abstract?CRETRY=1&SRETRY=0 with the source data in .xls format here: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ljungqvist2009/ Don't think there's any Tiljander data there (Scandinavian lakes are a smallish subset, and the data is from NCDC which has no Tiljander in the author search), there are four bristlecone series easily removed, no oaks, and yet the 20th Century uptick happily remains in a great many proxies, enough to show quite clearly in an overall average of the series. This involves no principal components, or computer code to do. See the link below, the results of which I have replicated with a couple of hours work on Excel, using nothing more complex than AVERAGE, IF or STDEV: http://www.skepticalscience.com/Tai-Chi-Temperature-Reconstructions.html And have you actually looked at Mann's supplementary figure S8, which removes 7 problem series (the Tiljander proxies) and the tree rings, yet still shows basically the same shape? I linked to the figure in my previous post. No sleight-of-hand, though MacIntyre would have credulous people believe it. The Ljungqvist data amongst others shows that Mann's results are hardly implausible and certainly not deliberately misleading. We're back to one of the fundamental issues dealt with by Muir Russell: that the data is available, and any competent researcher can download it themselves and analyse it. I would hold this true for both the instrumental series and for the millennial-scale proxies. MacIntyre spent a lot of time bleating that he couldn't get data (when he either actually had it, or had straightforward access to it), and bleating about the code, when he could have, were he a competent researcher, analysed the available data himself, using his own code or favourite statistical package. But of course he didn't, he cried 'foul' wherever he could, as like Watts and the failed surfaceStations project (Menne et al proved that one a red herring), if you actually do the analysis, you'll find the original researchers were either right, or as near as right as makes no difference! I fear you're a little too keen to use your scepticism on the published science, but are not using your natural scepticism on the sources of the fallacious information you keep presenting, as above. I thought you were signed up to Fraudit from your comment that you were a member of their club BTW, no slight intended as I really do hope you're rigorous enough to be truly sceptical of the things people like MacIntyre say as you would any other piece of science. The only thing I will agree on is that Mike Baillie's comments, referring specifically to his irish oak sequence means that the Irish series is no good for palaeoclimatology, mainly due to the way in which the series was collected from random locations across Ireland, which was never standard enough for a palaeo series. On the other oaks, the only source seems to be a one-liner by Rob Wilson in the Times article - not where I get my scientific information! Do you have a peer-reviewed source that says oaks of all kinds are no good for reconstructions like Mann's? They're definitely fine for precipitation (though not Baillie's for the reasons he cited), not necessarily for temperature. Quite a lot of literature on oaks out there... Lots of links in my previous post on competence, 2000-year glacier retreats, vindication of scientists by multiple independent panels, I won't repeat them here. Enjoy your weekend, relax and apply as much scepticism to the climate skeptics as you would in every one of the papers you publish annually, Y.S. sss

methinks the black helicopters are on therir way... Yes, Y.S., it's obvious you subscribe to Climate Fraudit, and it's also obvious that you credulously believe everything they have to say. Five independent investigations find no evidence of scientific misconduct, yet clearly Fred Pearce, a journalist who has money to make over a very dubious book on the climategate story is obviously right where the inquiries are all wrong! Riiiiiight... WIll someone please tell the glaciers to stop melting [see links lower down], the boreholes to stop warming, the instrumental temperatures to stop rising etc etc, they can safely stop now that Steve MacIntyre has said there's been a load of whitewashes. For an alternative view (with evidence): http://climateprogress.org/2010/07/07/muir-russell-emails-climategate-vindicates-climate-science-cru/ There's no evidence that incriminating emails were actually deleted, and hence no evidence of an actual crime, but that's not enough to quell your suspicions is it or crucify Jones, and clearly you're happy to cry "guilty" without and direct evidence of a crime. Fortunately the multiple independent inquiries are able to do so, and while criticising Jones' comments, they categorically state that no crime was comitted. If I say I'm going to, or can my friend Mike please drive at 120mph down the A1 a.s.a.p., does it mean a crime has been comitted? http://www.realclimate.org/index.php/archives/2010/07/the-muir-russell-report/ [among many others] Quoting Y.S.: "The published critisisms made by McIntyre have not been refuted in this area [1]. Also, the use of Tree-ring proxy data is also universally accepted as being very questionable (and I am being charitable with this statement) [2]. Yet it is used in the majority of papers supporting the original Mann publications. Why on earth did the hockey stick need to splice 20th century temperature instrumental records on top of the proxy data when they had proxy data to 1980 if not to hide the fact that the 20th century proxy data they had showed a downturn in temperatures [3]. This would have sort of questioned the value in the tree-ring proxy data to begin with." [1] Er, yes they have - MacIntyre critcises the original paper, but numerous subsequent papers have found Mann's conclusions to be basically OK, by using a variety of different methods and proxies. Some of these are linked to in the NAS report, others are more recent than that. "As part of their statistical methods, Mann et al. used a type of principal component analysis that tends to bias the shape of the reconstructions. A description of this effect is given in Chapter 9. In practice, this method, though not recommended, does not appear to unduly influence reconstructions of hemispheric mean temperature; reconstructions performed without using principal component analysis are qualitatively similar to the original curves presented by Mann et al. (Crowley and Lowery 2000, Huybers 2005, D’Arrigo et al. 2006, Hegerl et al. 2006, Wahl and Ammann in press)." [NAS report] Bristlecone Pines affect the early part of the 1999 curve, but not the later part too. [2] "universally accepted" err, by who, the denier community? MacIntyre? Certainly seems alive and well to me, and to the wider climate science community who are happy to use it. See the NAS report among others, and numerous peer-reviewed publications. The 'Divergence problem' is specific to some trees in some regions, but does not show up in other tree records, instrumental records, and crucially other long timeseries proxies - hence why you can still use the tree rings alongise other methods. [3]All you have to do is look at a load of these reconstructions to see that this one is blatantly false. The reconstructions, whether tree-ring derived, or specifically not tree-ring derived do not show a downturn at their cut-off in the 20th Century. See the many figures in links here. As I linked to in my previous post, and you can do for yourself, you can reproduce the 20th Century's kinked rise very nicely with just proxy records. The only difference when adding the instrumental record is it tends to produce a higher spike at the end of the 20th Century. But all this does is take the temps from as high/slightly higher than the MCA up to much higher than the MCA. That's still a valid line of debate, but with Arctic temperatures and some individual retreating glaciers/ ice caps proving locally higher temperatures than in thousands of years, I suspect the instrumental record to be the best on here. http://climateprogress.org/2009/09/03/science-study-hockey-stick-human-caused-arctic-warming-overtakes-natural-cooling/ http://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/langswitch_lang/in/ http://bprc.osu.edu/Icecore/Buffen%20et%20al%202009.pdf [Quelccaya Ice Cap smallest in 5000 years] Anderson et al 2008: A millennial perspective on Arctic warming from 14C in quartz and plants emerging from beneath ice caps. GRL: http://www.agu.org/pubs/crossref/2008/2007GL032057.shtml [Arctic ice caps melted for first time in >1700 years] Here's all the data that went into the Mann et al 2008 PNAS paper: http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/ http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/NHcps_no7_v_orig_Nov2009.pdf Note the specific figure that shows what the curve is without tree rings and 7 'problem series'. Seriously, Y.S., when you can go yourself and reproduce the results reasonably well of both the instrumental records and the 'Hockey Stick' from the raw timeseries, and this has been done by many independent research groups, researchers and bloggers, you wonder at the competency of those who bleat that they could not get access to the data, or could not do the reconstructions. Prof Peter Clarke's comment seems particularly pertinent to Steve MacIntyre and his ilk: "It's very clear that anyone who'd be competent enough to analyse the data would know where to find it. It's also clear that anyone competent could perform their own analysis without let or hindrance." Competent? MacIntyre? Aye right! sss

Definitely! I feel the aim sometimes is to buy just the right amount of food so your fridge is empty of perishables (and you haven't binned any/much) by the time of your next shop. And being on a budget certainly concentrates the mind on that one...

Put me down for something close to 2007, finishing a little higher (say around 4.2-4.5million sq km). Though I doubt the weather will be as favourable as in 2007, the thinner ice, as G-W notes will do the rest for loss in area given an average melt season. With the lower ice volume than 2006, you're asking for a truly remarkably low melt this year 4wd. Weather will, of course play a significant role in which of us all will be closest to the actual figure! Oh, if Joe B is predicting a low melt, it probably means it'll be a record high melt given his 'track record' - see this article and links within: http://climateprogress.org/2010/07/06/joe-laminate floori-worst-long-range-forecaster-accuweather-global-warming/ how good are his weather forecasts?: http://groups.google.com/group/uk.sci.weather/msg/c1c2bd6e12d9e7c6 If he can't even predict weather, what on earth will he know about Arctic ice? NSIDC June report: http://nsidc.org/arcticseaicenews/2010/070610.html Fastest June loss on record, lowest June extents. Very interesting analysis, and a suggestion of a somewhat slower melt in July due to melt reaching slightly thicker ice. Interesting talk on the Arctic dipole weather pattern and on the Nares Strait. sss

Very intersting indeed VP - was reading it as you posted. Looks like as far as CRU are concerned, their basic science is good (in as much as the emails do not cast doubt on it, however they are spun), but their approach to openness with their data has been quite strongly criticised. This sounds similar to the previous reports' findings, and I think we'll see a general move to make data from relevant publications a lot more accessible. That said, most of the data is there if you go looking for it, as said above in point 16 of the report: e.g. palaeo data to reproduce things that look like 'hockey sticks (NCDC, and a great example at Skeptical Science posted yesterday: http://www.skepticalscience.com/Tai-Chi-Temperature-Reconstructions.html, based on the work of Ljungqvist 2009) - I've had a go with this and it's rather intriguing the kind of analysis you can do with just palaeo data and get rather close to some of the published reconstructions (this isn't accounting for spatial distributions any more than NH, SH), and not splicing on temperatures. Using this data, and accepting significant spatial limitations, the 20th Century 'uptick' (and it's specific kinked shape) is quite a robust feature, with or without bristlecone pines, though not always passing peak Medieval warmth... Y.S. will enjoy hearing some of that! and e.g. for temperatures themselves - Tamino and others have independently replicated the temperature records from http://tamino.wordpress.com/2010/03/01/replication-not-repetition/ http://clearclimatecode.org/the-1990s-station-dropout-does-not-have-a-warming-effect/ http://rankexploits.com/musings/2010/a-simple-model-for-spatially-weighted-temp-analysis/ I think all using GHCN raw data. Now I'm not here to drive more discussions on hockey sticks , or 20th Century temperature reconstructions, but to say that the best way of testing the conclusions of any study or research group is by accessing the raw data and replicating the conclusions through your own analysis. If you can show your methodology is sound, and others can do the same from the same raw data then your result is all the more sound. It seems that with CRU, they fell down a bit in how they gave access to certain kinds of information (albeit that not all raw data was theirs to give out), but that their results are sound, replicable, and replicate the results of other groups. In an Internet age with easy access to data, this is all the more important. So I'd see the report as a step forward for bridging the gap between published science and the wider community, if its findings are acted upon where they haven't been already. One thing I haven't seen - any comment in there about access to published research, e.g. key papers behind paywalls as far as non-University people are concerned? Although my opinion is that you can get most by visiting a University library and some even in other libraries. sss

Yeah, I think that's part of the issue is how much more media-savvy certain elements of the debate are, and it's something that mainstream climate scientists need to combat. I wonder how much of it is the fact that if you want to find the opinion of a respectable 'climate sceptic' you really only have about five or six people to choose from, worldwide, compared to thousands on the pro-AGW side. Those five or six have a fame far exceeding their scientific talents, indicating they are called on rather often! I'd get writing if my academic climate science credentials were sufficiently good, but they're not, compared to specialists in that field. In the case of this article, it's pretty plain Fred Pearce wanted to set an angle of controversy so he could sell his book, so I doubt he searched very hard for good 'pro-AGW' scientists. sss