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sunny starry skies

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  1. And the key thing about the Karakorum glaciers is their debris cover (really high, steep mountainsides tend to have that sort of effect on glaciers- lots of debris), which protects the ablation area from mass loss and frontal retreat like you would see on a 'normal' glacier. Advance/retreat is not the best marker of glacier mass balance change under those circumstances. As ever it is enlightening the way some like to highlight trivial and acknowledged errors to make a point, when the bigger picture very clearly shows otherwise. VP, I think that was the reason your first post on the topic was not reasonable, I'm sure you understand the narrow scope of the acknowledged IPCC error, and the context within which it lies, that the vast majority of glaciers around the world are retreating.
  2. Would the following link be of use? Santer et al 2003: Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes. http://www.sciencemag.org/content/301/5632/479.abstract Not sure it really answers many of your questions. There's also the Solomon et al paper from last year on stratospheric water vapour, which might be a starting point for references. The following Skeptical Science article may also be of use, based on the Solomon paper: http://www.skepticalscience.com/water-vapor-stratosphere-global-warming.htm @weather ship: On reflection, I see where I have gone wrong there - the lower troposphere has clearly warmed, and this is reflected in average 500mb height increases. [That may possibly lead to stronger blocking events where you get warm air advection such as those that occurred in Dec 2009, and especially Dec 2010.] Where I was wrong is to make the connection between that and the tropopause, whose changes are more directly linked to CO2 (warming troposphere and cooling stratosphere). Thanks for pointing that out, always good to keep learning!
  3. I've quite happily referred to the Lockwood study in previous posts about hypotheses relating to blocking and our winter weather (so far as I recall this solar connection was restricted to winter, and so its potential explanatory power is limited to that season). I also presented an hypothesis about reduced sea ice having an impact. It would seem that you can add the increased height of the tropopause to that list as well. The crucial thing about all of these hypotheses is that they are related to the redistribution of energy in the climate system, not the addition or removal of energy from the system. You talk as if the science does not consider all contributing factors? Yet it does exactly that, in quite excruciating detail - look at the IPCC reports if you don't believe me. The balance of evidence very strongly favours the aGHG forcing to be dominating 'natural' drivers over the past 40 years, with no sign at all that this will change in coming decades, as the GHG signal increases rapidly, with the power to overwhelm even a Maunder Minimum-like decrease in solar output. Internal oscillators do not add or remove energy from the system (ENSO, PDO etc). If a large decrease in solar output happens, which would be a contribution by natural causes, it will have an impact, but it can't put us back into the LIA. Only a very large volcanic eruption, significantly bigger than Pinatubo, could do that, and even then only temporarily. Or we find a way of reducing the amount of CO2 in the atmosphere. The CO2-specific changes in surface and satellite-measured longwave radiation, plus the fingerprint signature patterns of warming mark out the culprit for late 20th Century warming clearly. As I see it, part of the problem in these debates is the determinantion by some people to believe that there is a real balance to the discussion, with AGW on one side, and some as-yet undefined alternative hypothesis on the other. From a scientific standpoint, there simply isn't, despite the fact that all aspects of these arguments have been discussed by thousands of scientists for decades, and so the prevailing theory of climate remains robust, having withstood a host of challenges. The media regularly falls into this trap, regularly interviewing cranks like Peiser or Corbyn, often giving them comparable airtime to climatologists despite their completely discredited views. On what is driving our local winter weather, there is plenty to discuss! Just as in the literature, there are several competing hypotheses, and it remains very interesting to see if one or other hypothesis will have greater support from observational data. It is plausible that all are playing a part to some degree.
  4. Sorry you feel that way jethro - I was hoping that somebody might pick up and run with the concept that a warmer atmosphere is more conducive to blocking events, which in turn will lead to an exaggeration of extreme weather under or around those blocks. It's an idea, and it's not meant to be an antagonistic one! It happens to have some parallels to unusual and newsworthy events weather-wise for quite a few years now, seems something quite intriguing. I don't have the data analysis means to determine whether that hypothesis stands up to scrutiny, but maybe others do? Surely it's a topic for discussion? And it's not really a case of being 'pro' or 'anti'... it's a case of following the evidence, and ignoring your personal leanings. There is a theory of climate, of which AGW is an unfortunate consequence. This theory is supported by a vast quantity of hard evidence. There is presently no plausible alternative which is capable of placing natural variations on a par with current anthropogenic forcing, and both physical theory and palaeoclimate data preclude strong negative feedbacks from operating. The natural variations exist of course, they produced phenomena including the MWP, LIA and the Quaternary Ice Ages, but these variations only work when incorporated into the larger theory of climate, where specific drivers operating at specific times push the climate on its way. The NAS, in its Science letter has gone as far as saying that this theory of climate is on a par with other well-established theories, such as the Big Bang or the age of the Earth: "Even as these are overwhelmingly accepted by the scientific community, fame still awaits anyone who could show these theories to be wrong. Climate change now falls into this category: There is compelling, comprehensive, and consistent objective evidence that humans are changing the climate in ways that threaten our societies and the ecosystems on which we depend." http://www.sciencemag.org/content/328/5979/689.full I'm happy to follow the evidence wherever it leads. I'd love for the prevailing theory and its unpleasant consequences to be wrong, and will truly celebrate if somebody can demonstrate, with sound evidence, this to be the case. But I'll follow the evidence.
  5. I'd guess it might be pretty dangerous - getting people to agree on the level of dimming would be an awful challenge in itself. Add to that the problem that the energy imbalance caused by increased GHGs is not the same as the energy imbalance caused by a brighter Sun, namely that opposite effects occur for day versus nighttime temperature, winter versus summer, stratospheric temperature, and high latitude temperature, so your treatment is not most effective where the impacts of AGW are most dramatic. To me it wouold be an exercise in treating the symptoms, not the causes, and surely only a last resort if things got really bad...
  6. You're very touchy on the subject! I was presuming that you didn't fall into the trap of assuming local or regional weather equalled global weather, despite your posting of a provocative article on cold weather in the US. I followed up with a description of an hypothesis as to why weather extremes might be on the rise as a result of a warming world through increased blocking - a description which I thought would be of interest to those who follow weather patterns. Do you think that such an hypothesis is workable, and do you think Ostro's data contributes positively to the science? By definition, if we expect to see more droughts, floods, heatwaves and winter snowstorms globally as a direct consequence of our warming world, I would expect to see fewer of these disruptive events in a world not experiencing these changes. Such weather might be globally a little cooler, with fewer extreme temperature and precipitation events. Anecdotal observation from the past 12 months, supported by further observations from the past decade do not appear to support this view, whether you live in the UK or whether you take a global view. Confirmation of AGW does not come from the weather, it comes from observations of radiation imbalances and the specific wavelengths at which they occur, along with other 'fingerprint' evidence. Alongside this, we expected to see the types of unusual weather we are observing - coincidence? EDIT: Noggin, it sounds a lot like Bill Ruddiman's Early Anthropocene hypothesis - where he links mass deaths in the Medieval and Middle Ages (plagues, wars etc) to drops in CO2 and cooler climate, as well as our climate modification starting 8,000 years ago with the dawn of agriculture nudging CO2 levels up a bit. Still an hypothesis, but certainly an interesting one! Kudos to the Mail for printing that one, given the necessary corollary!
  7. Newsflash, the Daily Mail doesn't like the BBC or accurate science about climate change, who knew . Getting past the Mail's political advocacy (it's certainly not a source for balanced reporting), if you read the links I posted to Stu Ostro's articles, you'll find a very reasonable mechanism for creating increased high latitude blocking in a warmer world. I presume, Jethro that you don't fall into the traps of the fools who say "look, it's cold outside so the world must be cooling". Global temperatures are unequivocally on the rise, with 2010 coming in as hottest or 2nd hottest depending on the dataset you use, despite the strong La Nina for the second half of the year. Stu Ostro's hypothesis (actually it isn't his, and has been in the scientific literature for a few years, but he's supporting it with some interesting data), is that the thickening of the troposphere (directly attributable to CO2) has manifest itself in an observed increase in 500mb anomalies. Now this is where my weather knowledge is a tad weaker, but when people on the models thread go nuts about a Greenland or Scandinavian high, they tend to be most interested in the strength of the blocking induced by 500mb height rises. So the strong rising trend in 500mb height anomalies provides the ingredients for strong blocking systems. Depending on where you are in relation to that block you can be subjected to more exceptional weather - Stu Ostro has documented a link between this and many of the big floods, heatwaves and snowstorms that have occurred in recent years (his powerpoint presentation runs to over 700 slides). It certainly seems a reasonable hypothesis with a good causal chain to me... 1: The radiative forcing from increased CO2 raises the height of the tropopause, allowing greater 500mb heights 2: Stronger and longer-lasting blocking patterns in the atmosphere can occur 3: the increased water vapour in the atmosphere is then concentrated onto specific areas, depending on the positioning of the block. 4: Suitable block positioning can provide an excellent conduit for cold air to exit the Arctic in winter, affecting localities in the mid-latitudes. BTW, excellent debunk on the GM, Hiya. Any issues with GM certainly don't include increased ingestion of toxins!
  8. I watched the program, and thought it was excellent. Perhaps you're right about the GM part though - the evidence for human impact on global climate is much more comprehensive! The parallels between HIV-AIDS denial and climate change skepticism are more apt, as in both cases there is an overwhelming body of evidence on one side, and very little evidence on the other. The parallel between tobacco smoking disinformation and climate disinformation should perhaps have been mentioned, as it is well established that both the same tactics, and in some cases the very same people, were involved in spreading misinformation about the science in both cases (See 'Merchants of Doubt' by Oreskes and Conway, or 'The Inquisition of Climate Science' by James Powell for more information). The thrust of the programme's argument, that sources such as internet blogs and pages such as these very pages on Netweather, now have the ability to reach the general public (and media echo chambers such as Delingpole who openly admitted he doesn't read the science) as effectively as the peer-reviewed journals, is the key. How do you know who, myself included, is telling the truth, if you are not a specialist in that subject? Science as a whole has reached an unusual position, where it is now easy to spread misinformation to the general public through the Internet, and so information that has at least had some form of quality control now looks similar to the untrained eye as information that has no quality control at all. One of the challenges for the 21st Century will be to ensure that we base decisions affecting our personal or community wellbeing on understanding that is supported by sound evidence and has not been diluted by misinformation. Climate science is unusual in that so much data is also readily available to those who would look for it. If you're genuinely skeptical, go analyse it yourself. If you doubt the temperature record, go and analyse it! For example you can extract the whole GHCN temperature station database, and run analyses of it, should you wish. You can extract palaeoclimate temperature series of all kinds and analyse those. The data is there, and when you independently run the analyses, you get results rather like what the professional climate scientists published in the first place. On other aspects, go read the original material (at your library or online where available), and determine independent of anybody else's commentary whether you think their data and methods was appropriate to answer the question they set themselves. It's a far superior way of reaching a level of understanding than gullibly believing what a misinformer like MacIntyre, Watts, Monckton or Delingpole tells you.
  9. Hi J, As I said before, I did not say that the events in Queensland were 'unprecedented' (though as far as I am aware, the flooding in Victoria is unprecedented), but that is beside the point. Your point about stratospheric WV seems unimportant as it is the tropospheric water vapour that we are interested in when considering weather extremes, and that has been observed to have increased. Indeed, lets stick to facts, as I did: I pointed out that increased GHGs ought to lead to more extreme weather, and that we have observed a lot of the kind of unusual weather that we expect under these conditions, as well as relevant progressive increases in temperature and water vapour. Nowhere did I assert that the two are definitely linked, yet the observed unusual global weather is just what we expect. Do you claim either that extreme weather is not a prediction of a warmer world, or that we have not seen any extreme weather? Stu Ostro has some interesting observations on weather patterns, and suggests a mechanism for AGW producing the unusual weather patterns through the development of blocking patterns. It's interesting as here we have a meteorologist who was once a vocal skeptic of AGW, but has, in his opinion, followed the data. In 2009, he discussed weather extremes and their link to unusually large 500mb anomalies: http://www.weather.c...er/8_20427.html "Nevertheless, there's a straightforward connection in the way the changing climate "set the table" for what happened this September in Atlanta and elsewhere. It behooves us to understand not only theoretical expected increases in heavy precipitation (via relatively slow/linear changes in temperatures, evaporation, and atmospheric moisture) but also how changing circulation patterns are already squeezing out that moisture in extreme doses and affecting weather in other ways. " 500mb and 1000mb heights for 30N-70N since 1975: From Stu Ostro's above post, data NCEP. I would of course be interested in the data for the rest of the globe, but the progressive rise is certainly of considerable interest in our latitudes, as it suggests an increased propensity for 'blocking' patterns, such as December's record event. And a note about the record December 500mb anomaly extreme at the bottom of this post: http://www.weather.c...er/8_23680.html
  10. Thanks for the info - bears out exactly what I said. Looks like 2011 would have had a higher flood stage than 1974 without the dam, according to your graph and the data from Seqwater (~6.25m). Not 'unprecedented' in height, but pretty remarkable with no tropical cyclone to provide the deluge. For unprecedented, that was your insinuation, but it does indeed get used a lot, in relation to other recent events in the context of the past century or more, 'unprecedented' CO2 levels, 'unprecedented' global instrumental temperature anomalies, 'unprecedented' low levels of sea ice, 'unprecedented' coral bleaching or ocean acidification... I'd use it to describe the number of high temperature records versus low temperature records this year, or the 2007 summer Arctic sea ice extent, or the present rate of retreat of world glaciers, or the rate & magnitude of warming over the past 100 years when compared to the last 10,000 years. It's particularly 'unprecedented' when all these indicators of warming occur at the same time, despite natural drivers all pointing to cooling. Useful word, when used in it's right scientific context
  11. Excellent graph BFTV - a useful resource for those interested in seeing in how much reduced the sea ice is throughout the year, even since the 1980s and 1990s. All the recent curves trace among the lowest curves on the plot, except for rare excursions to 'normality', usually crowed about among skeptical commentators. The trend in minima is particularly striking - we can only dream of a 7M sq km minimum now. Might be interesting to see the chart with the last 5 years highlighted?
  12. And the prize for the first person to totally misunderstand my point goes to.... I'll repeat my quote: The Wivenhoe Dam and other defences mean that floods (maximum river stage) down the Brisbane river are lower than they were before. This is of course a good thing! How much lower, I am not sure, though it would be interesting to find out - Wiki puts specifically the flood defence part of the Wivenhoe Dam at a capacity of 1.45 million megalitres (1.45 cubic km) of water, presumably all not immediately contributing to peak discharge. Add to that the conspicuous lack of a tropical cyclone in initiating exceptional rainfalls, as present in previous exceptional floods, and you have a distinct event for Brisbane. How much rain fell in comparison to the events of yesteryear cannot be determined from the above graph. You might also want to point me to where I claimed the Brisbane flood was unprecedented?
  13. Brisbane floods - You cannot compare present floods to past floods just by peak river flow, as since 1974, flood defences have been built such as the Wivenhoe Dam. Consequently the same peak reainfall does not have the same peak discharge down the Brisbane River, so unless you can show that there was less precipitation, then you cannot say the event was less bad weather-wise than 1974 or 1893. [bTW, there may well have been less precipitation, I haven't seen the data yet]. It's worth keeping an eye on John Cook's 'Skeptical Science', as he is a resident of Brisbane and will be doing a summary of the event at some point once it is all over. Add to that a crucial point that has been overlooked by the mass media: past extreme floods in Brisbane have been the products of tropical cyclones dropping extreme rainfall on top of wet conditions... this year it did not take a tropical cyclone to do the job, it just rained. http://www.newscient...f-flooding.html Jethro you seem pretty unhappy when people relate extreme weather events to AGW. Yet these kinds of weather events are precisely what we expect of a warmer world, namely a world with more water vapour in the atmosphere, and higher sea and land temperatures. So we expect to see more intense floods when it rains (think Tennessee, Pakistan, Sri Lanka, Brazil, China, Queensland); We expect to see more high temperature records than low temperature records (19 countries set high temperature records, none set low temperature records in 2010); we expect to see more droughts in the places it doesn't rain - higher temperatures are more effective at drying out the land - think of large areas of Russia. And of course you get snowstorms when all that extra moisture is falling in regions where the temperature is below freezing (worth noting that most blizzards in North America historically happen in warm years). So you can get all upset about someone linking an individual weather event to anthropogenic climate change, but the pattern of weather events is precisely what is expected of a warmer world. Would all of these events have happened, or been as bad, had global temperatures been 0.7C cooler than present and about 4% less water vapour in the atmosphere? Very unlikely. Some say you can attribute any old extreme event to a warming world - I say you can only attribute those you expect to see as a consequence of increased water vapour in the atmosphere and higher global temperatures; the events we observe are perfectly consistent with that. It's as much a prediction of a warming world due to increased CO2 as retreating glaciers or a cooling stratosphere or warmer nighttime temperatures. Actually it's like the tropospheric hotspot or rising sea levels - it's not a fingerprint of AGW, but a fingerprint of a warming world. 2010's warmth is all the more remarkable given the low solar activity and La Nina for more than half of the year and internal oscillators like the PDO in a negative state. The forcing due to increased CO2 is not only actually expected and observed, but is the only thing that can drive our continued increase in global temperature, as natural drivers are pointed the other way. Exactly what the climate science has said all along... Edit: Jethro, on the vagiaries of European weather - it's well known that European weather (and climate) is relatively more variable than many other regions of the globe, and notably more variable than global climate. So the paper you link to is interesting, but not unprecedented. Past papers on documentary sources show exactly that - for example Medieval years 'without a winter', or the very marked switches in storminess in the North Atlantic recorded in NA+ ion concentration in the GRIP ice core. Variations must have a cause, and large variations indicate that the result of a small change (solar or whatever) has a large result. The variability is documented by those who compile multiprioxy records, and it is an important reason why these multiproxy records need to be global in scale, after all the consequence of a limited proxy record showing large variability is that climate sensitivity is very high...
  14. Show your working. Baseless claims such as these have no place unless they are supported by evidence - you have provided none. You made one single correct claim out of a collection of wrong ones - CO2 effect does diminish with increasing concentration - the problem is that doubling CO2 at present concentrations still has a large enough effect to be very siginificant: See for example: http://chriscolose.w...fect-revisited/ , or http://www.realclima...gument-part-ii/ As for sea level: Church et al (2008): http://academics.eck...8SLRSustain.pdf Figure 3 from Church et al: Sea level rise is not only not 'discounted', but the rate of rise is at its highest since records began and is accelerating. This puts the observed rise in the upper edge of the range of IPCC projections: http://www.skeptical...predictions.htm With meltwater from Greenland and Antarctica factored in, that means somewhere between 75cm and 2m before the end fo the century. Doesn't seem like much? Many people in coastal regions around the world would beg to disagree. The PIT - tipping points can be present if it is harder to regrow what you have lost (am trying not to think of a dog going to the vet ). For sea ice, I am not sure of the processes, but if others can link to papers please do so - but if the ice is melted, and the open water accumulates heat, it may be that you have to reduce temperatures below those of present to cool the water and regain the same sea ice extent. For ice sheets such as Greenland it is much clearer - increase temperature, melt ice, and so lower the total elevation of the ice sheet. This leads to a smaller accumulation area, and so increased melting the following year without any further increase in temperature required. Rinse and repeat, bye bye ice sheet. Once your ice sheet begins to melt downwards or flow away faster than it is being replenished, you can't grow the ice sheet back without lowering the equilibrium line below the initial state, and so you're in a tricky position if you pass the tipping point. The southern portion of the GIS is quite vulnerable to this kind of loss, and probably did so in the Eemian, when sea levels were significantly higher than present with only slightly higher temperatures. The GIS regrew because temperatures subsequently dropped much below those of interglacial values, so this is an example of how you can cross a tipping point, yet cross back if conditions are right. I'd expect ocean water to be much more responsive, and Polyak et al (2010) indicate reduced, but not absent, sea ice during the early Holocene. Until I know better, I'm much more concerned about ice sheet tipping points than sea ice ones, but that is only because I don't know how serious a sea ice tipping point could be. I'm certainly concerned about the albedo feedback, and the weather implications of ever increasing areas of open water during all seasons in the Arctic. http://www.cgd.ucar....eaiceArctic.pdf On feedbacks, Knutti and Hegerl 2008 is always worth a read: http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf (equilibrium sensitivity being the sum of feedback responses, including the negative ones such as clouds). These two recent posts by Chris Colose at RealClimate are also worth the read, and include many references: http://www.realclimate.org/index.php/archives/2010/09/introduction-to-feedbacks/ and http://www.realclimate.org/index.php/archives/2010/11/more-on-feedbacks/. They are kind of 'intermediate' and 'advanced' levels concerning feedbacks. 4wd, to call the scientific understanding of feedbacks 'guess-casting' is disingenuous at best. 'Not even wrong' might be closer.
  15. I agree wholly with most of what you say there VP. I stated that it is an hypothesis that heat being released from exposed Arctic water in the autumn is affecting our weather patterns - it is not elevated to theory or any higher degree of scientific acceptance than 'hypothesis'. It is some way from that hypothesis being verified by the evidence, though as most of these papers were written before the last two winters, the evidence is growing. Still it is far too short a time for significance, while the alternative hypothesis I mentioned, that low solar activity leads to cooler winters at least in the UK/North Atlantic region, is much more established and supported by longer term data. The indicator for me would be if these conditions persist, either repeating over too many years for it even to be solar-related (few occasions even in the LIA had long unbroken streches of cold winter years), or if the conditions repeat even when solar activity rises to a peak. Additionally, if we see truly unprecedented synoptic patterns, especially if repeated, alarm bells may ring. For this particular hypothesis, I wouold suggest that the years 2012-2016 may be key, around the next solar maximum, which although not a strong one, should be strong enough to negate the solar-driven cold winter weather pattern and we may be able to determine the strength of this hypothesised new driver of Northern Hemisphere weather. As yet, I remain open-minded, as I cannot forget shivering through the coldest nights on record in December 1995, and that probably had a 'low solar' component to the blocking! I read a 1999 paper discussing how we might see climate change expressed in the dominance of one or other weatehr pattern - ie the anthropogenic signal forces the pattern, rather than being altered by it, link below: http://www.nature.co...s/398799a0.html While not quite exactly relevant here, particularly as this is perhaps the emergence of an almost unprecedented pattern, I think the general comment would be that with a warming atmosphere, and modified parts of the land-ocean-atmosphere linkages such as reduced sea ice, we might expect to see unusual weather patterns emerging (or the increased frequency of particular patterns). The result is that any one region may see sharp changes in local climate by comparison to what is thought of as 'normal' rather than a difficult-to-spot gradual 0.17C/decade warming trend. You'd be hard-pressed to clearly identify the gradual trend, but you'll notice if there are events happening that have never happened before (2 feet of snow in Edinburgh)! Some regions see large warmings, others even coolings (seasonal or overall), yet others see large changes in prevailing wind direction or precipitation. But as you say, too early to call it a trend yet - I remember the long period of +ve NAO, but the next few years will provide interesting weather watching... It will be very interesting to see if we get a full repeat of the Warm Arctic - Cold Continents pattern - at the moment, the November temperature anomaly plot shows the UK and Scandinavia alone as a patch of blue in a sea of red warm anomalies above ~45deg N. Places like China and the US that were affected last winter were dominantly above average in November's record global warmth. Edit: Interesting blog post too - well worth a read!
  16. Recent winter weather patterns make fascinating viewing, especially as one who loves a snowy and cold winter! There will likely be a grerat many people who will be desperate to equate a snowy winter on these shores to global cooling of some form, but the below papers are well worth bearing in mind: Petoukhov and Semenov (2010): A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents. JGR: http://www.agu.org/p...9JD013568.shtml ScienceDaily version here: http://www.scienceda...01117114028.htm Note the date - it was published before this year's recent cold spells began, and the initial paper was received in Nov 2009, before last year's cold spells began. At present, I remain open-minded about whether the current anomalous patterns (including remarkable NAO values) are at least partly due to low solar activity, which has been flagged frequently as a possible cause (for example: Lockwood et al (2010): Are cold winters in Europe associated with low solar activity? http://www.nature.co...s.2010.184.html) But I find it intriguing that we are having a series of remarkable cold winters while the rest of the world has high temperatures. Check out http://data.giss.nas...vs2005+1998.pdf (record high Nov temperature despite strong La Nina) and http://climateprogre...-solar-minimum/ - note that the only NH mid-high latitude region with anomalous cold is UK/Scandinavia! To me, you have to ask the question - are we seeing the first strong impact on our weather due to reduced Autumn sea ice? It is still clouded by the remarkable low solar activity, but if we see these kinds of patterns persisting through the coming solar max, then we may have to adapt to them as a consequence of AGW, namely hot globe, cold UK winters. Perhaps the Arctic can't hold in it's winter cold anymore. If I was to bet, I'd go for a combination of the two, strengthening the signal to produce extreme remarkable synoptics, but where we go from here with continuing losses in the Barents-Kara Seas and elsewhere, yet rising solar activity till 2014, I have no idea. Other (reasonably) recent sea ice-winter climate papers, some published before even last year's winter: Francis, J. A., W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron, 2009: Winter northern hemisphere weather patterns remember summer Arctic sea-ice extent. Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274. Honda, M., J. Inoue, and S. Yamane, 2009: Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters. Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079. Overland, J. E., and M. Wang, 2010: Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice. Tellus, 62A, 1–9. Warm Arctic-cold continents... our future? "In December 2009 (Fig. A7b) and February 2010 (Fig. A7c) we actually had a reversal of this climate pattern, with higher heights and pressures over the Arctic that eliminated the normal west-to-east jet stream winds. This allowed cold air from the Arctic to penetrate all the way into Europe, eastern China, and Washington DC. As a result, December 2009 and February 2010 exhibited extremes in both warm and cold temperatures with record-setting snow across lower latitudes. Northern Eurasia (north of 50° latitude to the Arctic coast) and North America (south of 55° latitude) were particularly cold (monthly anomalies of -2°C to -10°C). Arctic regions, on the other hand, had anomalies of +4°C to +12°C. This change in wind directions is called the Warm Arctic-Cold Continents climate pattern and has happened previously only three times before in the last 160 years." http://www.arctic.no...atmosphere.html Would I be right in saying that this pattern is repeating/has repeated this year, making it twice in consecutive years? Whatever the cause, this Edinburgh resident knows the conditions are truly remarkable!
  17. It's an excellent point about weather boards - I wonder how many people realise that this instinctive bias is present? Add to that a prevalence among meteorologists to think either that climate cannot be changed by people, or that people cannot measure climate (think Watts, Joe IKEA-Flooring, or whatever he's called), and you end up with an odd situation where the very people who might be in a position to observe some of the subtleties of the changes happening in our atmosphere prefer to think it is or must be cooling/all natural/ anything but people. I remember an article about different groups and their views on AGW - meteorologists featured remarkably negative views, in contrast to other science fields and of course climate scientists, and the climate data itself. Goes to show that weather isn't climate...
  18. Looks like a coincidence. They seem to suggest a significant reason being that in some areas evapotranspiration slows down because there is no more water to evaporate once everything's dried out. Also, specific humidity continues to rise in neat agreement with temperature rise, which has of course continued through the past decade despite the 1998 anomalous year. Se the below post from Tamino at Open Mind, with data from the State of the Climate 2009 report: http://tamino.wordpress.com/2010/08/08/urban-wet-island/
  19. That's a hoary old piece of misinformation stewfox: http://www.skepticalscience.com/OISM-Petition-Project-intermediate.htm (there's a 'basic' version too ) 'scientists' in this context is anyone with a science undergraduate degree. In the USA alone, that would include over 10 million people since 1971, of which 31,000 is a measly 0.31%! The truth is that >97% of publishing climate scientists say 'yes', and frankly I'd rather go to those who specialise in a field, and preferably have more than an undergraduate degree to their name. noggin, laying aside your claims of 'scaremongering' for a moment as Dev has dealt with them... (I trust you've seen the lastest sea level projections that are mostly >1m this century, and I was walking along ther Thames last week with the water lapping up to pubs' outdoor tables on the Thames path). Why do you think there should be a 'balance' with the Earth's temperature? It's a common misconception, brought up by phrases like 'recovering from the Little Ice Age'. We know full well from distant and more recent palaeoclimate that the Earth has happily existed at rather higher and rather lower temperatures than present (with attendant large sea level shifts). We also understand that every shift in the Earth's temperature must have a forcing that drives the shift. The pot on the hob does not boil by itself, you have to light the gas under it! For the Earth, those shifts, and our very existence at a temperature above -19C are very well explained by a combination of CO2, orbital and solar forcings of different magnitudes and at different timescales, aided and abetted by carbon cycle, water vapour, albedo and other feedbacks. There's no divine reason for a 'normal' temperature of the Earth, it just sits at whatever it's allowed (or made) to be. The absolute boundaries are far away - 'snowball Earth' didn't turn into an ice cube because the snowball interfered with the absorbtion limb of the carbon cycle and CO2 built up, triggering warming. At the upper end, the feedbacks are such that so far no condition (even the PETM) has successfully driven a runaway greenhouse a-la Venus with evaporating oceans and the like, but temperatures have been many degrees above present-day values. But there's a lot of scope for a lot of variation in between, and not much of that lies within the scope of human existence, agriculture or coastal dwelling. And you can only go where the forcing drives you, not to a mythical 'normal'. Maybe very large changes won't happen in our lifetimes (though we'll live to see an ice-free Arctic Ocean), but ask people in Moscow or Swat Valley what they think about 'climate shocks'. They won't think them so inconceivable. Maybe next year, it will be Guildford, Glasgow or York... Extreme weather events are entirely consistent with, and expected from, an atmosphere that is both warmer and has more water vapour in it. Hansen's discussion of climate and extreme weather is interesting: http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/ "would these events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?", an appropriate answer in that case is "almost certainly not." That answer, to the public, translates as "yes", i.e., humans probably bear a responsibility for the extreme event. Some 'alarm'... 500-year events occuring more frequently? http://climateprogress.org/2010/09/30/north-carolina-500-year-rainfall-deluge-global-warming/ Despite the deepest solar minimum in decades, and a very deep La Nina in progress, temperatures continue to break records, and the last 12 months continue to be the hottest 12 months on record... http://climateprogress.org/2010/10/04/endless-summer-hottest-september-record-high-temperatures/ http://climateprogress.org/2010/09/28/1california-prop-23-los-angeles-heat-wave/
  20. And Gore is no more at the core of the science than you or I, though he did get rather closer to the mark with his presentations (not always in the gold) than most other non-specialists' interpretations of the science. But I'd always listen to the actual specialists first, or read their published work. All Hal Lewis ever did was read a garbage book by Montford (see http://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/ for one review and links to two more). Pretty poor from someone who professes to be an academic, really. I must admit I'm looking forward to seeing Wegman and his cronies squirm now some of their misconduct is making major US news outlets, and there is a formal misconduct investigation ongoing. This spreads all the way to junk paper McShane and Wyner, who indirectly plagiarised Bradley by way of Wegman... dearie dearie me, naughty! As Eric Steig says at RealClimate, the serious part is not just copying someone else's work, but it is the distorting of some key elements to substantially change their meaning (like pretending that Bradley said you couldn't generate a proxy temperature series from tree rings, when of course he said you could!). The scholarship of Wegman and cohorts stinks.
  21. Interesting news... looks like Wegman's shoddy plagiarism may be coming home to roost at last. SkepticGate, here we come... http://deepclimate.o...son-university/ http://scienceblogs....investigate.php For the unitnitiated, the Wegman Report is a 'gold-standard' skeptic pillar of disinformation, comissioned by US Republicans in an attempt to discredit Mann et al's (and by implication the myriad other) 'hockey sticks'. The 'report' wqas comissioned by oil-funded Congressmen for the US Congress, the misleading of which is indeed a criminal offence. It has been referred to in almost reverent terms by Watts, MacIntyre and other skeptics as absolute proof of a cancer in climate science and the falseness of the palaeoclimatic 'hockey stick'. Unfortunately, the Wegman report appears to be chock-full of plagiarism and distortion, fitting with it's failure to comprehend the science it pertains to discredit. A proper assessment of Mann's (and others) work is found in the relevant National Academy of Sciences report http://books.nap.edu...id=11676&page=1 vindicates Mann's general result while finding minor quibbles with some of the methods. Subsequent work by many authors have vindicated the general findings further. John Mashey has completed a detailed assessment of the Wegman Report's plagiarism and published his findings, and people are taking notice, not least George Mason University, home of one Edward Wegman. 'Investigations' are rather more serious than 'inquiries' - the latter is to determine if there is perhaps any wrongdoing, the former is to establish the seriousness of wrongdoing discovered. All the past year's bluster about 'inquiries' into palaeoclimatic science found nothing to investigate; by contrast, here we have a piece of work held up repeatedly by skeptics as crucial to their cause, and it would clearly fail a standard University assessment of what determines plagiarism, let alone distortion. In academic circles, plagiarism is an incredibly serious charge, which leads to expulsion of undergraduates, let alone members of staff. From Eli Rabett: "When a formal research or professional misconduct complaint is received, universities are required to open an inquiry. This is a less formal procedure, usually conducted by administrative personnel with or without academics taking part. it is very confidential. Only when the inquiry finds strong evidence of misconduct is a formal investigation opened." In my opinion, the evidence presented by John Mashey in his report: (linked here, http://deepclimate.o...-wegman-report/) is compelling for serious academic misconduct, and in a piece of work which has massive policy implications that is not at all trivial. ----- Edit: more on Hal Lewis here.. hardly news when someone with no real clue about climate science tries to make some noise? http://climateprogre...ety/#more-34723
  22. NDS, you might also want to check out the peer-reviewed literature, and at the least verify data that comes from sources with a 'slant' such as WUWT or Spencer. They may not tell you that the PDO is a spatial phenomenon, not a measure of absolute temperature, and that the overall North Pacific has warmed up neatly in line with global temperatures. This means that a PDO 'cold' occurrence now does not contain ocean waters that are necessarily 'cold' on average (or in fact any colder than the PDO 'warm' phases), and that the local warmings and coolings of the spatial pattern must have warmed on average over the past decades. Presumably the most interesting observations relates to the waters around the Bering Strait - What influence does the overall North Pacific warming trend have on those waters during equivalent PDO oscillation phases? There were some very high SST observations in the seas north of the Bering Strait this summer, presumably simply because the ice melted and the ocean water absorbed lots more energy? More information here: http://www.skepticalscience.com/Pacific-Decadal-Oscillation-intermediate.htm And worth noting that they're doing 'advanced' versions of many of the topics so yet more information may come soon!
  23. Intriguing, slightly mind-bending stuff! I agree with you that such notions lie at the heart of science, but I would follow it up with the notion that every brand new idea you come up with has to be tested against the known reality or the known physics, and if it fails that test, then the idea should be discarded. For example, what if someone comes up with the idea that the Moon is made of cheese [hey, it's an idea, right... it's 'possible'!]? Sounds absurd, but it's little more absurd than many of the self-contradictory ideas floating around some climate skeptics' heads. Obviously, the man in the street cannot test that idea, in that unless you have a dog called Gromit, you're not likely to be taking a trip to the Moon anytime soon. But scientific knowledge of the Moon's properties, including its density, spectral properties, and the samples retrieved by astronauts tell us unequivocally that the Moon is in fact a ball of rock, not of cheese. People are willing to trust the science on this matter, even if they can't test it themselves. A similar argument can be forged around observations of global climate and the plausible dominant forcing factors - internal oscillations, solar variability or other non-anthropogenic factors come up against some very serious observational problems - they do not fit the data, be it the observed radiative properties of Earth or the scale of the forcings they can plausibly exert. Yet people continue to support these notions, sometimes with considerable passion, often claiming that they cannot be dismissed because they are 'possible'. Yes, they might have been 'possible' at one point, but once they have been tested, surely they must be excluded from the realms of 'possible'? {in case anyone thinks otherwise, I am not arguing for solar/internal oscillations having no effect at all, just that they cannot be the dominant forcing factor in operation in recent times}
  24. I think the problem comes from those who pretend that somehow we know less about the natural cycles than we do about current warming. A new paper (Ljunqvist 2010) has added yet another strand to the spaghetti of 1000+ year reconstructions, and once again finds the overall magnitude of natural cycles to be on the order of <0.5C globally from MWP to LIA, adding yet further support to the consensus that past historical climate changes are not of the same magnitude or rate as present ones (>1C LIA min-present). But once again, there is no pretence that the natural variations of the past didn't exist, fundamentally because in order to understand climate as forced by anthropogenic CO2 we have to understand climate as forced otherwise - that is the climate scientist's day job. You simply can't understand the anthropogenic without understanding the natural. Natural changes have not been so rapid since (at least) the catastrophic ice sheet retreats at the end of the Pleistocene, and the physics of the forcing works very well to explain both recent and palaeoclimatic changes. Natural variations, presumably the same variations that have operated over the past 1000+ years, have not achieved anything like this, and I find it hard to believe that natural variation would coincidentally go into overdrive at the same time we are releasing a known powerful greenhouse gas into the atmosphere at a rate neatly consistent with the observed change. I'll secong weather eater - boy would I love to be wrong on this, but there's as ever no coherent evidence for natural cycles playing a strong enough role to do more than slow our rate of warming. BFTP - the exceptional late start to this year's melt still resulted in a near-tie or tie for 2nd place as the lowest sea ice extent on record (and was a clear 1st place just two months after the start of melt), why do you think the date of ice melt, or growth, start matters a jot if the overall ice extent continues to decline at an accelerating rate? 2010 finished almost exactly on the quadratic curve fit through the past 30 years of data. I am happy to see the rapid extent increase of th last week or so, though I hope it's real area increase and not just spreading out of ice due to wind changes, as some have suggested. Another hypothesis, discussed over at Neven's blog, is that because we had a remarkably low concentration fragmented inner pack this year, the freeze-up of this inner region is accelerated by the seeding of <15% concentration areas by the fragmented ice debris already present. Previous years had little fragmentation in the inner pack, so growth had to be only around the edges. Another reason why 'extent' can be a misleading measure? Bring on Cryosat volume!
  25. Claims about net feedbacks being much lower than IPCC projections, Y.S., still fail woefully to account for palaeoclimate, quite apart from being materially observed, in contrary to what you posted. Remind me how you get glacial-interglacial cycles without positive feedbacks, and remind me again why those same feedback mechanisms should not operate today (and why clouds should have even a chance to reduce the CO2 doubling effect to <=1C as you suggest. While you're there, you should take in the fact that the tropospheric hotspot merely indicates a warming world, not what causes the warming. Fingerprints, which clouds don't explain are the stratospheric cooling, extra nighttime warming etc. Your continued reliance on Spencer and Taylor is, as ever, illuminating, as are the accusations such as 'the climate system is assumed to be hypersensitive' - it's not 'assumed', as the feedbacks are a natual product of the physics, and match well with observations of increased water vapour, reduced albedo etc. If it didn't we couldn't have had ice ages!
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