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  • shepherd table S8 « Climate Audit
    Idsos James Annan Jeff Id Josh Halpern Judith Curry Keith Kloor Klimazweibel Lubos Motl Lucia s Blackboard Matt Briggs NASA GISS Nature Blogs RealClimate Roger Pielke Jr Roger Pielke Sr Roman M Science of Doom Tamino Warwick Hughes Watts Up With That William Connolley WordPress com World Climate Report Favorite posts Bring the Proxies up to date Due Diligence FAQ 2005 McKitrick What is the Hockey Stick debate about Overview Responses to MBH Some thoughts on Disclosure Wegman and North Reports for Newbies Links Acronyms Latex Symbols MBH 98 Steve s Public Data Archive WDCP Wegman Reply to Stupak Wegman Report Weblogs and resources Ross McKitrick Surface Stations Archives Archives Select Month February 2016 January 2016 December 2015 September 2015 August 2015 July 2015 June 2015 April 2015 March 2015 February 2015 January 2015 December 2014 November 2014 October 2014 September 2014 August 2014 July 2014 June 2014 May 2014 April 2014 March 2014 February 2014 January 2014 December 2013 November 2013 October 2013 September 2013 August 2013 July 2013 June 2013 May 2013 April 2013 March 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 June 2012 May 2012 April 2012 March 2012 February 2012 January 2012 December 2011 November 2011 October 2011 September 2011 August 2011 July 2011 June 2011 May 2011 April 2011 March 2011 February 2011 January 2011 December 2010 November 2010 October 2010 September 2010 August 2010 July 2010 June 2010 May 2010 April 2010 March 2010 February 2010 January 2010 December 2009 November 2009 October 2009 September 2009 August 2009 July 2009 June 2009 May 2009 April 2009 March 2009 February 2009 January 2009 December 2008 November 2008 October 2008 September 2008 August 2008 July 2008 June 2008 May 2008 April 2008 March 2008 February 2008 January 2008

    Original URL path: http://climateaudit.org/2015/12/02/antarctic-ice-mass-controversies/shepherd-table-s8/ (2016-02-08)
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  • ipcc_fig_4_16_annotated « Climate Audit
    David Stockwell Icecap Idsos James Annan Jeff Id Josh Halpern Judith Curry Keith Kloor Klimazweibel Lubos Motl Lucia s Blackboard Matt Briggs NASA GISS Nature Blogs RealClimate Roger Pielke Jr Roger Pielke Sr Roman M Science of Doom Tamino Warwick Hughes Watts Up With That William Connolley WordPress com World Climate Report Favorite posts Bring the Proxies up to date Due Diligence FAQ 2005 McKitrick What is the Hockey Stick debate about Overview Responses to MBH Some thoughts on Disclosure Wegman and North Reports for Newbies Links Acronyms Latex Symbols MBH 98 Steve s Public Data Archive WDCP Wegman Reply to Stupak Wegman Report Weblogs and resources Ross McKitrick Surface Stations Archives Archives Select Month February 2016 January 2016 December 2015 September 2015 August 2015 July 2015 June 2015 April 2015 March 2015 February 2015 January 2015 December 2014 November 2014 October 2014 September 2014 August 2014 July 2014 June 2014 May 2014 April 2014 March 2014 February 2014 January 2014 December 2013 November 2013 October 2013 September 2013 August 2013 July 2013 June 2013 May 2013 April 2013 March 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 June 2012 May 2012 April 2012 March 2012 February 2012 January 2012 December 2011 November 2011 October 2011 September 2011 August 2011 July 2011 June 2011 May 2011 April 2011 March 2011 February 2011 January 2011 December 2010 November 2010 October 2010 September 2010 August 2010 July 2010 June 2010 May 2010 April 2010 March 2010 February 2010 January 2010 December 2009 November 2009 October 2009 September 2009 August 2009 July 2009 June 2009 May 2009 April 2009 March 2009 February 2009 January 2009 December 2008 November 2008 October 2008 September 2008 August 2008 July 2008 June 2008 May 2008 April 2008 March 2008 February

    Original URL path: http://climateaudit.org/2015/12/02/antarctic-ice-mass-controversies/ipcc_fig_4_16_annotated-3/ (2016-02-08)
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  • zwally 2015 table 8 « Climate Audit
    David Stockwell Icecap Idsos James Annan Jeff Id Josh Halpern Judith Curry Keith Kloor Klimazweibel Lubos Motl Lucia s Blackboard Matt Briggs NASA GISS Nature Blogs RealClimate Roger Pielke Jr Roger Pielke Sr Roman M Science of Doom Tamino Warwick Hughes Watts Up With That William Connolley WordPress com World Climate Report Favorite posts Bring the Proxies up to date Due Diligence FAQ 2005 McKitrick What is the Hockey Stick debate about Overview Responses to MBH Some thoughts on Disclosure Wegman and North Reports for Newbies Links Acronyms Latex Symbols MBH 98 Steve s Public Data Archive WDCP Wegman Reply to Stupak Wegman Report Weblogs and resources Ross McKitrick Surface Stations Archives Archives Select Month February 2016 January 2016 December 2015 September 2015 August 2015 July 2015 June 2015 April 2015 March 2015 February 2015 January 2015 December 2014 November 2014 October 2014 September 2014 August 2014 July 2014 June 2014 May 2014 April 2014 March 2014 February 2014 January 2014 December 2013 November 2013 October 2013 September 2013 August 2013 July 2013 June 2013 May 2013 April 2013 March 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 June 2012 May 2012 April 2012 March 2012 February 2012 January 2012 December 2011 November 2011 October 2011 September 2011 August 2011 July 2011 June 2011 May 2011 April 2011 March 2011 February 2011 January 2011 December 2010 November 2010 October 2010 September 2010 August 2010 July 2010 June 2010 May 2010 April 2010 March 2010 February 2010 January 2010 December 2009 November 2009 October 2009 September 2009 August 2009 July 2009 June 2009 May 2009 April 2009 March 2009 February 2009 January 2009 December 2008 November 2008 October 2008 September 2008 August 2008 July 2008 June 2008 May 2008 April 2008 March 2008 February

    Original URL path: http://climateaudit.org/2015/12/02/antarctic-ice-mass-controversies/zwally-2015-table-8/ (2016-02-08)
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  • Antarctic Ice Mass Controversies « Climate Audit
    isostatic response is obviously a legitimate concern but Laden was obviously incorrect in using this as a stick against Zwally as noted above the impact of GIA adjustments is six times higher on GRACE gravity estimates than on altimetry estimates To the extent that Laden is worried about this factor he should pin that much less weight on the GRACE estimates which he likes Laden and other readers even wondered why Zwally would publish an article showing ice mass gain in Antarctica and how it passed peer review Greg Laden speculated on its present appearance as follows Sometimes to close out a grant you need to submit a promised peer review publication This looks to me like a paper that might have been hanging around a while Clearly the paper had been hanging around a while the reasons for this remain unexplained Sou purported to shrug off the difference as an uninteresting dispute among scientists So one group of scientists find that ice has been on balance increasing while others find that ice has been on balance decreasing Had IPCC taken the same position the topic would be of little interest Bamber at Realclimate The most coherent warmist response came from Jonathan Bamber an opposing specialist who writing at realclimate here posed the question as follows why does it contradict a plethora of previous studies that suggest Antarctica has been losing mass over the same time period Unfortunately Bamber did not rebut or even analyze Zwally s thoughtful and detailed commentary on GRACE gravity estimates or Rignot s input output estimates a commentary which provides a plausible explanation of how Zwally arrived at different answers than others Bamber instead challenged Zwally s conversion of altimetry data on height to estimation of mass Bamber pointed out that small biases in the laser and radar data can have a big effect when the signal is only on the order of 1 cm year This is true enough but the same criticism is even more valid against highly negative GRACE gravity estimates on which Bamber had been silent As support for this criticism Bamber pointed out that Zwally s 2012 IMBIE calculations from the same satellite data were only about half of his most recent estimates Bamber challenged whether the new calculations were an improvement editorializing that it is probably more accurate to say that it is just different rather than better Bamber didn t mention that GRACE estimates had changed far more dramatically as shown above for the change between Velicogna et al 2009 and Velicogna et al 2014 Further the change in East Antarctica the main issue was only 22 Because the overall mass balance is an offset between East Antarctic mass gain and West Antarctic Peninsula mass loss the percentage change on the overall balance looks larger than the change in the component Bamber also observed that the laser altimetry data used in Zwally et al 2015 came from the IceSat satellite which had a life span of 2003 2009 and that results from the most recent satellite equipped with laser altimetry Cryosat 2 may yield a different picture yet again noting that intercomparisons thus far are not very encouraging Bamber also stated that there is another way to measure the changing mass of the ice sheet and that is to weigh it using the Gravity Recovery and Climate Experiment GRACE twin satellites As an editorial comment the term weigh in this context is a huge exaggeration The GRACE satellites measure gravity as they pass over The estimation of the weight of the ice sheet results from a very complicated by difference calculation that appears to have just as many if not more problems and assumptions as the competing altimetry calculations Bamber conceded that the satellite cannot distinguish changes in gravity due to changes in ice thickness from changes in gravity due to relative change in height of continental mass arising from changes in ice loading over thousands of years Bamber conceded that some critical variables are not well known and that there was very limited information for the very large East Antarctica interior Geophysicists have attempted to model how the solid Earth responds to changes in ice loading and although the physics is fairly well known some critical variables such as the viscosity of the lower mantle and the history of ice load changes are not in the interior of East Antarctica we have very limited information on how big the bedrock signal is Bamber then said that Zwally had argue d that GRACE GIA adjustments in East Antarctica were wrong because they do not know the full ice loading history Zwally argues that the GIA estimates that have been used for correcting GRACE data are wrong in East Antarctica because they do not know the full ice loading history over the last 22 000 years Maybe But GIA in the EAIS is poorly constrained and there is in general poor agreement among different estimates of GIA over the EAIS my bold This summary is both tendentious and incoherent GIA specialists Ivins Peltier Whitehouse and others have themselves taken the position that their earlier GIA estimates were incorrect in light of improved knowledge and additional data Zwally et al 2015 used up to date GIA estimates from Ivins et al 2013 estimates that have also been widely used in more recent GRACE articles e g Velicogna et al 2014 Further to the extent that Bamber is correct that there is poor agreement among different estimates of GIA over East Antarctica this is a much larger problem for the GRACE gravity estimates which are approximately six times more sensitive as Gt year relative to mm year than altimetry estimates If this is an issue for Bamber he ought not to have been silent on the GRACE studies Bamber concluded that the difference between Zwally and other studies ultimately rested in Zwally making a different set of assumptions about East Antarctica and that these assumptions were by their nature subjective and difficult without additional evidence to corroborate So what is really happening One thing that Zwally s study does highlight is how difficult it is to nail what is happening in East Antarctica because the signal is small and contaminated by unwanted effects that are as large or even larger Zwally et al get a different result from previous studies because they make a different set of assumptions Those assumptions are by their nature subjective and difficult without additional evidence to corroborate This is hardly an argument for disregarding Zwally s conclusions The problem of the East Antarctic signal being contaminated by unwanted effects that are as large or even larger as the signal itself is much larger for the GRACE survey data than for Zwally s laser altimetry data Bamber ought to have spoken out earlier Despite seeming to concede that it was impossible to get past a subjective interpretation of the Antarctic satellite data Bamber himself remained undeterred in his conviction of Antarctic mass loss falling back on the difficulty of explaining observed sea level rise without an Antarctic contribution There are however other lines of evidence that suggest that Antarctica is unlikely to have been gaining mass in the last few decades That would for example make closing the sea level budget a whole lot harder that is making the sum of the sinks and sources match the observed rate of sea level rise However this is a very indirect argument IPCC Table 13 1 attributed only 0 27 of 3 2 mm year sea level rise from 1993 2010 to the Antarctic ice sheet equivalent to about 90 Gt year rating multiple other factors thermal expansion non icesheet glaciers Greenland ice sheet changes in water storage on land as greater contributors Uncertainties for thermal expansion and glaciers were each greater than the contribution attributed to Antarctica In addition a recent study argued that groundwater extraction could have contributed up 0 8 mm year far higher than values contemplated by IPCC While Bamber is correct that mass gain in Antarctica would make closure of the sea level budget more difficult there is clearly considerable play in the numbers Nor was this line of argument relied upon in the IPCC chapter on the cryosphere in which the IPCC reported high confidence in its estimates of large Antarctic mass loss Conclusions While it is obviously up to specialists to try to ultimately figure out whether Antarctic ice mass was increasing in the periods 1992 2001 and 2003 2008 per Zwally or whether it was decreasing as IPCC and others had previously asserted there does not appear to be any objective basis by which for example Gavin Schmidt could reasonably pin more weight to highly negative estimates from GRACE gravity data than to Zwally s positive estimates from laser altimetry The size of the GIA adjustment for GRACE gravity estimates is the same order of magnitude as the estimate of ice mass loss and in many cases is larger These GIA adjustments have been dramatically reduced by specialists over the past decade and have concurrently reduced estimates of ice mass loss Many popular warmist discussions of Antarctic ice mass loss continue to use obsolete overly high estimates of ice mass loss e g NASA s estimate of 134 billion tons per year Such estimates rely on GRACE estimates using obsolete GIA adjustments The estimates of mass loss in IPCC AR5 were highly questionable They were much higher nearly double than contemporary specialist IMBIE estimates They appear to have been based on studies using GIA adjustments already known to be obsolete It was separately highly questionable to attribute high confidence and relatively narrow confidence intervals to these very high estimates of mass loss Most of the Antarctic continent especially East Antarctica appears to be experiencing ice mass gain with ice mass loss being localized to less than 5 of the continent parts of the Antarctic Peninsula and est Antarctica especially Pine Island and Thwaites glaciers This peculiar localization requires its own explanation Recent specialist literature has concluded that West Antarctica was up to 3 km higher in the LGM while the height of East Antarctica has changed little and might even have increased slightly through the Holocene West Antarctica has experienced dramatic ice mass loss through the Holocene attenuating to the present AR4 had pointed out the possibility that localized ice mass loss in Antarctica was continued Holocene ice mass loss This possibility vanished in AR5 without discussion In an inline comment to Bamber s realclimate article Eric Steig said that his opinion and that of 50 of experts was that the connection of Antarctic glacier retreat to anthropogenic global warming was weak and that the localization of the glacier retreat to West Antarctica was well understood and something that he had written about extensively I think the evidence that the current retreat of Antarctic glaciers is owing to anthropogenic global warming is weak The literature is mixed on this about 50 of experts agree with me on this So you ll get no argument from me there Second the localization in West Antarctica is well understood and I ve written about it extensively Elsewhere Steig has attributed the West Antarctic glacier retreat to erosion of the grounding line of the glaciers by relatively warm Circumpolar Water rather than to very slight warming of air temperatures above West Antarctica Given the continuous retreat of West Antarctic grounding lines over the Holocene it seems implausible to attribute present grounding line erosion to a different cause than past grounding line erosion that has taken place over the Holocene Steig s position on this point seems entirely reasonable However it still seems like one of those too typical situations where the less alarming explanation is presented in specialist literature but left unmentioned or unconfronted when retreat of West Antarctic glaciers is presented as a cause of alarm Like this Like Loading Related This entry was written by Steve McIntyre posted on Dec 2 2015 at 2 16 PM filed under Uncategorized and tagged antarctic bamber glacier velicogna zwally Bookmark the permalink Follow any comments here with the RSS feed for this post Post a comment or leave a trackback Trackback URL Shukla s Gold What Science is Telling Us About Climate Damages to Canada 107 Comments milodonharlani Posted Dec 2 2015 at 2 44 PM Permalink Reply Discovery of a subglacial volcano under the West Antarctic Ice Sheet was announced in 2013 http www sci news com othersciences geophysics science active volcano west antarctica 01555 html Steve this is not material to climate There are enough real issues in this thread that I do not wish to have this coatracked Klapper Posted Dec 2 2015 at 3 10 PM Permalink Reply I m at work so only have time to skim this now but it looks to be a most excellent source for discerning the truth about continental ice sheet melting No doubt some of what was discerned here is applicable to Greenland too Bob Tisdale Posted Dec 2 2015 at 3 31 PM Permalink Reply Thanks Steve Lots to digest here Cheers DayHay Posted Dec 2 2015 at 3 53 PM Permalink Reply What are the odds that warmists like Mann etc 100 ALWAYS come out for the CAGW side of the narrative Have they EVER thought even one supposed fact they dribble out could be wrong Richard Drake Posted Dec 2 2015 at 5 27 PM Permalink Reply Gavin Schmidt told VICE news that he would pin more weight on gavinmetric data Well that s how it read to me initially Superb explanation of the various issues Steve This almost reads like an assessment of the available scholarly literature gymnosperm Posted Dec 2 2015 at 11 45 PM Permalink Reply Pin the tail on his own donkey but seriously West Antarctica and the peninsula are the Greenland of the southern hemisphere In the several senses of propensity to accumulate lose massive volumes of ice experience dizzyingly rapid temperature fluctuations and having low mantle viscosity hot thin crust An intriguing combination The ice accumulation in both cases might be explained by hoisting a salient into the hurricanes of planetary winds The rapid variations perhaps to the complete wildcard of mantle heat flux BTW Totally know you are going to delete the first phrase Just for you Mike Jonas Posted Dec 2 2015 at 5 48 PM Permalink Reply Force as long a delay on the paper as you can then when it comes out say it can be ignored because it is out of date Neat By the time that it was presented it was criticized for being out of date raising an obvious question of why there was such a delay between availability of data and its technical presentation mpainter Posted Dec 2 2015 at 7 34 PM Permalink Reply Steve possibly you will want to can this comment Are you aware of recent studies that attribute ice loss in west Antarctica to sub ice geothermal activity volcanism etc These are convincing and resolve the climate issues regarding ice mass loss there I would imagine such studies are ignored by mainstream types I only mention this because I thought that you might be unaware of them Ralph Reiter Posted Dec 2 2015 at 8 59 PM Permalink Reply Question word firn at end of sentence that starts paragraph Zwally converted changes in altitude of the ice sheet to mass through a model of changes from snow to firn eloris Posted Dec 3 2015 at 10 22 AM Permalink Reply Googling that it means granular snow especially on the upper part of a glacier where it has not yet been compressed into ice thomaswfuller2 Posted Dec 2 2015 at 9 48 PM Permalink Reply The whole issue seems like a discussion of whether one drop exited the tap and fell into the bathtub or not days after the fact There are what 150 million Gt in the Antarctic Ice Sheets The discussion on WAIS has been ongoing since the Twenties IIRC and they specifically mentioned the threat to ice there due to mechanical reasons long before there was talk of climate change In any event I read on the Internet so it must be true that it takes 361 Gt to raise ocean sea level by one millimeter 9 137 Gt to raise sea level by one inch I think NASA wrote a few years back that nothing much is happening in Antarctica That seems to be true Why they felt they needed to promote warming seems unclear given climate change theory which divorced melt in the NH from events in the SH Another unforced error I hope you enjoyed unraveling the tangled skein here Otherwise I would lament that you had to expend so much effort Howard Posted Dec 3 2015 at 5 04 PM Permalink Reply Nice order of magnitude points Tom However I don t agree that SLR is the only important side effect Getting the ice balance right is a very important factor for figuring out what is going on Especially since some researchers believe that the LGM was ended by a shift in Antarctica dynam01 Posted Dec 3 2015 at 12 19 AM Permalink Reply Reblogged this on I Didn t Ask To Be a Blog AntonyIndia Posted Dec 3 2015 at 12 41 AM Permalink Reply The crafting of an Antarctic ice hockey stick during IPCC AR5 An up hill struggle but they kind of delivered what was expected from them Hopefully they have good protective gear maxberan Posted Dec 3 2015 at 8 50 AM Permalink Reply The conclusion section should perhaps also draw out your two findings 1 the understatement by IPCC of confidence interval through the absence of the error term due to the GIA uncertainty and 2 the flaw in the justification of a significant quadratic term leading to acceptance of acceleration Steve I am aware that I haven t pulled the conclusions together particularly well Often the conclusions emerge as you write and get articulated better in a re draft or after discussion After a while I had too much time tied up in this and just wanted to get finished The acceleration issue is an interesting distinct issue which seems incontrovertible It would be nice to have actual unadjusted data without having to reverse engineer laborious digitizations Toml Posted Dec 3 2015 at 10 10 AM Permalink Reply Steve Has anybody addressed the question of spatial resolution of the GRACE data My understanding is that it is around 300 km implying that the shortest wavelength that can be meaningfully measured is around 600 km Is it possible to say anything meaningful at all about a feature the size of e g Thwaits Glacier at that resolution Jeff Norman Posted Dec 3 2015 at 1 44 PM Permalink Reply Christmas comes early Thank you Steve Your posts are always educational GIA Glacial Isostatic Adjustment had to look it up I did look Zwally et al attributed the differences to different assumptions on the density of the snow firn ice as the altitude changed noting that the Zwally estimates were based on density of 900 kg m 3 the density of ice whereas the Davis and Wingham estimates were based on density of 350 kg m 3 the density of snow I would have thought the field would have standardized this sort of thing Like Mann Phil Plait and several butchers aprons Willis Eschenbach Posted Dec 3 2015 at 2 09 PM Permalink Reply Dang you continue to amaze I did so much appreciate this line emphasis mine They observed that the inconsistency could result from Late Holocene recent millenia accumulations and attempted ad hoc patches I also noted you saying that the IMBIE comparison does not incorporate uncertainty error from changing GIA adjustments about which IMBIE noted uncertainty of up to 130 Gt year though this uncertainty was not carried forward into the mass loss uncertainties For me the takeaway message confirms my general rule of thumb which is that the error range of the final result of any data adjustment I make needs to incorporate the estimated error in my adjustments themselves and in turn the estimated error of the adjustments needs to consider the possibility that my adjustment is totally incorrect One hopes that that possibility is small but it is usually not zero And that doesn t even touch the problems with autocorrelation Finally is the calculation of the mean in the Shepherd et al 2008 Antarctic Figure 8 correct It looks to me like they have simply averaged the errors rather than summing them in quadrature etc what am I missing here Best regards and thanks for a most interesting overview of the uncertainty in calculating the uncertainty w Steve there are numerous peculiar technical details and I could not write up every rabbit hole I too scratched my head at the averaging in Shepherd et al Also in their Table S2 If you get inconsistent answers from different methods it seems more logical to me that this shows very wide uncertainties though I can t point to a statistical authority for this Also the errors in Table S2 are very different in nature they calculated standard deviations of estimates from different groups for the GRACE series but they only had one IOM example and I coulnd t figure out how its error was calculated Zwally s persuasive criticism indicated that its error wasnt worth the powder to blow it to hell anyway Pointman Posted Dec 3 2015 at 2 28 PM Permalink Reply Nice to see you reappearing on radar I was getting worried Pointman Tom Wiita Posted Dec 3 2015 at 3 11 PM Permalink Reply From me too welcome back You had me worried that you took a squash racket to the face or something which has happened to me more than once jorgekafkazar Posted Dec 4 2015 at 12 16 AM Permalink Reply I ve been checking in often Glad to see this post appear Jit Posted Dec 3 2015 at 2 58 PM Permalink Reply The Velicogna 2009 figures are interesting Adjust by 176 Gt yr and then report on the significance of the mass balance over time This is like using y x on the y axis and plotting it against x and then remarking that the y variable i e y x is negatively dependent on x This used to happen in population biology where population change was plotted against population size which was used to diagnose density dependence i e that high populations tend to decline and v v If I have misunderstood this please someone enlighten me Also if the GIA is large and negative is it ever possible to arrive at a ve mass balance Steve I don t entirely understand your analogy however you ve clearly understood the peculiar feature of the acceleration calculations In my own thinking I viewed the data in two parts 1 you have data that goes up a smidge in the first half and down a smidge in the second half neither significant relative to the autocorrelation 2 you then subtract a steeply increasing amount And voila you have acceleration of mass loss And if Zwally s critique of East Antarctica are right we don t even know the sign of the GIA adjustment in East Antarctica maxberan Posted Dec 4 2015 at 4 37 PM Permalink Reply I would presume the alleged high significance of the quadratic acceleration term is conditional on the slope and intercept of the subtracted trend line being treated as known quantities If they were to be fed into a combined statistical model as parameters subject to sampling error then one may expect that significance to disappear along with the degrees of freedom doubly so if allowance were to be made for autocorrelation One could even end up with more parameters than data points Of course this tendency to ignore the error contribution of pre assumed quantities pervades climate science and indeed many other branches of science In a sense it pervades the entire IPCC enterprise which is explicitly predicated on the truth of the AGW hypothesis so all that is left is how much not if This allows all those opportunities for the data to be explained by other hypotheses and all those other observations that don t accord with the hypothesis may safely be bundled into the paradigm and not be allowed to contribute to a final error Steve McIntyre Posted Dec 4 2015 at 5 37 PM Permalink Reply I would presume the alleged high significance of the quadratic acceleration term is conditional on the slope and intercept of the subtracted trend line being treated as known quantities I am unable to replicate the claimed significance It looks like they might have calculated the significance based on smoothed versions of the data but I haven t parsed this yet vangelv Posted Dec 3 2015 at 3 50 PM Permalink Reply Great posting I have to say that I am envious of both the intellect and the patience that is required to put it together Nice job Steve The melting in Western Antarctica can be attributed to volcanic activity under the ice sheet As has been made clear many times before by many commentators we are looking at a complex system in which there are many factors in play Human emissions of CO2 are being ignored as time passes and the literature points to natural factors that play a bigger role http www theregister co uk 2015 07 13 geothermal heat from planets core is melting the west antarctic ice Steve There is geothermal heat but it is much too low to account for the melt There is convincing evidence that the West Antarctica ice sheet is being eroded at the grounding line by warm Circumpolar Water as it has throughout the Holocene I like geology and find it interesting but this issue is a distraction and I dont want to divert any discussion onto this topic Some commenters at WUWT are interested in the topic and you d be better off discussing it there DB2 Posted Dec 4 2015 at 7 18 AM Permalink Reply Geophysics could slow Antarctic ice retreat http www eurekalert org pub releases 2015 11 mu gcs110915 php Gomez and co authors David Pollard of Pennsylvania State University and David Holland of New York University also factor another important variable into their simulations When an ice sheet retreats the solid Earth beneath it freed from the load of the ice rebounds upward This rebound occurs in two parts an elastic component that happens right away and a viscous component that happens over hundreds to thousands of years Our simulations show that when we assume a structure for the Earth s interior that resembles the structure underneath the West Antarctic the Earth s surface rebounds higher and more quickly near the edge of the retreating ice sheet says co author Holland of NYU This makes the water along that edge shallower which slows the retreat of the ice sheet Les Johnson Posted Dec 4 2015 at 2 21 PM Permalink Reply While geothermal heat does contribute to some local melting it is still insignificant to the ice cap as a whole This paper gives an average of about 0 14 W m2 heat flux which is quite small And again it is a quite small geographical area I agree with Steve There is little to add to this discussion using geothermal http www pnas org content 111 25 9070 Howard Posted Dec 4 2015 at 8 48 AM Permalink Reply Look at the shape of Antarctica West Antarctica and the peninsula are one appendage sticking out into the ocean from East Antarctica the main portion of the continent The surrounding ocean water is way way warmer than the air it circulates from warmer climes it has 1 000 times the thermal mass than air is relatively incompressible and has essentially zero shear strength Coupled with the rift valley structure the narrow isthmus connection to the main portion of the continent the abundant basal ice streams and water saturated sediments the WAIC is much more mobile than the ice sheets of the stable East Antarctica craton This geographically determined ice sheet instability is clearly evident in the Mackintosh figures in the OP mpainter Posted Dec 4 2015 at 10 22 PM Permalink Reply the abundant basal ice streams and water saturated sediments No permafrost beneath that ice cap That 12 million year old ice cap Surely there is Water saturated sediments does not seem right Howard Posted Dec 5 2015 at 9 58 AM Permalink Google is more informative than the voices in your head and or the mutterings of like minded fantasists http www montana edu priscu DOCS Publications LanoilEtAlBacteriaWAIS pdf The abundance of subglacial water is a key factor in the dynamics of ice sheets and for isolated life in an environment beneath hundreds to thousands of meters of ice Vogel et al 2005 Fricker et al 2007 Seismic and borehole evidence indicate that regions of fast moving ice known as ice streams move over a layer of uncon solidated water saturated sediments These ice streams are the primary route for mass loss from the West Antarctic Ice Sheet WAIS with about half of the ice mass flow feeding into the Ross Ice Shelf Oppenheimer 1998 Water flows along the hydrological potential gradient towards the coastal ocean forming a hydrological system with lakes freshwater saturated sediments wetlands and subglacial drainage pathways Fricker et al 2007 Priscu et al 2008 While studies of accretion ice indicate that life may be present in subglacial lakes like Lake Vostok Karl et al 1999 Priscu et al 1999 Christner et al 2001 Bulat et al 2004 no direct evidence has been described for the presence of microbial communities in other parts of the Antarctic subglacial hydrological system Here we present such evidence from subglacial sediments recovered from beneath the Kamb Ice Stream KIS one of the six major West Antarctic ice streams draining into the Ross Ice Shelf mpainter Posted Dec 5 2015 at 1 51 PM Permalink Reply One source gives that half of the WAIS is underlain by meltwater even lakes Lakes And no permafrost only water saturated sediments No permafrost Hmmm Have any of the specialists offered an explanation for this extraordinary phenomenon I can think of only one Howard Posted Dec 5 2015 at 3 12 PM Permalink Only one Don t quit your day job kuhnkat Posted Dec 5 2015 at 5 02 PM Permalink The lakes are associated with hydrothermal features but our host doesn t want to side track the discussion Steve exactly right NO more coatrack James at 48 Posted Jan 15 2016 at 4 20 PM Permalink Reply Steve The Antarctic Peninsula and perhaps by extension West Antarctica might be thought of as poleward extensions of The South Pacific Littoral and hence more Polar neighbors of the Marine West Coast regime of Chile Similarly I would deem East Antarctica an extension of The South Atlantic Littoral and hence a more Polar neighbor of the Humid Continental grading into Continental Subarctic regime of Patagonia YMMV Michael Jankowski Posted Dec 3 2015 at 7 35 PM Permalink Reply My fave Zwallyism albeit about Greenland http www standeyo com NEWS 06 Earth Changes 060625 Greenland html Zwally joined his colleagues there on May 8 in the regular spring migration of scientists to the Arctic He has been coming to Swiss Camp every year since 1994 and has been studying the polar regions since 1972 monitoring the polar ice through satellite sensors Eventually he realized he had to study the ice firsthand Appears that Zwally studied polar ice regions for over 2 decades before he actually went too take a look at it for himself Unbelievable maxberan Posted Dec 4 2015 at 6 20 AM Permalink Reply Bit of a cheap jibe if you don t mind me saying Many roles in research including in the environmental sciences are basically deskbound While knowledge of the rigours and problems of fieldwork are necessary they don t have of necessity to be gained at first hand His seat in the chopper and use of resources out there may well have been put to better use by a real field scientist mpainter Posted Dec 4 2015 at 11 28 AM Permalink Reply There is seldom any satisfactory substitute for actual observation of the subject when one is studying natural processes True such firsthand observation might not be practicable or even possible for the researcher but this is a disadvantage imo mpainter Posted Dec 4 2015 at 11 34 AM Permalink There is seldom any satisfactory substitute for actual observation of the subject when one is studying natural processes True such firsthand observation might not be practicable or even possible for the researcher but this is a disadvantage imo Allow me to rephrase there is seldom any substitute as satisfactory as actual observation of the subject when studying natural processes maxberan Posted Dec 4 2015 at 1 00 PM Permalink I do not know of course what hands on experience you and Michael Jankowski have of the practicalities of environmental research but you must surely recognise that 1 different people have different skills and 2 there are so many hours in a day For myself I was one of those decried deskbound scientists There is doubtless a long list of reasons why my researches into floods and droughts might have been deficient but I do not judge the fact that I was a user of field data collected by others rather than a participant in its collection to rank high on that list I have no reason to think that Zwally would be less aware of the deficiencies of the data he was analysing than I was of those in the data I was supplied with Howard Posted Dec 5 2015 at 10 03 AM Permalink Yes Mpainter please extol us with your vast experience as a field geologist Do you prefer the Brunton or Silva Do you play pool with the rig hands or do they dope your hardhat mpainter Posted Dec 5 2015 at 1 53 PM Permalink Interesting comment by Howard Michael Jankowski Posted Dec 4 2015 at 1 16 PM Permalink Reply Great point except that Zwally himself obviously realized the importance of seeing it himself and doing so regularly So it seems that you are taking a cheap jibe at him for making annual visits Can t have it both ways John F Hultquist Posted Dec 3 2015 at 8 22 PM Permalink Reply So far I ve gotten to the chart with the 2 blinks first and second Am I the only person with the blink rate so fast my eyes water and my head hurts I ll take 2 aspirin and maybe I ll be fine in the morning Is it possible for me to change the rate on my computer Steve I was experimenting with a new to me program when I produced this I ll fix it in a day or two Bob Koss Posted Dec 4 2015 at 1 40 AM Permalink Reply I made one with a 5 second blink rate mrsean2k Posted Dec 6 2015 at 4 41 AM Permalink Reply Thanks Bob John F Hultquist Posted Dec 8 2015 at 8 51 PM Permalink Reply Awesome Geoff Sherrington Posted Dec 3 2015 at 8 40 PM Permalink Reply Hi Steve it is great to see at last your essay on Climate Audit Here is a shortened version of a view on the same topic It uses mass as a fundamental parameter starting with reference to BIPM the International Bureau of weights and measures HQ in France http www bipm org metrology mass activity focuses on the unit of mass the kilogram

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  • Antarctic Ice Mass Controversies « Climate Audit
    Concern about glacial isostatic response is obviously a legitimate concern but Laden was obviously incorrect in using this as a stick against Zwally as noted above the impact of GIA adjustments is six times higher on GRACE gravity estimates than on altimetry estimates To the extent that Laden is worried about this factor he should pin that much less weight on the GRACE estimates which he likes Laden and other readers even wondered why Zwally would publish an article showing ice mass gain in Antarctica and how it passed peer review Greg Laden speculated on its present appearance as follows Sometimes to close out a grant you need to submit a promised peer review publication This looks to me like a paper that might have been hanging around a while Clearly the paper had been hanging around a while the reasons for this remain unexplained Sou purported to shrug off the difference as an uninteresting dispute among scientists So one group of scientists find that ice has been on balance increasing while others find that ice has been on balance decreasing Had IPCC taken the same position the topic would be of little interest Bamber at Realclimate The most coherent warmist response came from Jonathan Bamber an opposing specialist who writing at realclimate here posed the question as follows why does it contradict a plethora of previous studies that suggest Antarctica has been losing mass over the same time period Unfortunately Bamber did not rebut or even analyze Zwally s thoughtful and detailed commentary on GRACE gravity estimates or Rignot s input output estimates a commentary which provides a plausible explanation of how Zwally arrived at different answers than others Bamber instead challenged Zwally s conversion of altimetry data on height to estimation of mass Bamber pointed out that small biases in the laser and radar data can have a big effect when the signal is only on the order of 1 cm year This is true enough but the same criticism is even more valid against highly negative GRACE gravity estimates on which Bamber had been silent As support for this criticism Bamber pointed out that Zwally s 2012 IMBIE calculations from the same satellite data were only about half of his most recent estimates Bamber challenged whether the new calculations were an improvement editorializing that it is probably more accurate to say that it is just different rather than better Bamber didn t mention that GRACE estimates had changed far more dramatically as shown above for the change between Velicogna et al 2009 and Velicogna et al 2014 Further the change in East Antarctica the main issue was only 22 Because the overall mass balance is an offset between East Antarctic mass gain and West Antarctic Peninsula mass loss the percentage change on the overall balance looks larger than the change in the component Bamber also observed that the laser altimetry data used in Zwally et al 2015 came from the IceSat satellite which had a life span of 2003 2009 and that results from the most recent satellite equipped with laser altimetry Cryosat 2 may yield a different picture yet again noting that intercomparisons thus far are not very encouraging Bamber also stated that there is another way to measure the changing mass of the ice sheet and that is to weigh it using the Gravity Recovery and Climate Experiment GRACE twin satellites As an editorial comment the term weigh in this context is a huge exaggeration The GRACE satellites measure gravity as they pass over The estimation of the weight of the ice sheet results from a very complicated by difference calculation that appears to have just as many if not more problems and assumptions as the competing altimetry calculations Bamber conceded that the satellite cannot distinguish changes in gravity due to changes in ice thickness from changes in gravity due to relative change in height of continental mass arising from changes in ice loading over thousands of years Bamber conceded that some critical variables are not well known and that there was very limited information for the very large East Antarctica interior Geophysicists have attempted to model how the solid Earth responds to changes in ice loading and although the physics is fairly well known some critical variables such as the viscosity of the lower mantle and the history of ice load changes are not in the interior of East Antarctica we have very limited information on how big the bedrock signal is Bamber then said that Zwally had argue d that GRACE GIA adjustments in East Antarctica were wrong because they do not know the full ice loading history Zwally argues that the GIA estimates that have been used for correcting GRACE data are wrong in East Antarctica because they do not know the full ice loading history over the last 22 000 years Maybe But GIA in the EAIS is poorly constrained and there is in general poor agreement among different estimates of GIA over the EAIS my bold This summary is both tendentious and incoherent GIA specialists Ivins Peltier Whitehouse and others have themselves taken the position that their earlier GIA estimates were incorrect in light of improved knowledge and additional data Zwally et al 2015 used up to date GIA estimates from Ivins et al 2013 estimates that have also been widely used in more recent GRACE articles e g Velicogna et al 2014 Further to the extent that Bamber is correct that there is poor agreement among different estimates of GIA over East Antarctica this is a much larger problem for the GRACE gravity estimates which are approximately six times more sensitive as Gt year relative to mm year than altimetry estimates If this is an issue for Bamber he ought not to have been silent on the GRACE studies Bamber concluded that the difference between Zwally and other studies ultimately rested in Zwally making a different set of assumptions about East Antarctica and that these assumptions were by their nature subjective and difficult without additional evidence to corroborate So what is really happening One thing that Zwally s study does highlight is how difficult it is to nail what is happening in East Antarctica because the signal is small and contaminated by unwanted effects that are as large or even larger Zwally et al get a different result from previous studies because they make a different set of assumptions Those assumptions are by their nature subjective and difficult without additional evidence to corroborate This is hardly an argument for disregarding Zwally s conclusions The problem of the East Antarctic signal being contaminated by unwanted effects that are as large or even larger as the signal itself is much larger for the GRACE survey data than for Zwally s laser altimetry data Bamber ought to have spoken out earlier Despite seeming to concede that it was impossible to get past a subjective interpretation of the Antarctic satellite data Bamber himself remained undeterred in his conviction of Antarctic mass loss falling back on the difficulty of explaining observed sea level rise without an Antarctic contribution There are however other lines of evidence that suggest that Antarctica is unlikely to have been gaining mass in the last few decades That would for example make closing the sea level budget a whole lot harder that is making the sum of the sinks and sources match the observed rate of sea level rise However this is a very indirect argument IPCC Table 13 1 attributed only 0 27 of 3 2 mm year sea level rise from 1993 2010 to the Antarctic ice sheet equivalent to about 90 Gt year rating multiple other factors thermal expansion non icesheet glaciers Greenland ice sheet changes in water storage on land as greater contributors Uncertainties for thermal expansion and glaciers were each greater than the contribution attributed to Antarctica In addition a recent study argued that groundwater extraction could have contributed up 0 8 mm year far higher than values contemplated by IPCC While Bamber is correct that mass gain in Antarctica would make closure of the sea level budget more difficult there is clearly considerable play in the numbers Nor was this line of argument relied upon in the IPCC chapter on the cryosphere in which the IPCC reported high confidence in its estimates of large Antarctic mass loss Conclusions While it is obviously up to specialists to try to ultimately figure out whether Antarctic ice mass was increasing in the periods 1992 2001 and 2003 2008 per Zwally or whether it was decreasing as IPCC and others had previously asserted there does not appear to be any objective basis by which for example Gavin Schmidt could reasonably pin more weight to highly negative estimates from GRACE gravity data than to Zwally s positive estimates from laser altimetry The size of the GIA adjustment for GRACE gravity estimates is the same order of magnitude as the estimate of ice mass loss and in many cases is larger These GIA adjustments have been dramatically reduced by specialists over the past decade and have concurrently reduced estimates of ice mass loss Many popular warmist discussions of Antarctic ice mass loss continue to use obsolete overly high estimates of ice mass loss e g NASA s estimate of 134 billion tons per year Such estimates rely on GRACE estimates using obsolete GIA adjustments The estimates of mass loss in IPCC AR5 were highly questionable They were much higher nearly double than contemporary specialist IMBIE estimates They appear to have been based on studies using GIA adjustments already known to be obsolete It was separately highly questionable to attribute high confidence and relatively narrow confidence intervals to these very high estimates of mass loss Most of the Antarctic continent especially East Antarctica appears to be experiencing ice mass gain with ice mass loss being localized to less than 5 of the continent parts of the Antarctic Peninsula and est Antarctica especially Pine Island and Thwaites glaciers This peculiar localization requires its own explanation Recent specialist literature has concluded that West Antarctica was up to 3 km higher in the LGM while the height of East Antarctica has changed little and might even have increased slightly through the Holocene West Antarctica has experienced dramatic ice mass loss through the Holocene attenuating to the present AR4 had pointed out the possibility that localized ice mass loss in Antarctica was continued Holocene ice mass loss This possibility vanished in AR5 without discussion In an inline comment to Bamber s realclimate article Eric Steig said that his opinion and that of 50 of experts was that the connection of Antarctic glacier retreat to anthropogenic global warming was weak and that the localization of the glacier retreat to West Antarctica was well understood and something that he had written about extensively I think the evidence that the current retreat of Antarctic glaciers is owing to anthropogenic global warming is weak The literature is mixed on this about 50 of experts agree with me on this So you ll get no argument from me there Second the localization in West Antarctica is well understood and I ve written about it extensively Elsewhere Steig has attributed the West Antarctic glacier retreat to erosion of the grounding line of the glaciers by relatively warm Circumpolar Water rather than to very slight warming of air temperatures above West Antarctica Given the continuous retreat of West Antarctic grounding lines over the Holocene it seems implausible to attribute present grounding line erosion to a different cause than past grounding line erosion that has taken place over the Holocene Steig s position on this point seems entirely reasonable However it still seems like one of those too typical situations where the less alarming explanation is presented in specialist literature but left unmentioned or unconfronted when retreat of West Antarctic glaciers is presented as a cause of alarm Like this Like Loading Related This entry was written by Steve McIntyre posted on Dec 2 2015 at 2 16 PM filed under Uncategorized and tagged antarctic bamber glacier velicogna zwally Bookmark the permalink Follow any comments here with the RSS feed for this post Post a comment or leave a trackback Trackback URL Shukla s Gold What Science is Telling Us About Climate Damages to Canada 107 Comments milodonharlani Posted Dec 2 2015 at 2 44 PM Permalink Reply Discovery of a subglacial volcano under the West Antarctic Ice Sheet was announced in 2013 http www sci news com othersciences geophysics science active volcano west antarctica 01555 html Steve this is not material to climate There are enough real issues in this thread that I do not wish to have this coatracked Klapper Posted Dec 2 2015 at 3 10 PM Permalink Reply I m at work so only have time to skim this now but it looks to be a most excellent source for discerning the truth about continental ice sheet melting No doubt some of what was discerned here is applicable to Greenland too Bob Tisdale Posted Dec 2 2015 at 3 31 PM Permalink Reply Thanks Steve Lots to digest here Cheers DayHay Posted Dec 2 2015 at 3 53 PM Permalink Reply What are the odds that warmists like Mann etc 100 ALWAYS come out for the CAGW side of the narrative Have they EVER thought even one supposed fact they dribble out could be wrong Richard Drake Posted Dec 2 2015 at 5 27 PM Permalink Reply Gavin Schmidt told VICE news that he would pin more weight on gavinmetric data Well that s how it read to me initially Superb explanation of the various issues Steve This almost reads like an assessment of the available scholarly literature gymnosperm Posted Dec 2 2015 at 11 45 PM Permalink Reply Pin the tail on his own donkey but seriously West Antarctica and the peninsula are the Greenland of the southern hemisphere In the several senses of propensity to accumulate lose massive volumes of ice experience dizzyingly rapid temperature fluctuations and having low mantle viscosity hot thin crust An intriguing combination The ice accumulation in both cases might be explained by hoisting a salient into the hurricanes of planetary winds The rapid variations perhaps to the complete wildcard of mantle heat flux BTW Totally know you are going to delete the first phrase Just for you Mike Jonas Posted Dec 2 2015 at 5 48 PM Permalink Reply Force as long a delay on the paper as you can then when it comes out say it can be ignored because it is out of date Neat By the time that it was presented it was criticized for being out of date raising an obvious question of why there was such a delay between availability of data and its technical presentation mpainter Posted Dec 2 2015 at 7 34 PM Permalink Reply Steve possibly you will want to can this comment Are you aware of recent studies that attribute ice loss in west Antarctica to sub ice geothermal activity volcanism etc These are convincing and resolve the climate issues regarding ice mass loss there I would imagine such studies are ignored by mainstream types I only mention this because I thought that you might be unaware of them Ralph Reiter Posted Dec 2 2015 at 8 59 PM Permalink Reply Question word firn at end of sentence that starts paragraph Zwally converted changes in altitude of the ice sheet to mass through a model of changes from snow to firn eloris Posted Dec 3 2015 at 10 22 AM Permalink Reply Googling that it means granular snow especially on the upper part of a glacier where it has not yet been compressed into ice thomaswfuller2 Posted Dec 2 2015 at 9 48 PM Permalink Reply The whole issue seems like a discussion of whether one drop exited the tap and fell into the bathtub or not days after the fact There are what 150 million Gt in the Antarctic Ice Sheets The discussion on WAIS has been ongoing since the Twenties IIRC and they specifically mentioned the threat to ice there due to mechanical reasons long before there was talk of climate change In any event I read on the Internet so it must be true that it takes 361 Gt to raise ocean sea level by one millimeter 9 137 Gt to raise sea level by one inch I think NASA wrote a few years back that nothing much is happening in Antarctica That seems to be true Why they felt they needed to promote warming seems unclear given climate change theory which divorced melt in the NH from events in the SH Another unforced error I hope you enjoyed unraveling the tangled skein here Otherwise I would lament that you had to expend so much effort Howard Posted Dec 3 2015 at 5 04 PM Permalink Reply Nice order of magnitude points Tom However I don t agree that SLR is the only important side effect Getting the ice balance right is a very important factor for figuring out what is going on Especially since some researchers believe that the LGM was ended by a shift in Antarctica dynam01 Posted Dec 3 2015 at 12 19 AM Permalink Reply Reblogged this on I Didn t Ask To Be a Blog AntonyIndia Posted Dec 3 2015 at 12 41 AM Permalink Reply The crafting of an Antarctic ice hockey stick during IPCC AR5 An up hill struggle but they kind of delivered what was expected from them Hopefully they have good protective gear maxberan Posted Dec 3 2015 at 8 50 AM Permalink Reply The conclusion section should perhaps also draw out your two findings 1 the understatement by IPCC of confidence interval through the absence of the error term due to the GIA uncertainty and 2 the flaw in the justification of a significant quadratic term leading to acceptance of acceleration Steve I am aware that I haven t pulled the conclusions together particularly well Often the conclusions emerge as you write and get articulated better in a re draft or after discussion After a while I had too much time tied up in this and just wanted to get finished The acceleration issue is an interesting distinct issue which seems incontrovertible It would be nice to have actual unadjusted data without having to reverse engineer laborious digitizations Toml Posted Dec 3 2015 at 10 10 AM Permalink Reply Steve Has anybody addressed the question of spatial resolution of the GRACE data My understanding is that it is around 300 km implying that the shortest wavelength that can be meaningfully measured is around 600 km Is it possible to say anything meaningful at all about a feature the size of e g Thwaits Glacier at that resolution Jeff Norman Posted Dec 3 2015 at 1 44 PM Permalink Reply Christmas comes early Thank you Steve Your posts are always educational GIA Glacial Isostatic Adjustment had to look it up I did look Zwally et al attributed the differences to different assumptions on the density of the snow firn ice as the altitude changed noting that the Zwally estimates were based on density of 900 kg m 3 the density of ice whereas the Davis and Wingham estimates were based on density of 350 kg m 3 the density of snow I would have thought the field would have standardized this sort of thing Like Mann Phil Plait and several butchers aprons Willis Eschenbach Posted Dec 3 2015 at 2 09 PM Permalink Reply Dang you continue to amaze I did so much appreciate this line emphasis mine They observed that the inconsistency could result from Late Holocene recent millenia accumulations and attempted ad hoc patches I also noted you saying that the IMBIE comparison does not incorporate uncertainty error from changing GIA adjustments about which IMBIE noted uncertainty of up to 130 Gt year though this uncertainty was not carried forward into the mass loss uncertainties For me the takeaway message confirms my general rule of thumb which is that the error range of the final result of any data adjustment I make needs to incorporate the estimated error in my adjustments themselves and in turn the estimated error of the adjustments needs to consider the possibility that my adjustment is totally incorrect One hopes that that possibility is small but it is usually not zero And that doesn t even touch the problems with autocorrelation Finally is the calculation of the mean in the Shepherd et al 2008 Antarctic Figure 8 correct It looks to me like they have simply averaged the errors rather than summing them in quadrature etc what am I missing here Best regards and thanks for a most interesting overview of the uncertainty in calculating the uncertainty w Steve there are numerous peculiar technical details and I could not write up every rabbit hole I too scratched my head at the averaging in Shepherd et al Also in their Table S2 If you get inconsistent answers from different methods it seems more logical to me that this shows very wide uncertainties though I can t point to a statistical authority for this Also the errors in Table S2 are very different in nature they calculated standard deviations of estimates from different groups for the GRACE series but they only had one IOM example and I coulnd t figure out how its error was calculated Zwally s persuasive criticism indicated that its error wasnt worth the powder to blow it to hell anyway Pointman Posted Dec 3 2015 at 2 28 PM Permalink Reply Nice to see you reappearing on radar I was getting worried Pointman Tom Wiita Posted Dec 3 2015 at 3 11 PM Permalink Reply From me too welcome back You had me worried that you took a squash racket to the face or something which has happened to me more than once jorgekafkazar Posted Dec 4 2015 at 12 16 AM Permalink Reply I ve been checking in often Glad to see this post appear Jit Posted Dec 3 2015 at 2 58 PM Permalink Reply The Velicogna 2009 figures are interesting Adjust by 176 Gt yr and then report on the significance of the mass balance over time This is like using y x on the y axis and plotting it against x and then remarking that the y variable i e y x is negatively dependent on x This used to happen in population biology where population change was plotted against population size which was used to diagnose density dependence i e that high populations tend to decline and v v If I have misunderstood this please someone enlighten me Also if the GIA is large and negative is it ever possible to arrive at a ve mass balance Steve I don t entirely understand your analogy however you ve clearly understood the peculiar feature of the acceleration calculations In my own thinking I viewed the data in two parts 1 you have data that goes up a smidge in the first half and down a smidge in the second half neither significant relative to the autocorrelation 2 you then subtract a steeply increasing amount And voila you have acceleration of mass loss And if Zwally s critique of East Antarctica are right we don t even know the sign of the GIA adjustment in East Antarctica maxberan Posted Dec 4 2015 at 4 37 PM Permalink Reply I would presume the alleged high significance of the quadratic acceleration term is conditional on the slope and intercept of the subtracted trend line being treated as known quantities If they were to be fed into a combined statistical model as parameters subject to sampling error then one may expect that significance to disappear along with the degrees of freedom doubly so if allowance were to be made for autocorrelation One could even end up with more parameters than data points Of course this tendency to ignore the error contribution of pre assumed quantities pervades climate science and indeed many other branches of science In a sense it pervades the entire IPCC enterprise which is explicitly predicated on the truth of the AGW hypothesis so all that is left is how much not if This allows all those opportunities for the data to be explained by other hypotheses and all those other observations that don t accord with the hypothesis may safely be bundled into the paradigm and not be allowed to contribute to a final error Steve McIntyre Posted Dec 4 2015 at 5 37 PM Permalink Reply I would presume the alleged high significance of the quadratic acceleration term is conditional on the slope and intercept of the subtracted trend line being treated as known quantities I am unable to replicate the claimed significance It looks like they might have calculated the significance based on smoothed versions of the data but I haven t parsed this yet vangelv Posted Dec 3 2015 at 3 50 PM Permalink Reply Great posting I have to say that I am envious of both the intellect and the patience that is required to put it together Nice job Steve The melting in Western Antarctica can be attributed to volcanic activity under the ice sheet As has been made clear many times before by many commentators we are looking at a complex system in which there are many factors in play Human emissions of CO2 are being ignored as time passes and the literature points to natural factors that play a bigger role http www theregister co uk 2015 07 13 geothermal heat from planets core is melting the west antarctic ice Steve There is geothermal heat but it is much too low to account for the melt There is convincing evidence that the West Antarctica ice sheet is being eroded at the grounding line by warm Circumpolar Water as it has throughout the Holocene I like geology and find it interesting but this issue is a distraction and I dont want to divert any discussion onto this topic Some commenters at WUWT are interested in the topic and you d be better off discussing it there DB2 Posted Dec 4 2015 at 7 18 AM Permalink Reply Geophysics could slow Antarctic ice retreat http www eurekalert org pub releases 2015 11 mu gcs110915 php Gomez and co authors David Pollard of Pennsylvania State University and David Holland of New York University also factor another important variable into their simulations When an ice sheet retreats the solid Earth beneath it freed from the load of the ice rebounds upward This rebound occurs in two parts an elastic component that happens right away and a viscous component that happens over hundreds to thousands of years Our simulations show that when we assume a structure for the Earth s interior that resembles the structure underneath the West Antarctic the Earth s surface rebounds higher and more quickly near the edge of the retreating ice sheet says co author Holland of NYU This makes the water along that edge shallower which slows the retreat of the ice sheet Les Johnson Posted Dec 4 2015 at 2 21 PM Permalink Reply While geothermal heat does contribute to some local melting it is still insignificant to the ice cap as a whole This paper gives an average of about 0 14 W m2 heat flux which is quite small And again it is a quite small geographical area I agree with Steve There is little to add to this discussion using geothermal http www pnas org content 111 25 9070 Howard Posted Dec 4 2015 at 8 48 AM Permalink Reply Look at the shape of Antarctica West Antarctica and the peninsula are one appendage sticking out into the ocean from East Antarctica the main portion of the continent The surrounding ocean water is way way warmer than the air it circulates from warmer climes it has 1 000 times the thermal mass than air is relatively incompressible and has essentially zero shear strength Coupled with the rift valley structure the narrow isthmus connection to the main portion of the continent the abundant basal ice streams and water saturated sediments the WAIC is much more mobile than the ice sheets of the stable East Antarctica craton This geographically determined ice sheet instability is clearly evident in the Mackintosh figures in the OP mpainter Posted Dec 4 2015 at 10 22 PM Permalink Reply the abundant basal ice streams and water saturated sediments No permafrost beneath that ice cap That 12 million year old ice cap Surely there is Water saturated sediments does not seem right Howard Posted Dec 5 2015 at 9 58 AM Permalink Google is more informative than the voices in your head and or the mutterings of like minded fantasists http www montana edu priscu DOCS Publications LanoilEtAlBacteriaWAIS pdf The abundance of subglacial water is a key factor in the dynamics of ice sheets and for isolated life in an environment beneath hundreds to thousands of meters of ice Vogel et al 2005 Fricker et al 2007 Seismic and borehole evidence indicate that regions of fast moving ice known as ice streams move over a layer of uncon solidated water saturated sediments These ice streams are the primary route for mass loss from the West Antarctic Ice Sheet WAIS with about half of the ice mass flow feeding into the Ross Ice Shelf Oppenheimer 1998 Water flows along the hydrological potential gradient towards the coastal ocean forming a hydrological system with lakes freshwater saturated sediments wetlands and subglacial drainage pathways Fricker et al 2007 Priscu et al 2008 While studies of accretion ice indicate that life may be present in subglacial lakes like Lake Vostok Karl et al 1999 Priscu et al 1999 Christner et al 2001 Bulat et al 2004 no direct evidence has been described for the presence of microbial communities in other parts of the Antarctic subglacial hydrological system Here we present such evidence from subglacial sediments recovered from beneath the Kamb Ice Stream KIS one of the six major West Antarctic ice streams draining into the Ross Ice Shelf mpainter Posted Dec 5 2015 at 1 51 PM Permalink Reply One source gives that half of the WAIS is underlain by meltwater even lakes Lakes And no permafrost only water saturated sediments No permafrost Hmmm Have any of the specialists offered an explanation for this extraordinary phenomenon I can think of only one Howard Posted Dec 5 2015 at 3 12 PM Permalink Only one Don t quit your day job kuhnkat Posted Dec 5 2015 at 5 02 PM Permalink The lakes are associated with hydrothermal features but our host doesn t want to side track the discussion Steve exactly right NO more coatrack James at 48 Posted Jan 15 2016 at 4 20 PM Permalink Reply Steve The Antarctic Peninsula and perhaps by extension West Antarctica might be thought of as poleward extensions of The South Pacific Littoral and hence more Polar neighbors of the Marine West Coast regime of Chile Similarly I would deem East Antarctica an extension of The South Atlantic Littoral and hence a more Polar neighbor of the Humid Continental grading into Continental Subarctic regime of Patagonia YMMV Michael Jankowski Posted Dec 3 2015 at 7 35 PM Permalink Reply My fave Zwallyism albeit about Greenland http www standeyo com NEWS 06 Earth Changes 060625 Greenland html Zwally joined his colleagues there on May 8 in the regular spring migration of scientists to the Arctic He has been coming to Swiss Camp every year since 1994 and has been studying the polar regions since 1972 monitoring the polar ice through satellite sensors Eventually he realized he had to study the ice firsthand Appears that Zwally studied polar ice regions for over 2 decades before he actually went too take a look at it for himself Unbelievable maxberan Posted Dec 4 2015 at 6 20 AM Permalink Reply Bit of a cheap jibe if you don t mind me saying Many roles in research including in the environmental sciences are basically deskbound While knowledge of the rigours and problems of fieldwork are necessary they don t have of necessity to be gained at first hand His seat in the chopper and use of resources out there may well have been put to better use by a real field scientist mpainter Posted Dec 4 2015 at 11 28 AM Permalink Reply There is seldom any satisfactory substitute for actual observation of the subject when one is studying natural processes True such firsthand observation might not be practicable or even possible for the researcher but this is a disadvantage imo mpainter Posted Dec 4 2015 at 11 34 AM Permalink There is seldom any satisfactory substitute for actual observation of the subject when one is studying natural processes True such firsthand observation might not be practicable or even possible for the researcher but this is a disadvantage imo Allow me to rephrase there is seldom any substitute as satisfactory as actual observation of the subject when studying natural processes maxberan Posted Dec 4 2015 at 1 00 PM Permalink I do not know of course what hands on experience you and Michael Jankowski have of the practicalities of environmental research but you must surely recognise that 1 different people have different skills and 2 there are so many hours in a day For myself I was one of those decried deskbound scientists There is doubtless a long list of reasons why my researches into floods and droughts might have been deficient but I do not judge the fact that I was a user of field data collected by others rather than a participant in its collection to rank high on that list I have no reason to think that Zwally would be less aware of the deficiencies of the data he was analysing than I was of those in the data I was supplied with Howard Posted Dec 5 2015 at 10 03 AM Permalink Yes Mpainter please extol us with your vast experience as a field geologist Do you prefer the Brunton or Silva Do you play pool with the rig hands or do they dope your hardhat mpainter Posted Dec 5 2015 at 1 53 PM Permalink Interesting comment by Howard Michael Jankowski Posted Dec 4 2015 at 1 16 PM Permalink Reply Great point except that Zwally himself obviously realized the importance of seeing it himself and doing so regularly So it seems that you are taking a cheap jibe at him for making annual visits Can t have it both ways John F Hultquist Posted Dec 3 2015 at 8 22 PM Permalink Reply So far I ve gotten to the chart with the 2 blinks first and second Am I the only person with the blink rate so fast my eyes water and my head hurts I ll take 2 aspirin and maybe I ll be fine in the morning Is it possible for me to change the rate on my computer Steve I was experimenting with a new to me program when I produced this I ll fix it in a day or two Bob Koss Posted Dec 4 2015 at 1 40 AM Permalink Reply I made one with a 5 second blink rate mrsean2k Posted Dec 6 2015 at 4 41 AM Permalink Reply Thanks Bob John F Hultquist Posted Dec 8 2015 at 8 51 PM Permalink Reply Awesome Geoff Sherrington Posted Dec 3 2015 at 8 40 PM Permalink Reply Hi Steve it is great to see at last your essay on Climate Audit Here is a shortened version of a view on the same topic It uses mass as a fundamental parameter starting with reference to BIPM the International Bureau of weights and measures HQ in France http www bipm org metrology mass activity focuses on the unit of

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  • The Times Atlas and “Y2K” « Climate Audit
    shed it through glacial flows Being larger scale than the topography of the land form they occupy ice flow in an ice sheet is primarily defined by the structure of the sheet itself It will follow the mean gradient of the underlying topography rather than the detail omnologos Posted Sep 20 2011 at 1 24 PM Permalink Too thick to understand thickness and until they come out clean I ll stick to my Wikipedia explanation see WUWT Michael J Posted Sep 21 2011 at 1 53 AM Permalink Might possibly be that Wikipedia got their data from NSIDC and made the same mistake as the Atlas authors Never subscribe to malice Daniel Posted Sep 20 2011 at 1 50 PM Permalink Indlandsisen Ice cap Danish John Cooknell Posted Sep 20 2011 at 1 57 PM Permalink It shows that the authors and editors expected to find a large decrease in ice coverage just as Hansen expected to see a temperature increase The mistake is only made one way in favour of AGW and is not recognised so many times Steve McIntyre Posted Sep 20 2011 at 2 16 PM Permalink Yup An error going the other way would have been spotted instantly John Cooknell Posted Sep 21 2011 at 2 06 PM Permalink Climate Science finds the trends it wants to find The following UK Met office study a spatial analysis of trends in the UK climate since 1914 using gridded data sets contains the following statement in the conclusions However there was vitually no trend in mean temperature between 1914 and 1987 and it is only since 1987 that the temperature has notably started to increase http www metoffice gov uk climate uk about UK climate trends pdf I would be suspicious that the analysis of data only found an increasing trend when it became scientific consensus Perhaps the data since 1987 contains confirmation bias similar to this thread bender Posted Sep 20 2011 at 6 27 PM Permalink confirmation bias again bubbagyro Posted Sep 20 2011 at 2 53 PM Permalink Steve As usual good detective work Times Atlas MUST have used experts A 20 year old clerk drawing the maps had to take orders from somebody or something Who was it Who were the experts consulted for this artists rendering May I suggest a few names Gore Romm Trenberth Mann Hansen Editors of Science Nature Sci Am NY Times Chu Pachauri Lord xxxx Prince yyyy Who is on the payroll as a consultant What did Romm know and when did he know it tty Posted Sep 20 2011 at 3 07 PM Permalink As a matter of fact much of the missing ice is indeed connected to the main ice sheet The reason it is not in the NSIDC ice thickness map is simple the area around Scoresby sound was not covered by the flights that measured the ice thickness see figure 2 in this paper http nsidc org data docs daac nsidc0092 greenland ice thickness parca paper1 pdf The reason for this in turn is almost certainly that this area is the highest and most mountainous in Greenland I ve overflown the area a couple of times it is a heavily dissected high plateau that reaches to about 11 000 feet The area is very strongly glacierized and there are several fairly large icecaps the Renland cap for example but mostly it is a complex network of huge valley glaciers Measuring the thickness of the ice in this area from an aircraft would be next to impossible so it is understandable that NSIDC skipped it Ironically this is almost certainly the part of Greenland that has been ice covered for the longest time and which would not become ice free even during extreme global warming It is known that tidewater glaciers has existed in East Greenland for 30 million years and the enormous glacier carved fiords in this area must have taken a very long time to form Scoresby Sound the biggest fiord of all actually has Pliocene deposits right inside the fiord proving that it already existed in essentially its current form even before the Quaternary glacial period begun Just as a curiosity the Old Norse knew of Scoresby Sound and called it Öllumlaengri the longest one of all kim Posted Sep 21 2011 at 12 14 AM Permalink At a book discussion once I spoke to a CRESIS engineer and mentioned that Greenland was bowl shaped He responded that it was higher in the middle and had a divide I subsided until I realized he was talking about the ice mass too When I tasked him again with the generally bowl shaped island he said that the shape of the land couldn t be told well through the ice The meme that the whole mass could slip off suddenly is the preferred one tty Posted Sep 21 2011 at 12 41 AM Permalink Greenland is indeed largely shaped as a shallow bowl If the ice was to melt the center would become a large fairly shallow freshwater lake surrounded by lake dotted lowlands There would be low hills around most of the periphery except for the east and south east where the mountains would rise to 6 10 000 feet This would be temporary though Once the isostasy had adjusted probably a few hundred thousand years without ice would be required most of Greenland would be a flat Precambrian plain much like the Canadian or Fennoscandian shields The mountains in the east like the ones in Norway are a result of the process that Greenland from Scandinavia 60 million years ago kim Posted Sep 21 2011 at 1 26 AM Permalink So the depressed bowl is the shield resiling from the icecap and the isostatic adjustment in rebound is the shield resiling from the earth 98 more times and I ll have it Teach Steven Mosher Posted Sep 21 2011 at 1 32 AM Permalink Öllumlaengri nice ianl8888 Posted Sep 20 2011 at 4 07 PM Permalink tty Thank you for your informative posts much appreciated Jeff Norman Posted Sep 20 2011 at 4 08 PM Permalink The conclusion that was drawn from this that 15 of Greenland s once permanent ice cover has had to be erased That s cool They erased the ice and the land mass appeared It s like one of those magic colouring books my kids used to get Alan Watt Posted Sep 20 2011 at 4 26 PM Permalink Typo 2nd paragraph resiling from its press release but standing by I may simply not be aware of Canadian usage but when I search for definitions of resiling in Google the closest it can come is information on a certain grape varietal used for white wines which which I m already familiar And I rather doubt it grows in Greenland or will even by 2050 How was that sentence supposed to read theduke Posted Sep 20 2011 at 7 41 PM Permalink resile to jump to bounce to spring back To come back into position after being pressed or stretched Websters New World simon abingdon Posted Sep 20 2011 at 11 31 PM Permalink resile v no obj abandon a position or a course of action Oxford Dictionary of English Ross McKitrick Posted Sep 20 2011 at 4 27 PM Permalink Too bad the folks at the Times don t know how to use Google maps Will Delson Posted Sep 20 2011 at 5 06 PM Permalink Resiling Simpliciter Take it easy on the country folk Steve You don t want to sound like Monkton do you EdeF Posted Sep 20 2011 at 6 48 PM Permalink Etymology 16c from Latin resilere to recoil or leap back one of the benefits of an Oxford education Gary Posted Sep 20 2011 at 5 07 PM Permalink As someone who frequently compiles a variety of data for others to use I find it strange that sources evidently were not cited somewhere in the atlas The publishers certainly didn t take the measurements themselves so why not give credit or plausibly share some blame if the data are erroneous And does failure to cite sources here border on plagiarism steven mosher Posted Sep 20 2011 at 6 08 PM Permalink There should be citation instructions with the datasets I dont have time to check so someobdy else go look mpaul Posted Sep 20 2011 at 9 52 PM Permalink Here is NSIDC s use and copyright statement You may download and use any imagery or text from our Web site unless it is specifically stated that the information has limitations for its use Please credit the National Snow and Ice Data Center Citations and acknowledgements Please cite the use of our data in your work with a formal citation Citation acknowledges our data contributors and allows us to track the use and impact of our data It also helps us report data distribution activity to funding agencies and to assist others who may contact us about data that are referenced in publications See Citing NSIDC Data for our policy on citing and acknowledging the use of our data sets If you need additional help please contact User Services Its a very valid question why no citation Tom Gray Posted Sep 21 2011 at 11 49 AM Permalink Much of the data shown on maps and charts and in alases will have bene derived from the work of innumerable people msot of whom arte long dead So if the coast of Vancouver Island was surveyed by Captain Cook in the 18th century does this mean that his work and that of all earky naviagtors would have to be cited This seems very impractical to me Gary Posted Sep 21 2011 at 1 20 PM Permalink Not necessary to cite essentially public domain information such as the original surveys But new measurements of ice extent definitely should be cited to credit those who did the work and to let users of the product the atlas judge its credibility or contact the originators tty Posted Sep 21 2011 at 12 54 AM Permalink As far as I can see the data are well described and labelled However you do have to read and understand the descriptions Further the division between icecap and glaciers is rather artificial In most cases the glaciers are contiguous with the icecap and in the cases where they are outlet glaciers from the icecap they are in my opinion most definitely part of it whatever NSIDC may say In other cases they form separate small icecaps that are from a glacier dynamic viewpoint separate entities though you can walk from them to the main icecap without ever stepping on rock Finally there are physically separated glaciers like the Renland icecap and the glaciers in Washington land north of Scoresby Sound In my opinion it is only the last are not part of the Greenland Icecap ZT Posted Sep 20 2011 at 6 38 PM Permalink This is probably a valued added activity whereby sources and methods can never be revealed Earle Williams Posted Sep 20 2011 at 7 40 PM Permalink Ouch That s gonna leave a mark wr Posted Sep 21 2011 at 2 19 AM Permalink Does this mean that the Editor of the Times Atlas will have to resign not holding my breath on that one Hu McCulloch Posted Sep 21 2011 at 10 07 AM Permalink Only if he or she corrects the error omnologos Posted Sep 21 2011 at 2 25 AM Permalink Are any other data sources referenced anywhere else in the Atlas Pointman Posted Sep 21 2011 at 4 46 AM Permalink Infowar really just some activist cell moving the thickness coverage goalposts to reinforce the North pole melting meme What s really interesting is the science establishment pulling up the green propaganda machine for once Perhaps the shape to things to come http thepointman wordpress com 2011 09 15 polar bears going extinct yawn Pointman Max Beran Posted Sep 21 2011 at 8 19 AM Permalink It doesn t stop at Greenland according to James Delingpole the atlas is to pull the same trick with some South Pacific islands by omitting them In his Teleraph blog Delingpole writes In its upcoming 14th edition unconfirmed rumours suggest it will completely omit Tuvalu the Maldives and major parts of Bangladesh in order to convey the emotional truth about man made climate change Wonderful concept that emotional truth seemingly well known in literary criticism but it could catch on in science especially science of the post normal style Vinny Burgoo Posted Sep 21 2011 at 8 27 AM Permalink This morning at least two Maldivian newspapers reported Delingpole s sarcastic blog as if it were a news report and a Maldivian opposition MP texted all his followers blaming the imminent erasure of the Maldives on the president kim Posted Sep 21 2011 at 8 32 AM Permalink Acts of commission follow where acts of omission fail to adequately convey the needed emotional truth Matthew W Posted Sep 21 2011 at 12 59 PM Permalink emotional truth Vs Rational Reality Vinny Burgoo Posted Sep 21 2011 at 8 45 AM Permalink Here s some apparent confirmation that the Times cartographers used NSIDC ice sheet thickness data rather than elevation data and treated all areas covered by ice less than 500m thick as ice free land The edge of the ice on the Times map more or less matches the 500m ice thickness contour on the NSIDC map The elevation contours within the Times s ice sheet match the other NSIDC ice thickness contours That s the easy bit Now for some daftness The NSIDC ice sheet map at the Atlas of the Cryosphere treats the Petermann Glacier as part of the ice sheet Its tongue is part of the purple protrusion in the centre of the map on the right This means that perhaps uniquely that part of the NSIDC ice sheet map shows floating ice The floating ice is less than 500m thick What happens if you choose not to show ice that s less than 500m thick and assume that everything beneath that thin ice is land Most of an enormous fjord becomes land The elevation bands for the real land around there look a bit dodgy too Steve McIntyre Posted Sep 21 2011 at 9 30 AM Permalink It s been observed in other commentary that the Times shows glaciers of less than 500 m in other parts of the world The tropical glaciers are all less than that and sometimes much less than that Vinny Burgoo Posted Sep 21 2011 at 12 29 PM Permalink You ve probably already seen this but just in case http www spri cam ac uk media pressreleases timesatlas html omnologos Posted Sep 21 2011 at 12 25 PM Permalink Tom Gray your explanation doesn t sound reasonable Surely it should be easy a matter of course and mandatory for the Atlas compilers to include citations for the stuff that they ve changed for the new edition On what other basis would they change any detail on any map mpaul Posted Sep 22 2011 at 5 12 PM Permalink Reveling their data source would no doubt damage international relations have an adverse effect on intellectual property rights and destabilize the orbits of neighboring planets Hoi Polloi Posted Sep 21 2011 at 2 06 PM Permalink The Times Atlas is renowned for its authority and we do our utmost to maintain that reputation In compiling the content of the atlas we consult experts in order to depict the world as accurately as possible For the launch of the latest edition of the atlas The Times Comprehensive Atlas of the World 13th edition we issued a press release which unfortunately has been misleading with regard to the Greenland statistics We came to these statistics by comparing the extent of the ice cap between the 10th and 13th editions 1999 vs 2011 of the atlas The conclusion that was drawn from this that 15 of Greenland s once permanent ice cover has had to be erased was highlighted in the press release not in the Atlas itself This was done without consulting the scientific community and was incorrect We apologize for this and will seek the advice of scientists on any future public statements We stand by the accuracy of the maps in this and all other editions of The Times Atlas The Clarification Alan Watt Posted Sep 21 2011 at 2 50 PM Permalink Re resiling Thank you Learn something new every day at this site I ll toast my new knowledge with a glass of chilled Riesling jgc Posted Sep 21 2011 at 3 56 PM Permalink Just for curiosity I downloaded the data from the NSIDC rasterized the glacier shapefiles and compared it to the Greenland Ice sheet without glaciers This was only counting cells in one dataset minus the other so there are for sure large errors due to projection errors in the rasterization etc A graphical result showing surface elevation glaciers blue green red Ice Sheet greyscale is here http img822 imageshack us img822 6374 greenland jpg The results are Total Glaciers Ice Sheet 1m 11 8 change Total Glaciers Ice Sheet 100m 14 3 change Total Glaciers Ice Sheet 500m 20 2 change So it looks very likely as a possible explanation Gerald Machnee Posted Sep 21 2011 at 9 17 PM Permalink Has anyone looked at the report noted at RC by Tedesco et al 2011 which suggests a near record melt of Greenland ice in 2011 Is this mostly modelling jgc Posted Sep 22 2011 at 1 30 AM Permalink Here you have the report http greenland2011 cryocity org Summary Melting in Greenland in 2011 was still above the average 1979 2010 baseline period exceptionally high over the west coast and reaching close to record simulated surface mass balance bare ice exposure albedo

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  • greenland « Climate Audit
    In most long presentations of climate change in the IPCC framework we see Vostok ice core going back to about 800 Kyr covering most of the Pleistocene What easily gets lost sight of in this format is just how unusual the Pleistocene itself is It is one of only a few glaciations in the entire By Steve McIntyre Posted in Geological Proxies Also tagged pliocene Comments 21 Tip Jar The Tip Jar is working again via a temporary location Pages About Blog Rules and Road Map CA Assistant CA blog setup Contact Steve Mc Econometric References FAQ 2005 Gridded Data High Resolution Ocean Sediments Hockey Stick Studies Proxy Data Station Data Statistics and R Subscribe to CA Tip Jar Categories Categories Select Category AIT Archiving Nature Science climategate cg2 Data Disclosure and Diligence Peer Review FOIA General Holocene Optimum Hurricane Inquiries Muir Russell IPCC ar5 MBH98 Replication Source Code Spot the Hockey Stick Modeling Hansen Santer UK Met Office Multiproxy Studies Briffa Crowley D Arrigo 2006 Esper et al 2002 Hansen Hegerl 2006 Jones Mann 2003 Jones et al 1998 Juckes et al 2006 Kaufman 2009 Loehle 2007 Loehle 2008 Mann et al 2007 Mann et al 2008 Mann et al 2009 Marcott 2013 Moberg 2005 pages2k Trouet 2009 Wahl and Ammann News and Commentary MM Proxies Almagre Antarctica bristlecones Divergence Geological Ice core Jacoby Mann PC1 Medieval Noamer Treeline Ocean sediment Post 1980 Proxies Solar Speleothem Thompson Yamal and Urals Reports Barton Committee NAS Panel Satellite and gridcell Scripts Sea Ice Sea Level Rise Statistics Multivariate RegEM Spurious Steig at al 2009 Surface Record CRU GISTEMP GISTEMP Replication Jones et al 1990 SST Steig at al 2009 UHI TGGWS Uncategorized Unthreaded Articles CCSP Workshop Nov05 McIntyre McKitrick 2003 MM05 GRL MM05 EE NAS Panel Reply to Huybers Reply to von Storch Blogroll Accuweather Blogs Andrew Revkin Anthony Watts Bishop Hill Bob Tisdale Dan Hughes David Stockwell Icecap Idsos James Annan Jeff Id Josh Halpern Judith Curry Keith Kloor Klimazweibel Lubos Motl Lucia s Blackboard Matt Briggs NASA GISS Nature Blogs RealClimate Roger Pielke Jr Roger Pielke Sr Roman M Science of Doom Tamino Warwick Hughes Watts Up With That William Connolley WordPress com World Climate Report Favorite posts Bring the Proxies up to date Due Diligence FAQ 2005 McKitrick What is the Hockey Stick debate about Overview Responses to MBH Some thoughts on Disclosure Wegman and North Reports for Newbies Links Acronyms Latex Symbols MBH 98 Steve s Public Data Archive WDCP Wegman Reply to Stupak Wegman Report Weblogs and resources Ross McKitrick Surface Stations Archives Archives Select Month February 2016 January 2016 December 2015 September 2015 August 2015 July 2015 June 2015 April 2015 March 2015 February 2015 January 2015 December 2014 November 2014 October 2014 September 2014 August 2014 July 2014 June 2014 May 2014 April 2014 March 2014 February 2014 January 2014 December 2013 November 2013 October 2013 September 2013 August 2013 July 2013 June 2013 May 2013 April 2013 March 2013 January 2013 December 2012

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  • times « Climate Audit
    al 2009 Marcott 2013 Moberg 2005 pages2k Trouet 2009 Wahl and Ammann News and Commentary MM Proxies Almagre Antarctica bristlecones Divergence Geological Ice core Jacoby Mann PC1 Medieval Noamer Treeline Ocean sediment Post 1980 Proxies Solar Speleothem Thompson Yamal and Urals Reports Barton Committee NAS Panel Satellite and gridcell Scripts Sea Ice Sea Level Rise Statistics Multivariate RegEM Spurious Steig at al 2009 Surface Record CRU GISTEMP GISTEMP Replication Jones et al 1990 SST Steig at al 2009 UHI TGGWS Uncategorized Unthreaded Articles CCSP Workshop Nov05 McIntyre McKitrick 2003 MM05 GRL MM05 EE NAS Panel Reply to Huybers Reply to von Storch Blogroll Accuweather Blogs Andrew Revkin Anthony Watts Bishop Hill Bob Tisdale Dan Hughes David Stockwell Icecap Idsos James Annan Jeff Id Josh Halpern Judith Curry Keith Kloor Klimazweibel Lubos Motl Lucia s Blackboard Matt Briggs NASA GISS Nature Blogs RealClimate Roger Pielke Jr Roger Pielke Sr Roman M Science of Doom Tamino Warwick Hughes Watts Up With That William Connolley WordPress com World Climate Report Favorite posts Bring the Proxies up to date Due Diligence FAQ 2005 McKitrick What is the Hockey Stick debate about Overview Responses to MBH Some thoughts on Disclosure Wegman and North Reports for Newbies Links Acronyms Latex Symbols MBH 98 Steve s Public Data Archive WDCP Wegman Reply to Stupak Wegman Report Weblogs and resources Ross McKitrick Surface Stations Archives Archives Select Month February 2016 January 2016 December 2015 September 2015 August 2015 July 2015 June 2015 April 2015 March 2015 February 2015 January 2015 December 2014 November 2014 October 2014 September 2014 August 2014 July 2014 June 2014 May 2014 April 2014 March 2014 February 2014 January 2014 December 2013 November 2013 October 2013 September 2013 August 2013 July 2013 June 2013 May 2013 April 2013 March 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 June 2012 May 2012 April 2012 March 2012 February 2012 January 2012 December 2011 November 2011 October 2011 September 2011 August 2011 July 2011 June 2011 May 2011 April 2011 March 2011 February 2011 January 2011 December 2010 November 2010 October 2010 September 2010 August 2010 July 2010 June 2010 May 2010 April 2010 March 2010 February 2010 January 2010 December 2009 November 2009 October 2009 September 2009 August 2009 July 2009 June 2009 May 2009 April 2009 March 2009 February 2009 January 2009 December 2008 November 2008 October 2008 September 2008 August 2008 July 2008 June 2008 May 2008 April 2008 March 2008 February 2008 January 2008 December 2007 November 2007 October 2007 September 2007 August 2007 July 2007 June 2007 May 2007 April 2007 March 2007 February 2007 January 2007 December 2006 November 2006 October 2006 September 2006 August 2006 July 2006 June 2006 May 2006 April 2006 March 2006 February 2006 January 2006 December 2005 November 2005 October 2005 September 2005 August 2005 July 2005 June 2005 May 2005 April 2005 March 2005 February 2005 January 2005 December 2004 October 2004 January 2000 NOTICE Click on the

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