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  • February « 2009 « RealClimate
    local connections become more difficult to establish This is due to the combined effect of the resolutions of climate models the intrinsic variability of the system and the empirical climatic environmental or ecological data the signal to noise ratio of possible causes and observed effects Thus recent work by ecologists climate scientists and hydrologists in the western United States relating global climate change regional climate change and regional ecological change is of great significance Together their results show an increasing ability to link the chain at smaller and presumably more viscerally meaningful and politically tractable scales More Comments pop up 254 Bushfires and extreme heat in south east Australia Filed under Climate Science group 16 February 2009 Guest commentary by David Karoly Professor of Meteorology at the University of Melbourne in Australia On Saturday 7 February 2009 Australia experienced its worst natural disaster in more than 100 years when catastrophic bushfires killed more than 200 people and destroyed more than 1800 homes in Victoria Australia These fires occurred on a day of unprecedented high temperatures in south east Australia part of a heat wave that started 10 days earlier and a record dry spell This has been written from Melbourne Australia exactly one week after the fires just enough time to pause and reflect on this tragedy and the extraordinary weather that led to it First I want to express my sincere sympathy to all who have lost family members or friends and all who have suffered through this disaster There has been very high global media coverage of this natural disaster and of course speculation on the possible role of climate change in these fires So did climate change cause these fires The simple answer is No Climate change did not start the fires Unfortunately it appears that one or more of the fires may have been lit by arsonists others may have started by accident and some may have been started by fallen power lines lightning or other natural causes Maybe there is a different way to phrase that question In what way if any is climate change likely to have affected these bush fires More Comments pop up 399 On replication Filed under Climate Science gavin 8 February 2009 This week has been dominated by questions of replication and of what standards are required to serve the interests of transparency and or science not necessarily the same thing Possibly a recent example of replication would be helpful in showing up some of the real as opposed to manufactured issues that arise The paper I ll discuss is one of mine but in keeping with our usual stricture against too much pro domo writing I won t discuss the substance of the paper though of course readers are welcome to read it themselves Instead I ll focus on the two separate replication efforts I undertook in order to do the analysis The paper in question is Schmidt 2009 IJoC and it revisits two papers published in recent years

    Original URL path: http://www.realclimate.org/index.php/archives/2009/02/ (2016-02-13)
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  • January « 2009 « RealClimate
    Baltic coast would then all be high and dry and ports like Rotterdam or Tokyo would be far from the sea Imagine it More Comments pop up 68 Reindeer herding indigenous people and climate change Filed under Climate Science rasmus 24 January 2009 The Sámi are keenly aware about climate change and are thus concerned about their future Hence the existence of the International Polar Year IPY project called EALÁT involving scientists Sámi from Norway Sweden Finland as well as Nenets from Russia The indigenous people in the Arctic are closely tuned to the weather and the climate I was told that the Sámi have about 300 words for snow each with a very precise meaning More Comments pop up 83 State of Antarctica red or blue Filed under Arctic and Antarctic Climate modelling Climate Science Instrumental Record eric 21 January 2009 A couple of us Eric and Mike are co authors on a paper coming out in Nature this week Jan 22 09 We have already seen misleading interpretations of our results in the popular press and the blogosphere and so we thought we would nip such speculation in the bud The paper shows that Antarctica has been warming for the last 50 years and that it has been warming especially in West Antarctica see the figure The results are based on a statistical blending of satellite data and temperature data from weather stations The results don t depend on the statistics alone They are backed up by independent data from automatic weather stations as shown in our paper as well as in updated work by Bromwich Monaghan and others see their AGU abstract here whose earlier work in JGR was taken as contradicting ours There is also a paper in press in Climate Dynamics Goosse et al that uses a GCM with data assimilation and without the satellite data we use and gets the same result Furthermore speculation that our results somehow simply reflect changes in the near surface inversion is ruled out by completely independent results showing that significant warming in West Antarctica extends well into the troposphere And finally our results have already been validated by borehole thermometery a completely independent method at at least one site in West Antarctica Barrett et al report the same rate of warming as we do but going back to 1930 rather than 1957 see the paper in press in GRL More Comments pop up 128 Older Entries Site Google Custom Search Recent Comments What is the best description of the greenhouse effect Jim Eager What is the best description of the greenhouse effect Patrick Eriksson What is the best description of the greenhouse effect Kevin McKinney Anti scientists Carbomontanus What is the best description of the greenhouse effect Spencer Marvel et al 2015 Part III Response to Nic Lewis SteveS What is the best description of the greenhouse effect Chris Colose Blizzard Jonas and the slowdown of the Gulf Stream System doiknow What is the best description of the

    Original URL path: http://www.realclimate.org/index.php/archives/2009/01/ (2016-02-13)
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  • December « 2008 « RealClimate
    Thus we are sure that you will soon read that 2008 was warmer than any year in the 20th Century with the exception of 1998 that is was the coolest year this century starting from 2001 and that 7 or 8 of the 9 warmest years have occurred since 2000 There will undoubtedly also be a number of claims made that aren t true 2008 is not the coolest year this decade that was 2000 global warming hasn t stopped CO 2 continues to be a greenhouse gas and such variability is indeed predicted by climate models Today s post is therefore dedicated to cutting through the hype and looking at the bigger picture More Comments pop up 393 Ozone holes and cosmic rays Filed under Climate Science Sun earth connections gavin 14 December 2008 Browsing through the blogosphere recently I came across an interesting little story about the scientific method scientific progress and un scientific spin h t Hank Roberts The subject concerns the polar ozone hole in Antarctica and a possible role for cosmic rays in its variability on solar cycle timescales The proponents of this link are a small research group at the University of Sherbrooke in Canada who find themselves up against the mainstream stratospheric chemistry community and whose ideas are twisted out of all recognition by the more foolish of the usual suspects More Comments pop up 121 Contrarians and consensus The case of the midwife toad Filed under Climate Science skeptics gavin 7 December 2008 I recently came across an old copy of Arthur Koestler s The Case of the Midwife Toad Originally published in 1971 it s an exploration of a rather tragic footnote in the history of evolutionary science Back in the early years of the 20th Century prior to the understanding of DNA but after Mendelian genetics had become well known there was still a remnant of the biological community who preferred the Lamarckian idea of the inheritance of acquired characteristics over the Darwinian idea of natural selection of random mutations One of the vanguard for the Lamarckian idea was Paul Kammerer whose specialty was the breeding of amphibians that apparently few others could match He claimed that he could get his toads and salamanders to acquire characteristics that were useful in the new environments in which he raised his specimens This was touted loudly in the New York Times for instance as proof of Lamarckian inheritance and Kammerer was hailed as a new Darwin It all ended very badly when one toad specimen was found to be faked by who remains a mystery and Kammerer killed himself shortly afterwards though there may have been more involved than scientific disgrace The details of the experiments and controversy can be read online with various slants here and here and a more modern non replication of one of his experiments is described here However the reason I bring this up here is much more related to how the scientific community and Koestler dealt

    Original URL path: http://www.realclimate.org/index.php/archives/2008/12/ (2016-02-13)
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  • November « 2008 « RealClimate
    As many people will have read there was a glitch in the surface temperature record reporting for October For many Russian stations and some others September temperatures were apparently copied over into October giving an erroneous positive anomaly The error appears to have been made somewhere between the reporting by the National Weather Services and NOAA s collation of the GHCN database GISS which produces one of the more visible analyses of this raw data processed the input data as normal and ended up with an October anomaly that was too high That analysis has now been pulled in under 24 hours while they await a correction of input data from NOAA Update now partially completed More Comments pop up 815 FAQ on climate models Filed under Climate modelling Climate Science FAQ group 3 November 2008 We discuss climate models a lot and from the comments here and in other forums it s clear that there remains a great deal of confusion about what climate models do and how their results should be interpreted This post is designed to be a FAQ for climate model questions of which a few are already given If you have comments or other questions ask them as concisely as possible in the comment section and if they are of enough interest we ll add them to the post so that we can have a resource for future discussions We would ask that you please focus on real questions that have real answers and as always avoid rhetorical excesses Part II is here More Comments pop up 464 Site Google Custom Search Recent Comments What is the best description of the greenhouse effect Jim Eager What is the best description of the greenhouse effect Patrick Eriksson What is the best description of the greenhouse effect Kevin McKinney Anti scientists Carbomontanus What is the best description of the greenhouse effect Spencer Marvel et al 2015 Part III Response to Nic Lewis SteveS What is the best description of the greenhouse effect Chris Colose Blizzard Jonas and the slowdown of the Gulf Stream System doiknow What is the best description of the greenhouse effect James Powell Unforced Variations Feb 2016 Jim Galasyn With Inline Responses Marvel et al 2015 Part III Response to Nic Lewis SteveS Marvel et al 2015 Part III Response to Nic Lewis steve s Marvel et al 2015 Part III Response to Nic Lewis Andrew Kerber Blizzard Jonas and the slowdown of the Gulf Stream System Hank Roberts Blizzard Jonas and the slowdown of the Gulf Stream System doiknow Marvel et al 2015 Part III Response to Nic Lewis MartinM Anti scientists Don McKenzie Marvel et al 2015 Part III Response to Nic Lewis Matt Skaggs Anti scientists mikeworst New On line Classes and Models Marcus Pages Acronym index Data Sources Categories Climate Science Aerosols Arctic and Antarctic Carbon cycle Climate impacts Climate modelling El Nino Geoengineering Greenhouse gases Hurricanes Instrumental Record IPCC Oceans Paleoclimate Sun earth connections Communicating Climate Reporting on climate

    Original URL path: http://www.realclimate.org/index.php/archives/2008/11/ (2016-02-13)
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  • October « 2008 « RealClimate
    best success in their efforts Watch this space for an announcement if and when they launch something For my part I ll be especially enthusiastic if the Nature Conservancy doesn t limit itself to talking about its various projects around the world interesting as those may be What I d really like to see is a site that provides their perspective on some of the more difficult but really important questions in the area of climate change impacts How much danger are polar bears in really How will agriculture in Asian monsoon regions be affected What are the broader effects of ocean acidification beyond the immediate impact on coral reefs The Nature Conservancy won t be the last word on this any more than RealClimate is But their perspective from field scientists on the ground could prove extremely valuable One additional thought In several of the sessions I attended at the Nature Conservancy meeting reference was made to the need to stabilize global temperature rise at no more than 2 C and correspondingly to stabilize CO 2 levels at no greater than 450 ppm strictly speaking this should be 450 ppm CO 2 radiative equivalent there is a big difference and it is often neglected In each case reference was made to the IPCC reports as the source of these numbers Yet these numbers really don t derive from the IPCC which rightly shied away from being policy prescriptive Rather they have their origin in a small number of documents notably the 1995 report of the German Advisory Council on Global Change papers related to the Exeter conference on avoiding dangerous climate change and in European Union Council decisions see the 1996 and 2006 Presidency Conclusions here Clearly the 2 C 450 ppm numbers have completely permeated the policy advocacy realm Yet while they are arguably derivable from the IPCC reports it is actually not clear to what extent the larger scientific community really believes these are the right numbers There simply has not been a process to evaluate this that compares in depth and breadth with the IPCC A new and much more comprehensive analysis by a much greater group of scientists would be valuable at this juncture Scientists are fond of saying that they cannot summarize their projections with a small handful of simple numbers but simple numbers are what are being discussed in policy circles If the right numbers are really so low as Jim Hansen believes see our post on this here then the Nature Conservancy has an even more difficult task ahead For those interested in slogging through it there s a video of our session here It s not just about me There is also some really interesting stuff from Nature Conservancy staffer Jonathon Colman and from the folks who started the conservation clearinghouse and collaboration websites www conservationyellowpages org and wiserearth org as well as a demonstration not altogether successful of the emerging virtual reality conferencing technology which when it works might help

    Original URL path: http://www.realclimate.org/index.php/archives/2008/10/ (2016-02-13)
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  • September « 2008 « RealClimate
    Lett 2 2007 Hansen proposes a rate of sea level rise of 5 m this century This is hypothetical but he is confident that it is a far better estimate than a linear response This is accompanied by his statement that he finds it almost inconceivable that BAU climate change would not yield a sea level change of the order of meters on the century timescale The provisional nature of his discussion is irrelevant it is an explicit statement that 5 m of sea level rise in this century is a possibility he regards as viable published in the scientific literature by the person who is arguably and deservedly the most visible and authoritative climate scientist in the world No reader of this paper would assume that Hansen didn t actually mean what he said Hansen reinforced this idea in other publications and statements including in his briefing to Congress on 23 June 2008 sea level rise of at least two meters is likely this century Our analysis specifically tested the likelihood of next century sea level rise of more than 2 m and Hansen explicitly hypothesized 5 m of sea level rise in this century Hansen has gone on record with specific numbers but other published studies including the 2006 Overpeck and Otto Bliesner Science papers left the upper limit open ended and certainly implied it could be quite high The fact that this idea was present in the scientific community was confirmed for us by 8 scientific presentations we gave on this topic in the past year 5 in the US including the Fall 2007 AGU and 3 in Europe At none of those talks did anyone in the audience question what high forecasts we were referring to The comments we got back on our work were overwhelmingly positive and were along the lines that what we had presented was a good next step both to move past the IPCC s low sea level forecasts and as a response to the persistent hypotheses of very high rates of sea level rise that were circulating Criticisms where they were voiced were largely that we were underestimating the power of dynamics and that rates of sea level rise well in excess of 2 m century might occur in spite of our conclusions We agree that the media coverage of our paper as well as others before it has undesirable side effects Wherever we had the opportunity we pressed media writers not to use terms like exaggerated or high sea level forecasts debunked and we have consistently stressed that our results indicate a very significant sea level rise and are no justification for any kind of complacency We have stressed that even our low end scenario of 0 8 m of SLR would have tremendous consequences However we stand by our statements that sea level rise at rates of substantially more than 2 m this century were in fact put forward as a likely possibility Earlier this summer Andy Revkin published

    Original URL path: http://www.realclimate.org/index.php/archives/2008/09/ (2016-02-13)
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  • August « 2008 « RealClimate
    in many forums The current wave of interest has been piqued by Paul Crutzen s 2005 editorial and a number of workshops commentary and high profile advocacy But most of the discussion has occurred in almost total ignorance of the consequences of embarking on such a course A wider range of people have now started to publish relevant studies showing clearly the value of continued research on the topic and a key one came out this week in JGR Atmospheres Robock et al used a coupled GCM with interactive aerosols to see what would happen if they injected huge amounts of SO 2 the precursor of sulphate aerosols into the tropical or Arctic stratosphere This is the most talked about and most feasible geoengineering idea based on the cooling impacts of large tropical volcanic eruptions like Mt Pinatubo in 1991 Bottom line This is no panacea More Comments pop up 145 Are geologists different Filed under Climate Science RC Forum skeptics rasmus 19 August 2008 The International Geological Congress IGC is sometimes referred to as the geologists equivalent of the Olympic Games and is an extremely large gathering of geologists from all over the world taking place at 4 year intervals This time the IGC took place in Lillestrøm a small place just outside Oslo Norway August 6 14 The congress was opened by the Norwegian King before he continued to the real games in Beijing and was attended by some 6 000 scientists from 113 countries Even the Danish Minister of Energy Climate participated in a panel discussion on climate change In other words this was a serious meeting More Comments pop up 314 Hypothesis testing and long range memory Filed under Climate Science Instrumental Record gavin 10 August 2008 What is the actual hypothesis you are testing when you compare a model to an observation It is not a simple as is the model any good though many casual readers might assume so Instead it is a test of a whole set of assumptions that went into building the model the forces driving it and the assumptions that went in to what is presented as the observations A mismatch between them can arise from a mis specification of any of these components and climate science is full of examples where reported mismatches ended up being due to problems in the observations or forcing functions rather than the models ice age tropical ocean temperatures the MSU records etc Conversely of course there are clear cases where the models are wrong the double ITCZ problem and where the search for which assumptions in the model are responsible is ongoing More Comments pop up 196 Older Entries Site Google Custom Search Recent Comments What is the best description of the greenhouse effect Jim Eager What is the best description of the greenhouse effect Patrick Eriksson What is the best description of the greenhouse effect Kevin McKinney Anti scientists Carbomontanus What is the best description of the greenhouse effect Spencer Marvel et

    Original URL path: http://www.realclimate.org/index.php/archives/2008/08/ (2016-02-13)
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  • July « 2008 « RealClimate
    the vagaries of weather patterns and ocean currents make it hard to see climate changes but the variability in what are often termed the Earth System components complicates the picture enormously These components specifically aerosols particulates in the air dust soot sulphates nitrates pollen etc and atmospheric chemistry ozone methane are both affected by climate and affect climate since aerosols and ozone can interact absorb reflect or scatter solar and thermal radiation This makes for a rich research environment but can befuddle the unwary More Comments pop up 356 Weekend round up Filed under Climate Science group 12 July 2008 A few interesting pieces from around the web relevant to some previous postings The latest satellite imagery from the Wilkins Ice Sheet discussed recently is not looking good And most curiously the collapse is happening in winter The Weather Channel Forecast Earth team make a valiant attempt to explain the problems and promise for regional climate change projections by 2050 See our post on the general subject from last year And for those of you following the various sagas of political interference in the communication of climate science a nice interactive graphic summary courtesy of UCS Next week will be a little quiet it is mid summer after all so apologies in advance if the moderation is a somewhat slow You may also note that we have instituted a captcha step to the commenting process This uses reCAPTCHA which as well as providing protection against spam helps with the digitization of old books Comments pop up 52 All paper salutes to the environment Filed under Climate Science Communicating Climate group 11 July 2008 The Onion last week had a great recycled spoof on the various green special issues being published but not to be outdone the contributors to RealClimate have also been busy producing paper products about the environment Surprisingly perhaps as well as having day jobs and writing for this blog collectively we have written a number of popular science books about climate change Some of these have already been published but there are a few more in the pipeline We try not to overdo self promotion on this website for instance we don t blog about most of our own technical publications but since these projects are synergistic with our aims here it makes sense to let people know what we ve been up to We have therefore set up a page listing Our Books that we will keep up to date as more titles become available It s also linked from the new animated gif image on the side bar Comments pop up 25 Older Entries Site Google Custom Search Recent Comments What is the best description of the greenhouse effect Jim Eager What is the best description of the greenhouse effect Patrick Eriksson What is the best description of the greenhouse effect Kevin McKinney Anti scientists Carbomontanus What is the best description of the greenhouse effect Spencer Marvel et al 2015 Part III Response to Nic

    Original URL path: http://www.realclimate.org/index.php/archives/2008/07/ (2016-02-13)
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