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Tom Dayton at 09:15 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
Geo Guy wrote "Yes CO2 has increased but so has water vapor, and while some believe that is atrributed ot a feedback mechanism, other disagree." Geo Guy, please see my comment on the thread "Water Vapor is the Most Powerful Greenhouse Gas." If you can come up with actual citations of the "others" who you claim disagree, please post them in a comment on that thread. (Water vapor is not really on topic in this Greenland's Ice Mass thread.) -
Riccardo at 09:14 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
Geo Guy, my point was just clarify that no one belives that the process was just plain melting as if "people posting here do not have an understanding of glaciology". Noteworthy is the paper you quote (Stone et al.) which well describe the complexity other people and myself were trying to push, while you insisted on your point on ablation. I hope that now this oversimplification is over. -
Doug Bostrom at 08:56 AM on 1 April 2010Models are unreliable
cloneof, you'll notice that on a year-by-year basis, model output is noisy. For instance, a few years from now the Model B scenario shows a predicted dip in temperature of some two tenths of a degree, passing below your "1 degree limit", a feature we can probably agree is unlikely to be reproduced with exactitude by the actual climate. Equally, expecting Earth's annual temperature to track model output in any given year with faithful reproduction of the model output is bound to lead to disappointment. Rather than throw up my hands in sorrow over the matter, I think I'll go and try to discover why the model output graphs are not smoothed. It's a choice made by the authors, with good reason I suspect, if nothing else intended to convey that we're not to expect a monotonously predictable rise. I can well imagine the hue and cry over divergence from a smoothed result come to think of it. -
Geo Guy at 08:46 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
Let me step back a bit and then focus on the mechanics of glaciers. It would appear that this post was originally wrritten to support the premise that the loss of ice in Greenland is another piece of evidence that the earth is warming due to man's activities. From my persepctive, this is an incorrect assumption and that by understanding the dynamics and mechanics involved with glaciers, we know that advances and retreats of glaciers have happened in the past, well before there was any proposed warming related to increases in atmosphereic CO2. As far as Greenland is concerned, there is a multitude of data available for people to review and publish/speak about their own theories. It would appear that some people posting here do not have an understanding of glaciology, how they are formed, what dynamics they undergo, etc - especially when it comes to assessing what is being observed in Greenland and Antarctica. There are a number of excellent papers that have been written on the subject that I recommend be read: Glacier Mass Balance and Regime: Data of Measurements and Analysis, Mark Dyurgerov, Editors: Mark Meier (INSTAAR), Richard Armstrong (NSIDC), Institute of Arctic and Alpine Research University of Colorado, Boulder, Colorado 80309 The effect of more realistic forcings and boundary conditions on the modelled geometry and sensitivity of the Greenland ice-sheet E. J. Stone, D. J. Lunt, I. C. Rutt, and E. Hanna the journal The Cryosphere (TC).Occasional Paper 55 INSTAAR/OP-55 ISSN 0069-6145 To appreciate the concept of mass balance of glaciers I suggest people visit the World Glacier Monitoring Service at http://www.geo.unizh.ch/wgms/ I also point out my previous reference by Fountain, Lewis and Doran who identifed that the main process whereby glacier lose mass in the polar regions is by sublimation and not melting. The actual article is Spatial climatic variation and its control on glacier equilibrium line altitude in Taylor Valley, Antarctica, Global and Planetary Change Volume 22, Issues 1-4, October 1999, Pages 1-10 and it is NOT the article that was linked by Doug in # 36 (had he looked at the reference he would have noted that I included the name Volume and pages of the publication it appeared in.) In response to GFW # 36, the water vopor content of the world's atmosphere as measured by ballon launches in Boulder Colorado, has increased on average 1% per year since 1980. It is obvious from that build up that the atmosphhere can accommodate more water vapor. In addition, the premise regaring the increased water vapor from sublimation of snow and ice in the polar regions, precipitates back out as snow, not water and contributes to the accumulation of snow in the upper regions of a glacier. Jeff # 37 - I am not where you got your 300 gigatons per year - according to a report entitled " Recent Greenland Ice Mass Loss by Drainage System from Satellite Gravity Observations, originally published in Science Express on 19 October 2006, Science 24 November 2006, the rate is more like a net loss of 113 gigatons per year, obtained from the GRACE mission. I also did not say (or mean to say) that the observations have no scientific basis - it's the definitive conclusions that people make from the observations that are questionable. That position is based on the understanding that the the morpholgy and dynamics of a gacier, let alone one the size of Greenland, are too complex to make conclusions based on a few pieces of data - Jeff # 41 - I don't dispute what you posted - it is in line with normal glacial activity. The one point I will make is what we see happening to glacers today, is not related to what is happening in the atmosphere today but rather it is a result of some past event relative to that glacier. The premise of this blog is to support the contention that gloabl warming is attributable to the burning of fossil fules by man and that the many postings on the blog are meant to debunk the arguments made by people who question that theory. If I am right, then the declaration that "Greenland's ice mass loss has spread to the northwest" was made to further the argument that the earth is warming and is linked to increases in CO2 due to man's activities. My point in joining the discussion is to put forth the position that there are many other valid reasons to support alternative theories as to why Grfeenland's ice mass is in a decline. I certainly am not questioning the interpretation that the mass is on a decline. I do think however some seem to exaggerate claims (such as a loss of 300 megtons per year) and forget to factor in items such as while the fringe is losing mass, the centre of the glacier is accumulating mass. Doug # 42 - My purpose of brining up sublimation is that I do not believe (and it has been confirmed by posts here) that epople really understand the role sublimation plays in the polar regions. It is more significant than most people apparently want to give it. With regards to arctic ice disappearing, my personal view is that it is more related to warmer ocean currents (currents that have been warming since the 30's, plus incrased solar energy in the 1980's. It cannot happen due to a marginal change of 1 degree in air temperature...that was the point I was making. Ricardo # 43 - I did read that article and it is in contrast to that posed by the authors in the articles I mention above. Ned # 44 - I would dispute what you have indicated in your post. The one thing climate models have not been able to forecast (without veering off their temperature relationships) is the accommodation of the melting arctic ice cap and the observations being made in both Greenland and Antarctica. Hence your "The mainstream scientific view of climate change impacts on the mass balance of the Greenland ice sheet is a model of clarity and consistency (both internal consistency and model-observation consistency)." is not valid IMHO. Yes CO2 has increased but so has water vapor, and while some believe that is atrributed ot a feedback mechanism, other disagree. Whatever the reason, water vapor acts much more strongly towards increased CO2 and while models may interprest the results of this warming, as you have indicated, models are a close environment wheras the earth's climate is an open environment. As for polar amplification, there is conflicting views on the validity of that concept after all it was coined by Manabe and Stouffer in 1980 in their climate model's response to increasing green house gas levels. However I did read somewhere (don't have the link..sorry) where the effect of cosmic and solar radiation can be amplified at the poles - something to do with the concentration of the earth's magentic field. Your reference to physical models of glaciers isn't quite right either. Glaciers are reacting today from events that happened previously. Yes they are receeding (while some are advancing) but that is a normal characteristic of them. The current retreating of glaciers has been occurring since the 1930's (and earlier if you want to go back to the last major ice age). As for glaciers moving at an accelerated rate, that can be related to a number of factors, including calfing which is usually followed by an increase in velocity because the ice doesn't have th push that ice that fell off into the ocean. (simplistic but makes the point). In my years working in the field, one thing I have learned is in many instances things are not what they appear to be and consequently I have learned to challenege an argument by identifying alternative theories as to what is happening. That processis actually a part of the scientific process - as soon as we stop questioning the validity of an argument, we stop advancing...nuff said. With regards to Greenland, I encourage you to read the article by Mark Dyurgerov who addresses the issues with Greenland. As for the mechanism you are asking about, it has always been there. Ice melts at 0 degrees C (32F) at sea level. However, snow and ice fields are known to lose their mass at temperatures well below that figure (we are taking significant magnitudes here and not decreases related to slainity etc). That loss happens because of sublimation. I live in a place where we experience warm winter winds from time to time. We can have two feet of snow on the ground and after several days of these winds, that snow can virtually be reduced by a factor of 75% with no water run-off. As for remote sensing identifying melting - sorry it identifies the reduction in mass (gravity survey) - what we need to understand is what factors contribute to that loss in mass. That is waht I have identified in my posts - alternatives to an increase in air temperatures causing ice to melt. GFW # 45 - the water content change I cited was from regular balllon launches from Boulder CO. While the rate may not reflect the entire atmosphere - it does reflect the fact the water content during the period cited did increase (and was reported by the IPCC as to having done so). Also with repect to the increase in ocean levels, not all of it is attributable to melting glaciers. Finally carbon black isn't the same as soot so I believe you are referring to soot (carbon black is manufactured as a additive to rubber products.). Yes microspcopic pieces of carbon from incomplete burning do have a role to play in melting (soot falls on snow/ice, sun radiates energy, soot absorbs sun's energy, soot heats up, snow/ice melts. Initially it was thought that the disappearing snows on Mt. Kilamanjaro was the reult of just that process - they thought it was dust blown up from lower valleys. However after some further studies, the consensus now is the disappearing snow/ice is attributed to sublimation. -
GFW at 08:40 AM on 1 April 2010CO2 is not the only driver of climate
A great addition to this page would be a link to the page with the evolution of relative forcings over the past century or so. I just can't find that page at the moment.Response: Good idea. I may reshape the content to include the graph you're talking about but in the meantime, here it is:
Separate global climate forcings relative to their 1880 values (GISS). -
muoncounter at 07:25 AM on 1 April 2010CO2 is not a pollutant
Tom#3: These references seem to suggest those 'limiting factors' to potential sequestration are significant and supportive of your quotes under 'the bottom line'. From an older issue of Nature: "Doubts concerning the potential of natural vegetation for sustained response to rising CO2 have arisen from experiments on infertile soils, where the stimulus to growth was curtailed by mineral nutrient limitations. Here we present evidence that mineral nutrient constraints on the fertilizer effect of elevated carbon dioxide can also occur on fertile soil " Also from Nature: "Soil carbon was lost at subambient Ca, but was unchanged at elevated Ca where losses of old soil carbon offset increases in new carbon. ... differences in sensitivity of carbon storage to historical and future Ca and increased nutrient limitation suggest that the passive sequestration of carbon in soils may have been important historically, but the ability of soils to continue as sinks is limited." From Frontiers in Ecology and the Environment: "research suggests that the fertilization effect is limited by nutrients and air pollution, in addition to the well documented limitations posed by temperature and precipitation. This review suggests that existing forests are not likely to increase sequestration as atmospheric CO2 increases." -
cloneof at 07:18 AM on 1 April 2010Models are unreliable
O.k, I'm sorry if my first post sounds agressive towards a side or another, I just want this to get out of my "do-to" list. It's 2010 now and even with El Nino from what I can see from Climate4You (wich I presume is one of the most objective sources there is for climate information), no dataset reaches the 1 degree limit, like the Hansen's "B" scenario seems to have finally gone over. While indeed if I'm not incorrect and that seems to have happened, we can only hope that we have learned trough the decades (wich Hansen 2006 seems to suggest :) ) and at this day of age have had the resources and the time to create the best damn models we can[/End the dramatic b-grade speech]. -
Marcel Bökstedt at 06:55 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
The record of ice cover in the Arctic is full of rapid growths and rapid collapses. I don't think it makes much sense to discuss the trend over a month or over a year, it looks too random in the short perspective. The long term decreasing trend is clear though : look for instance at the tale of the tape from "cryosphere today". -
Doug Bostrom at 06:42 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
GFW, sheer speculation on my part but since we earlier had a powerful positive temperature anomaly over much of the Arctic ocean this winter, perhaps things were "primed" for a rapid growth of ice once air temperature slid back into a more normal regime? Easy come, easy go, maybe. For my part I'm going to reserve any judgment about the health of Arctic ice until much later, August or September. Extent is has been dethroned, seems to me, with volume being the real story now. But again, I'm speculating. -
GFW at 06:33 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
That's probably enough about Geo Guy. Does anyone have any insight into what the heck is going on with arctic sea ice extent? Is this just a short term weather phenomenon? It's pretty weird to see this kind of growth in late March. As significant as the mass loss from Greenland has been, I don't think freshwater bergs are contributing that much to sea ice. -
Jeff Freymueller at 06:11 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
#40, Geo Guy, I just noticed this in your comment: "Also glaciers move as a result of the build-up of ice in their centers which pushes the underlying ice outwards. When glaciers are retreating, you don't see that movement." This is wrong. Glaciers retreat when the melting/ablation/calving at their terminus causes more mass loss than is made up by flow. But glaciers are always flowing. If more mass flows out of a section of a glacier than is replaced by new accumulated snow->firn-ice and flow from even higher up, the glacier loses mass in that section. Some glaciers flow very slowly, but given gravity and a slope, any large mass of ice flows downhill. -
jsam at 05:18 AM on 1 April 2010A database of peer-reviewed papers on climate change
Removing a "controversial" (aka crap) journal will give succor to the sceptics. "look, they ignore us." Poor things. Maybe a separate category for those that don't pass muster?Response: I'm not removing any links. Each link is categorised. Eg - blog, peer-review study, mainstream media, etc. There are probably a few Energy & Environment articles categorised as peer-review. In order to make the database more accurate, these should be recategorised. I'll probably have to add a new category - not sure what to call it. Non-peer-review journal? Grey literature? -
Tom Dayton at 04:50 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
Geo Guy, it's good that you "find it difficult to accept that climate is being affected by only one factor - the rise in atmospheric CO2, (simply because there are multiple factors at play when it comes to climate)," because nobody else accepts that, either. It's a straw man. See CO2 is not the only driver of climate. -
GFW at 04:24 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
@Geo Guy, you're wrong on so many levels. Others have so thoroughly hammered on the "ice flow and berg calving" vs "melt in place" issue that I haven't felt it necessary to mention it until now. But again, that's the dominant means of mass loss from Greenland. And yes, the increase in ice flow and calving is driven by the "marginal" increase in global temperature (which is both predicted and observed to be greater at high latitudes - see "polar amplification"). I'm going to pick on something else. Your ludicrous assertion that "water content [of the entire atmosphere] has increased on average at a rate of 1% per year since 1980" Wrong. Water content of the stratosphere may have done that (see Wikipedia), but not the whole atmosphere. Such an increase in the stratosphere would deprive the ocean of ... wait for it ... less than 0.0025 mm/y. That is of course negligible compared to the 3mm/y rise we currently see, and the glacial contribution to same. There probably has been a small increase in tropospheric water vapor too, but on a similar absolute scale (not % scale). And of course that increase in tropospheric water vapor is predicted as a positive feedback in global warming. Finally, we know CO2 isn't the only factor, so fighting that position is a complete straw man argument. However CO2 is the "biggest control knob". Carbon black (aka soot) is known to be an important player in reducing ice albedo, thus contributing to the warming/melting of ice. But even if there was some way to eliminate soot emissions without changing our fossil fuel economy, that would only slow down the warming. (And indeed, there are people working very hard to reduce soot emissions.) -
Ned at 04:21 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
This discussion has gotten very strange. The mainstream scientific view of climate change impacts on the mass balance of the Greenland ice sheet is a model of clarity and consistency (both internal consistency and model-observation consistency). 1. We know CO2 and other greenhouse gases are increasing, and physical models suggest that should lead to warming overall and particularly in the northern hemisphere high latitudes (polar amplification). Observed warming from multiple sources matches this. 2. Physical models of glaciers and ice sheets suggest that this warming should lead to a negative mass balance and loss of ice via both melting (primarily in summer below the equilibrium line) and the accelerated discharge from marine terminating outlet glaciers. Remote sensing data specifically confirm (a) an increase in melting, and (b) an increase in glacier velocity. 3. Other techniques (GRACE, high-precision GPS) confirm the overall negative mass balance that would be expected from the mechanisms in (2) above. That's a very clear, coherent picture. I'm a bit mystified as to why Geo Guy would write Sometimes in science we have to step back and ask ourselves "Does it make sense?" In this case it doesn't make sense to me. Whereas to me, this topic (Greenland ice sheet) seems quite sensible and straightforward, and trying to introduce other explanations for the observed loss of mass raises more problems: What mechanism would produce a large and rapidly increasing rate of sublimation in Greenland? What evidence is there for this increase in sublimation? Why would all the remote sensing data on melting and velocity be wrong? Occam's Razor suggests that the straightforward explanation is preferable to the convoluted and mysterious one. -
Riccardo at 03:49 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
Geo Guy, you might be interested in digging a little deeper. Following van den Broeke et al. 2009, they calculated the overall mass balance (surfaces mass balance SMB minus discharge D) and compared it with GRACE results. The former (SMB-D) compares well with the latter (r=0.99, fig. 1 in the paper). Next they show that from somewhere in the '90s SMB has been increasingly negative and D also increased (fig. 2a). The two mechanisms turn out to be comparable in magnitude. In fig. 2b you'll find the components of SMB, namely precipitation, runoff and sublimation. Sublimation had almost no part in the balance. Also very interesting is fig.3 where they quote SMB and D separately for various regions of the ice sheet.Response: The paper van den Broeke et al 2009 is expounded upon in some detail in an earlier blog post Why is Greenland's ice loss accelerating? -
Tom Dayton at 03:35 AM on 1 April 2010CO2 has a short residence time
Excellent post, Doug! If you can find the time, will you please comment on whether the iconic list and graphic that is touted so widely on the web, contains only studies about individual molecules' lifetimes? Many skeptics throw that on the table to counter explanations such as the one you've given. -
Pete Dunkelberg at 03:25 AM on 1 April 2010A database of peer-reviewed papers on climate change
Google ""E&E is not a science journal" -
Doug Bostrom at 03:25 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
Geo Guy, perhaps I'm misunderstanding you, or maybe you need to add just a jot of qualification to your writing. When you say "...my point is the ice loss identified by GRACE is not due to melting. There are other factors at work there - similarly to what is going on in the arctic. " I take it you do not discount the loss of ice mass, but you are pointing out that no single process is accountable for all of the loss of mass, the movement of water in space and state? I'm sure you're right about that. Of course, nobody here or elsewhere (well, the sane, anyway) has said that every last gram of ice seen to vanish in the past few decades is down to a single factor, so you won't find anybody worthwhile to argue that point with you. What we can say (and I imagine you could model this if you cared to take the time) is that sublimation alone cannot account for the entire loss of mass on the Greenland ice sheet. As to your speculation about the available amount of extra energy required to produce a phase change of a given mass of water from solid to liquid (melt ice), as an exercise take a look at the summer Arctic sea ice anomaly for any of the past few years and then compute for yourself the additional energy being absorbed by the ocean due to the loss of albedo. In case you don't want to do that work, I'll cut to the denouement, plot spoil and say that where energy arrives counts for a lot; using global temperature change to predict the behavior of ice in a given region is a futile approach. -
Jeff Freymueller at 02:55 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
#40 Geo Guy, the mechanism for much of or most of the ice loss is glaciers flowing and dumping ice into the ocean. John said this in the original post. The ice does not have to melt in place. If the lower part of a glacier accelerates due to, for example, its interactions with warmer water at its terminus, or increased lubrication due to melting on its lower part, accelerated ice flow will propagate up glacier and into the ice fields/ice sheet that feed the glacier. The ice thickness changes as a result of this flow, and these changes have been observed directly in addition to the indirect observation of Khan et al. (the earth is responding like a scale to the ice, and the GPS is measuring the upward displacement of the scale as the weight on it is removed). This is not my idea -- it is based on direct observations (visual, time-lapse photos), glacier velocity observations, basic glacier physics, and even seismic recordings. And nobody here is saying that the ice loss is all due to melting in place, except perhaps those who suggest they don't believe any of this because the ice can't be melting in place. -
Jesús Rosino at 02:20 AM on 1 April 2010A database of peer-reviewed papers on climate change
These are the ones I've seen: 'It hasn't warmed since 1998' Limits on CO2 Climate Forcing from Recent Temperature Data of Earth 'Oceans are cooling' Cooling of the global ocean since 2003 'Hockey stick is broken' A 2000-year global temperature reconstruction based on non-treering proxies 'Climate's changed before' A 2000-year global temperature reconstruction based on non-treering proxies -
Geo Guy at 02:04 AM on 1 April 2010Greenland's ice mass loss has spread to the northwest
# 37 - Jeff Its not the observations that are wrong, its the interpretation to those observations that are off base. With regards to sublimation, if that is not the driving force for ice loss in sub zero weather, perhaps you can tell us what is. Please don't say a 1 degree increase in atmospheric temperatures brought on by man made CO2 - that just does not make any sense. Even if the temperatures went from minus 20 to minus 10, that still will not result in melting of polar glaciers etc. With regards to GFW - your view assumes a constant level of water vapor in the atmosphere but in face the water content has increased on average at a rate of 1% per year since 1980 - hence the water resulting from the sublimation of ice fields does not all end up in the ocean. Everyone seems to assume when glaciers reduce in size it is because they are melting. What I am trying to point out is that in the polar regions and higher elevations, a small increase in average global temperatures will not and cannot melt those glaciers by itself. Something else is at work and we need to look at the other driving forces that affect glaciers to determine just that. Also the disappearance of glaciers at their margins is a normal observation - they disappear in the areas of ablation. Also glaciers move as a result of the build-up of ice in their centers which pushes the underlying ice outwards. When glaciers are retreating, you don't see that movement. Simply posting maps here showing larger areas of ice loss over a given period of time is meaningless. It certainly is no way near being "Quad Erata Demonstratum". As for Doug, # 34, my point is the ice loss identified by GRACE is not due to melting. There are other factors at work there - similarly to what is going on in the arctic. Those observations reported do NOT support the theory that man-made CO2 is causing warmer temperatures that are resulting in the disappearance of the Greenland ice. Also the glaciers in South America and in Africa that have disappeared are not closed systems and their disappearance has been attributed to sublimation and not warmer temperatures. As I mentioned in a previous post, the thermodynamics required to melt that ice simply from a rise in temperature just are not there. For instance, the energy needed to melt a volume of ice is the same temperature needed to raise the temperature of the resulting water to a 140 F level. With a global temp average increase of under 1 degree over 100 years, you do not need a science degree to figure out that polar ice is not disappearing from that marginal increase in temperature. One last word on the subject, the IPCC identified in one of its reports that glacial melting has been noticeable since 1970. In fact, geological literature identified glacier melting in the 1930's - well before the recorded increase in CO2 levels as measured in Mauna Loa. In addition, the rising temperatures in the arctic oceans were identified in the 1930's so what were are seeing today started well before 1970. Just as I find it difficult to accept that climate is being affected by only one factor - the rise in atmospheric CO2, (simply because there are multiple factors at play when it comes to climate), I also find it difficult to accept that the polar ice cap and glaciers are reducing simply due to one factor when there are so many others at play. Sometimes in science we have to step back and ask ourselves "Does it make sense?" In this case it doesn't make sense to me. -
mspelto at 23:25 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
2009 melt anomaly in Greenland was not that large. For the Bulletin American Meteorological Society 2009 State of the Climate (in press), I write the Glacier and Ice Sheets section. Here is the line on the melt anomaly..."On the Greenland ice sheet SSM/I brightness temperature daily variations (Tedesco, 2008) identifies melt extent and number of melting days compared to the 1979-2008 average. Negative anomalies occurred in 2009 along Southern and West Greenland, positive anomalies along Northern and East Greenland. The melt extent was 670, 000 km2, slightly lower than in 2008. Surveys of Greenland marine terminating outlet glaciers from MODIS imagery (J.Box, Ohio State U. Byrd Polar Research Center) indicate that the 34 widest glaciers collectively lost 106.4 km2 of ice between late summer 2008 and late summer 2009. " So melt anomalies were above normal in the northern section of the ice sheet, but not a record. -
Jesús Rosino at 23:24 PM on 31 March 2010A database of peer-reviewed papers on climate change
John, inline comment in #6: "[E&E] no, it's not a peer-reviewed journal" Then, shouldn't they be removed from the peer reviewed papers list? I also agree that E&E shouldn't be considered peer-reviewed, because it is not a scientific journal, but a social science journal. It is not carried in the ISI listing of peer-reviewed journals. Its peer reviewed process has been widely critizised for allowing the publication of substandard papers. The editor has said “I’m following my political agenda — a bit, anyway. But isn’t that the right of the editor?”. See also this article published in Environmental Science and Tecnology (a journal of the American Chemical Society), and has recently made it clear that she is interested in the conclusions of the papers rahter than the methodology.Response: Fair call, it's probable that E&E papers are currently categorised as peer-review in my database. Feel free if you find any such papers to let me know which skeptic argument they're listed under and I'll recategorise them. -
Ned at 23:17 PM on 31 March 2010The 5 characteristics of scientific denialism
And yet another entry in the do-it-yourself surface temperature programs! New ones seem to be popping up about one per week. Once again, the results closely match those from GISS, CRU, NCDC, and the other "amateur" analyses linked above. Here's a comparison of eight different versions:Not shown in that graph are results from Tamino (who's temporarily offline while moving) and Clear Climate Code (whose results are identical to GISSTEMP). What does this comparison show? (1) The increasing global mean surface temperature trend is not caused by "manipulation" of the data by NASA or UEA-CRU. (2) The increasing global mean surface temperature trend is not an artifact of particular algorithms or methods (multiple studies using the same input data but different methods get the same results). (3) Several of these people have now done comparisons of stations that were dropped in the 1990s vs those that were not dropped, and have found no significant difference in the trends. (I.e., Watts and D'Aleo are clearly wrong.) (4) "Amateurs" (no insult intended; these people are highly skilled ... but climate science is an avocation rather than vocation for them) can make a very substantial contribution to the field. IMHO this is pretty neat.
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Dennis at 23:16 PM on 31 March 2010A database of peer-reviewed papers on climate change
Re: Energy & Environment -- Given the competing claims that Energy & Environment is/is not peer reviewed, this is a good time for any climate scientists (or, for that matter, any other scientists) who have peer reviewed papers published in Energy & Environment to step forward and identify yourselves. You don't have to identify the paper, only that you have peer reviewed for E&E. -
Berényi Péter at 22:35 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
For a historical perspective: Was there a 1930s Meltdown of Greenland Glaciers? by Adam Herrington True, it is an undergraduate rersearch paper at the Ohio State University, still, it says something. It also provides plenty of literature on the subject. -
Ari Jokimäki at 21:51 PM on 31 March 2010A database of peer-reviewed papers on climate change
Energy & Environment is not generally considered as peer reviewed even though they claim to be one. They seem to be only publishing papers that go against the mainstream climate science, and the papers also seem to be of questionable quality. -
Mikko at 21:25 PM on 31 March 2010A database of peer-reviewed papers on climate change
http://en.wikipedia.org/wiki/Energy_&_Environment Many of the "sceptical papers" have been published in the Energy & Environment. Is it Peer-Reviewed, Academic Journal as EBSCO lists it? Or is it a trade journal as Scopus lists it? Which is more reliable EBSCO or Scopus list?Response: My understanding is all articles published in Energy and Environment were reviewed by the editor Sonja Boehmer-Christiansen. In other words, no, it's not a peer-reviewed journal. -
Ari Jokimäki at 20:44 PM on 31 March 2010A database of peer-reviewed papers on climate change
Thanks for the traffic, John! :) -
Jesús Rosino at 19:16 PM on 31 March 2010A database of peer-reviewed papers on climate change
Ari's AGW Observer has a useful index page listing all the paperlists: http://agwobserver.wordpress.com/index/ -
Mikko at 19:14 PM on 31 March 2010A database of peer-reviewed papers on climate change
http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html Hi experts. Pleas comment this link. I have feeling that it is another hoax of the denialits. -
RSVP at 18:32 PM on 31 March 2010The human fingerprint in global warming
In tracking global atmospheric composition, the implications of change goes beyond effects on Earth's temperature. In fact, climate may be the least significant issue. For instance, life (as we know it) cannot be sustained without oxygen. Mathematical projections on global ice melting, temperatures, sea level rise, etc., are commonplace on this site, yet general questions on bio-sustainability are typically avoided. And while these issue may hold a higher priority for limiting fossil fuel burning, the focus here attemps to limit itself to safeguarding the climate theory behind AGW (i.e., the relationship between CO2 levels and global warming). And with all the data and resources currently dedicated to this issue, it would seem proper to apply it to a higher purpose. Not only would there be more interest and motivation, there is a higher chance of actually acheiving goals relative to the reduction of GHG emissions. -
Jeff Freymueller at 16:32 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
#33 Geo Guy, yes, but 300 gigatons per year by sublimation due to changes in winds? Please. Not credible. You are going to have to do better than a blanket claim that all of the observations being made about Greenland have no scientific basis. On what basis do you make that sweeping claim? -
GFW at 16:26 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
And even beyond that, let's consider an imaginary ice sheet somewhere undergoing significant annual mass loss via sublimation. Um, where does the ice go? Into the air as water vapor. And then? It rains out ... and winds up in the ocean. Simple fact - any loss from any ice sheet winds up in the ocean. Yes, humans have created some extra lakes with dams, and a warming atmosphere will almost certainly retain more water vapor, but the former is a relatively small (though measured!) effect while the latter is obviously something that an AGW denier isn't going to want to talk about. -
Doug Bostrom at 16:07 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
By the way, here is the paper Geo Guy cites, and here is a full text article fully disclosing the context of the situation Geo Guy believes overturns ice mass loss in a completely different situation. -
Doug Bostrom at 16:00 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
Geo Guy, just to be clear are you in doubt about the GRACE results indicating loss of ice mass on Greenland, observed acceleration of ice loss at the margins of Greenland? Also, you probably did not notice that the paper you cite refers to closed drainages and has no particular relevance to Greenland or other locations where glaciers or ice sheets are connected to outflows. Sublimation or melting is the only available means of attaining mass balance for glaciers in closed drainages. The Greenland ice sheet and associated glaciers are of course not confined to closed drainages. -
Geo Guy at 14:43 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
In response to Ned 23 and Jeff 26 (and others who find it difficult to believe that sublimation does not play a role in the disappearance of glaciers), when air temperatures fail to move above melting (even in the summer) plus when you factor in the thermodynamics of the amount of heat needed to melt ice, and given the polar regions are sub zero for half the year, the melting of glaciers at the rates indicated in the loss of mass just are not possible from an increase in atmospheric temperatures. For anyone who has worked in the far north in the winter, the sublimation of snow cover is quite observable as is the reduction in ice on the lakes. Geologists Andrew Fountain, Karen Lweis and Peter Doran authored an article in Global Planetary hange (Vol 22 Issues 1-4) from which I took the following quote: "In polar regions, where melting is typically absent, sublimation is the only significant process by which glaciers lose mass and its rate largely depends on wind speed rather than temperature." The reduction in glaciers located in high elevations in Chile and Mount Kilimanjaro etc are attributed to sublimation and not melting. Observations being made about Greenland and interpretations as to the cause of the change in Mass blaance that are posted here simply have no scientific basis attached to them. -
muoncounter at 13:41 PM on 31 March 2010Greenland's ice mass loss has spread to the northwest
GeoGuy #20: "temperature plots from 1930 onwards from stations located on Greenland show consistent temperatures and no rising temperatures - especially the the heights needed to melt glacial ice." Perhaps we should listen to the local population: "A Greenlandic supermarket is stocking locally grown cauliflower, broccoli and cabbage this year for the first time. Eight sheep farmers are growing potatoes commercially. Five more are experimenting with vegetables. And Kenneth Hoeg, the region’s chief agriculture adviser, says he does not see why southern Greenland cannot eventually be full of vegetable farms and viable forests."" ... Cod, which prefer warmer waters, have started appearing off the coast again. Ewes are having fatter lambs, and more of them every season. The growing season, such as it is, now lasts roughly from mid-May through mid-September, about three weeks longer than a decade ago." -- http://www.nytimes.com/2007/10/28/world/europe/28greenland.html Again, evidence of warming that isn't dependent on temperature data. Wonder if there's any beachfront property available in Narsarsuaq.
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yocta at 13:34 PM on 31 March 2010A database of peer-reviewed papers on climate change
John, you should convert this hobby into a PhD given the amount of literature reviewing you do!Response: If any universities are interested, I'm happy to discuss thesis ideas :-) -
Berényi Péter at 13:30 PM on 31 March 2010Is the science settled?
#92 Ned at 14:40 PM on 27 March, 2010 "To illustrate the point about positive feedbacks, here are graphs of two cases, one where f > 1 (resulting in a runaway increase) and one, like the real-world positive water vapor feedback, where 0 < f < 1, so that the temperature increase is bounded (2C in this case)" I see. Your model should go something like this: 1 Average SST (Sea Surface Temperature) s is a monotonic function H of average IR optical depth y of atmosphere: s = H(y) where H(y1) > H(y2) for all y1 > y2. 2 For a given optical depth y0 there is an equilibrium temperature s0 so that s0 = H(y0). 3 This equilibrium is stable against small transient perturbations. 3.1 If H is considered to be a functional acting on optical depth histories y0 + y(t) such that y(t) is bounded (y0 >> |y(t)|) and zero outside t1 > t > 0 for some t1, then H(y0 + y(t)) tends to s0 in the long run. 4 H is smooth around y0, that is if the integral of y(t) squared is sufficiently small, there is some linear transform H such that H(y0 + y(t)) = H(y0) + Hy 5 H is time shift invariant. That is if h(t) = H(y(t)), then h(t+t1) = H(y(t+t1)) for all t1. In this case the linear transform H defined above is a filter and is fully specified by its impulse response function or the Fourier transform of it, the transfer function. 6 Let H be a first order lowpass filter. It's easier to visualize its response to a step function y(t) which is y1 for t > 0 and zero otherwise. If this forced increase in optical depth (relative to the equilibrium value of y0) induces a long term increase of s1 in SST, the response function defined by H is h(t) = s1/y1(1-e-t/t0) where t0 is relaxation time. Now. Average water contents of the atmosphere is somewhere around 4000 ppmv, highly variable. It is more than ten times the current CO2 level. Also, H2O has much more absorption lines in thermal infrared, so even tiny changes in humidity imply changes in overall IR optical depth. Also, as the story goes, vapor pressure of H2O over open water surfaces increases with temperature, so overall optical depth is also expected to increase. As average annual precipitation on Earth is close to 1000 mm and atmospheric moisture is low (only 0.24% by weight), turnover time has to be short (approx. 9 days). Therefore atmospheric IR optical depth change should be an almost instantaneous response to a change in SST. We have already postulated a rise of s1 in SST in response to an increase in optical depth of y1. Now it is done the other way around. If SST is increased by s1, it causes an immediate increase of optical depth by f*y1 (with some coefficient f). This is the water vapor feedback. From now on attention is restricted to the supposed linear regime around the equilibrium state defined above, so only anomalies are dealt with. Let x be the IR optical depth anomaly due to GHGs other than H2O. We have two equations: s = Hy (1) y = f*y1/s1*s + x (2) From these we have s = (H-1-f*y1/s1)-1x = Gx (3) Let's switch to the frequency domain. The Fourier transform of H is H and w is angular frequency. In this case Hw = s1/y1/(1+j*t0*w) (4) If it is put back to (3) Gw = 1/(1-f)*s1/y1/(1+j*t1*w) (5) where t1 = t0/(1-f) is obtained. From this (by inverse Fourier transform) the response to a step function of magnitude x1 in GHG induced increase of IR optical depth is g(t) = 1/(1-f)*s1/x1*(1-e-t/t1) (6) Indeed, an amplification factor of 1/(1-f) is seen which is larger than one if 1 > f > 0. There is no runaway warming in this case. However, we also have this relaxation time thingy. Could anyone give an order-of-magnitude guess about how large it is supposed to be? Also, the assumptions going into the WV amplification theory are made explicit, so they can be scrutinized. -
shdwsnlite at 13:09 PM on 31 March 2010A database of peer-reviewed papers on climate change
Sure one more thing to do in your all your spare time. Thank you for all the work you do on this site. -
shdwsnlite at 13:05 PM on 31 March 2010Climategate CRU emails suggest conspiracy
nice to see what the supporters have been saying confirmed, but many will say the judgment was rigged. Inquiry backs scientists in global warming row -
Jonathan E Markham at 12:36 PM on 31 March 2010A database of peer-reviewed papers on climate change
But mere cataloging isn't particularly helpful. One can just go to ISI and search for 'climate change' if you want a catalog of peer reviewed papers. Much more useful is a catalog of important peer reviewed papers, for which there are many possible judging criteria, times citied (self-citation excluded) is a good one, reflecting how well the paper was received and its influence.Response: It's helpful in grouping them to particular skeptic arguments. So if someone says to you "Greenland isn't losing ice" and you want to look up peer-reviewed research on this exact question, you can go to our links to papers on Greenland ice mass loss. Re additional info on citations to establish the credibility of a paper, I may just add that info to the database at a later stage - why not?! -
Yngtor at 12:31 PM on 31 March 2010A database of peer-reviewed papers on climate change
Excellent! This is just the stuff we need out here to argue coherently. Thanks. -
From Peru at 11:04 AM on 31 March 2010Greenland's ice mass loss has spread to the northwest
When will arrive the MELTING ANOMALY MAP FOR 2009? GRACE show it will probably be a record-breaking one! -
Philippe Chantreau at 09:21 AM on 31 March 2010Is the science settled?
My hypothesis is not the only one to be speculative and there is some work to back it up. Trenberth' model showing decreasing cloud cover leading to more insolation and the majority of warming happening from insolation is an example. That was linked multiple times in earlier threads. -
Lou Grinzo at 09:16 AM on 31 March 2010Greenland's ice mass loss has spread to the northwest
Thanks for the pointer to that article, Albatross. The exact quote from New Scientist: ---------------------------- The model suggests that within 100 years, PIG's grounding line could have retreated over 200 kilometres. "Before the retreating grounding line comes to a rest at some unknown point on the inner slope, PIG will have lost 50 per cent of its ice, contributing 24 centimetres to global sea levels," says Richard Hindmarsh of the British Antarctic Survey, who did not participate in the study. ---------------------------- Source: http://www.newscientist.com/article/dn18383-major-antarctic-glacier-is-past-its-tipping-point.html I wish people would push Lovelock (and everyone else) harder to back up such pronouncements. -
Albatross at 08:18 AM on 31 March 2010Greenland's ice mass loss has spread to the northwest
Thanks John, sorry to make work for you. You must feel like you are a school teacher at times, making sure everyone is behaving and also having to help out :) NewScientist (13 January 2010) has an article on the potential impact on global SL if the PIG were to slide into the ocean-- they reckon that would increase global SL by about 24 cm. And yes, scientists think PIG exceeded its tipping point in 1996..... -
shawnhet at 08:17 AM on 31 March 2010Is the science settled?
Phillippe, I fail to see where I have engaged in wild speculation. I have merely raised the simple hypothesis that more WV in the air will lead to both more clouds and more precipitation. Warmer air will hold more WV cooler air everything else being equal and, thus, cooling it by the same amount will cause more precipitation for a warm climate than a cool one. How Much More Rain Will Global Warming Bring? Frank J. Wentz,* Lucrezia Ricciardulli, Kyle Hilburn, Carl Mears Climate models and satellite observations both indicate that the total amount of water in the atmosphere will increase at a rate of 7% per kelvin of surface warming. However, the climate models predict that global precipitation will increase at a much slower rate of 1 to 3% per kelvin. A recent analysis of satellite observations does not support this prediction of a muted response of precipitation to global warming. Rather, the observations suggest that precipitation and total atmospheric water have increased at about the same rate over the past two decades. While the energy from condensation doesn't disappear, it does disappear from the surface resulting in cooling of the surface. In the Kiehl and Trenberth model, the surface temperature is the solar heating of the surface + backradiation minus evapotranspiration(and the energy absorbed by the Earth). Your idea that cloud lifetimes will be lessened is of course possible, but does seem a little speculative to me. Cheers, :)
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