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Comments 129601 to 129650:

129601. Quietman at 04:05 AM on 15 October 2008
        Volcanoes emit more CO2 than humans
        Patrick Re: My response to chris. It is exactly what he/she? has accused me of on several occasions because I often do not accept an authors conclusions, especially Hansens.
129602. Quietman at 04:00 AM on 15 October 2008
        Volcanoes emit more CO2 than humans
        Patrick (and chris) The papers (all papers, peer reviewed or otherwise) present an argument. That state their observations, methods used (so you can duplicate the test) and references to avoid restating prior arguments. The argument is presented largely in the "conclusions". The papers are all worth reading but it must be remembered that the paper IS AN ARGUMENT, attempting to persuade others to see the authors viewpoint. Accepting the authors conslusions is not mandatory. Peer review indicates that at least one other person in the same field of research agrees, it does not make it fact. If you read the papers carefully, in particular the methods and results you can often come to a totally different conclusion using a wider bas of information. All of the articles cited are related but the authors have not connected the dots. Ignore their conclusions, connect the dots and draw your own conclusions. THAT is what science is all about.
129603. Patrick 027 at 14:38 PM on 14 October 2008
        Volcanoes emit more CO2 than humans
        "To save time and server space, I ask you to read the comments in "Arctic sea ice melt - natural or man-made?"" ... will do, eventually... -------- a few loose ends: quasistationary planetary waves - they don't tilt much with height - at least not relative to their wavelengh. Systems can/could also grow through barotropic instability, which is an instability caused by larger horizontal wind shear (such as on the sides of a jet stream). I don't know as much about that.
129604. Patrick 027 at 12:42 PM on 14 October 2008
        Volcanoes emit more CO2 than humans
        "But in fact the thinned crust is the northern end of Greenland (in the articles linked in this thread) and surrounding Arctic ocean and that is exactly where the largest glacial melt is AND IT IS FROM THE BOTTOM. " I only read the abstract. It sounds like chris may have read more. Is he incorrect about the article? "But top down melting would not produce the same results" It depends on what exactly the results are. Meltwater could come from the surface, flowing down into the glacier through moulins - this source would explain the seasonality of any meltwater-induced lubrication of the glacier. (Of course, however the ice is melted or induced to flow, the resulting thinning would lower the ice surface and cause warming of the ice surface that way.) -- "Ice albedo will remain until all the ice is gone. Soot in the top layers lower the albedo so fresh ice will have a higher albedo if we control the output of soot." Dark aerosols are/have contributed to arctic warming and melting in that way; that is true. tropospheric ozone has also contributed to Arctic warming and melting. So has CO2, CH4, etc. However, the highest albedo is from fresh snow. Old snow and ice tends to have a lower albedo. When snow melts and refrezes or otherwise changes to form larger particles, the reflectivity is reduced - light may penetrate deeper before being reflected, giving it greater chance to be absorbed. Aerosols (and rocks), natural or anthropogenic, will be concentrated as the ice volume is reduced. Sea ice will become more transparent and thus darker when it gets thin enough to see the water beneath. The loss of sea ice will likely have a warming effect (in the winter, at least) on the region, not just where the ice was lost. -- "suggest that vulcanism is a "contributer" in an earlier article" Potentially so but only in a few locations, whereas the ice mass loss and general warming are far far far more widespread and general. "They do not say if it is AGW either." I think at least some of the articles you referenced did say that, not about some of the specific locations but about much of the other warming. ____________________________________ Entering danger zone? "Keep in mind that while you and I can speak openly for or against the AGW concept. there are others who need to be politically correct or they will lose their jobs or grant money and therefore skirt the issue." Scientists and politicians and everyone else are only human. However, if a scientist does work that has errors, and especially if it is a matter of interest to people, I expect some other scientist would want to capitalize on the opportunity to point out those errors. Can scientists be friends with each other? Yes, but that doesn't prevent them from pointing out each other's errors - especially if they don't take it personally. There may be actual examples to back up that point but I'll leave that to others. What about money and prestige? If there were no 'climate crisis', then there would be less money available to study AGW and climate in general, right? Well, I hardly think there's a Higg's particle crisis (that we know of :) ), and yet we've got a Large Hadron Collider now. Still, though, the argument is plausable. Then again, if there were more controversy than there would need to be more work done to resolve it, so... Still, though, whereever the bulk of the money and attention are going, there could be some scientists out there who would like to make a big name for themselves by successfully overturning the conventional wisdom of the day. If they are not able to do so, then there might be a reason why. And unless scientists are actually making up the data, the data is what it is, the potential error in that data and all, the theory (logic) is what it is, and any scientist, or student, with sufficient education can ask, does this make sense? There are people with an interest in overturning the current accepted science of global warming. Some of them have lots and lots and lots of money. Yet, rather than having funded real science on the matter (at least any that would successfully accomplish their goals), they instead lobby the government while launching silly propaganda campaigns about how CO2 'is life' (or that any effort to reduce CO2 emissions will harm the poor (often arguments ironically made by people who would rather not have the government do the poor any special favors, I think), or that free market capitalism will solve everything and any government involvement works against innovation - when in fact a carbon tax or some equivalent, etc, could help spur innovation and may be justified by (market) economic principles) ... Meanwhile, my impression is that, if anything, the IPCC summary for policymakers is watered down in favor of anti-alarmism, rather than hyped in the other direction. "Then there are those, like one poster at this site, that are environmental fanatics who look upon AGW as a bible thumper looks to the word of God." I can't help but wonder if this is the result of misunderstanding (not that I would pretend to know how your conversations with others have gone - I don't know). Not that it can't happen - many people don't understand science, regardless of what they have come to believe or accept as true (although the people who do understand science are more likely to accept or lean towards the accepted science or at least one or more promising contenders). But sometimes people who do know stuff just get tired and impatient from explaining and explaining and explaining and explaining and explaining and explaining and explaining and explaining and explaining again, especially when so many turn a deaf ear towards it or come back with accusations of communism, or just keep making the same arguments over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over, no matter how well it's been refuted to them (and maybe in some cases, being caught telling other people something totally false about what you told them - this has happened to me). Then what may happen is that people misread each other, assuming that the other guy is a member of the group of ignorant jerks s/he's become accustomed to dealing with. It may happen in particular when a new face advances an argument that the other person has seen before, perhaps from an actual 'denier/contrarian'. Or to save time, a person might refer to the 'scientific consensus', from which the other person may unfairly conclude that the other is just arguing 'from authority', rather than understanding the significance of such a consensus (ie sure, we can't be 100% sure about much, but there comes a time when we've got to make a decision - what do we put in our science textbooks? What do base public policy on? While there are loose ends still being worked out, relativity and quantum mechanics are scientific consensus. Many details have not been found, but the general picture of biological evolution by natural selection and some other things is scientific consensus. That the Earth is ~ 4.5 billion years old ... etc. PS Relativity didn't overturn Newtonian mechanics entirely (we still use the later for many things), and aside from that, if the argument is made that Einstein successfully overturned a consensus, 1. does that mean we could expect that Einstein will also be shown to be wrong someday, and 2. for every Einstein, how many had an idea that didn't pan out?) Although it is unfair, it is sometimes understandable why a person may make an assumption about someone's attitude to reality. There is also the time constraint - if a person smells 'silly' in an argument, they may decide (rationally) to not bother with it, hence, dismissing it. Certainly if I didn't have the time I couldn't have been discussing/arguing with you about the merits of various possibilities. I myself am quite satisfied that 'it' (you know what I mean) is mainly AGW. There are many arguments I won't look into further, because I judge them ahead of time to be wild-goose chases that will lead nowhere - I can do that with some confidence because of the arguments I have looked into that turned out to be just that, empty fluff. Occasionally I will look into such an argument though, just to debunk it - but of course, if I can't debunk it, that will tell me something, won't it? (Either that it may be possible, or that it is beyond my knowledge). Another aspect to this - perhaps an application of Occam's razor - there are so many things that are known, that lead to an expectation of significant CO2 causing significant warming - that Arrhenius (sp?) predicted as much long before CO2 emissions ever rose to such a level - the understanding of how radiation transfer actually opperates has been refined since then, as have the radiative properties of gases, etc, - but not in a way to discredit the basic idea, rather just to refine the theory. Then there is paleoclimatology, the computer models, the observations so far, etc. - they all inform each other, of course, but even taken independently they point in the same general direction. Given all that, some of these alternative explanations - it seems like throwing in extra Rube Goldberg devices and lasers to explain how the toaster works, after you've already seen the nichrome wires glowing red... Now, I may still want to learn about some things for other reasons - I don't think the tidal-driven ocean mixing will account for much of recent changes but I find it interesting as a phenomenon all by itself, for example. "Hopefully we will get to the truth behind all this regardless of their attempts to "enlighten" us "deniers" (that is their demonization of skeptics vocabulary, not mine)." This is messy. Take out the 'offensive words', and what is left behind essentially describes, in my mind, what I hoped to accomplish - enlighten you. Why wouldn't I call you a denier or contrarian? Well, because you've been polite and seem willing to listen, you haven't accused me of being a communist, a dumb parrot, or having malice or indifference towards innocent people, and you aren't trying to cast yourself as a climatologist or a scientist in some related field. I was actually afraid I've 'led you on' when you implied someone else might consider me a denier, so now - in jest - I will say that some of those I have argued with would call you a communist. As for those words - denier, contrarian - there are people out there to whom I think they would justifiably apply. For example, dare I say Fred Singer and Richard Lindzen. I don't say this just because they say things I disagree with - I say it because they say things that can't be backed up, they make arguments that are shot full of holes, and especially in Fred Singer's case, I am tempted to doubt whether he himself could possibly buy into his own arguments - or else, I think he must be horribly confused and sloppy - yet, perhaps some of his sleight-of-hand reasoning is too clever for that explanation? Other people - whether they knowlingly lie or just want to believe in those things that help them politically - Rush Limbaugh, Michael Crichton, Ann Coulter, James Inhoffe, James Dobson, CEI, etc... and even Jon Stossel and Glenn Beck, - well, ... they don't identify themselves as scientists, but in some cases they are quite biased in their work, and in some cases there furosity ... Some would say 'denier' is offensive because it may have been inspired by the use of the word next to 'Holocaust'. I can see that, however, I can also see that it is a word, like red, and certainly no one thinks cherries are communist. Does a person 'deny' in an irrational or dishonest way? Your response to chris: "Yes but first you have to examine it instead of dismissing anything you don't like off hand or because you don't like the author or what he/she says. You can't skip through and ignore key words and phrases the way you like to and you can't assume that a paper is fact, peer reviewed or not. It is an argument, ie. a hypothesis." Actually, I think chris may have been saying somewhat the same thing to you. Aside from that, of course one shouldn't assume a paper, even having passed peer review, reaches the correct conclusions. But there are so many many papers ... the balance of evidence tilts clearly toward significant AGW. That there are uncertainties in feedbacks - this applies to any climate forcing, so AGW still 'has a leg up on' various alternatives (in the sense of contenders to being the major forcing of relevant changes), and the 'burden of proof' doesn't fall all the way back to showing CO2, et. al., as big players, just because of feedback uncertainties. In particular with 'dismissing offhand' - see somewhere above...
129605. Patrick 027 at 10:16 AM on 14 October 2008
        Climate sensitivity is low
        "Actually you dismissed the idea rather abruptly" But I did explain why I was dismissing it (or perhaps more accurately, debunking it, or at least trying to debunk it). So what would really be helpful is if you could find errors in my reasoning - the gist of which was that Spencer was considering temperature response to cloud variability on short timescales, short enough that thermal inertia would limit the temperature response. And now I don't remember off hand, but I do wonder how it could be determined with such an apparently simple method to what extent the cloud variability caused the temperature and vice-versa. And the other problem - it seems to me cloud feedback is a part of climate sensitivity to other things, but there is little (on these short timescales) CO2 feedback to cloud 'forcing', and even less so feedback by changes in solar activity, etc.
129606. chris at 09:56 AM on 14 October 2008
        Volcanoes emit more CO2 than humans
        Re #80/#81 That makes no sense at all. The reason I questioned your choice of links is that I downloaded and read each paper thoroughly (rather than just the press releases). So I certainly "examined it"! In fact I thought the papers were excellent (papers have to be pretty good to be accepted in Proc Natl Acad Sci or Science and so on...). I thought the authors were fine and I was perfectly happy with what they said (male and female alike!). So your odd accusations don't apply and one wonders why you don't address the critique of your interpretations, rather than reply with inappropriate insults. There's clearly valid questions of whether (a) undersea volcanic/tectonic activity has increased in a manner that could have a causal relationship with the rather large global-scale warming of the last 100 years, especially the last 30; (b) whether tectonic activity has made a significant contribution to widescale polar ice melt. A skeptic should like to see some real world evidence. The point is that the papers that you cited don't support your notion. In other words you can't use as evidence of undersea tectonic contributions to Greenland melt, a paper that describes high level ice sheet surface melt at the ablation zone 1500-2000 metres in altitude in Western Greenland. That's not the result of undersea tectonic activity. It's a consequence of enhanced atmospheric warmth. Likewise one cannot use as evidence of enhanced tectonic contributions to global warming a paper whose essential analysis is to describe the continual steady decrease in thermal heat from plate boundaries due to their consolidation from previously smaller fragments over millions of years. And it's obvious that every paper about tectonics does not willy-nilly constitute an "argument" about tectonic contributions to global warming! We all know that plate tectonics is a fundamental element of the earth system. The question with respect to largescale global warming is whether this activity has increased recently. So there's nothing wrong with the papers - you've just chosen to cite papers that provide data and evidence that contradicts the notion that you are pursuing. And one should be careful in relying on press releases for scientific information.
129607. Quietman at 09:13 AM on 14 October 2008
        Volcanoes emit more CO2 than humans
        Patrick "Sandwiched between Earth's crust and molten outer core, the vast mantle accounts for 83 percent of the planet's volume. It is filled with solid rock but, heated by the core and by its own radioactive decay, it circulates like a pot of impenetrable soup. That circulation is the driving force behind the surface motion of tectonic plates, which builds mountains and causes earthquakes." Ref: Geophysicists Propose A New Model Of Earth's Mantle ScienceDaily (Mar. 19, 1999) - Earth's mantle, a region as scientifically remote as outer space and the object of the most heated debate in geophysics, gets a remodeling this Friday by researchers at UC Davis and MIT PS I would remind you that the capacity for "sudden" changes was covered in my post 36. But I found a good link for the article at ScienceDaily (June 20, 2008) — Surprisingly Rapid Changes In Earth’s Core Discovered " The movements in the liquid part of the Earth’s core are changing surprisingly quickly, and this affects the Earth’s magnetic field, according to new research from DTU Space." ... “What is so surprising is that rapid, almost sudden, changes take place in the Earth’s magnetic field. This suggests that similar sudden changes take place in the movement of the liquid metal deep inside the Earth which is the reason for the Earth’s magnetic field,” Nils Olsen explains. Ref: The Abstract in Nature. Viewed with the article of Tectonics acting as the Earths thermostat it can be seen how the thermostat can become suddenly reset for periods of time.
129608. Quietman at 08:46 AM on 14 October 2008
        CO2 lags temperature
        Re: "On the other hand it's not obvious why you consider a truism to be an assumption! It's been known since the middle of the 19th century that the earth's temperature is defined by the insolation from the sun (which gives the Earth a black body temperature near -15 oC) and the greenhouse effect arising largely from water vapour and CO2 that supplements the black body temperature by around 30 oC." Because it has been determined slightly more recently that your truism isn't. It is incomplete. Because it is incomplete the concepts that assumed it to be correct are also incorrect albeit not entirely. Just enough to skew the results and point in the wrong direction.
129609. Quietman at 08:40 AM on 14 October 2008
        Volcanoes emit more CO2 than humans
        PS Re: "SO how/why would global warming alter storm tracks?" I thought that you made a good explanation or at least a good argument for that in the Bertha thread.
129610. Quietman at 08:36 AM on 14 October 2008
        Volcanoes emit more CO2 than humans
        Patrick That was directed at chris. You put forward a good argument regardless of what points I disagree with and do so using logic rather than a peer review bible. Keep it up, you do a good analysis.
129611. Quietman at 08:32 AM on 14 October 2008
        Volcanoes emit more CO2 than humans
        In science it's all about the evidence Quietman. Yes but first you have to examine it instead of dismissing anything you don't like off hand or because you don't like the author or what he/she says. You can't skip through and ignore key words and phrases the way you like to and you can't assume that a paper is fact, peer reviewed or not. It is an argument, ie. a hypothesis.
129612. Quietman at 08:28 AM on 14 October 2008
        Climate sensitivity is low
        Patrick Re: "I covered that very argument in some of our last comments in "Science and Society"." Actually you dismissed the idea rather abruptly, but that's OK. But it doesn't mean that I did. On the solar wind I will have to find the links again. I know I posted them on this site somewhere.
129613. chris at 22:33 PM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Re #74: The suggestion that scientists "skirt the issue" because of worries about funding/grant money or political correctness is ludicrous and isn't a scientific argument. It's a conspiracy theory. The essential element of science and one that allows us to address difficult and complex issues relating to real world phenomena is that it is evidence-based. All discoveries/interpretations that are supported by the evidence have a place in science and are likely to appear in the peer-reviewed scientific literature. If interpretations are not supported by real world evidence they are very unlikely to appear in the literature or to be taken very seriously, especially be scientists who are pretty skeptical people. And of course we should all be skeptical of assertions/arguments without an evidence-base. Of course we're free to discuss unsupported hypotheses to our hearts content, but unless evidence accrues to support these, one should remain skeptical. Castigating individuals as "environmental fanatics who look upon AGW as a bible thumper looks to the word of God", seems more like an insult that a scientific argument! I haven't posted here that long and haven't come across any people that seem to have unreasonable concern for the environment. However surely one should address their argument/evidence rather than insult them. In science it's all about the evidence Quietman.
129614. chris at 20:36 PM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Re #66, 67, 71, 73 etc. The notion of significant volcanic/tectonic contribution to polar ice melting simply isn't supported by the evidence, Quietman, and most of the articles that you link to don't support that notion either. Much of the analysis of enhanced melt/glacial runoff that is contributing to nett mass loss in Greenland is from regions far from the Gakkel ridge in the far NE region N of Greenland where some tectonic activity has been found. It's already been pointed out by Patrick that the surface melt highlighted by Tedesco et al in their EOS article is incompatible with the effects of undersea tectonic activity. This is highlighted by Tedesco himself who indicates that the snow melt is associated with surface/air maximum temperatures 3 oC above average. Clearly that cannot be the result of undersea volcanos. The situation is similar to the article you linked to on the Greenland thread (your link in post #66 above). It's easy to see that this article (citation below) discusses surface melt on the Western region of the Greenland ice sheet, and specifically concerns surface melt in the ablation zone 1500-2000 metres high up in the ice sheet. This enhanced surface melt cannot be the result of undersea volcanic activity 1000 miles away. and so on. The papers you link to are inconsistent with the effects of undersea tectonic activity. An additional problem relates to the question whether this activity (undersea tectonics) has increased in a manner that is consistent with the timescale of enhanced warming. You linked to a paper in your post #13 above which you consider to be some sort of support for a contribution from tectonic activity to the very marked enhanced warming of the last century and especially the last 30-0dd years. However this paper (Loyd et al, 2007; citation below) simply doesn't support that notion. The specific point of the Loyd paper that you link to is that the release of thermal heat from the earth's tectonic activity has steadily decreased over the last many million years. Now it may be that there is some evidence for enhanced tectonic activity, but the paper you linked to certainly doesn't provie any. If anything it provides completely contrary evidence to your hypothesis. R. S. W. van de Wal (2008) “Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet” Science 321, 111 – 113. S. J. Loyd et al (2007) "Time variability in Cenozoic reconstructions of mantle heat flow: Plate tectonic cycles and implications for Earth's thermal evolution" Proc. Natl. Acad. Sci. USA 104, 14266-14271.
129615. Patrick 027 at 16:12 PM on 13 October 2008
        Climate sensitivity is low
        "You apparently confuse ocean tides with tectonic tides" No, but I do recognize that solid earth tides must respond to oceanic tides and vice versa, but except maybe for around the Bay of Fundy and that one place in France - well... "The concept that the solar wind does not have an effect on climate is wrong." Could you explain how it works or describe the observations supporting it? For example, from the article on Forbush and Heliospheric current sheet crossings etc. (PS you'd have to quantify the radiative forcing of that and then figure out a multidecadal trend...) Or does it affect circulation patterns directly via the E-region dynamo (within the base of the thermosphere) - ps mass of E-region dynamo is something like a millionth of the whole atmopshere, give or take a factor of ten (just because I can't look it up right now), but if you could find some mechanism to propogate a pressure perturbation or pattern downward while amplifying it... "I have a link posted here to Spencer's argument in comment 9. " I covered that very argument in some of our last comments in "Science and Society".
129616. Patrick 027 at 16:00 PM on 13 October 2008
        Volcanoes emit more CO2 than humans
        *A3*. If anticyclones are larger horizontally they will then tend to propogate westward relative to the wind faster than cyclones (beta effect), so cyclones will tend to move eastward with the overall wind faster than anticyclones, or in order to move at the same speed, anticyclones would have to be closer to a westerly jet ... etc... AND as anticyclones sort out equatorward of stormtracks, they would experience higher beta and so their eastward movement would be slower for that reason as well - unless there is another effect that counteracts this. PS to be clear, My understanding is that: In baroclinic instability, eddies grow by taking available potential energy (APE) from the average state (averaged along a storm track across a full eddy wavelength, for example, or a full zonal average across all longitudes for the overall midlatitude storm track activity) and thus creating eddy APE, essentially by moving the cold air and warm air into each other (creating a wave pattern in the isotherms or isentropes along a horizontal or near horizontal surface) - at the same time, this disrupts geostrophy so that a thermally direct circulation occurs, with winds moving from high to low pressure horizontally, with warmer air rising and colder air sinking. This converts some of that eddy APE to eddy kinetic energy (KE), which enables the eddy to distort the isotherms even more, and thus continue to grow - for small disturbances, growth can initially be exponential. Two things: when warm air is pushed as a protrusion into colder air, the resulting pressure perturbation is initially unbalanced by the coriolis effect and so the warmer air rises - warmer air that was initially surrounded (horizontally) by air of a more similar temperature is now surrounded by colder air, and so rises, just as actually adding heat to a region of air tends to make it rise. However, depending on the geometry, some of the surrounding colder air may also sink as it is now next to warmer air. The effect may not be as strong as in the warmer air since the colder air is not surrounded by the warmer air, however (mathematically, it depends on the laplacian of the temperature advection). But if new warm air continues to flow from the main warm air mass into the cold air, the cold air will eventually adjust and stop sinking while the warmer air is still coming into a new situation and will still rise. IF the temperature gradient is initially constant from warmer to colder, than, for the sake of clarity, assuming an initially north-south temperature gradient (east-west isotherms), a wave pattern of flow that is limited from north to south will pull isotherms apart in the warmer side while pushing them together in the colder side, or vice versa, and where isotherms are pulled apart, a thermally indirect circulation will develop, converting KE to APE. However, where isotherms are pushed together, the thermal gradient can get higher and higher (until some ageostrophic effects associated with frontal zones get strong), whereas the pulling apart of isotherms can at most reduce the gradient to zero (PS I haven't actually calculated this but I would assume this means the thermally direct circulation eventually dominates while the themally indirect circulation dies out). Also, if the initial thermal gradient is concentrated near or along the storm track, there might not be so much pulling apart of isotherms even initially to cause a balancing thermally indirect circulation. Anyway, an east west cross section of an idealized series of such growing eddies may show alternating high and low pressure centers tilting westward with height, regions of rising and sinking motion, strongest in midlevels (air won't rise into space or go down into the surface) which also tilt westward with height but not as much, and regions of warmer and colder air that tilt eastward with height. The air flows through these features from west to east higher up and from east to west closer to the surface. Because the temperature and vertical motion patterns don't tilt the same way with height, there can be some pockets of thermally indirect circulation, but overall it is mostly thermally direct. What is really interesting about these kinds of systems - you might well wonder, how can they grow - how can the pressure systems get stronger - when the thermally-direct motions that create the kinetic energy associated with the wind requires that air is on average flowing into low pressures and out of high pressures? The answer: by temperature advection (transport of air)(not actually by heating, although that will occur but is not part of this explanation), the air in between the highs and lows is warmed or cooled because of the north-south flows. But the east-west flows through the system act on this pattern, so that the resulting temperature field doesn't tilt as much as the pressure field and actually tilts the other way. The vertical motion reduces the growth of the temperature pattern by adiabatic cooling and warming of the warmer and colder air, respectively, and this effect is greatest at midlevels (or tends to be, but will also be greater at levels with higher static stability). Near the surface, warmer air is closer to lower pressure; at higher levels it is closer to the higher pressure (opposite for colder air). Pressure drops faster with height through colder denser air than through warmer air, so the low pressure tilts with height over the colder air to its west, and the high pressure tilts with height over the warmer air to its west. The temperature field explains the way pressure changes with height, but what explains the actual pressure field at any one level, such as the surface? There has to be some total divergence through the whole column of air above the surface low pressure to result in lowering the pressure (assuming flat topography - pressure systems can also be produced by motion over slopes). There has to be convergence into the low pressure on average in order to increase kinetic energy. But with height, the high pressure tilts part of the way over to above the surface low, so divergence from that high pressure can lower the pressure at the surface, while convergence at the surface increases the high pressure aloft. What about angular momentum? Air is vertically stretched beneath warm rising air at midlevels, while also being transported by relative westward motion (relative to this whole pattern) into the low pressure at low levels levels; so cyclonic relative vorticity is created that can nearly balance the pressure - but not quite, or else their could not be net convergence into the low (actually, there could also be some effect of centrifugal force, which affects high and low pressures asymmetrically - although centrifugal force depends on the trajectories, whereas vorticity is determined from streamlines**), and at upper levels, air is vertically stretched above sinking motion while being transported westward into the low pressure at that level. And so on for the growth of anticyclonic vorticity in the high pressure areas. The whole pattern can grow exponentially, up to a point. When the flow pattern of the disturbances is stronger, the warmer air is not just moved east west toward low and high pressure centers, but continues to move north and south more significantly due to the wind of the disturbances. Thus warm air flows northward from south of the low (did I mention I'm describing a Northern Hemisphere version) east of the low and westward relative to the low, into the low as the low moves east, but also continues northward and goes north of the low. Rising motion and the surface low itself will follow. Another way of looking at it is that the flow of air above the low is not just westward but northwestward, between a trough and a ridge at mid-to-upper levels... and generally, features at one level in the atmosphere tend to propogate with the wind at another level because the wind at that level must adjust to the feature, and the feature must adjust to that adjustment... So in the 'sorting out' process where the highs and lows at the surface tend to end up on different sides of the jet stream and temperature contrast associated with the storm track, when the motions are averaged along the length of the storm track, it may appear that colder air is rising and warmer air is sinking, but this may largely be (?) the result of warmer air rising while surrounded by colder air, and colder air sinking that is surrounded by warmer air. Mathematically this can be worked out as a thermally direct eddy circulation which is producing more kinetic energy than is being taken back by the weaker thermally indirect averge motion. At some point, though, I could imagine that even while the warmer air and colder air are still warmer and colder than their immediate surroundings, they may have cooled and warmed enough, respectively, that they are no longer warmer and colder than each other, respectively; at that point the average thermally indirect motion would be stronger than the eddy thermally direct motion, I think, so that in total kinetic energy is being converted to APE. Of course, the eddy motion itself might start converting some KE to APE at some point during the decay stage (?)- perhaps frictional dissipation may force cold air up in the lower levels of the low pressure system, for example - which would strengthen the low pressure aloft but reduce it at the surface (although the convergence at the surface would reduce it at all levels, but at higher levels the disruption of geostrophy would induce flow to counteract whatever pressure tendency there is - not entirely unlike the way electric currents respond to a changing magnetic field). I did see your most recent comments and I'll get back to you about that.
129617. Patrick 027 at 12:59 PM on 13 October 2008
        Volcanoes emit more CO2 than humans
        SO how/why would global warming alter storm tracks? I know a good amount about circulation patterns in the atmosphere and yet there is A LOT I don't know, but what I know, have been able to deduce, or otherwise have gotten the impression of, is: Remember hot air tends to rise and cold air tends to sink; this happens because of the pressure variations caused by the variations in air density. For a column of warmer air, the pressure is either lower than otherwise below it, higher than otherwise above it, or some combination of the two (at least for the hydrostatic approximation). The coriolis effect, on the large scale more than on smaller scales, tends to impede the simple 'thermally direct' circulation just described by causing wind to blow nearly parallel to isobars (or lines of constant geopotential on isobaric surfaces). The atmosphere is generally at least somewhat stable to dry vertical motion; this means that dry adiabatic cooling and warming are such that, the rising/sinking induced by a warm/cold anomaly tends to reduce the anomaly. Midlatitude storms do get some energy from latent heating (as with tropical storms), but unlike tropical cyclones, midlatitude storms get much of their energy from the available potential energy of a background horizontal thermal gradient. This thermal gradient supports a vertical wind shear (hence the jet streams). In the hydrostatic approximation (which is a good approximation in the asence of significant vertical acceleration, which is generally the case of larger scale motions), horizontal divergence/convergence must occur along with vertical compression/stretching (in pressure coordinates), respectively, which implies variations in vertical velocity with height (in pressure coordinates). In order to conserve angular momentum, which is the case in the absence of friction (and friction is generally weaker than the pressure gradient and coriolis forces in the midlatitudes), horizontal convergence/divergence must occur with an increase/decrease in the magnitude of vorticity - vorticity is a measure of the air's 'spin'. It's important to realize that this pertains to absolute vorticity, which is the sum of planetary vorticity (which is proportional the coriolis effect itself) and relative vorticity. Relative vorticity can be cyclonic or anticyclonic, such as in cyclones or anticyclones, respectively (although horizontal shear also contributes to vorticity). But the absolute vorticity is never anticyclonic except near the equator. Thus, vertical stretching, such as below rising motion or above sinking motion, tends to cause cyclonic motion, which requires a low pressure area to be balanced; and the opposite tends to cause anticyclonic motion, etc. *A1*.(Notice that if continued to extremes, relative anticyclonic vorticity can be at most equal and opposite to planetary vorticity, whereas there isn't such an upper bound to cyclonic vorticity, aside from the limits of the vertical stretching itself). Related to that, centrifugal forces allow for, for a given wind speed, greater pressure gradient around a low center than around a high center. (?? Another potential reason for assymetry is that divergence is ultimately limited by space but convergence is not ??, and also, a divergent air mass is growing larger in area whereas a converging air mass is shrinking ??, although air diverging from one point must ultimately also be converging toward another. ??) PS the measure of absolute angular momentum that is conserved during any inviscid (frictionless) adiabatic motion is isentropic potential vorticity. With constant static stability, potential vorticity (PV) is higher where absolute vorticity is higher; with constant absolute vorticity, PV is higher where static stability is greater. AND THEN: Disturbances in a region of vertical shear that are tilted into the shear - that is, if the vertical shear is westerly (eastward) with increasing height, the tilt of the pressure perturbations is westward with height - and moving at an intermediate speed between the extremes that occur higher and lower in the troposphere - can grow because the configuration allows for ...(Baroclinic instability) ... okay, well that's too complicated to go into right now, but to summarize: I think these disturbances can grow faster when the vertical static stability is lower - that is, when the laspe rate is higher. At the same time, higher lapse rates favor shorter-wavelength systems for maximum growth rates. Development is enhanced by greater horizontal temperature gradients and associated vertical wind shear. Although these disturbances could start out sufficiently small that linearized equations may describe them initially, they may eventually grow to the point that nonlinearities become important, and nonlinearities may be important to start with depending... so surface low pressure systems develop east of developing upper level troughs (assuming overall westerly average winds) and west of developing upper level ridges, and high pressure systems at the surface would develop east of upper level ridges and west of upper level troughs. There are also fronts. warm air heads poleward east of the low and rises, cold air west of the low heads equatorward and sinks. The configuration is such that (generally**) the low pressure system itself will tend to build poleward, eventually with the center attached to the warm air mass at the surface by an occluded front that underlies warmer air aloft. The high pressure will build equatorward. The pressure systems eventually lose some of their tilt, and thus their ability to strengthen vanishes. At this point, due to the sorting out of surface highs and lows, there is an overall westerly flow at lower levels in between them. If the north-south transport of heat by these systems was fast enough relative to the gradients in radiative and latent heating, vertical shear will have been reduced within the heart of the storm track, though it and the temperature gradient may actually have increased on the edges of the storm track as the warm fronts push into the cold air and the cold fronts push into the warm air. The overall effect of the disturbances may generally be to concentrate westerly momentum at upper levels into the storm track but also to transfer westerly momentum from upper levels to lower levels. Eddy potential energy and kinetic energy have both been produced from some of the available potential energy of the original horizontal thermal gradient, but also some has been produced from eddy-correlated latent heating and perhaps radiative heating (??) patterns, although radiative heating in the absence of cloud or humidity variations will tend to reduce eddy energy; some eddy kinetic energy is transferred back into the kinetic energy of an average across disturbances, and some of this kinetic energy is actually converted back into available potential energy by a thermally indirect circulation. I think this is because as the lows and highs 'sort out' and the warm air and cold air masses move past each other, the rising motion is shifted to the cold side of the storm track and the sinking motion is shifted to the warm side of the storm track. One way of quantifying this is with something called the EP flux, which is related to a potential vorticity flux. Factors, such as the horizontal shear of the average state, may affect the 'sorting' out process and the life cycles of the disturbances... Energy generated in the troposphere in these disturbances is spent in the lower stratosphere by lifting colder air and 'pulling' warmer air down. I'm not sure whether this energy is lost (radiatively ?) or is transferred back into the troposphere (to the extent the stratosphere acts like a trampoline). The thermal pattern produced in the lower stratosphere acts to reduce the strength of the disturbances at yet higher levels, thus they do not penetrate much above the lower stratosphere (though larger scale features do). Larger scale features (longer wavelength troughs and ridges) exist which do not grow in strength from baroclinic instability (although different waves can interact through nonlinearities), but rather propogate westward throw the air at all levels in the troposphere. These larger scale features may be excited by the wind's flow over topography and by some variations in temperature, and also by propogation around the globe of barotropic Rossby waves that are produced by convection over tropical sea-surface temperture anomalies, etc. These features affect the distribution/patterns of storm track activity. ------- So with global warming (in general, not generally specific to cause): The expected pattern in the Northern hemisphere (which would, I think, be expected in both hemispheres in the longest-term equilibrium states) is enhanced warming in the mid-to-upper troposphere in low-latitudes and, especially in the colder seasons, in the lower troposphere and surface at higher latitudes. This is because: At high latitudes, there is a strong albedo feedback, associated with reduced seasonal snow where there is some sunlight in winter, and summer sea-ice loss nearer the pole, which has a warming effect in winter by absorbing summer sun and taking longer to freeze while giving off more heat in the process during winter. The atmosphere is generally more stable at higher latitudes, especially in colder months, so the additional heat at lower levels may not be transfered to the rest of the troposphere by convection so much as it otherwise would. At low latitudes, there is a negative feedback over the ocean and moist surfaces (so long as they remain moist) as evaporation is faster at higher temperatures; the upper level heating is from the corresponding condensation of moisture. Some of that heat can be transported out of cloudy areas by circulation, of course. The changing lapse rate can be related to the temperature dependence of the moist adiabat. Thus the equator-to-pole temperature gradient, and thus the vertical wind shear at some point in between, is reduced at lower levels (except perhaps in summer or around that time of year) and increased at upper levels. These trends won't be distributed at both levels in the same way and won't be distributed evenly at all latitudes and longitudes, but starting with an even distribution assumption: 1. Due to the temperature gradient changes in the lower troposphere, one would expect reduced midlatitude storm track activity overall (except perhaps in or around summer, when it is not as great to start with, although mesoscale circulation (thunderstorms, squall lines, MCCs, etc.) do produce severe weather and intense precipitation events at that time, and severe thunderstorms are aided by vertical wind shear as well as moisture and moisture contrasts **). It might also perhaps allow for greater poleward-penetration of conditions that allow tropical cyclone development. HOWEVER: 2. Due to the temperature gradient trend at upper levels, one might expect greater midlatitude storm track activity (although this may be more sensitive to lower level thermal gradients and wind shear than upper level thermal gradients and wind shear), and also perhaps limit the regions that allow tropical cyclone development. 3. Interesting feedbacks: greater thermal gradients tend to enhance storm track activity which itself mixes the air on large scales which ultimately reduces the thermal gradient, so changes in storm track activity can be a negative feedback to changes in thermal gradients. If the reduced thermal gradient at lower levels reduces storm track activity, heat transport may be reduced at all levels, allowing the thermal gradient to increase at upper levels. If the increased thermal gradient at upper levels increases storm track activity, heat transport may be increased at all levels, reducing the thermal gradient at lower levels. Although of course the heat transport for a given circulation pattern will be greatest where the thermal gradient is greatest. (note that general circulation models, although not perfectly, will incorporate these effects, so the expected pattern of temperature change described before wouldn't necessarily be different because of storm track activity feedbacks). 4. Greater overall moisture in the atmosphere will also enhance storm track activity by adding to eddy available potential energy (and through that, to kinetic energy) by greater latent heating. *A2*. Since this affects essentially only precipitating systems, it's effect is asymmetrical between cyclones and anticyclones (as might also be the case with eddy-correlated cloud feedbacks). However, the more intense latent heating tends to be concentrated on smaller scales, so I'm not to what degrees it would enhance the synoptic-scale system, enhance mesoscale features, or change the character of the low pressure system, perhaps by making it more intense but more compact with more intense precipitation over a smaller area (?). Would there be more subtropical storms? PS more moisture overall in the air may also imply greater moisture transport across a given moisture gradient, and if temperature were rising equally everwhere, the moisture concentration gradients would increase - except of course, the temperature is not rising evenly everywhere. But temperature increases could increase the effect on regional and global circulation patterns of any given SST (Sea Surface Temperature) anomaly, such as that associated with ENSO (which itself may increase due to the delayed warming of upwelling cold water). Mesoscale humidity contrasts (drylines) are important in many severe thunderstorms, including tornadic storms. 5. IF the lapse rate were to remain constant, the greater latent heating would reduce the static stability effect on cyclones, which might then develop more rapidly, especially those with smaller horizontal sizes, but not on anticyclones. The greater latent heating itself may reduce the lapse rate, perhaps reducing but not eliminating the changes in cyclone development, while also slowing the development of anticyclones, especially smaller anticyclones. (If larger anticyclones are preferred ??, would that lead to larger airmasses, with reduced thermal gradients across some regions but enhanced thermal gradients around the edges of anticyclones, perhaps if wind is delivering air from longer distances without getting side-tracked, and hence over shorter times ??). 6. Note also that the overall expected temperature change pattern is such that vertical static stability is increasing at lower latitudes, but is decreasing at higher latitudes. This could concievably account in part for a tendency to shift the storm track activity poleward Notice this may mean a poleward expansion of subtropical dry regions into the midlatitudes as well as an increase in precipitation at higher latitudes on top of what might be expected from higher humidity alone. 7. Interesting feedbacks. When the overall thermal gradient is increased from a low value, the circulation due to synoptic scale eddies (includes storm track extratropical cyclones) increases. This includes vertical motion. Hence, there is greater vertical heat transport, which tends to increase vertical static stability, which slows the development of these baroclinic disturbances (baroclinic eddies; a.k.a. midlatitude storms and anticyclones), especially those of shorter wavelengths. In actual 'dishpan' experiments (a spinning pan filled with fluid and differentially heated and cooled), when the thermal gradient is very low, there is a Hadley cell; when it is increased, baroclinic disturbances form, when it is increased further, the wavelengths of the disturbances increase (as I recall), up to a point, until the wavelength of unstable disturbances is too large to fit into the pan, and so the Hadley cell resumes. However, there isn't an actual short wave cutoff in the atmosphere, although some simplified mathematical descriptions produce one - but it is true that the most unstable wavelength increases with increasing vertical stability. In the actual atmosphere one can also have small scale overturning as in cumulus clouds and thunderstorms. If the large scale overturning of either the Hadley cells or the extratropical circulations or both were reduced, one might expect that the vertical stability would decrease until and causing the smaller scale overturning to pick up the slack. 8. The coriolis effect is of course also very important. The coriolis effect varies with latitude, increasing away from zero at the equator. The variation of the coriolis effect over a north-south distance is called beta, and beta effects tend to cause disturbances, especially larger horizontal wavelength disturbances, to propogate westward relatively to the air flow; this produces a long-wave cutoff where some wavelengths are too large to develope by baroclinic instability. If the wavelengh, beta, and windspeed are right, a wave may remain nearly stationary - such quasistationary planetary waves can be excited by topography and variations in temperature, as mentioned before. I think beta also reduces the mechanism by which baroclinic disturbances grow through baroclinic instability, by contributing to convergence where there is divergence and vice-versa - at upper levels, anyway (maybe the opposite at lower levels, however - do the effects cancel?). Perhaps not as much if the overall flow is somewhat northward or southward over a whole wavelength of ridges and troughs...? - actually, this might turn out to be mathematically equivalent to some fraction of the other beta effect in the prior paragraph. Beta decreases away from the equator, to zero at the poles. So if the storm tracks move, the coriolis and beta effects will vary as applied to the storm track activity. Also, the tropopause is expected to rise. But the tropopause slopes downward toward higher latitudes. So it is unclear what happens to tropopause height at a moving storm track. A higher tropopause could affect storm track activity - for example, for a given wind shear, the total variation in wind would be greater across the troposphere. Perhaps the effect of topography would be slightly reduced at the upper levels ???? - And a given level of divergence in the air through the troposphere could increase the surface pressure fall if occuring through a greater thickness of air ????. And the relationship to the stratospheric circulations... the energy generated in the troposphere relative to that expendended in the stratosphere, that relationship would change.... More generally, deeper convection = more intense precipitation, and higher cloud tops increase the cloud's contribution to the greenhouse effect. 9. So the storm track activity changes. This changes the average wind patterns. That affects the way quasistationary planetary waves develope from topography and temperature variations, which again affects the wind and thus the storm tracks. Changes in SST affects how the SST anomalies (which themselves could change in frequency/intensity/location/etc.)affect all of the above (including but not limited to ENSO, PNA?). Etc. One way storm track activity can change is by changing the motion of storms - if storms move more slowly or are farther apart, for example, one could have greater risks of floods or droughts, and the opposite for the reverse; a greater portion of precipitation coming in intense events may lead to greater runoff; the frequency and locations of blocking events could change; blocking anticyclones are associated with dry spells and heat waves; I suppose they might lead to the opposite somewhere else since cyclones may be rerouted around such anticyclones...Etc. Changing winds, wind shear, and static stability, affect the distribution of gravity waves and whether and how they propogate vertically, which would affect transfer of momentum from the troposphere to the mesosphere; the vertical propogation of planetary waves into the stratosphere could also be affected and that is associated within 'Sudden Stratospheric Warmings', and stratospheric circulation can then affect the troposphere. Related: would NAM, SAM, NAO, and QBO be affectd? Etc. I might be wrong about some things - especially towards the end, some of that was speculation (where I was unsure I tried to indicate as much). But at least I hope to have given you a sense of how global warming can alter weather patterns.
129618. Quietman at 11:31 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick To save time and server space, I ask you to read the comments in "Arctic sea ice melt - natural or man-made?" as that is where I presented my hypothesis en todo. It technically should have been placed here, but I got angry and a little carried away when I got double teamed. But there were some good points made by all in my opinion.
129619. Quietman at 11:24 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick Keep in mind that while you and I can speak openly for or against the AGW concept. there are others who need to be politically correct or they will lose their jobs or grant money and therefore skirt the issue. Then there are those, like one poster at this site, that are environmental fanatics who look upon AGW as a bible thumper looks to the word of God. Hopefully we will get to the truth behind all this regardless of their attempts to "enlighten" us "deniers" (that is their demonization of skeptics vocabulary, not mine).
129620. Quietman at 11:18 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        They do not say if it is AGW either. In fact they do not say why at all (in that article). But top down melting would not produce the same results, nor would it be restricted to only northern Greenland where the crust is thin (they DO describe it as a "hot spot" in the other article and suggest that vulcanism is a "contributer" in an earlier article. I do think they are at last on track.
129621. Quietman at 11:12 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Ice albedo will remain until all the ice is gone. Soot in the top layers lower the albedo so fresh ice will have a higher albedo if we control the output of soot.
129622. Quietman at 11:09 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick But in fact the thinned crust is the northern end of Greenland (in the articles linked in this thread) and surrounding Arctic ocean and that is exactly where the largest glacial melt is AND IT IS FROM THE BOTTOM.
129623. Patrick 027 at 09:51 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        "My tectonic argument based on "the solar jerk" offers an explanation for this change while the IPCC argument does not." 1. But the 'IPCC argument' (also the argument of many others) may very well explain it... (more on that later) 2. How 'on earth' is the tectonic argument linked to the solar jerk? a. is it that tides, which may be correlated with solar jerk, are acting on either the geodynamo or tectonics or volcanism (all of which I strongly doubt (tidal variations weak, variations over relavent time periods weaker still), outside butterfly effects that take time and are not discernable as predictable links among individual causes and effects)? or b. that solar activity affects Earth's magnetic field, which of course does happen, BUT - I am very doubtful (with the same caveats as in a.) of any significant role of solar jerk or tides on the sun in changing solar activity, or of any significant link between changes in the outer core geodynamo and tectonics on the relavent timescales (mantle is very slow and reacts very slowly to changes in outer core convection), or of much effect, at least on the relavent timescales, that solar and space 'weather/climate' perturbations on Earth's magnetosphere and E-region dynamo could have on motions and magnetic field in the core, considering how much much much more massive the core is and how much more intense the field is in the core (yes, there is a lot of momentum and energy per unit mass in the magnetosphere, but still I expect much more total momentum and kinetic energy within the outer core), and also that, at least as far as I know, the strongest (relative?) perturbations of the magnetic field due to space weather occur at greater distances, where the field is even weaker still. ------------ Back to 1: Greenland article abstract (referenced in comment 66): the effect of meltwater is to lubricate the base of the glacier causing faster flow; sudden changes can occur as water flows. Effect may be limited. Nowhere does it state that the meltwater has increased due to geothermal heating - not that that's not a possibility but - without actual eruptions or sudden magma movement up through cracks, changes in geothermal heating must be slow - could it account for a significant change over only decades? How much heat would be necessary to account for the amount of water melting? Wouldn't there be some indication of volcanic activity (from a pattern of earthquakes (discernable from icequakes or quakes due to changing ice mass and isostatic adjustments??); sulfur concentration in meltwater outflow????)... I think this phenomenon of basal lubrication of the ice is not limited to the area where a underlying hotspot is thought to be. --- Arctic sea ice loss article: "Rising Arctic Storm Activity Sways Sea Ice, Climate ScienceDaily (Oct. 6, 2008)" http://www.sciencedaily.com/releases/2008/10/081006180815.htm What I got from that is: There was an expectation from climate theory ("derived from model results") that a warmer climate would lead to a northward shift in storm tracks and increased storminess in the arctic. This expectation has been verified from the observations. Observations also indicated that the changing circulation patterns have affected, through wind, the Arctic Ocean circulation, via movement of sea ice. Transport of sea ice: "The team found that the pace of sea ice movement along the Arctic Ocean's Transpolar Drift Stream from Siberia to the Atlantic Ocean accelerated in both summer and winter during the 55-year period." "Progressively stronger storms over the Transpolar Drift Stream forced sea ice to drift increasingly faster in a matter of hours after the onset of storms." (I'm not sure how similar this flow pattern is to the flow of ice associated with the 2007 circulation anomaly that pushed warmer air into Siberia - in that case, however, the atmospheric circulation pattern was not unprecedented, but resulted in record minimum ice because it was acting on top of an overall warmer atmosphere and thinner sea ice, etc. - because of ongoing global warming. There will be highs and lows; on top of an upward trends the highs and lows with both be higher, except potentially for the trend's effect on the shorter term variability itself.) Ocean mixing: "The moving sea ice forces the ocean to move which sets off significantly more mixing of the upper layers of the ocean than would occur without the "push" from the ice. The increased mixing of the ocean layer forces a greater degree of ocean convection, and instability that offers negative feedback to climate warming." That last part is potentially great! - that more CO2 might go into the oceans - BUT it is also potentially worrisome - will it speed up ice loss? Will it make it harder for new ice to form each winter as the fresher meltwater is mixed into the saltier water? - and of course because of the ice albedo feedback?
129624. Quietman at 05:14 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick In other words it would appear that the arctic is subject to some very unusual weather causing much of the problem for the past half century. The question now becomes, what caused the change in pattern. My tectonic argument based on "the solar jerk" offers an explanation for this change while the IPCC argument does not.
129625. Quietman at 05:08 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        correction: comment 257 (not 267).
129626. Quietman at 05:07 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        PS I posted a link in comment 267 in Arctic sea ice melt - natural or man-made? which is also applicable as a response.
129627. Quietman at 05:03 AM on 13 October 2008
        Climate sensitivity is low
        PPS I have a link posted here to Spencer's argument in comment 9.
129628. Quietman at 04:58 AM on 13 October 2008
        Volcanoes emit more CO2 than humans
        Patrick In the Greenland thread I have added an abstract that is applicable in answer.
129629. Quietman at 04:52 AM on 13 October 2008
        Climate sensitivity is low
        PS You apparently confuse ocean tides with tectonic tides.
129630. Quietman at 04:50 AM on 13 October 2008
        Climate sensitivity is low
        Patrick 1: His idea that CO2 sensitivity is low. 2.A: The concept that the solar wind does not have an effect on climate is wrong. 3: Tectonics
129631. Quietman at 04:44 AM on 13 October 2008
        Can animals and plants adapt to global warming?
        Mizimi Well, that paper *and any other paper, is an argument. The authors interpretation of his/her research, and as such is hypothetical. But I did find it interesting and as it relates to our prior discussions, thought you might find it of interest.
129632. Mizimi at 07:42 AM on 12 October 2008
        Can animals and plants adapt to global warming?
        QM: #59...thanks, very interesting. I have always regarded paleo-data as indicative of trends rather than absolutes because there seemed to be too many other factors that could influence the results that cannot be 'pinned down' with any exactitude. Now it seems the basis for one proxy is suspect; how many others might also be compromised?
129633. Patrick 027 at 04:53 AM on 12 October 2008
        Volcanoes emit more CO2 than humans
        Interesting article. Is meltwater perculating up from below to heat the ice? Geothermal heating would melt the bottom first; even with infinite thermal conductivity, the melting point of ice is lower at higher pressure. Depending on the thickness of the ice at that location, it might take considerable time for a change in heating to propogate upward. I think a majority is from AGW.
129634. Patrick 027 at 03:58 AM on 12 October 2008
        Climate sensitivity is low
        But 1. which of Spencer's arguments do you agree with? 2. -A. if the climate sensitivity is low than how does one explain the recent changes being caused by the minor changes in solar forcing or likely small forcing of changes in geomagnetism (?) or likely very very small forcing if any of submarine volcanic activity (volcanic aerosols already having been accounted for by IPCC etc.)? OR -B. what values do you expect when quantifying changes in non-TSI (and non-UV/TSI, as I expect that the UV enhancement associated with TSI is already accounted for (?)) solar forcing, geomagnetic forcing, tidal forcing, etc, in terms of radiative forcing or some equivalent or direct 'temperature' forcing by circulation changes in the ocean? For example, that article you referenced some time ago back in Science and Society regarding effects on transmissivity in clear air due to heliospheric current sheet crossing or 'Forbush' - whatever those things were (PS could you explain that to me?).
129635. chris at 23:42 PM on 11 October 2008
        CO2 measurements are suspect
        Re #3: Sure, the atmosphere is a relatively well-mixed medium. The specific point of interest is the locational variability of atmospheric CO2 levels. It only requires a brief perusal of the CO2 data from different sites around the world to show that CO2 mixes relatively quickly on an annual basis, even if there are very clear hemispheric differences in CO2 production and sequestration and so on. The relatively well-mixed nature of the atmosphere with respect to CO2 can be seen by observing the similarity in atmospheric CO2 levels at Manua Loa or averaged over the marine surface. i.e. compare the two data sets here: http://www.esrl.noaa.gov/gmd/ccgg/trends/ or look at an entirely seperate data set. For example the atmospheric CO2 measure at the South Pole: http://cdiac.ornl.gov/trends/co2/csiro/CSIROCO2SOUTHPOLE.JPG These differ by very small amounts (less than 1%) Your link is highlighting something quite different. This is a temporary "equator" that exists only during the monsoon season and that temporarily stops atmospheric mixing with respect to atmospheric pollutants. However if one considers the distribution of the atmosphere on an annually averaged basis as one does when considering atmospheric CO2 levels then the atmospheric is relatively well-mixed. That's not to say that macroscopic/particulate pollutants may not be concentrated over either their production sources or follow wind patterns. Nothern hemisphere skies are more polluted than Southern hemisphere skies on average. Thus brown clouds and other sulphurous aerosolic clouds may not disperse and mix so quickly. But if one considers the point of interest for this thread, namely the mixing of atmospheric CO2 with respect to obtaining valid atmospheric CO2 measures for monitoring short and long term changes, the atmosphere is a relatively well-mixed medium. The proof is in the pudding!
129636. Mizimi at 20:15 PM on 11 October 2008
        Can animals and plants adapt to global warming?
        "We take sequential steps towards switching our energy supplies towards the sustainable supplies that are clearly the only possible future of mankind." Totally agree: As I stated in another thread it is imperative we shift away from fossil fuels (and long term nuclear power) NOT because it will reduce CO2 emissions but because these fuels are finite. So we agree on that. That it also has the added effect of reducing CO2 emissions is a bonus (maybe).
129637. Quietman at 14:21 PM on 11 October 2008
        Climate sensitivity is low
        Patrick My argument is that the sensitivity is low (always has been) ie. I agree with Spencer. My agrument is for the earth itself combined with the sun are the primary drivers and while I do not actually argue against the Green House Effect, I feel that it is overstated. That the problem 1975-2007 was caused by high solar activity and vulcanism/tectonic activity. I have posted the most current articles in the volcano thread, the greenland glaciers thread and an abstract in the "Arctic sea ice melt - natural or man-made?" thread.
129638. Quietman at 10:50 AM on 11 October 2008
        CO2 measurements are suspect
        Re: "relatively well-mixed medium" SEE Earth's Air Divided by Chemical Equator By Andrea Thompson, Senior Writer posted: 30 September 2008 06:53 am ET
129639. Patrick 027 at 10:49 AM on 11 October 2008
        Climate sensitivity is low
        (refering again to your comment, 8, above) The part you would want to argue against starts on p. 3: "Attribution of Observed Changes Although confidence is high both that human activities have caused a positive radiative forcing and that the climate has actually changed, can we confidently link the two? This is the question of attribution: Are human activities primarily responsible for observed climate changes, or is it possible they result from some other cause, such as some natural forcing or simply spontaneous variability within the climate system?"
129640. chris at 10:48 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Re #58 that's excellent Quietman. One should always strive for truthful exposition... ..and the greenhouse effect really isn't difficult to comprehend..
129641. Patrick 027 at 10:42 AM on 11 October 2008
        Climate sensitivity is low
        Back to basics: Remind me again what it is that makes you doubtful of AGW? Because it occurs to me we're on the climate sensitivity thread now, and your position is not the climate is more stable but that it it is more stable specifically to greenhouse forcing and not to some various other factors... --- "Articles and Papers are much more appreciated as links (less opinion and more facts)" - understandable, but in matters of science (and some other things), good opinion writing includes reasoning and facts, and/or references to facts and reasoning. --- From comment 8 above: Your argument must be against the title of that section, "Drivers of Climate Change". Because climate sensitivity has nothing to do with how sure we are that it is human activity that is responsible for the recent changes in those things.
129642. chris at 10:38 AM on 11 October 2008
        Is Antarctic ice melting or growing?
        abstracts for articles cited in post #13: Sabine, CL et al. (2004) "The oceanic sink for anthropogenic CO2" Science 305, 367-371. "Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for similar to48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential." Feely, RA et al (2004) "Impact of anthropogenic CO2 on the CaCO3 system in the oceans" Science 305, 362-366. "Rising atmospheric carbon dioxide (CO2) concentrations over the past two centuries have led to greater CO2 uptake by the oceans. This acidification process has changed the saturation state of the oceans with respect to calcium carbonate (CaCO3) particles. Here we estimate the in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data, and we also discuss the future impacts of anthropogenic CO2 on CaCO3 shell forming species. CaCO3 dissolution rates, ranging from 0.003 to 1.2 micromoles per kilogram per year, are observed beginning near the aragonite saturation horizon. The total water column CaCO3 dissolution rate for the global oceans is approximately 0.5 +/- 0.2 petagrams of CaCO3-C per year, which is approximately 45 to 65% of the export production of CaCO3." Le Quere C et al (2007) "Saturation of the Southern Ocean CO2 sink due to recent climate change" 316, 1735-1738. :"Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale." Schuster U et al (2007) “A variable and decreasing sink for atmospheric CO2 in the North Atlantic” J. Geophys. Res. Oceans 112, art # C11006 “A time series of observations from merchant ships between the U. K. and the Caribbean is used to establish the variability of sea surface pCO(2) and air-to-sea flux from the mid-1990s to early 2000s. We show that the sink for atmospheric CO2 exhibits important interannual variability, which is in phase across large regions from year to year. Additionally, there has been an interdecadal decline, evident throughout the study region but especially significant in the northeast of the area covered, with the sink reducing > 50% from the mid-1990s to the period 2002-2005. A review of available observations suggests a large region of decrease covering much of the North Atlantic but excluding the western subtropical areas. We estimate that the uptake of the region between 20 degrees N and 65 degrees N declined by similar to 0.24 Pg C a(-1) from 1994/1995 to 2002-2005. Declining rates of wintertime mixing and ventilation between surface and subsurface waters due to increasing stratification, linked to variation in the North Atlantic Oscillation, are suggested as the main cause of the change. These are exacerbated by a contribution from the changing buffer capacity of the ocean water, as the carbon content of surface waters increases.” Nemani RR et al. (1999) “Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999” Science 300, 1560-1563. “Recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes. However, a comprehensive analysis of the impact of global climatic changes on vegetation productivity has not before been expressed in the context of variable limiting factors to plant growth. We present a global investigation of vegetation responses to climatic changes by analyzing 18 years (1982 to 1999) of both climatic data and satellite observations of vegetation activity. Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally. The largest increase was in tropical ecosystems. Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation.” Beedlow PA et al. (2004) “Rising atmospheric CO2 and carbon sequestration in forests” Fronteriers Ecol. Environ., 315-322. “Rising CO2 concentrations in the atmosphere could alter Earth's climate system, but it is thought that higher concentrations may improve plant growth through a process known as the "fertilization effect". Forests are an important part of the planet's carbon cycle, and sequester a substantial amount of the CO2 released into the atmosphere by human activities. Many people believe that the amount of carbon sequestered by forests will increase as CO2 concentrations rise. However, an increasing body of 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. It is imperative, therefore, that we manage forests to maximize carbon retention in above- and belowground biomass and conserve soil carbon.” Fung IY et al. (2005) “Evolution of carbon sinks in a changing climate” Proc. Natl. Acad. Sci. USA 102, 11201-11206. “Climate change is expected to influence the capacities of the land and oceans to act as repositories for anthropogenic CO2 and hence provide a feedback to climate change. A series of experiments with the National Center for Atmospheric Research-Climate System Model 1 coupled carbon-climate model shows that carbon sink strengths vary with the rate of fossil fuel emissions, so that carbon storage capacities of the land and oceans decrease and climate warming accelerates with faster CO2 emissions. Furthermore, there is a positive feedback between the carbon and climate systems, so that climate warming acts to increase the airborne fraction of anthropogenic CO2 and amplify the climate change itself. Globally, the amplification is small at the end of the 21st century in this model because of its low transient climate response and the near-cancellation between large regional changes in the hydrologic and ecosystem responses. Analysis of our results in the context of comparable models suggests that destabilization of the tropical land sink is qualitatively robust, although its degree is uncertain.” Field CB et al. (2007) “Feedbacks of terrestrial ecosystems to climate change“ Anu. Rev. Environment. Res. 32 , 1-29. “Most modeling studies on terrestrial feedbacks to warming over the twenty-first century imply that the net feedbacks are negative-that changes in ecosystems, on the whole, resistwarming, largely through ecosystem carbon storage. Although it is clear that potentially important mechanisms can lead to carbon storage, a number of less well-understood mechanisms, several of which are rarely or incompletely modeled, tend to diminish the negative feedbacks or lead to positive feedbacks. At high latitudes, negative feedbacks from forest expansion are likely to be largely or completely compensated by positive feedbacks from decreased albedo, increased carbon emissions from thawed permafrost, and increased wildfire. At low latitudes, negative feedbacks to warming will be decreased or eliminated, largely through direct human impacts. With modest warming, net feedbacks of terrestrial ecosystems to warming are likely to be negative in the tropics and positive at high latitudes. Larger amounts of warming will generally push the feedbacks toward the positive.” Kurz WA et al. (2008) “Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances?” Phil. Trans. Roy. Soc. B., 363, 2261. “To understand how boreal forest carbon (C) dynamics might respond to anticipated climatic changes, we must consider two important processes. First, projected climatic changes are expected to increase the frequency of fire and other natural disturbances that would change the forest age-class structure and reduce forest C stocks at the landscape level. Second, global change may result in increased net primary production (NPP). Could higher NPP offset anticipated C losses resulting from increased disturbances? We used the Carbon Budget Model of the Canadian Forest Sector to simulate rate changes in disturbance, growth and decomposition on a hypothetical boreal forest landscape and to explore the impacts of these changes on landscape-level forest C budgets. We found that significant increases in net ecosystem production (NEP) would be required to balance C losses from increased natural disturbance rates. Moreover, increases in NEP would have to be sustained over several decades and be widespread across the landscape. Increased NEP can only be realized when NPP is enhanced relative to heterotrophic respiration. This study indicates that boreal forest C stocks may decline as a result of climate change because it would be difficult for enhanced growth to offset C losses resulting from anticipated increases in disturbances.” Zhang XB (2007) "Detection of human influence on twentieth-century precipitation trends" Nature 448, 461-465. "Human influence on climate has been detected in surface air temperature(1-5), sea level pressure(6), free atmospheric temperature(7), tropopause height(8) and ocean heat content(9). Human-induced changes have not, however, previously been detected in precipitation at the global scale(10-12), partly because changes in precipitation in different regions cancel each other out and thereby reduce the strength of the global average signal(13-19). Models suggest that anthropogenic forcing should have caused a small increase in global mean precipitation and a latitudinal redistribution of precipitation, increasing precipitation at high latitudes, decreasing precipitation at sub-tropical latitudes(15,18,19), and possibly changing the distribution of precipitation within the tropics by shifting the position of the Intertropical Convergence Zone(20). Here we compare observed changes in land precipitation during the twentieth century averaged over latitudinal bands with changes simulated by fourteen climate models. We show that anthropogenic forcing has had a detectable influence on observed changes in average precipitation within latitudinal bands, and that these changes cannot be explained by internal climate variability or natural forcing. We estimate that anthropogenic forcing contributed significantly to observed increases in precipitation in the Northern Hemisphere mid-latitudes, drying in the Northern Hemisphere subtropics and tropics, and moistening in the Southern Hemisphere subtropics and deep tropics. The observed changes, which are larger than estimated from model simulations, may have already had significant effects on ecosystems, agriculture and human health in regions that are sensitive to changes in precipitation, such as the Sahel." Malhi Y et al. (2008) “Climate change, deforestation, and the fate of the Amazon” Science 319, 179-182. “The forest biome of Amazonia is one of Earth's greatest biological treasures and a major component of the Earth system. This century, it faces the dual threats of deforestation and stress from climate change. Here, we summarize some of the latest findings and thinking on these threats, explore the consequences for the forest ecosystem and its human residents, and outline options for the future of Amazonia. We also discuss the implications of new proposals to finance preservation of Amazonian forests.” Feeley KJ et al. (2007) “Decelerating growth in tropical forest trees” Ecology letters 10, 461-469. “The impacts of global change on tropical forests remain poorly understood. We examined changes in tree growth rates over the past two decades for all species occurring in large (50-ha) forest dynamics plots in Panama and Malaysia. Stem growth rates declined significantly at both forests regardless of initial size or organizational level (species, community or stand). Decreasing growth rates were widespread, occurring in 24-71% of species at Barro Colorado Island, Panama (BCI) and in 58-95% of species at Pasoh, Malaysia (depending on the sizes of stems included). Changes in growth were not consistently associated with initial growth rate, adult stature, or wood density. Changes in growth were significantly associated with regional climate changes: at both sites growth was negatively correlated with annual mean daily minimum temperatures, and at BCI growth was positively correlated with annual precipitation and number of rainfree days (a measure of relative insolation). While the underlying cause(s) of decelerating growth is still unresolved, these patterns strongly contradict the hypothesized pantropical increase in tree growth rates caused by carbon fertilization. Decelerating tree growth will have important economic and environmental implications.” Kurz WA et al. (2008) “Mountain pine beetle and forest carbon feedback to climate change “ Nature 452, 987-990. “The mountain pine beetle ( Dendroctonus ponderosae Hopkins, Coleoptera: Curculionidae, Scolytinae) is a native insect of the pine forests of western North America, and its populations periodically erupt into large- scale outbreaks(1-3). During outbreaks, the resulting widespread tree mortality reduces forest carbon uptake and increases future emissions from the decay of killed trees. The impacts of insects on forest carbon dynamics, however, are generally ignored in large- scale modelling analyses. The current outbreak in British Columbia, Canada, is an order of magnitude larger in area and severity than all previous recorded outbreaks(4). Here we estimate that the cumulative impact of the beetle outbreak in the affected region during 2000 - 2020 will be 270 megatonnes ( Mt) carbon ( or 36 g carbon m(-2) yr(-1) on average over 374,000 km 2 of forest). This impact converted the forest from a small net carbon sink to a large net carbon source both during and immediately after the outbreak. In the worst year, the impacts resulting from the beetle outbreak in British Columbia were equivalent to similar to 75% of the average annual direct forest fire emissions from all of Canada during 1959 - 1999. The resulting reduction in net primary production was of similar magnitude to increases observed during the 1980s and 1990s as a result of global change(5). Climate change has contributed to the unprecedented extent and severity of this outbreak(6). Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large- scale modelling analyses.” Piao S (et al) (2008) “Net carbon dioxide losses of northern ecosystems in response to autumn warming” Nature 451, 49-52. “The carbon balance of terrestrial ecosystems is particularly sensitive to climatic changes in autumn and spring1, 2, 3, 4, with spring and autumn temperatures over northern latitudes having risen by about 1.1 °C and 0.8 °C, respectively, over the past two decades5. A simultaneous greening trend has also been observed, characterized by a longer growing season and greater photosynthetic activity6, 7. These observations have led to speculation that spring and autumn warming could enhance carbon sequestration and extend the period of net carbon uptake in the future8. Here we analyse interannual variations in atmospheric carbon dioxide concentration data and ecosystem carbon dioxide fluxes. We find that atmospheric records from the past 20 years show a trend towards an earlier autumn-to-winter carbon dioxide build-up, suggesting a shorter net carbon uptake period. This trend cannot be explained by changes in atmospheric transport alone and, together with the ecosystem flux data, suggest increasing carbon losses in autumn. We use a process-based terrestrial biosphere model and satellite vegetation greenness index observations to investigate further the observed seasonal response of northern ecosystems to autumnal warming. We find that both photosynthesis and respiration increase during autumn warming, but the increase in respiration is greater. In contrast, warming increases photosynthesis more than respiration in spring. Our simulations and observations indicate that northern terrestrial ecosystems may currently lose carbon dioxide in response to autumn warming, with a sensitivity of about 0.2 PgC °C-1, offsetting 90% of the increased carbon dioxide uptake during spring. If future autumn warming occurs at a faster rate than in spring, the ability of northern ecosystems to sequester carbon may be diminished earlier than previously suggested9, 10.” Ciais P et al. (2005) Europe-wide reduction in primary productivity caused by the heat and drought in 2003” Nature 437, 529-533. “Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration(1,2). But although severe regional heatwaves may become more frequent in a changing climate(3,4), their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country- level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model(5) to assess continental- scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide ( 0.5 Pg Cyr(-1)) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration(6). Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon- climate feedbacks already anticipated in the tropics and at high latitudes(1,2).” Lotsch A et al. (2005) “Response of terrestrial ecosystems to recent Northern Hemispheric drought” Geophys. Res. Lett. : 32, art #L06705. “Satellite normalized difference vegetation index (NDVI) observations reveal large and geographically extensive decreases in vegetation activity in Eurasia and North America between 1999 and 2002. In 2001, 73% of central southwest Asia exhibited NDVI anomalies that were more than one standard deviation below 21-year average conditions, and in 2002, fully 95% of North America exhibited below-average NDVI. This episode of large-scale vegetation browning coincided with a prolonged period of below-normal precipitation in the Northern Hemisphere, which limited moisture availability for plant growth. Spatio-temporal dynamics of NDVI, precipitation, and sea surface temperature data reveal that synchronous patterns of ocean circulation anomalies in the Pacific, Atlantic, and Indo-Pacific are strongly correlated with observed joint variability in NDVI and precipitation in the Northern Hemisphere during this period.” Olsson L (2005) “A recent greening of the Sahel — trends, patterns and potential causes” J. of Arid Environ. 63, 556–566. "For the last four decades there has been sustained scientific interest in contemporary environmental change in the Sahel (the southern fringe of the Sahara). It suffered several devastating droughts and famines between the late 1960s and early 1990s. Speculation about the climatology of these droughts is unresolved, as is speculation about the effects of land clearance on rainfall and about land degradation in this zone. However, recent findings suggest a consistent trend of increasing vegetation greenness in much of the region. Increasing rainfall over the last few years is certainly one reason, but does not fully explain the change. Other factors, such as land use change and migration, may also contribute. This study investigates the nature of a secular vegetation trend across the Sahel and discusses several potential causative factors."
129643. Quietman at 10:30 AM on 11 October 2008
        Arctic sea ice melt - natural or man-made?
        Rising Arctic Storm Activity Sways Sea Ice, Climate ScienceDaily (Oct. 6, 2008) — A new NASA study shows that the rising frequency and intensity of arctic storms over the last half century, attributed to progressively warmer waters, directly provoked acceleration of the rate of arctic sea ice drift, long considered by scientists as a bellwether of climate change.
129644. Quietman at 10:27 AM on 11 October 2008
        Volcanoes emit more CO2 than humans
        Satellite Data Reveals Extreme Summer Snowmelt In Northern Greenland ScienceDaily (Oct. 10, 2008) — The northern part of the Greenland ice sheet experienced extreme snowmelt during the summer of 2008, with large portions of the area subject to record melting days, according to Dr. Marco Tedesco, Assistant Professor of Earth & Atmospheric Sciences at The City College of New York (CCNY), and colleagues.
129645. Patrick 027 at 10:26 AM on 11 October 2008
        Climate sensitivity is low
        

        More on radiation transfer within and through the atmosphere: Regional Climate Projections (25,26*,55**,56**,57**,58**,83***,85***,104,110****,111,146,191) asterisks pertain more to visualizing greenhouse effect physics  (171-173,174*,175,176*,180~,181~,184*****,189****,192***,193,194,203,214,215,218 (*** near bottom),232**,235,238,245,246) Real Climate (105**,144**,168 (LTE) ,170** (and LTE),172 (mainly LTE),192**,229**,241**(ext),251***(BB),252***(BB),261**(ext),274*,275*,285*,289) LTE = local thermodynamic equilibrium BB = fundamentals of blackbody radiation and radiative physics ext = what happens in extreme scenarios

        Moderator Response:

        [RH] Fixed links that were breaking page formatting.

129646. chris at 10:24 AM on 11 October 2008
        Is Antarctic ice melting or growing?
        DB2 I suspect that we might agree that there are two essential considerations with respect to enhanced CO2 concentrations (and its consequences) on plant growth: 1. The ability of the terrestrial environment to sequester CO2 in a world with rapidly growing atmospheric CO2 concentrations. Will enhanced plant growth and thus carbon sequestration protect us significantly against rising atmospheric CO2 and its consequences? 2. The effect of raised atmospheric CO2 levels on agricultural production. This is really an entirely separate consideration compared to (#1). In my understanding the prognosis is negative in each of these. Here’s what the science seems to say (I’ve put all the citations at the bottom of the post and dumped the abstracts in a separate post below where it’s eminently ignorable!): 1. The terrestrial environment is not going to help us out with respect to significant carbon sequestration. It will do to a small extent for a while but this is more likely to lead us towards a false sense of optimism, and any small initial benefits are unsustainable. Here’s why: The terrestrial environment absorbs a very small amount of our CO2 emissions. Something around 10%. Around 40-50% of our emissions are currently absorbed by the oceans [1,2]. If we’re interested in mitigating the effects of raised atmospheric CO2 levels by sequestration from the atmosphere, it’s to the oceans we should look. Unfortunately it’s expected that the abilitiy of the oceans to sequester atmospheric CO2 will reduce. This may already to be happening [3,4]. 2. Whatever we might think, hope or surmise about the possibility of enhanced sequestration of carbon, the real world observations aren’t encouraging. Whether or not the terrestrial environment has shown enhanced overall carbon sequestration in recent decades ([5]; i.e. the Nemani paper that you cited in your post #8, for example; and there is good evidence that the Amazon has experienced a net increase in productivity over the last couple of decades, as has parts of China and India), this has obviously not had much of an effect on the rapidly increasing concentrations of atmospheric CO2, as direct inspection of the atmospheric Co2 record makes clear. 3. Any enhanced sequestration of carbon into the terrestrial environment is unlikely to be sustainable [6,7,8,9]. Firstly, because there is only so much room for plant growth, and so much potential for carbon sequestration unless we embark on an enormous reforestation programme (an excellent idea btw...at least we should be protecting our forests!). Secondly, because as the earth continues to warm, and the water-restricted regions extend from the central latitudes, more and more of the terrestrial environment will find itself in the water-limited regions. At present the increased drought that results from the warming of the last several decades is restricted to the region from around 0 -30 o North [10]. Apart from the extreme Northern regions where drying has started [11], the Amazon has seen either no drying or enhanced precipitation [11]. The expectation is that this so-far acceptable situation will not continue in a warming world…the Amazon is threatened with a continued shift in the drying zone southwards as warming continues. 4. The effects of warming are already apparent, and it doesn’t take a lot of warming to turn net carbon sinks into net carbon sources. If one moves out of the Amazon below the drying zone, and moves a bit northwards into the drying zone one observes loss of primary production in rainforests in Central America and Malaysia [12], the loss of primary production in Canadian forests under the combined/linked influence of warming and infestation [13], observations already of a trend towards net carbon loss in Northern ecosystems [14], and large decreases in N. hemisphere primary productivity in response to periods of anomalous heat (which in the future are likely to become increasingly less anomalous) [15,16]. While regions of China and India have seen enhanced plant growth in recent decades, this is unlikely to be sustainable into the future. 5. The effects on agricultural production are rather as I indicated in my post above. In addition to the papers I cited, the expectation is that agricultural production will decrease in a warming world without enormous efforts and costs to maintain this. Costs are unlikely to be affordable by many especially in the large belt of the world in the drying region encompassing the latitude belt from around 0o to 30 oN. The paper that you cited on the Sahel [17] is not as encouraging as one might think. As the authors indicate, some of the enhanced growth is due to enhanced precipitation in recent years; however much of it is unexplained, and as far as food production is concerned only two countries in the region have seen enhanced production (Burkino Faso and Mali). The authors consider that some of the greening might be due to war and the migration away from rural areas. If enhanced greening is the result of the recolonisation of neglected agricultural land by vegetation that’s not particularly positive with respect to the prospects for agricultural production. As the authors state “The vast belt of significantly increasing vegetation across the central Sudan corresponds to a large extent to provinces with large numbers of internally displaced people”. [1] Sabine, CL et al. (2004) "The oceanic sink for anthropogenic CO2" Science 305, 367-371. [2] Feely, RA et al (2004) "Impact of anthropogenic CO2 on the CaCO3 system in the oceans" Science 305, 362-366. [3] Le Quere C et al (2007) "Saturation of the Southern Ocean CO2 sink due to recent climate change" 316, 1735-1738. [4] Schuster U et al (2007) “A variable and decreasing sink for atmospheric CO2 in the North Atlantic” J. Geophys. Res. Oceans 112, art # C11006 [5] Nemani RR et al. (1999) “Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999” Science 300, 1560-1563. [6] Beedlow PA et al. (2004) “Rising atmospheric CO2 and carbon sequestration in forests” Fronteriers Ecol. Environ., 315-322. [7] Fung IY et al. (2005) “Evolution of carbon sinks in a changing climate” Proc. Natl. Acad. Sci. USA 102, 11201-11206. [8] Field CB et al. (2007) “Feedbacks of terrestrial ecosystems to climate change“ Annu. Rev. Environment. Res. 32 , 1-29. [9] Kurz WA et al. (2008) “Could increased boreal forest ecosystem productivity offset carbon losses from increased disturbances?” Phil. Trans. Roy. Soc. B., 363, 2261. [10] Zhang XB (2007) "Detection of human influence on twentieth-century precipitation trends" Nature 448, 461-465. [11] Malhi Y et al. (2008) “Climate change, deforestation, and the fate of the Amazon” Science 319, 179-182. [12] Feeley KJ et al. (2007) “Decelerating growth in tropical forest trees” Ecology letters 10, 461-469. [13] Kurz WA et al. (2008) “Mountain pine beetle and forest carbon feedback to climate change “ Nature 452, 987-990. [14] Piao S (et al) (2008) “Net carbon dioxide losses of northern ecosystems in response to autumn warming” Nature 451, 49-52. [15] Ciais P et al. (2005) Europe-wide reduction in primary productivity caused by the heat and drought in 2003” Nature 437, 529-533. [16] Lotsch A et al. (2005) “Response of terrestrial ecosystems to recent Northern Hemispheric drought” Geophys. Res. Lett. : 32, art #L06705. [17] Olsson L (2005) “A recent greening of the Sahel — trends, patterns and potential causes” J. of Arid Environ. 63, 556–566.
129647. Quietman at 10:17 AM on 11 October 2008
        Models are unreliable
        New Study Increases Concerns About Climate Model Reliability ScienceDaily (Dec. 12, 2007) — A new study comparing the composite output of 22 leading global climate models with actual climate data finds that the models do an unsatisfactory job of mimicking climate change in key portions of the atmosphere.
129648. Quietman at 10:10 AM on 11 October 2008
        Greenland is gaining ice
        However: Science 4 July 2008: Vol. 321. no. 5885, pp. 111 - 113 DOI: 10.1126/science.1158540 Reports Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet R. S. W. van de Wal,* W. Boot, M. R. van den Broeke, C. J. P. P. Smeets, C. H. Reijmer, J. J. A. Donker, J. Oerlemans Continuous Global Positioning System observations reveal rapid and large ice velocity fluctuations in the western ablation zone of the Greenland Ice Sheet. Within days, ice velocity reacts to increased meltwater production and increases by a factor of 4. Such a response is much stronger and much faster than previously reported. Over a longer period of 17 years, annual ice velocities have decreased slightly, which suggests that the englacial hydraulic system adjusts constantly to the variable meltwater input, which results in a more or less constant ice flux over the years. The positive-feedback mechanism between melt rate and ice velocity appears to be a seasonal process that may have only a limited effect on the response of the ice sheet to climate warming over the next decades. Institute for Marine and Atmospheric research Utrecht, Utrecht University, Netherlands.
129649. Quietman at 10:01 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        Mizimi Jast an FYI: Global synchronous changes in the carbon isotopic composition of carbonate sediments unrelated to changes in the global carbon cycle Peter K. Swart Department of Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 Edited by John M. Hayes, Woods Hole Oceanographic Institution, Woods Hole, MA, and approved July 24, 2008 (received for review April 15, 2008) Abstract The carbon isotopic (δ13C) composition of bulk carbonate sediments deposited off the margins of four carbonate platforms/ramp systems (Bahamas, Maldives, Queensland Plateau, and Great Australian Bight) show synchronous changes over the past 0 to 10 million years. However, these variations are different from the established global pattern in the δ13C measured in the open oceans over the same time period. For example, from 10 Ma to the present, the δ13C of open oceanic carbonate has decreased, whereas platform margin sediments analyzed here show an increase. It is suggested that the δ13C patterns in the marginal platform deposits are produced through admixing of aragonite-rich sediments, which have relatively positive δ13C values, with pelagic materials, which have lower δ13C values. As the more isotopically positive shallow-water carbonate sediments are only produced when the platforms are flooded, there is a connection between changes in global sea level and the δ13C of sediments in marginal settings. These data indicate that globally synchronous changes in δ13C can take place that are completely unrelated to variations in the global carbon cycle. Fluctuations in the δ13C of carbonate sediments measured during previous geological periods may also be subject to similar processes, and global synchroniety of δ13C can no longer necessarily be considered an indicator that such changes are related to, or caused by, variations in the burial of organic carbon. Inferences regarding the interpretation of changes in the cycling of organic carbon derived from δ13C records should be reconsidered in light of the findings presented here.
129650. Quietman at 09:42 AM on 11 October 2008
        Can animals and plants adapt to global warming?
        chris Of course, how could I have been so stupid as not to see the light. Amen.

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