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HumanityRules at 22:18 PM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
9.Dappledwater There is a new paper in JGL-Oceans (presently it's flagged as the most popular download) which uses a new method for calculating 20th SLR. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115, C08013, 15 PP., 2010 doi:10.1029/2009JC005630 Reconstruction of regional mean sea level anomalies from tide gauges using neural networks Manfred Wenzel and Jens Schröter While they find similar 20th C SLR to other papers, such as Church & White 2006 they do not see any late 20th C acceleration. They explain this as follows "This is obviously due to the missing depression in sea level prior to 1950 that is the main difference of our result to CW06" I can't comment on the neural network method used in their calculations but it does suggest there is still more to learn about this particular metric. -
Rob Painting at 22:16 PM on 27 August 2010Can humans affect global climate?
BP, what's the 30 year trend at Armagh?. -
Rob Painting at 22:11 PM on 27 August 2010Arctic sea ice... take 2
HR @18 - that's not what those passages suggest, however who knows?, it's not discussed in the paper. Pete Hogarth - the multi year ice ain't what it's cracked up to be either -
CBDunkerson at 22:10 PM on 27 August 2010Comparing volcanic CO2 to human CO2
RSVP, also 250 ppm was indeed the 'pre-Industrial Revolution' CO2 level... if you are talking about ~13,000 years before the Industrial Revolution. Immediately before industrialization began it was around 280 ppm. -
CBDunkerson at 22:03 PM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
johnd #26: Yes, I mentioned that I was skipping over the details of feedback effects entirely since 'at' was asking about the '3 C per doubling of CO2' estimate specifically. However, the broad strokes of the hydrological cycle aren't really as much of a mystery as you seem to suggest. Where and when a particular precipitation incident will occur, aka 'weather', is much more difficult to predict than average precipitation, aka 'climate'. The increased water vapor content of the atmosphere is the single largest positive feedback included in that '3 C per doubling' estimate. Rain, snow, clouds, and other incidental effects of that increased atmospheric water vapor have been studied and found to have fairly negligible effects... to the point where it isn't clear whether they are a net positive or negative feedback, but IS clear that they are a tiny fraction of the positive feedback effect of the water vapor itself. -
Berényi Péter at 21:44 PM on 27 August 2010Can humans affect global climate?
#14 John Chapman at 15:03 PM on 27 August, 2010 Why doesn't the Armagh Observatory have records since 2002?? They have them, it's just data beyond 2002 are not processed like this. In fact daily data in the archive are in a reasonable format only since July 2000, prior to that date they only have the scanned images of handwritten forms. Anyway, it is imperative not to go beyond 2002, because monthly temperature anomalies (relative to 1930-1989 means) recovered from the archive look like this between July 2000 and 2010:
As you can see, after 2002 Armagh Observatory is cooling at an alarming rate of 13.2°C/century.
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Peter Hogarth at 21:38 PM on 27 August 2010Arctic sea ice... take 2
HumanityRules at 09:43 AM on 27 August, 2010 There is also an update (to April 2010) of the Maslanik and Fowler 2007 "age of ice" animation which these guys kindly did for me in the second article on Arctic sea ice. As older ice is generally thicker, this is pertinent. -
Ned at 21:23 PM on 27 August 2010Comparing volcanic CO2 to human CO2
RSVP: Total emissions since 1750 from fossil fuels and cement production are 337 GT carbon (from ORNL-DAAC). Note that this is equivalent to 92 GT of CO2. If all of this accumulated in the atmosphere, it would represent an increase of 158 ppmv CO2 (2.13 GT carbon per 1 ppmv CO2). However, quite a bit goes into the ocean, so the actual rise has only been about 112 ppmv so far. It's still quite an increase over the pre-industrial conditions:
Figure 1: CO2 levels (parts per million) over the past 10,000 years. Blue line from Taylor Dome ice cores (NOAA). Green line from Law Dome ice core (CDIAC). Red line from direct measurements at Mauna Loa, Hawaii (NOAA).
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Peter Hogarth at 21:21 PM on 27 August 2010Arctic sea ice... take 2
HumanityRules at 09:43 AM on 27 August, 2010 There are some more post 2007 articles in Arctic ice, a reality check. I have a small amount of even more recent information, but will try to collate this. There are however multiple smaller scale studies for ice thickness, using all sorts of methods, but difficult to draw arctic wide conclusions as thickness and melt rate are not uniform over the sea ice area. -
RSVP at 20:33 PM on 27 August 2010Comparing volcanic CO2 to human CO2
The presentation is straighforward and informative, yet something seems to be missing.. (i.e., another cloud graphic that represents some other major, yet natural source(s) of CO2). Supposedly, pre-Industrial Revolution CO2 levels were around 250 ppm, whereas now they are around 380 ppm, an increment ratio of 1.5:1. On the otherhand, according to the above, man-made fossil fuel emission is around 100 times that of volcanos. If one assumes nature is only equipped to absorb the CO2 emitted by volcanos, one would expect current CO2 ppm to be much higher. What exactly is not being explained here? -
Ned at 19:45 PM on 27 August 2010Increasing CO2 has little to no effect
Stylo, "more longwave radiation returning back to Earth" means "more than previously." The atmosphere still radiates in all directions, and John actually is referring to absorption/emission rather than reflection. Imagine an Earth with no greenhouse gases in its atmosphere. 100% of the thermal radiation leaving the surface and passing through the atmosphere goes upward and out into space. Now add a small concentration of greenhouse gases. A small part of that longwave radiation will be absorbed by GHG molecules, which will then emit energy in all directions, including downward. So now somewhat less than 100% of the thermal radiation within the atmosphere is moving in an upwards direction. And as you increase the concentration of GHGs, the downward component becomes correspondingly larger. The downward thermal IR flux is indeed caused by emittance, not reflectance. -
Ned at 19:32 PM on 27 August 2010Greenhouse effect has been falsified
Will writes: The problem lies in the lack of understand of the fact that the atmosphere both radiates and insulates at the same time. Insulates what? From what? The only way that the Earth loses heat is by radiating to space. The only way that I can see the word "insulation" being relevant in this process is ... the effect of greenhouse gases repeatedly absorbing and re-radiating energy from the surface, slowing its outward flux and raising the temperature of the Earth system. But that's exactly the process you claim doesn't occur, so you presumably mean something else, right? In addition, I'm still curious about this remark from an earlier comment of yours: Thermal radiation is heat. Vibrating matter. Gas molecules are vibrating matter. [...] In the vacuum of space full spectrum EMR produces no thermal radiation, heat. Thermal infrared radiation is just another part of the electromagnetic spectrum; it's called "thermal" because it's the range at which normal Earth-surface objects radiate. It obviously does propagate through space (we use thermal sensors operating in the 8-14 micrometer window to measure this from satellites). Oh, and not to overload you with questions, but it would be nice if you could answer the questions from this comment. At what wavelength ranges does nitrogen in the Earth's atmosphere absorb and emit radiation? Thanks. muoncounter writes: Note: Any rumors that I have started a 'Ned Fan Club' are categorically false. Hey, I like that idea. -
Argus at 19:29 PM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Thanks, Dappledwater, CBDunkerson, Ned, CBW, nigelj, for your responses to my questions about sea level and CO2! Sea level was an example of what models try to predict. Now back to the posted text about models in general. The following is stated: "The models used to predict future global warming can accurately map past climate changes." This measure of accuracy is, of course, important. The next sentence reads: "If they get the past right, there is no reason to think their predictions would be wrong." No reason? That sounds, to me, a bit too optimistic. What if the model is wrong on some points, but repairs these errors by being wrong on other points as well? Then, even if the model fits known historical data, it will not necessarily fit future data. Recently some preliminary results of a study of the atmosphere, undertaken this year, were presented. It seems that some assumptions about both greenhouse gasses and black carbon may have to be modified. See article here! Two quotes: Among the surprises to come out of HIPPO data are nitrous oxide concentrations that consistently seem to increase with altitude. "Yet the models all show concentrations decreasing with altitude," says Wofsy. The implication, he adds, is that models are either not properly accounting for the transport of nitrous oxide or they are missing a source of the greenhouse gas.Wofsy and his colleagues report that the first HIPPO flight in January 2009 found levels of black carbon that average about five times lower than predicted by an ensemble of 14 global aerosol models […] The models underestimated how much black carbon is being scrubbed out of the air by precipitation, says lead author Joshua Schwarz, […]. -
Stylo at 19:22 PM on 27 August 2010Increasing CO2 has little to no effect
Poor Roy Spencer doesn't understand that what he is measuring is the temperature of the night air not the absorption of IR from the ground. He (perhaps subconsciously) confuses the phenomenon of emission with reflection. The IR emission of CO2 downwards depends only on the temperature of the air not on how that temperature was achieved; whether though IR absorption, convection, water condensation or sunlight. In this above article it says:"... Satellite measurements confirm less longwave radiation is escaping to space...Surface measurements find more longwave radiation returning back to Earth at these same wavelengths."
If the atmosphere is warmer, then it should emit more IR in both the down and up directions. If it's in fact radiating more IR downward but less upward, then this phenomena is reflection not absorption and emission. -
MattJ at 18:22 PM on 27 August 2010Comparing volcanic CO2 to human CO2
Great article. Maybe now the disinformation Rush Limbaugh inflicted on the public will finally die the slow, agonizing death it deserves. -
johnd at 17:47 PM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
CBDunkerson at 05:02 AM, calculating CO2 levels is only a small part of the complete picture. That complete picture has to include water vapour. Each degC rise equates to a 6-7.5% increase in water vapour, or about 20% for each doubling of CO2. If those relationships are linear, then during the ice age water vapour would have been about 15,000ppm, currently about 20,000ppm and with a doubling of CO2 about 24,000ppm. How all that extra water vapour transforms back to a liquid or a solid, and what it means in terms of cloud cover is I think the most interesting, and perhaps the most important process that needs to be understood.. -
David Horton at 17:28 PM on 27 August 2010Comparing volcanic CO2 to human CO2
This is nice, especially the graphic. The obvious reply to the Plimer madness is to observe how remarkable it is that the postulated increase in invisible volcanic activity, gradually, decade by decade over the last 40 years, should so precisely match the known increase in CO2 from industrial activity. -
Colorado Bob at 16:36 PM on 27 August 2010Polar bear numbers are increasing
I would add this item about the bears. We stopped shooting the crap out of them in 1973 due to a treaty. -
ScaredAmoeba at 16:07 PM on 27 August 2010Comparing volcanic CO2 to human CO2
A nice and simple explanation, but might the impact of the Terry Gerlach article in Earth Magazine be somewhat diluted by its footnote?Gerlach is an emeritus geologist at the U.S. Geological Survey, Cascades Volcano Observatory, in Vancouver, Wash. E-mail: tgerlach@usgs.gov. The views expressed are his own.
Of course, any that proceed to read the USGS reference will see that essentially the exact same observations are made, but with more references to the science. I'm ambivalent concerning the best approach, because I liked the Gerlach article and it's vitally important to hammer-home that Plimer's factually challenged book is useless as a guide to the science. But I'm glad that you provided the USGS as confirmation. Might a one sentence Gerlach biography might be useful? -
actually thoughtful at 15:40 PM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Wow - I feel like a butterfly flapping it's wings along a fractal coastline (said butterfly being blissfully unaware of the complexity it's simple actions represent) - I had no idea how much complexity lived behind "3C/doubling of CO2" - thanks CBDunkerson, KR and Riccardo for the insights. If anyone wanted to try a post fully explaining this bit in layman's term (hint: Guassian and Lorentzian don't qualify ;-)) - I at least would be grateful. I have enough to be happy with "3C/doubling" - but I could not defend an attack on that (although I have never seen an attack that realized how complicated the concept of climate sensitivity was (other than to say "no support for anything more than .75C/doubling - ie no positive feedbacks)). Back to muttering and puttering - perhaps I will awaken tomorrow and suddenly understand that which eludes me today (and too, perhaps all deniers will succumb to logic and facts - both outcomes are highly doubtful). -
John Chapman at 15:13 PM on 27 August 2010Can humans affect global climate?
In answer to #13, the words of David Karoly ... Burning fossil fuels produces carbon dioxide enriched with carbon isotope C12 and reduced C13 and essentially no C14, and it decreases atmospheric oxygen, exactly as observed. -
Can humans affect global climate?
nerndt - To put 2ppm/year into the atmosphere would require an additional years growth of the Amazon burning every year. That's every year for the last 100 or so. It would closely match the observed isotope ratios, but... At that rate we would have lost ~10 Amazons (assuming plant ages ~10yrs on average) in the last century. That simply hasn't happened. And as to natural variation, take a look at the last 425Kyr, from the Vostok ice core data:
The current 390ppm of CO2 simply isn't in the range of natural variations for the last half million years.
On the other hand, we know we're currently adding 29Gtn of CO2 to the air every year (enough for 4ppm increase), of which half seems to be sticking around in the air (2ppm yearly increase), the rest going into sinks like the ocean.
So we would have to disregard our CO2 output and believe that a few Amazons we haven't been tracking have burned/decayed? Or perhaps we can conclude that it's our CO2 output?
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John Chapman at 15:03 PM on 27 August 2010Can humans affect global climate?
Why doesn't the Armagh Observatory have records since 2002?? -
nerndt at 14:24 PM on 27 August 2010Can humans affect global climate?
Can someone truly explain how you can determine when CO2 is produced by humans burning fossil fuels versus natural decomposition of vegetation that would occur naturally as the temperature increases? The signature for all decomposing vegetation is the same (where atmospheric gases are slightly different because of the concentration of the Carbon isotope (C14 vs C15). I can not tell how you could separate the CO2 emitted by just more decomposition of plants when the planet warms up during natural oscillations. -
HumanityRules at 14:20 PM on 27 August 2010Can humans affect global climate?
Isn't H2O the most common GHG? (This is maybe unrelated but I like it so I'll try a tenuous justification) I don't disagree that we can affect many aspects of our planet, your example of atmospheric CO2 is a strong candidate for that argument. But I wonder if in considering that we aren't blinding ourselves to natural variability. Here's the official data from a long temperature record at Armagh Observatory stretching back to 1800. This will take you 5-10 minutes but grab the annual data and graph it. Smooth it with 25 year running mean.
What you get is a warming trend stretching back to the start of the record with low frequency oscillations. The most recent 'extreme' warming doesn't even show up as anything out of the ordinary. Tell me how humans have caused this and it is not natural variability?
Humans can change our planet doesn't mean they have changed it in all the ways we think.
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cruzn246 at 13:52 PM on 27 August 2010How we know global warming is still happening
All these short term charts don't mean squat. go back a few thousand years at least. We have been in a warm period for about the last 10K. Look at all of them rather than just the last 100 or so. How in the world can you call CO2 the dominant forcing when you know that if Water vapor was cut by 10% we would probably go into and ice age.Moderator Response: In the Search field at the top left of this page, type "Climate's Changed Before." Also "Water Vapor is the Most Powerful Greenhouse Gas." -
cruzn246 at 13:46 PM on 27 August 2010NASA-GISS: July 2010-- What global warming looks like
And why would you expect a one to one ratio? Nature seldom does that over thew short haul. Besides that, these records are for the last 100 years. Of course if you come up with couple warm decades you'll see high records fall. These records in a short time set, climatologically speaking. The longer you keep records the more likely you are to see it even out and records decrease in number. -
johnd at 13:04 PM on 27 August 2010Can humans affect global climate?
muoncounter at 11:45 AM, the chart below shows that the 440 + 260 +70, total 770 Gigatonnes released by natural means is roughly 30 times the 26 Gtonnes indicated as being released primariliy by fossil fuels.
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robert way at 12:41 PM on 27 August 2010Medieval Warm Period: rhetoric vs science
I disagree with steve's take on Moberg versus loehle. Loehle was clearly flawed whereas Moberg brought something new to the field with his novel wavelet technique. I think anyone who would give loehle's analysis the same credibility as Moberg's clearly has an agenda as methodologically the difference is clear. -
Chris Colose at 12:07 PM on 27 August 2010Can humans affect global climate?
//"Of course we can’t influence a single weather event, but we can and do have a long term influence on the climate that causes it."// Lorenz would be rolling in his grave... -
Climate Models: Learning From History Rather Than Repeating It
actually thoughtfull - The CO2 absorption band shape is between a Gaussian and a Lorentzian in shape (Riccardo posted about this here). The peak is saturated, but with every doubling the band blocked broadens enough to add an additional 3C. Not intuitive, perhaps, but if you think of it as scaling a clipped Gaussian it kind of makes sense. -
muoncounter at 11:45 AM on 27 August 2010Can humans affect global climate?
#8: "But natural sources far exceed human emissions by a factor of about 30. " Please substantiate that claim. Fossil fuel sources produced 30 Gtons (that's metric tons) CO2 in 2008. Perhaps you found it here? -
actually thoughtful at 11:41 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Thank you CBDunkerson - I see that it is still 3C per doubling, and I can accept that I don't completely understand why it isn't 3C/280ppm (I kind of do - once you double the CO2 the marginal harm of an additional ppm is lower, but the relationship of 3C/doubling still holds). I am thinking you need a given BTU to bump into twice as many CO2 molecules as the baseline to yield the 3C increase. I think I am proving my (lack of) mental powers here. Thanks again for clarifying the log bit. -
nigelj at 11:30 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Argus I think its good that as a sceptic you look at long term trends presented as a straight line rather than short term noise. I note the long term temperature trend since around 1880 to 20009 is a straight line pointing up. -
Ian Forrester at 11:24 AM on 27 August 2010Warming causes CO2 rise
johnd, please re-look at the data from Heidelberg you quoted. All of the divergence from natural levels is on the positive side of the curve. This is due to the highly industrialized area. It is not random. It is an excursion above normal levels. In your mind draw a curve at the lowest points in the data, you will see that that curve is very similar to non-industrialize areas. Your large sinks are imaginary. Maybe I was wrong in saying "daily" excursions to >410 ppm but they are, non the less, of very short duration and are due to local production of large quantities of CO2 which is then diluted out by normal air, not absorbed by your "large" sinks. Please do not confuse the issue. -
John Chapman at 11:07 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Looking at the graph in #9, a quadratic would be a better fit than a linear trend, thus indicating an accelerating rise, which is somewhat consistent with the CO2 rate of increase. -
johnd at 10:33 AM on 27 August 2010Warming causes CO2 rise
Ian Forrester at 09:51 AM, what are you talking about "per day"??? The study tracks the annual cycles!! You've have completely failed to grasp what exactly was being analyzed, perhaps reading it with preconceived notions. As noted in the study, Heidelberg has a fairly strong industrial influence to the East, but it is only one of the 16 stations, all which exhibit the same seasonal variation to varying degrees from a variety of locations across the globe, including some surrounded by your "country air". -
Crazy Bill at 10:19 AM on 27 August 2010The main culprit in mid-century cooling
What about the effects of nuclear testing? I know it's unfashionable to talk about "nuclear winter" but the fact remains that there were multitudes of atmospheric nuclear tests during the period 1945 to 1970s (France 1974, China perhaps even later). Most of these injected quantities of aerosols into the stratosphere where it evidently hung around for a few years. Many Russian tests were in the arctic where the stratosphere is much lower than elsewhere, so even more dust would have been injected there. -
daisym at 10:08 AM on 27 August 2010Station drop-off: How many thermometers do you need to take a temperature?
#17: Tom: Once again thanks for the links. As you said, there's a wealth of information there, and I've broadened my knowledge. I did not know that they has a life expectancy of 150 cycles. At 10 days per cycle, this translates to something like 4 years. Hopefully, they can be retrieved, refurbished, and reused. I was surprised that these buoys don't measure air temperatures when they surface. Perhaps this is an example of "parsimony"? It seems that an opportunity has been missed to gather unique atmospheric temperature data. Once again, thanks for the information. -
Ian Forrester at 09:51 AM on 27 August 2010Warming causes CO2 rise
No johnd, the Heidelberg data do not show a "sink" of 40 ppm per day. You have entirely misinterpreted the data provided and have failed to actually visualize what is happening. As I said, Heidelberg is an industrial city, it produces large quantities of CO2. However, the concentration of CO2 (the data presented in the paper you quote) is a very localized concentration. It may reach 410 or higher ppm in a single day when conditions are right (very little wind) However, the drop back to normal levels (370ppm) is due to unpolluted "country" air being blown in from the surrounding area. It is not due to a natural sink. Note how the levels never go below the global average, that should tell you that there is no local sink which is ten times greater than previously observed as you state in your posts at #6 and #23. Just to repeat, the drop of CO2 concentration from >410 ppm back to normal global levels is due to normal air displacing the highly polluted city air and is not due to some large and previously unknown sink. -
johnd at 09:47 AM on 27 August 2010Can humans affect global climate?
Mike at 09:11 AM Most markedly rising in concentration? Water vapour increases 6-7.5% per degC but being about 2% of the atmosphere in absolute terms it outstrips CO2. .............. Most significant in terms of changing climate? The direct effect of water vapour far exceeds the direct effect of CO2, with water vapour responding to ANY source of additional heating. However clouds are excluded as they are not considered a GHG, but are a major determinant of climate. ............. Most common GHG produced by human activity? Yes. But natural sources far exceed human emissions by a factor of about 30. -
HumanityRules at 09:43 AM on 27 August 2010Arctic sea ice... take 2
16.Dappledwater My understanding is that both your quotes relate to the idea that due to the natural variability wherever you start and end your data set will determine the trend. It's a different way of saying we should look beyond the recent arctic ice trend to the bigger picture. 17.CBDunkerson "There is no evidence of significant discrepancy in those volume calculations." I've shown you evidence! While PIOMAS is in it's own death spiral in 2009 scientists have been out in planes with radars showing that the ice is slightly thicker than it was in 2009. Planes with radars I mentioned in the post there is no good spatial coverage of ice thickness in the arctic. To turn things around where is the evidence that the post-2007 drops in PIOMAS do match reality? I've genuinely looked for them and can't find them. The Haas paper is probably the best actual measure of arctic ice thickness post-2007. I agree Cryosat II will be a big step forward. It should be noted Haas and his radar are part of the consortium generating thickness data in order to calibrate the satellite. -
Mike1637 at 09:11 AM on 27 August 2010Can humans affect global climate?
I think I sort of know what you really meant when you said "most common of greenhouse gases", but yeah, it sure is quite wrong as it's written! ;) Most markedly rising in concentration? Most significant in terms of changing climate? Most common GHG produced by human activity? -
Paul W at 09:04 AM on 27 August 2010CO2 has a short residence time
Doug, Nice article. I like all your points. I do agree with you that the fast removal of CO2 from the air is into the oceans by solution. Just as an additional process that removes CO2 from the atmosphere and eventually into sediments the rock weathering process should be mentioned. The calcium and to a lesser extent magnesium and other metals that form insoluble carbonates have cycles that play a part in CO2 draw down. In brief when rocks (particularly igneous rocks that have had any carbon removed by heat) weather, the soluble metals that can form insoluble carbonates are initially released by a combination of acidic rain water and the action of plants and their organic acids. Rain water is acidic from a combination of dilute sulphuric, nitric and carbonic acids. So the sulphur cycle, nitrogen cycle as well as the carbon cycle it's self are involved in the production of the acids that free the mostly calcium from the rocks. Once in solution the calcium remains soluble until it is either precipitated by high carbonate/ bicarbonate levels at higher pH or it is taken into aragonite and calcite forming marine shell fish and other marine creatures. It is then dropped into sediments at the end of the creatures life. As CO2 levels rise we can expect an increase in the weathering rate due to a drop in the pH of rain water. This rate is however too slow to helps up much. Paleo studies show the usual drop in CO2 takes millions of years. Also with higher CO2 in the oceans the rate of shell formation will slow as first aragonite then calcite forming creatures loose their ability to form shells due to ocean acidification. This is the very deep "do do" point of mass ocean life form extinctions from collapse of the ocean food chain that depends on the aragonite or calcite planktons. There is periods in the Paleo record at the past thermal maximums that ocean sediments show the absence of shell deposition. At the end of the thermal maximum the shells reappear and life slowly rebuilds. -
johnd at 08:37 AM on 27 August 2010Greenhouse effect has been falsified
Will at 21:34 PM , when you say that air is both a good insulator and a top radiator, does it not depend more on the movement of the air rather than it's inherent properties? Still air is indeed a very good insulator of heat, however moving air is a very efficient dispersant of heat. -
mdenison at 08:08 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Spencer Weart's The discovery of global warming Has interesting sections that provide a background to the models and how climate scientists learnt from them and developed them further by using them to investigate past and present climates. See Simple Models of Climate Change and General Circulation Models of Climate -
Phil at 06:50 AM on 27 August 2010Greenhouse effect has been falsified
Berényi Péter @61 Probably there was heating in the room that was turned off for the night and switched back in the morning just before the experiment started. It developed then maintained a temperature gradient between the positions of jar A and B on the table. Hmm, heating that is turned on about 8.00am, and then is left on all day while he's out at school(as his caption says) and is kept on until at least 8.00pm. I thought the kid said he was worried about global warming ! But at least his experiment is missing some of the glaring errors in Will's version. -
johnd at 06:48 AM on 27 August 2010Warming causes CO2 rise
Ian Forrester at 00:36 AM, regarding the Heidelberg site, yes we know where it is and why the CO2 levels are so high, but you blatantly choose to ignore the most obvious point that the seasonal fluctuations make, that is although the CO2 levels go off the scale, during the "growing season" when the CO2 is being sequestered by plants taking up extra CO2, the levels fall by 50ppm. If you missed that point, please ponder awhile as it indicates that the natural sinks in that region have the capacity to sequester far more CO2 than what occurs elsewhere, and if so, exactly why it is so. -
Rob Painting at 06:45 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Argus @ 12, wishful thinking may indeed be comforting, but it won't affect sea level rise. Notice the title of the Church & White paper I linked to @ 9?. And the "recent" sea level rise put into context.
The concern is for that 70 meters of sea level rise locked up in the Greenland and Antarctic ice sheets, the same ice sheets that are exhibiting accelerated melt, and the 1 to 2 meters of sea level rise anticipated for this century.
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Peter Hogarth at 06:10 AM on 27 August 2010Warming causes CO2 rise
johnd at 22:17 PM on 26 August, 2010 Just to add some detail to the charts Ned and KR posted:
(All data from NOAA Paleo site) This curve tracks known and estimated anthropogenic emissions back to pre-industrial times. I think in this case correlation is so high, and process so well understood, that uncertainties about causality are vanishingly small.
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