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Comments 111601 to 111650:
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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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Peter Hogarth at 05:37 AM on 27 August 2010Greenhouse effect has been falsified
muoncounter at 03:17 AM on 27 August, 2010 For some more updated classic science on the Thermosphere and Mesopause, UV heating, upwelling IR and radiative balance, see States 2000. -
CBDunkerson at 05:02 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
actually thoughtfull, ln(560/280) is 0.693147. If we assume that all feedbacks are logarithmic at the same scale (they aren't) and ignore lag times then that would mean a 3 C rise from a doubling of CO2 would be using a 'temperature forcing factor' (not actually how it works) of 3 / 0.693146 = 4.328085. Multiplying that factor by ln(840/280), the additional +280 ppm you asked about, would then yield TOTAL warming of 4.754888 C... so the first 280 ppm increase would give 3 C warming and the second 280 ppm about 1.75 C... the third would give about 1.25 C more, making the total at 1120 ppm (two 'doublings' over the baseline) 6 C. To get to 9 C you'd need 2240 ppm and so forth. -
Peter Hogarth at 05:00 AM on 27 August 2010Greenhouse effect has been falsified
muoncounter at 03:17 AM on 27 August, 2010 To be fair, some of the relevant information was only declassified in 1971 (if memory serves). -
perseus at 04:31 AM on 27 August 2010It's methane
"Hence the amount of warming methane contributes is calculated at 28% of the warming CO2 contributes" Does the first graph relate to the relative historic influence of each greenhouse gas emission to the radiative forcing we experience today? If so do we really need to know the relative effect of each greenhouse gas we emit today projected forward onto a certain timeframe to establish their real importance? Either way the graph needs to be clarified and referenced -
CBW at 03:49 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Argus, the planet has been warming since the mid-1800's, so one would expect sea level to rise over that period as well. The fact that it has risen is a proof of global warming -- no matter to what one attributes the cause of the warming. The attempt to connect fossil fuel consumption directly to sea level rise is a straw man. The warming seen up to about 1940 is thought to be caused in part by human activity and in part by solar activity. But solar output has been stable since that time. Initially, global temperatures stabilized for a few decades despite increasing CO2 in the atmosphere, likely due to the dimming effect of industrial particulates in the atmosphere. Since the 1970s, however, the CO2 effect has emerged as the dominant driver of global warming. So drawing a single line from 1850 through 2010 and claiming CO2 can't be the cause is disingenuous at best, and typical of the denialist literature. -
muoncounter at 03:17 AM on 27 August 2010Greenhouse effect has been falsified
#55 "For some historical context see Moe 1977." On the webpage we've been referred to by Will is this statement: The Governments of the world and the various space agencies such as NASA have conspired to stay quiet about the Diurnal Atmospheric Bulge In addition to the reference cited by Peter Hogarth, here's Harris and Priester 1965. Both were NASA scientists at the time. I found that by googling 'diurnal atmospheric bulge'; it was the 4th hit on the 1st search result page. Without opening a can of political worms, how is the existence of this phenomenon being kept secret? Note that I ask how, not why. And also note this reference further down the same search. One of the great things about skepticalscience is that you can quickly find a more reasoned explanation. Note: Any rumors that I have started a 'Ned Fan Club' are categorically false. -
CBW at 03:15 AM on 27 August 2010Can humans affect global climate?
A minor language nitpick. You write: "How can humans influence this? Well, yes, we can." "Yes" is not an answer to "How?". Either drop the "How" entirely and start with "Can", or answer the question: "Well, we do it by influencing the climate." Or some such. -
actually thoughtful at 03:08 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
CBDunkerson - the logarithmic nature of GHG forcings - does that mean we have already done the MOST damage with the CO2 already released. If the temp forcing of the first doubling is 3C - what would you estimate the temp forcing of the next 280PPM increase in CO2 is? (I fight, work, cajole, and live to push CO2 emissions to zero - so no hidden denier agenda here). Thankss. -
Peter Hogarth at 03:03 AM on 27 August 2010Greenhouse effect has been falsified
Will at 21:34 PM on 26 August, 2010 Heating in Thermosphere, as in increased kinetic energy per molecule or atom?, yes. Massive top down?, no, hardly any molecules (or mass) here. Further down, the UV is quite efficiently filtered by Stratospheric components such as Ozone (Ozone level peak around 20-25 km up - where it is cold?) - so that only 1-3% of total UV (mainly longer wavelength UVA) reaches the surface. You state: "as the atmosphere thins it looses more energy via radiation, yet at the same time it still has an insulating effect" How? I'm not sure what physical processes you are trying to communicate here. Approx 99.999% of the atmosphere is below the Thermosphere. Approx 99.9% is in the Troposphere. What substance exactly is providing insulating properties where? I suspect you may be stretching the definition of "air" a little thin... -
muoncounter at 02:50 AM on 27 August 2010Warming causes CO2 rise
#14: "The anthropogenic origin of the observed rise in CO2 is one of the clearest, most obvious physical facts in earth system science." I find it astounding that so many question this; I would love to figure out why the deniers give it so much traction and how to burst that bubble. And then there's the old chestnut: 'correlation is not causality.' Is this a fitting reply? Let me hold a rock over your head; the speed at which it hits your head correlates well with the height of the rock. -
cruzn246 at 02:46 AM on 27 August 2010Can humans affect global climate?
CO2 the most common greenhouse gas? Please. Water vapor is the most common by far. -
CBDunkerson at 02:27 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Argus #12: Nope, you didn't quite follow it. Warming due to CO2 and other GHGs is logarithmic. Therefor, in order for warming from GHGs to show a linear trend the rate at which these gases are increasing has to continually increase. That does not mean that warming would stop if the rate of GHG increase became constant... rather the rate of warming from GHGs would begin to slow. Now when you factor in feedback warming and factors leading to sea level rise (ice mass balance loss and thermal expansion of water) it gets more complicated. Both of those can go on for years after the GHG warming slows or even ceases. Again, look at your graph. There was a significant build up of CO2 emissions for DECADES prior to the 1940 line they identify. That CO2 increase caused warming, which was magnified by positive feedbacks, which caused sea level rise. The argument that accelerating CO2 emissions after 1940 should have led to a matching acceleration of sea level rise is simply false... there is no reason that the two factors must rise at exactly the same rate and many reasons (explained above) why they would not. Sea level rise IS accelerating... just not as fast as CO2 emissions. Which isn't at all surprising given the logarithmic nature of GHG temperature forcings. -
Ned at 02:06 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
Just off the top of my head, without putting a lot of thought into it, my explanation for the trend shown in the SLR graph is that a relatively slow increase in sea level was associated with the end of the Little Ice Age, and then graded into a slightly steeper (and accelerating) rise caused by anthropogenic global warming. In other words, it's a lot like the global mean temperature graphs -- a century-long rise, but with a different balance of causes in the first vs second halves of the century. In other words, we can't use the existence of SLR as proof of AGW, since it can and does have other causes at other times. But we can say that recent SLR is consistent with AGW. Does that make sense, Argus? -
John Hartz at 01:47 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
"Computer modeling of global climate is perhaps the most complex endeavor ever undertaken by mankind," writes MIT atmospheric scientist Kerry Emanuel in his short book What we know about climate change. This is the first paragraph of the article, "Powerful new climate model unveiled", published in yesterday's (Aug 26) edition of USA Today. Needless to say, this article has attracted anti-AGW bloggers like flies to honey. http://content.usatoday.com/communities/sciencefair/post/2010/08/powerful-new-climate-model-unveiled/1#uslPageReturn -
Greenhouse effect has been falsified
Berényi - On the contrary, changing a single variable is an essential method for conveying the effect of that variable. You could be more realistic in describing end-point conditions by looking at all the parameters, the interactions, feedbacks, etc. - but if what you wish to show (as in The Hoover Incident) is that current conditions could not hold true if that variable was changed, a single-variable approach is more than sufficient as a reductio ad absurdum proof. -
Berényi Péter at 01:20 AM on 27 August 2010Greenhouse effect has been falsified
#64 Ned at 23:33 PM on 26 August, 2010 You assumed it would stay constant, which is (a) not realistic, and (b) a misleading comparison to Venus, which has a much higher albedo It is just as arbitrary and misleading as constructing an "Earth" with neither atmosphere nor hydrosphere but with the same albedo as it actually has, considered as a baseline to the "greenhouse effect". -
Argus at 01:11 AM on 27 August 2010Climate Models: Learning From History Rather Than Repeating It
CBDunkerson, If I understand your first paragraph correctly, you are saying that a steep decrease in sea level during the years 1800-1850 is immediately replaced by a steep increase, from the moment they started burning measurable amounts of coal. The tiny amount burned around 1850 is impossible to read out from the graph, but it certainly seems to be less than one percent of the present figure. If I understand your second paragraph correctly, for the sea level to continue rising, we have to keep increasing CO2 emissions even further. So, if we just stay at the present level of production, sea level will also stay at the present level. That is kind of reassuring. -
DarkSkywise at 00:48 AM on 27 August 2010Humans are too insignificant to affect global climate
They don't. ;-) Fossil fuels are made from plants so they have the same C13/C12 ratio. The difference is not between fuel and plants, but between fuel/plants and "natural" CO2 content of the atmosphere. The atmosphere is a bit richer in 13C because plants have a slight preference for 12C. So if you burn fossil fuels (made from plants), the 13C/12C ratio drops, and you can calculate which part of the CO2 in the atmosphere comes from fuel. -
Warming causes CO2 rise
johnd - You asked if "...do the natural processes that drive the sources and sinks for CO2 follow a similar pattern as what occurs in business where the expenses, sinks, always seem to rise, or fall, just enough to consume all the income, sources, that becomes available?" Well, if you look at the record over the last 10,000 years:
Looking back even further, here's a graph from Wiki commons for the last 425KY:
The answer is "Just enough". It's only in the last 150 that this balance has changed, taking CO2 levels sharply out of the 180-300ppm range to the current ~390ppm.
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Ian Forrester at 00:36 AM on 27 August 2010Warming causes CO2 rise
johnd said:with one site, Heidelberg Germany typically 370ppm to perhaps 420ppm,
This shows how shoddy johnd's reasoning is. Heidelberg is a large industrial city which produces copious quantities of anthropogenic CO2. This is just a denier grabbing at the slimmest piece of evidence to try and bolster their well debunked arguments. Also, johnd, carbon isotope analysis shows conclusively that the increase in atmospheric CO2 is due to carbon derived from fossil fuels. -
muoncounter at 00:28 AM on 27 August 2010Warming causes CO2 rise
#9: "you confuse me with your "Well, no"" Your statement in #6 "magnitude of the nett increase of CO2 ... is very small against both the emissions and the sinks that occur naturally,"" gave me the impression that you meant the atmospheric CO2 increase is much less than emissions less natural sinks. It is not 'much less'. But I second Ned's suggestion: Where do all those Gtons of CO2 go each year? If they are absorbed by natural sinks, why is atmospheric CO2 increasing by 2ppm per year? Recall that a part per million by volume doesn't sound like much, but we're talking about the atmosphere -- a very large volume. -
Tom Dayton at 23:45 PM on 26 August 2010Greenhouse effect has been falsified
Okay, BP, the child's experiment was not airtight. (For folks whose first language is not English, that was a pun.) So for the next child let's bring in professional help from scientists and the MythBusters! -
Ned at 23:43 PM on 26 August 2010Warming causes CO2 rise
KR writes: Between Occams razor and basic substance conservation (what goes in comes out), it's pretty clear that our CO2 emissions are directly increasing the atmospheric CO2 levels. Yes, exactly. If johnd still disagrees with this, it would probably be helpful if he could provide a clear, concise statement of his argument. A simple version of the mainstream position would be something like this: Burning fossil fuels adds CO2 to the atmosphere. Part of this CO2 goes into the oceans and the biosphere, while the rest remains in the atmosphere. This explains the observed simultaneous increase in both atmospheric and oceanic CO2. johnd, can you offer a similarly straightforward and mechanistic example of your argument? Tell us what you think happens to the CO2 we produce and why CO2 is increasing in both the atmosphere and the ocean (or if you don't believe the data showing that increase, say so). -
Ned at 23:33 PM on 26 August 2010Greenhouse effect has been falsified
BP writes: Albedo is not a free parameter that you can simply give. Of course not. But your initial comment that claimed only a "5 C" increase in temperature was based on a particular assumption about the Earth's albedo. You assumed it would stay constant, which is (a) not realistic, and (b) a misleading comparison to Venus, which has a much higher albedo. I would repeat everything I say in my comment above, but for simplicity's sake I'll just link to it -
Berényi Péter at 23:23 PM on 26 August 2010Greenhouse effect has been falsified
#59 Ned at 21:05 PM on 26 August, 2010 All else being equal, if you put Earth and Venus at the same distance from the sun and gave them the same albedo Albedo is not a free parameter that you can simply give. Especially for atmospheres with a stuff that can condense to droplets provided it gets cool enough (both Earth and Venus have one). Also, with a practically infinite supply of GHG (the store is called ocean) the response of terrestrial climate to an increased opacity in a narrow IR band may be pretty counter-intuitive. The system as a whole does not have to get warmer to maintain power flux balance, it is enough to redistribute water vapor slightly. Not even average upper troposphere humidity has to decrease in order to decrease effective photosphere height (that is, bringing down the place radiation can escape to space from to a lower, therefore warmer level). It is quite enough to let humidity distribution getting a bit more uneven. -
Warming causes CO2 rise
johnd - I'd like to point out that your comment about atmospheric increases and "what is out there is an amount equivalent to the other half", but not caused by our emissions, requires a lot of belief statements. It requires us first to not believe that our CO2 emissions are affecting the atmosphere, while postulating some other, unknown cause that is simultaneously increasing at 2ppm/year. Your claims of uncertainties (what, +/-6% uncertainty from economic estimates as to CO2 going into the atmosphere) are really quite small, considering the multiple decade record showing a consistent increase. Between Occams razor and basic substance conservation (what goes in comes out), it's pretty clear that our CO2 emissions are directly increasing the atmospheric CO2 levels. -
wgray at 22:50 PM on 26 August 2010Humans are too insignificant to affect global climate
"Further confirmation that rising CO2 levels are due to human activity come by analysing the types of CO2 found in the air. The carbon atom has several different isotopes (different number of neutrons). Carbon 12 has 6 neutrons, carbon 13 has 7 neutrons. Plants have a lower C13/C12 ratio than in the atmosphere. If rising atmospheric CO2 comes fossil fuels, the C13/C12 should be falling. Indeed this is what is occuring (Ghosh 2003) and the trend correlates with the trend in global emissions." I'm having trouble understanding this statement, but the basic version is a bit too basic and doesn't answer the question, "How can scientists tell the difference between the CO2 from plants and that from fossil fuel consumption?" -
Ned at 22:43 PM on 26 August 2010Warming causes CO2 rise
johnd writes: Ned at 21:19 PM, re "But without those emissions the X/2 increase would not exist." What do you have to support that claim? I've given a simple and obvious explanation. If you want to claim that there's no connection between our addition of CO2 to the atmosphere and the observed increasing CO2 in the atmosphere, you need to explain that claim. It would be an extremely unintuitive situation, so you really need to provide an extremely convincing explanation. johnd continues: Are you claiming that without current emissions CO2 levels would instead be declining by X/2? No. CO2 levels would probably be basically stable, with the ocean, atmosphere, and biosphere close to an equilibrium. They would certainly not suddenly have risen 112 ppmv in the past century!
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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Ned at 22:29 PM on 26 August 2010Warming causes CO2 rise
johnd writes: The quantities of CO2 flowing through the sources and sinks are substantially larger, so the estimates made there either have to be done to a substantially higher degree of accuracy than that of estimating emissions or the margin of errors will be of such magnitude that the 2ppm becomes meaningless. Why? The 2ppm increase is an observed fact, it's not a guesstimate or a modeled output based on shaky ideas about individual sinks and sources. We know how much is accumulating in the atmosphere, with a very high degree of confidence. The uncertainty in emissions is also small in proportion to the atmospheric increase. Again, the long-term increases in both emissions and atmospheric concentration are remarkably consistent. There are small fluctuations in the rate of increase associated with, e.g., changes from El Nino to La Nina. But those are small fluctuations around a consistent exponential rise. johnd continues: it is not enough to claim that because two measurements move in concert they must be connected when there are bigger and equally relevant processes involved that are not adequately understood or quantified. I just don't want to assume it is not coincidental, the mechanisms have to be identified. Oh, come on! The mechanism is obvious! We burn fossil fuels, producing CO2. The CO2 goes into the atmosphere. We measure an increase in CO2 in the atmosphere. What could possibly be plainer than that? I'll take Occam's Razor, thanks. It seems exceptionally irrational to reject a simple and straightforward explanation in favor of a complicated, improbable, and poorly understood one. The anthropogenic origin of the observed rise in CO2 is one of the clearest, most obvious physical facts in earth system science. If you're determined to object to AGW, wouldn't it at least make more sense to ground that objection somewhere else? -
johnd at 22:25 PM on 26 August 2010Warming causes CO2 rise
Ned at 21:19 PM, re "But without those emissions the X/2 increase would not exist." What do you have to support that claim? Are you claiming that without current emissions CO2 levels would instead be declining by X/2? -
Alexandre at 22:25 PM on 26 August 2010Can humans affect global climate?
Same remark as Anne-Marie #1. Of course, the most abundant GHG is H2O. -
Berényi Péter at 22:22 PM on 26 August 2010Greenhouse effect has been falsified
#58 Will at 20:58 PM on 26 August, 2010 So 79% of the atmosphere is cooled by what process? Does the majority of the atmospheric mass have to transfer its energy through a bottle neck of 0.0385% CO2 in order to radiate to space? Not only CO2, there are others, the one major player being H2O. There is also an "atmospheric window" between 8 and 14 μm and another one called "Arctic window" above 16 μm, which is only "open" if there is very little moisture in the atmosphere. Through these windows radiation from the surface can escape to space directly. At ambient temperatures the only way for nitrogen to cool down is by frequent collisions with other stuff. If the atmosphere of a planet were made of pure N2 with no trace amount of anything else (it also has to be made of a single isotope of N, lets say 14N), it would not get cooler with increasing elevation. But you also have to make sure the surface was absolutely dry and dust free to make it work like that. -
johnd at 22:17 PM on 26 August 2010Warming causes CO2 rise
Ned at 21:19 PM , it is not enough to claim that because two measurements move in concert they must be connected when there are bigger and equally relevant processes involved that are not adequately understood or quantified. I just don't want to assume it is not coincidental, the mechanisms have to be identified. -
Lassesson at 22:13 PM on 26 August 2010Can humans affect global climate?
More detail picking: I noticed that the text say "... in just the last TWO hundred years the concentration of CO2 in the atmosphere has suddenly shot up from 280, to more than 380 parts per million", while the graph say that the 280 ppm level was at 1950, which is less than ONE hundred years ago. Correct me if I'm wrong but I think the graph should be changed to "1850" instead of "1950". Thanx for a good post otherwise!
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