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Comments 121351 to 121400:

121351. johnd at 09:03 AM on 4 April 2010
        Temp record is unreliable
        Some recent analysis of USA surface temperatures, 16th March 2010, by Dr. Roy Spencer (http://www.drroyspencer.com/category/blogarticle/) suggests that there is sufficient doubt and perhaps significant differences to be found when closely examining the published data that warrants closer examination to accurately quantify the UHI effect, and how it impacts on both the accepted trends and also on how it affects other data that was calibrated against accepted surface measurements.
121352. Tom Dayton at 09:02 AM on 4 April 2010
        There's no empirical evidence
        philc, see John Cook's "Response" in the green box below this comment.
121353. johnd at 08:57 AM on 4 April 2010
        A residential lifetime
        Tom @62. Thanks, I had read that discussion some time ago, but I see that it has had some recent additions. I'll post the link I provided above onto that discussion as it is more recent than any of the postings there.
121354. philc at 08:47 AM on 4 April 2010
        There's no empirical evidence
        "Satellite and surface measurements find less energy is escaping to space at CO2 absorption wavelengths. " It would seem to me that the total radiation outgoing is the critcal number. Of course CO2 would absorb in its natural wavelengths, but that doesn't mean an equal amount of energy isn't going out at other wavelengths.
121355. Tom Dayton at 08:29 AM on 4 April 2010
        A residential lifetime
        johnd, surface temperature measurements are off topic. If you want to continue discussing that, you should do so on the appropriate thread: Temp record is unreliable. (I suggest you read that posting and the existing comments on it first.)
121356. johnd at 08:24 AM on 4 April 2010
        A residential lifetime
        Philippe Chantreau @60, some recent analysis of USA surface temperatures by Dr. Roy Spencer (http://www.drroyspencer.com/category/blogarticle/) suggests that there is sufficient doubt and perhaps significant difference that warrants closer examination to accurately quantify the UHI effect. As a matter of interest, and to put it into perspective, is there any data that indicates the total weight of manmade structures world wide that would qualify as thermal mass? GFW @58. Are not albedo and thermal mass merely different sides of the same coin especially when dealing with the UHI effect?
121357. Philippe Chantreau at 06:13 AM on 4 April 2010
        A residential lifetime
        "the UHI effect which is significant enough to perhaps inflate global average surface temperatures" There is no credible evidence for this. The trends for urban areas aren't significantly different from rural areas. See this post, which references the papers listed below. http://www.skepticalscience.com/urban-heat-island-effect.htm http://pubs.giss.nasa.gov/docs/2001/2001_Hansen_etal.pdf http://www.ncdc.noaa.gov/oa/wmo/ccl/rural-urban.pdf http://journals.ametsoc.org/doi/abs/10.1175/JCLI3730.1 http://www.agu.org/pubs/crossref/2008/2008JD009916.shtml GC, your irrational fear mongering with things like the earlier "pestilence" (already adressed) or that new "horrific famine" is getting tiresome. It seriously undermines your argument, whatever that is. That kind of gross exaggeration, completely divorced from reality, is fine in tabloids or clumsy attempts at manipulating the public. Take it to that kind of forum.
121358. Doug Bostrom at 05:48 AM on 4 April 2010
        A database of peer-reviewed papers on climate change
        Harold,quite frankly to me Dr. McKitrick's essay is to me evidence only that he feels upset that his work was not published in the journal of his choice and has chosen to make his wounded feelings public. Even the amount of effort he's clearly devoted to constructing his "case" in such granular and almost obsessive detail is striking in a way that reflects poorly on Dr. McKitrick. It is actually surprisingly juvenile in tone and attitude, such his catty asides about Benestad. As to the merit of his charges, I read nothing in the work that could not describe the experience of a myriad of other researchers working on less controversial topics. Perhaps McKitrick has been treated somewhat more critically than other workers, but then his own posture and history of remarks about other researchers almost invites that. "Circling the Bandwagons" may be an effective title choice when talking to a private audience, but as an invitation to serious consideration by others it fails. Meanwhile, McKitrick's conclusion that "the IPCC used false evidence to conceal an important problem with the surface temperature data on which most of their conclusions rest" is hyperbole in the extreme and of course relies on the reader failing to remember that McKitrick's analysis (which he himself admits was flawed) dealt with but a single type of data from the plethora of research threads incorporated into IPCC's work.
121359. GFW at 05:20 AM on 4 April 2010
        A residential lifetime
        @55 John R. Yes, on very long time scales, there has been a net flow of carbon *through* the soil into fossil fuels. But that flow rate is very low. Other than that, what the soil takes up, it gives back (or else all the carbon would wind up in the soil, which obviously hasn't happened). So, while the woods near you may be building soil, there are other places in the world where soils are shrinking. Absent man, soil would be in pretty good equilibrium, except for that tiny net flow to fossil fuels. You are right that the size of the soil carbon reservoir is larger than that of the air (and smaller than that of the ocean). As long as near-equilibrium is maintained, that doesn't matter. However, one very possible concern is that because of human interference, the soil reservoir will shrink, pushing carbon into the air. Specifically, deforestation in tropical to temperate regions, and warming of soil/permafrost in subarctic regions are processes that have the potential for a significant transfer of carbon from the soil to the air.
121360. GFW at 05:05 AM on 4 April 2010
        A residential lifetime
        Apologies. My #57 was in response to #50, which I now see was also answered at #53. Heh, considerable similarity in points made - scientific understanding is consistent. To add value, I'll respond to #54. Thermal mass of anything on land is tiny compared to the thermal mass of the ocean. Also, adding thermal mass in some location while holding other factors the same will in general produce a moderation of temperature extremes, e.g. warmer nights and cooler days. The UHI has very little to do with thermal mass, and very much to do with albedo. Blacktop, dark roofs, and the three dimensional topography of buildings make a city a much better absorber of sunlight than natural landscapes are.
121361. Harold at 04:54 AM on 4 April 2010
        A database of peer-reviewed papers on climate change
        doug_bostrom, in your response to my observation in (19) that 'peer review is not necessarily a level playing field', you note that McKitrick was dismissive of Benestat as a blogger when he is a highly credentialed scientist. However, in context, Benestat is a 'blogger at realClimate.org' (whose byline is "Climate science by climate scientists") who objected to the way that McKitrick's paper handled spatial autocorrelation. This suggests to the credulous reader that Benestat probably has more credentials than most bloggers. I suspect that McKitrick does not share your opinion on the relative difference between a highly credentialed scientist and a mere blogger - he is a credentialed academic and a university professor who has co-authored papers with a 'blogger'. You further note that McKitrick 'jumps directly into characterizations of others' work as "fabrications"'. Actually, the only time he uses the word 'fabrication' is in reference to a paragraph in an IPCC draft that dismisses his work with misleading citations and an unsubstantiated assertion (which he explores and writes a paper to show is incorrect). I believe that the reason these items in McKitrick's article feel like 'rank hyperbole' is because he is casting a shadow on people you respect, and I probably would feel the same. However, this thread is about peer reviewed papers, and regardless of who is right in the AGW debate, McKitrick's article is first person evidence that the implications of papers on AGW affects peer review. Phil Jones' email about 'redefining peer review' is additional evidence. You mention that that you were going to 'leave the question of whether he was fairly treated in the hands of other, more easily believed folks, such as editors and reviewers with sufficient proven reliability to be found working for reputable journals.' Their reliability and absence of bias is precisely the question at hand. McKitrick gives personal experience as evidence
121362. GFW at 04:51 AM on 4 April 2010
        A residential lifetime
        Water vapor will respond to, and amplify any change in temperature, (although with the proviso that to amplify an upward change, there must be a source of water vapor). I would *suspect* that there is enough water vapor emitted in a city in exhaust and respiration for that to work.(**) However, while the UHI is locally important, averaged over the planet's surface it is tiny compared to the CO2 forcing. (**) There's a lot of other things going on with a city though. It's not just a heat island, it's a pollution island. Ground level ozone, aromatic hydrocarbons, NOx, ... you'd have to ask an atmospheric chemist specializing in such matters if those have any effect on urban humidity.
121363. gallopingcamel at 01:56 AM on 4 April 2010
        A residential lifetime
        doug_bostrom (#51), My post that John deleted related directly to your point. I will try again after pausing to show that this post is "on topic". On this thread we are discussing the "Residence Time" of CO2 in the atmosphere, so it seems relevant to consider whether mankind can affect this in any way. Most of us accept the idea that CO2 concentrations are in fact rising owing to human activity. The sequestration issue is the other side of the same coin. Can mankind reduce CO2 concentrations? In my opinion the answer is clearly YES and there are plenty of strategies for doing so that I would support. Doug's idea of storing non-perishable food in Tupperware is probably the best of all. Governments should provide incentives to farmers to produce non-perishable food mountains instead of the perishable "Butter Mountains" and "Wine Lakes" created by the European Economic Community. This will help reduce the horrific famines that will occur during the next "1816" (The Year Without a Summer). This is not science fiction; enlightened governments have used this strategy all the way back to biblical times. It used to be called "Building Granaries" rather than "Sequestration". Where can one find a Hammurabi in this modern world?
121364. John Russell at 00:57 AM on 4 April 2010
        A residential lifetime
        Doug Mackie @52. According to Wikipedia, (under the heading 'Soil Carbon') "over 2700 Gt of carbon is stored in soils worldwide, which is well above the combined total of atmosphere (780 Gt) or biomass (575 Gt), most of which is wood." I would say that counts as significant; don't you? I stand by my statement that natural biological processes -- if left alone by man (a critical qualification) -- will tend to build up the carbon content of the soil. I see this in my indigenous (to the UK) wet woodland year on year as rotting trees and leaves fall into the mud where only a few inches down it can become anoxic. Let's face it, this is how the fossil fuels formed in the first place. Note that I am not claiming that, left alone, soils can sequester all of our fossil fuel emissions -- can anything? -- but they do pull in the right direction. In Brazil I, personally, have witnessed deep, rich, soil full of organic matter being reduced to little more than sand within a decade or so, once it has been exposed by deforestation and turned over to agriculture. Forestation and even sustainable agricultural practices, if managed correctly, can sequester significant amounts of CO2. My point is that it can be more than just a temporary store while the trees/plants are growing, as your article suggests.
121365. johnd at 19:21 PM on 3 April 2010
        A residential lifetime
        Doug Mackie @ 53, thank you for indulging me. What I am asking is whether the billions? trillions? of tonnes, and ever increasing, thermal mass of manmade infrastructure has as much effect of storing heat energy as atmospheric CO2, thus also providing radiative forcing. The residential lifetime of such structures would generally exceed that of atmospheric CO2. Just a simple example to illustrate. Most brick, stone or concrete structures are built inside out with the thermal mass on the outside, insulated from the inside. When a structure is built with the thermal mass on the inside it modifies the internal climate due to the thermal mass both absorbing and dissipating heat energy albeit on a small scale. However structures built with the thermal mass on the outside have been built all over the planet on a massive scale and the effect is measurable as the UHI effect which is significant enough to perhaps inflate global average surface temperatures.
121366. Riccardo at 18:26 PM on 3 April 2010
        Greenland's ice mass loss has spread to the northwest
        HumanityRules, both are affected by rising temperatures but this is about the only relation between the two. They behave differently, as nicely and concisely explained by GWF.
121367. Doug Mackie at 18:11 PM on 3 April 2010
        A residential lifetime
        Johnd @50 Would the Urban Heat Island effect also qualify as a driver of water vapour? It certainly is measurable and widespread. This too is veering away from lifetime/residence time. However I shall indulge you, though without emoticons I am not sure you are serious. Do you mean to ask: “Do cities produce enough extra water vapour have the potential to control/change climate to a significant extent compared to extra water vapour in the atmosphere from general global increase in temperature”? If that is what you meant then no. The AR4 FAQ 1.1, 1.3. 2.1 and 3.2, and the main text they point to, answer this comprehensively and there is no point me pasting the text here. The issue is radiative forcing
121368. Doug Mackie at 17:53 PM on 3 April 2010
        A residential lifetime
        #34 John Russell (Sorry to anyone who has already read this comment: This is a repost. I am a potty mouth and John has made me delete bad words from the original. Where they are not being depleted by agriculture or deforestation the world's soils are all constantly deepening. No. This is false. As I said: with the exception of fossil fuel formation the carbon cycle is efficient at recycling carbon. Where precisely do you think significant accumulation is occurring? Please read TAR and AR4 on the subject of soils. There are certainly uncertainties but there is no way that soils can sequester a significant portion of fossil fuel emissions. My solution: Take a few unpopular low lying cities and flood them. Grow trees there. When mature, bulldoze the trees and repeat. It is essential to maintain anerobic conditions to promote peat/coal formation. Re the CO2 lifetime. I think the discussion tends to over-complicate a simple concept. The claim made by denialists is that CO2 has a short residence time and thus, they claim, cannot possibly cause warming over the 500 year timeframe discussed by IPCC. That is male cow excrement (can you guess what the offending word was?). Pure and simple. Through ignorance, malice, or both the denialists confuse lifetime with residence time. You go on to paraphrase my argument (that residence time is irrelevant) so I am not sure what your point is.
121369. Doug Bostrom at 17:38 PM on 3 April 2010
        A residential lifetime
        GC, I think someone could write an interesting science fiction novel, entailing a plot wherein inhabitants of a planet with insufficient greenhouse gases are facing an ice age and discover (a hero is forced to jump through hoops to enlighten his fellows, natch) enormous hydrocarbon reserves, sufficient if extracted and burnt to bring things into balance. Evildoers attempt to thwart the plan by suggesting that these hydrocarbons are instead used to manufacture something called "Polyware", storage containers for mountains of excess food, but are ultimately thwarted. The hero basks in warmth and affection at the end of the book. But that's science fiction, as I said. The situation we face is unfortunately the opposite, but we could still sequester hydrocarbons in actual Tupperware(tm) if we chose and in this version of the plot the folks recommending the combustion method do not play the role of protagonists.
121370. johnd at 15:48 PM on 3 April 2010
        A residential lifetime
        Doug Mackie @ 47 re "Point is that water vapour is the result of temperature while CO2 causes temperature" My point was/is, CO2 is not the only mechanism that can alter temperatures that water vapour may respond to. Would the Urban Heat Island effect also qualify as a driver of water vapour? It certainly is measurable and widespread.
121371. Tom Dayton at 15:30 PM on 3 April 2010
        A residential lifetime
        I believe that delaying the next ice age is off-topic for this "residential lifetime" thread. Gallopingcamel, you would be a more constructive commenter if you posted your comments in the appropriate threads instead of whichever one you happen to be reading at the moment.
        Response: I have deleted one of Gallopingcamel's recent comments for being off-topic. However, an upcoming ice age is somewhat on-topic in the sense that residential time of CO2 does affect whether we can fall into an ice age any time soon. Archer's studies find that a significant chunk of the CO2 we emit will remain in the atmosphere for thousands of years hence an ice age is indefinitely postponed.
121372. gallopingcamel at 15:17 PM on 3 April 2010
        A residential lifetime
        John Russell (#40), Thanks but I can't accept credit for the idea that the next Ice Age can be delayed if we put 5,000 Gtonne of C into the atmosphere. Two men deserve the credit, namely Archer and Ganopolski. I have been very careful to avoid offering an opinion on A&G's analysis. I was hoping to get a few insights from the clientele on this blog. Should we try to delay or accelerate the next Ice Age? Would the idea work? I do not buy Ned's argument that the next Ice Age is so remote in time that we don't need to think about it.
        Response: An ice age is only possible if northern ice sheets grow from year to year. So if you see a gigantic ice sheet creeping down northern Canada, then yes, it's time to start worrying that we're heading into a new ice age. For now, I think you can relax about an impending ice age (or as my daughter likes to say to me, chillax). Ice sheets can collapse relatively quickly because ice dynamics cause glaciers to slide faster into the ocean. But the speed that ice sheets can grow is limited by the amount of snow falling each winter.
121373. Doug Mackie at 15:05 PM on 3 April 2010
        A residential lifetime
        #42 John D Point is that water vapour is the result of temperature while CO2 causes temperature. AR4 FAQ does this in simple terms. As soon as water vapour concentration gets too high it rains. #43 John D The issue is timing. At glacial onsets/terminations it takes at least 10,000-15,000 years for CO2 to decrease/increase by ~100 ppm (and temperature change by ~10 decC). We have increased CO2 by 100 ppm (over and above the "usual maximum" of 280 ppm) in just 200 years. Temperature lags (but will follow CO2) and ecosystems are struggling to keep up with the rate of change.
121374. Doug Mackie at 14:54 PM on 3 April 2010
        A residential lifetime
        #36 Gallopingcamel Mammals predate dinosaurs and lived in their shadows for 160 million years. After the KT event birds (poncy dinosaurs) dominated in many ecosystems. Mammals were very late starters. Mammalas have less advantage in warm conditions but do have an advantage in colder conditions. (e.g. Think cold morning start up time).
121375. Doug Mackie at 14:32 PM on 3 April 2010
        A residential lifetime
        #33 RSVP Bugger. Note to self: Use emoticons. My comment re NH air conditioning was jocular. Energy use is not likely to change voluntarily. As Working Group II reports make clear: Warming will be good for a few people. E.g. (maybe) Canadian and Siberian grain belts. However, it isn’t it obvious that if, for example, the USA/China endured dust bowl conditions then they would pay what the Canadians/Russians asked to avoid their people starving. I mean, sure they have nukes and all that but they would never.... Would they?
121376. scaddenp at 13:50 PM on 3 April 2010
        A residential lifetime
        What is so hard about seeing the difference between a cooling over 10,000 years and warming over 150 in terms our capacity to adapt? If you are so desperate to avoid an ice age, then we should immediately sequester all fossil fuel so that 3000 years down the track, there will be something to burn for atmosphere enrichment. Frankly it seems to more like clutching at straws - believing anything rather than accept the need to deal with the problem.
121377. johnd at 13:14 PM on 3 April 2010
        A residential lifetime
        John Russell @34, it is clear from the vast deposits of coal that a tremendous amount of CO2 was stripped from the atmosphere by plants. As CO2 concentrations fell, so too would temperatures as well as plant growth until a glacial period took hold. At that point with plant growth almost stalled or plants dead or dying, the process of stripping atmospheric CO2 would be at a point where decomposition of plant amterial would begin releasing previously sequestered CO2 producing conditions to allow for a recovery from the glacial conditions.
121378. johnd at 13:00 PM on 3 April 2010
        A residential lifetime
        robhon, if water vapour responds so strongly with positive feedback to a relatively minor change in CO2 concentration, then it must also respond as strongly directly to any changes in temperature brought about by the Milankovitch cycles, even without any changes in CO2.
121379. GFW at 11:21 AM on 3 April 2010
        Greenland's ice mass loss has spread to the northwest
        HR, yes there appears to be *some* linkage between sea ice and the glacier flow/calving rate, but it's not quite the same story as how the more permanent ice shelves of Antarctica hold back glaciers there. Sea ice doesn't have the thickness or rigidity of an ice shelf so any back-pressure effect is much weaker. However, the less sea ice there is in general, the less protection Greenland has from warm winds and currents.
121380. HumanityRules at 09:56 AM on 3 April 2010
        Greenland's ice mass loss has spread to the northwest
        Riccardo #54 Is sea ice extent really unrelated to this topic? If it's true that most of the mass loss is due to calving rather than melting in-situ as suggested by many then surely open ocean for longer time periods must have an affect on the rate of ice loss. It would seem common sense that open water facilitates more calving than ice locked sea. The many animations of arctic sea ice suggest there has been change in sea ice freeze in the Baffin/Greenland sea since the 1980's.
121381. Rob Honeycutt at 08:03 AM on 3 April 2010
        A residential lifetime
        @HenryH... You should really watch the Richard Alley lecture that John suggested. It explains the whole issue extremely well. Google: Richard Alley The Biggest Control Knob. The point that Alley makes in the lecture is that Milankovitch cycles can only account for a small portion of temperature change. It's those cycles of orbit, precession, etc that set off feedbacks in CO2 and CH4 that result in the swings in global temps that we see.
121382. Philippe Chantreau at 05:13 AM on 3 April 2010
        The human fingerprint in global warming
        RSVP "For instance, life (as we know it) cannot be sustained without oxygen." That's incorrect. The oxygen in our atmosphere is owed to living organisms. Numerous organisms still exist that do not need oxygen. See for example this: http://www.scientificamerican.com/article.cfm?id=origin-of-oxygen-in-atmosphere
121383. John Russell at 04:33 AM on 3 April 2010
        A residential lifetime
        I like 'gallopingcamel's' suggestion that humans raising the temperature by a few degrees is acceptable on the grounds that we're pre-empting an ice-age that might possibly affect us, to some unknown degree, at some unknown point in the future! If only sceptics were as willing for humans to take dramatic actions to lower temperature by reducing emissions, in the face of the suggested 95% chance that increased temperatures will destroy our children's future.
121384. Ned at 03:59 AM on 3 April 2010
        A residential lifetime
        gallopingcamel writes: I am a little puzzled by your conclusion that a warmer earth would be "inhospitable" given that mammals became dominant during the Eocene when temperatures were much higher than today. Our agricultural system and all our infrastructure are predicated on the idea that climate is more or less constant, such that if the north-central US is a good place to grow wheat now, it will continue to be a good place to grow wheat in the future. Or, as another example, we build a fleet of ships/barges to operate on the Mississippi River or the St Laurence Seaway, with the assumption that water levels will not drop enough to prevent fully laden vessels to move through the system. In other words, there are a million ways in which our infrastructure is designed around a particular climate in particular places. Changes in temperature or more importantly precipitation can wreak havoc with this. You keep arguing that a few degrees of warming is OK because "it's better than another glacial advance." But no one is suggesting we should try to create another round of glaciation! The question isn't "Which is worse, too warm or too cold?" The question is "Which is better, the climate we have built our infrastructure around or a climate that's significantly warmer most places, with very different patterns of precipitation?" Please stop using a non-existent threat of rampaging glaciers as an excuse to ignore the actual threats associated with CO2-driven climate change.
121385. John Russell at 03:28 AM on 3 April 2010
        A residential lifetime
        Tom Dayton: I know, I know; hence my point 2 about the hole in the bucket (...dear Lisa, dear Lisa). I thought it worth making the point about the wider ability of naturally-occurring vegetation to sequester CO2 when left alone to do its thing, which many people choose to overlook. The irony is that not only are humans adding to atmospheric CO2 but -- through a lack of understanding -- we're also blocking the ecosystem's correcting mechanisms which have evolved to protect the existence of life on the planet. This is the basis for Lovelock's 'Gaia' theory.
121386. Tom Dayton at 02:24 AM on 3 April 2010
        CO2 has a short residence time
        I agree with you in general, Hugh. It is best to avoid repeating misinformation even in the context of disproving it, because repeating the disinformation actually publicizes it. That's why I greatly appreciate Doug's approach in this post, of stating the facts. But there is also the problem of icons such as this sacred list of 36 previous studies. That list is used by deniers as evidence that 36 other experts disagree radically with Doug and "a few" other people. That tactic could be neatly parried by saying that all those studies were about residence time of an individual molecule rather than adjustment time. Such a simple statement inserted as a single sentence in Doug's description of residence time would help a lot, I think. But we'd have to be sure such a statement was completely accurate, which is where a student project would be helpful.
121387. Tom Dayton at 02:10 AM on 3 April 2010
        A residential lifetime
        John Russell, the problem is that sequestration by trees (and plants in general) cannot keep up with CO2 increases due to humans. On the relevant thread CO2 Is Not a Pollutant there are some relevant comments containing links to sources: #3 by me followed by #4 by muoncounter. See also the USDA report I linked to in my comment #1 on that thread.
121388. gallopingcamel at 01:42 AM on 3 April 2010
        A residential lifetime
        Marcus (#36), I am a little puzzled by your conclusion that a warmer earth would be "inhospitable" given that mammals became dominant during the Eocene when temperatures were much higher than today. My idea of "inhospitable" would be the period ~74,000 years ago when it was so cold that the human race was near extinction. In spite of the technologies mankind is so proud, it will be very difficult for humanity when the next Ice Age arrives.
121389. Marcus at 01:01 AM on 3 April 2010
        A residential lifetime
        One important point is this-the carbon we're currently burning comes from a time when the planet had CO2 concentrations 10x to 20x higher than at any point during the Quaternary Era. Its important to note that temperatures were a good 4-6 degrees *warmer* then than during the entirety of the Quaternary Era-in spite of the sun being cooler during this earlier time period. This should give some idea of the maximum impact we could expect from raising CO2 emissions *if* we were somehow to burn every ounce of coal & oil ever created. Even if we don't burn that much (indeed, economics will probably demand that we stop burning coal long before this because it will become more expensive to mine than what it can ever be worth-indeed, this day has almost arrived in the bulk of Europe) we'll be able to burn enough to make life on this planet extremely uncomfortable-if not downright inhospitable-for our species. That doesn't sound very intelligent to me!
121390. John Russell at 21:58 PM on 2 April 2010
        A residential lifetime
        A couple of points. 1) Re: trees. Doug Mackie talks of trees as if they have very little effect on CO2 sequestration; "Every tree that grows will eventually die and decompose, thereby releasing CO2." The facts are more complex. True, trees in woods and forests do live and die but in fact the organic matter on the floor of a woodland or forest is gradually increasing (let's face it, that's one of the ways peat is formed) and it ends up as a net CO2 sink. Where they are not being depleted by agriculture or deforestation the world's soils are all constantly deepening. Even where soils are eroding mechanically, that soil ends up washing down rivers and it's that organic matter that ends up making a significant contribution to the sediments accumulating on the bottom of our oceans. 2) Re the CO2 lifetime. I think the discussion tends to over-complicate a simple concept. When describing the working of a business I always use the analogy of a bucket with a hole in the bottom. The work the company does, and product it sells, provides money to fill the bucket; while the costs -- wages, overheads, raw materials purchase -- bleeds money out of the hole in the bottom. Equilibrium is maintained while the inputs match outputs. The same analogy can be applied to atmospheric CO2. If we think of a molecule of CO2 as a molecule of H2O then the time a specific molecule exists in the bucket is irrelevant; all that matters is the balance between inputs and outputs. Increasing inputs will result in the water level rising; increasing output will cause the water level to fall. One can't push this analogy too far, but it does get the point across to some sceptics. It also helps to explain why man's relatively small contribution to the CO2 cycle is so significant. I hope that's useful.
121391. RSVP at 18:53 PM on 2 April 2010
        A residential lifetime
        CBDunkerson Thank you for the reply. Very interesting. & Doug Mackie Also interesting. Aside from the question, your answer brings up an idea... You refer to powering air conditioners and CO2 released for this. Would it make any sense then (i.e., benefit) to prohibit burning fossil fuels for energy during summer months? I would assume not, however, you always hear this point about air conditioners. Maybe air conditioners themselves should be completely banned to simply make people (including the elite) more conscious of global warming.
121392. Doug Bostrom at 17:39 PM on 2 April 2010
        A database of peer-reviewed papers on climate change
        Harold, McKitrick's essay is well written, but I once I spent a few moments checking his characterizations I ended up with a fairly firm conclusion not in his favor. McKitrick describes Dr. Rasmus Benestad as "a blogger at Real Climate", technically true, then McKitrick goes on to dismiss Benestad's failure to follow up on an invitation to submit a comment to JGR with the rather snide remark, "Yes, yes, time pressures: I understand. I guess blogging takes up a lot of time." Here's Dr. Benestad's bio as provided to Real Climate: I am a physicist by training and have affiliations with the Norwegian Meteorological Institute (met.no) and the Oslo Climate Group (OCG) [My views here are personal and may not necessarily represent those of RegClim, OCG, met.no, or the mentioned societies]. I have a D.Phil in physics from Atmospheric, Oceanic & Planetary Physics at Oxford University in the United Kingdom. Recent work involve a good deal of statistics (empirical-statistical downscaling, trend analysis, model validation, extremes and record values), but I have also had some experience with electronics, cloud micro-physics, ocean dynamics/air-sea processes and seasonal forecasting. In addition, I wrote the book ‘Solar Activity and Earth’s Climate’ (2002), published by Praxis-Springer, and I was a member of the council of the European Meteorological Society for the period (2004-2006), representing the Nordic countries and the Norwegian Meteorology Society. Here is Dr. Benestad's record of publications: Rasmus Benestad's Publication list Ross McKitrick jumps directly into characterizations of others' work as "fabrications" and swiftly moves to arguable distortions such as Dr. Rasmus Benestad being simply "a blogger," of course leaving a credulous reader with the impression that Benestad is insufficiently credentialed. I suppose McKitrick is trying to harm the credibility of his opponents, but instead such tactics leave me wondering how much fact-checking I'm required to do in order to attach any credibility to his claims. Life is too short, I won't bother and I must leave the question of whether he was fairly treated in the hands of other, more easily believed folks, such as editors and reviewers with sufficient proven reliability to be found working for reputable journals. If most of those persons chose not to publish McKitrick's work, my vote of confidence must go to them because for me McKitrick has ruined his own credibility by swerving into rank hyperbole.
121393. iskepticaluser at 17:04 PM on 2 April 2010
        CO2 has a short residence time
        Tom's comment #3 refers to lack of time and knowledge in pursuing an understanding of climate change, so I'll throw this out there, though it's a bit off topic. Regular readers of this blog come here often because we find the science fascinating, but I think that fascination can be a handicap when we're trying to communicate the central urgency of AGW to folks who may have a lot of other issues on their minds. If I were presented with the "iconic list" either in rebuttal or simple confusion, I would be tempted to simply by-pass it and say "Look, we KNOW (from direct and proxy measurements) that the planet's CO2 blanket is more than a third thicker than it was before the industrial revolution. We KNOW (through carbon isotope signatures) that we're the ones thickening it. We KNOW that CO2 traps infrared - we can measure the effect both in the lab and from satellites. And we KNOW that global (atmospheric and ocean) temperatures are rising." If anyone appreciates these basic facts, they'll GET global warming. Hockey-sticks, tropical troposphere hot-spots and ENSO variability are secondary issues that may or may not interest a general audience, but they are not critical to the basic narrative. It's important to address denialist arguments when they arise. But it's more important to be able convey - really well - the ESSENCE of the AGW threat. Widespread familiarity with, and repetition of, that central chain of evidence will be the most powerful antidote to whatever head-in-the-sand nonsense happens to be floating around.
121394. Doug Mackie at 16:03 PM on 2 April 2010
        A residential lifetime
        Johnd #24 And the heat capacity of seawater is...(hint: greater than air). As suggested above The long thaw makes scary bedtime reading. Emphasis on the long.
121395. Doug Mackie at 15:53 PM on 2 April 2010
        A residential lifetime
        RSVP #10 "Is residence time affected by temperature? And if so, what is the nature of this feedback?" I assume you mean residence time and not lifetime? If so then, no, residence time is not directly controlled by temperature. However, while I hate to give another equivocal answer, it depends: Residence time, as explained above, is simply size of reservoir divided by rate of throughput. Temperature will not directly alter the size of the reservoir, i.e. amount of CO2 in the atmosphere. (Though perhaps warming will mean less burning of fossil fuels for heating but equally it may lead to increased consumption to run air-conditioners etc). Temperature may have secondary effects on throughput rates: One removal process for CO2 is dissolution in the ocean. This is a physical process and the bottleneck is large scale circulation. Which is, in part, driven by winds and temperature gradients. (Though as a complicating factor warm water can hold less dissolved water than cold water).
121396. Doug Mackie at 15:28 PM on 2 April 2010
        A residential lifetime
        Alexandre #20: In the short term (centuries) CO2 in the atmosphere will slowly come to equilibrium with CO2 in the oceans. By definition this means that the final concentration of CO2 in both boxes will be greater than it was in preindustrial times. Exactly how much greater depends on the time scale we use and the total amount of fossil CO2 released. The oceans will acidify as a result of this process. This is a whole post in itself but I direct your attention to the UN Convention on Biological Diversity : “Ocean acidification is irreversible on timeframes of at least tens of thousands of years and is determined in the longer term by physical mixing processes within the ocean that allow ocean sediments to buffer the changes in ocean chemistry. Warming of the oceans as a result of global climate change may also reduce the rate of mixing with deeper waters, which would further delay recovery.”
121397. Harold at 15:10 PM on 2 April 2010
        A database of peer-reviewed papers on climate change
        You have an understandable emphasis on peer review as a validation for the various scientific arguments for/against AGW. However, peer review is not necessarily a level playing field. For an enlightening (and somewhat entertaining) look at the efforts of Ross McKitrick to get one of his papers through peer review, check out this link.
121398. shargash at 15:07 PM on 2 April 2010
        A residential lifetime
        HenryH@9 "Why should it happen today in another way like in former times?" There has never before in the history of the earth been a fossil fuel-burning, industrialized civilization. THAT is why what is happening today is different than in former times.
121399. Chris G at 13:26 PM on 2 April 2010
        A residential lifetime
        Having said that, now I'm not sure if the increase in temperature is inherently logarithmic, or if the net effect is a log because the higher increase in energy loss makes it that way. Might have to go dig that one up.
121400. Chris G at 11:38 AM on 2 April 2010
        A residential lifetime
        HenryH (#9) If you are asking why the earth hasn't headed toward a truly runaway greenhouse effect, another way to answer that is that the temperature increase due to an increase in a GHG is logarithmic in nature. It continually increases, but the rate of increase (1st derivative) continually declines. On the other hand, the amount of energy lost from radiation is proportional to the 4th power of the absolute temperature; energy loss accelerates rapidly with an increase in temperature. A new equilibrium, at a higher temperature, will always be reached, where the curves intersect again.

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