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monckhausen at 08:02 AM on 19 May 2010Heat stress: setting an upper limit on what we can adapt to
I do have a question about the effect of CO2 doubling. According to this speaker http://friendsofginandtonic.org/files/0ce6ebe7c0b2f2a2b093195e128c659e-112.html the greenhouse effect is 34.5C. CO2 accounts for 10% of this effect, which is 3.45%. Doubling the amount of CO2, according to the speaker, would cause further warming of 0.345C. This sounds far to simple to be true. According to the speaker, we do not have to worry about the heat stress. What is the presenter's reasoning for such simple maths? -
Species extinctions happening before our eyes
skepticstudent writes " the last few years have seen an incline in the Monarch Butterfly and the larvae only successfully grow to the butterfly stage in cooler temperatures." What is your source for this information? In fact, monarch butterfly populations are at an all-time low. -
chris at 06:50 AM on 19 May 2010Species extinctions happening before our eyes
you're missing the point in each of your posts skepticalstudent: skepticstudent at 04:11 AM on 19 May, 2010 Rather than "making the model do whatever" they "want", the model (which was something like: "based on our analyses of 200 sites in Mexico, here are a set of criteria by which we expect to find local habitats worldwide in which certain lizards will be stressed in relation to surviving Spring warming of such and such a degree"), was found to predict rather well the response of lizards in locations throughout 5 continents of the world In other words it seems to be a very good model for predicting how populations of certain species of lizard will fare in a warming world. skepticstudent at 04:20 AM on 19 May, 2010 Mount St. Helens. Not a good analogy. Mount St. Helens was one volcanic eruption in one place. After the eruption the forces causing environmental destruction ceased. So the environment was bound to recover and no doubt populations outside the affected area are recolonizing. In the case of the lizards, the warming insult is not going to stop. The lizards will not be returning to those habitats. Moreover this is happenining not just at one locale as a result of a single perturbation, but is happening in 5 continents in response to a continuing and increasing global scale warming. -
Doug Bostrom at 05:38 AM on 19 May 2010Species extinctions happening before our eyes
Slightly off-topic, but the unavailability of full-text papers is a sad impediment for amateurs such as most of us here when discussing findings such as this one. Before his remark was deep-sixed because he was unable to resist making some unfounded judgments, skepticalstudent referred to some missing temperature station data. Skepticalstudent, would you mind pointing us to an open copy of this paper's supporting materials, so we can take a look at what you're talking about? Thanks! -
Philippe Chantreau at 05:37 AM on 19 May 2010Species extinctions happening before our eyes
Skepticstudent displays a common misunderstanding of what a model is:"I can make a climate or any kind of model do what I want it to do." No, you can't. A very simple mathematical model would be y=ax+b. This model will do what its maths impose and you can't make it do anyting else. If one designs that model in order to predict where to find y, and the position predicted by the model is not verified in reality, the model is wrong and has to go back to the drawing board. If its prediction is verified, then it is good. The model described in Ned's post seems to be extremely successful, and would in fact be a rather impressive achievement. -
skepticstudent at 04:20 AM on 19 May 2010Species extinctions happening before our eyes
http://seattletimes.nwsource.com/html/localnews/2011876112_volcano16m.html http://seattletimes.nwsource.com/flatpages/video/mediacenterbc3.html?bctid=85750359001 Are two newspaper article videos of species that have made fantastic comeback/adaptation to their surroundings despite massive changes in their surroundings. Now before any of you try to make the assertion that this doesn’t equate to Mexico think for a second. Suddenly a massive volcano blows up wiping out trees for hundreds of square miles. Clogging rivers with ash, trees, choking them with ash, and acid and other poisons. Mt St Helens did to the Tuttle valley what evolutionary scientist said took 10 billion years, in 3 days. There were trout and salmon back in the rivers and lakes in less than 3 years. There were birds, lizards, salamanders. Trees were gone, thus the ground temperatures were far far warmer than they had ever been before. I was up at Mt St Helens a short time after the blast. It was like a Nuclear bomb, no roughly about 380 Nagasaki bombs went off. To try and tell me that lizards are dying because of supposed recent changes in temperatures over a 20 + year period because they can’t “evolve” fast enough is nonsense. Animals adapt to living conditions quickly every day all over the world. I think this is a very very poor representation for the climate warming side. -
monckhausen at 04:19 AM on 19 May 2010The significance of the CO2 lag
Addendum: Human-emitted CO2, in contrast to the ocean-emitted CO2, does not lag, it is emitted instantaneously. Following the logic applied by 'skeptics' like Joanne Nova, something 800 years ago must have triggered our present human CO2 emissions. This, of course, does not make any sense. However, since oceans and humans can emit CO2 simultaneously, CO2 can lag and lead at the same time, depending on its source. monckhausen http://friendsofginandtonic.org/ -
Marcel Bökstedt at 04:16 AM on 19 May 2010The significance of the CO2 lag
It seems to me that the paper by Scheffer does not apply the "lag" argument, instead it uses a very subtle approach, depending on several quite difficult estimates. Stating the upper limit as "78%" sounds a little ridiculous taking the great uncertainties into account. Is it possible to use the lag of CO2 levels after temperature to make an independent estimate on the feedback effect? -
skepticstudent at 04:11 AM on 19 May 2010Species extinctions happening before our eyes
Ned, I can make a climate or any kind of model do what I want it to do. I want to know if they studied the habitat. Did they study the food of the lizards. Did they study if anything has changed other than weather or are they strictly using weather models? Like I mentioned earlier there have been larger than normal monarch butterfly escape into North America. The monarch butterfly only has large escapes during years where winter and spring weather is cooler than normal. So one tends to wonder about their comments about warmer climes wiping out a species locally or otherwise. -
Ned at 03:32 AM on 19 May 2010Species extinctions happening before our eyes
skepticstudent writes: Why would lizards suddenly start dying in Mexico and no where else in the world? They did a study of lizard populations in Mexico, and derived a model that can be used to predict lizard population dynamics in general. Then, they tested this model by comparing its predictions to field studies from all over the world: "The global generality of our model is verified by concordant distributions of current observed and predicted local extinctions of lizard biotas from four other continents (table S7). Our model pinpoints exact locations of two Liolaemid species going extinct in South America (Liolaemus lutzae, Phymaturus tenebrosus: {chi}2 = 32.1, P < 0.0001). In addition, the model predicts recent (2009) extinctions among 24 resurveyed populations of L. lutzae ({chi}2 = 8.8, P = 0.003). In Europe, our resurvey of Lacerta vivipara revealed 14 extinct sites out of 46 (30%), which are predicted quite precisely by the model ({chi}2 = 24.4, P < 0.001). In Australia, the model pinpoints 2009 extinctions of Liopholis slateri ({chi}2 = 17.8, P < 0.00001) and 2009 extinctions of Liopholis kintorei ({chi}2 = 3.93, P = 0.047). In Africa, analysis of Gerrhosauridae and Cordylidae at 165 sites predicts <1% extinctions, and yet the model pinpoints the single extinction reported by 2009 (exact P-value = 0.006). We temper this value with extinction projections of 23% for 2009 at Malagasy Gerrhosauridae sites, which is validated by the observed 21% levels of local extinction across several lizard families in Madagascar nature reserves (23)." Tables S7A, B, C, and D in the Supplementary Online Material provide all the details about these surveys. It looks like a pretty massive effort. -
Ned at 03:17 AM on 19 May 2010Species extinctions happening before our eyes
No problem, Argus. By the way, I had no idea English is not your first language -- you write better than many native speakers. -
monckhausen at 03:09 AM on 19 May 2010The significance of the CO2 lag
Co2 lags and leads. 1. Increased solar activity leads to T increase. 2. Oceans warm up slowly 3. Once oceans have warmed up (the 800 year lag story), they cannot hold the CO2, which is emitted. 4. The emitted CO2 causes a positive feedback. At this point, CO2 leads. That's what the 'skeptics' generously ignore. 5. In the case of the Vostok ice core, deglaciation owing to CO2 followed initial CO2 release from oceans warmed by solar activity. monckhausen http://friendsofginandtonic.org/ -
skepticstudent at 03:04 AM on 19 May 2010Species extinctions happening before our eyes
I can't see the whole article so I don't know so i'm asking. Why would lizards suddenly start dying in Mexico and no where else in the world? Lizards survived 10 million years of heat warmer than what is currently anywhere in the world. Did they do any studies on the habitat itself or on the food sources in the area... Also I find it interesting that despite their claims of temperatures being higher in the areas, the last few years have seen an incline in the Monarch Butterfly and the larvae only successfully grow to the butterfly stage in cooler temperatures. I'm not just sayin... just sayin ya know? -
chris at 03:00 AM on 19 May 2010Species extinctions happening before our eyes
Arkadiusz Semczyszak at 21:17 PM on 18 May, 2010 Well now you're changing the subject. The examples you give are localized climate changes. No one disagrees that local climate changes like these can be large and quite fast, and no doubt these have had devastating effects on local populations, including extinctions. However your earlier post with its lazy snipe at Mann, that I responded to was about global/hemispheric (???; we don't know since you won't respond to a simple question about where your "data" is from) temperature variation during the last millenium and its comparison with modern global temperature change. It is the very rapid global scale temperature rise combined with additional human "insults" on the natural environment (especially habitat destruction/fragmentation) that is the concern. So going back to the paper at hand (Sinervo et al, 2010), the authors describe concurrent local extinctions of lizard populations across the 5 continents of the world, very likely in this case, due to global warming. -
CoalGeologist at 02:45 AM on 19 May 2010The significance of the CO2 lag
Although the present discussion rehashes concepts that have been explained many times before, scientists must never tire of the need to repeat them as often as necessary. Kudos to SkepticalScience.com for having taken up the gauntlet once again. The argument that the rise in temperature preceding the rise in CO2 (in the Pleistocene ice record) disproves AGW remains one of the most beloved and commonly-encountered arguments in AGW Denialism. The enduring appeal of this argument is partly related to its simplicity. After all, the correlation is so obvious, even a 'caveman' could see it: First temperature increases, then CO2. The other major appeal (to some) is that it (superficially) appears to 'debunk' AGW (so long as one doesn't look too carefully). Yet, in one of the many "ironies" that characterizes AGW Denialism, many wannabe skeptics cannot resist the temptation of piggybacking onto this another favorite Denialist argument: that "correlation does not imply causation". This scientific axiom is often conveyed with a sanctimonious withering (virtual) sneer, as if real scientists failed to grasp this concept, or as if the entire theory of AGW rested on this correlation. Check it out yourself: A Google search on: "correlation does not imply causation" + temperature increase leads CO2 yields ~4,500 'hits', most of them being denialist (i.e. pseudo-skeptical) in nature. Wouldn't it be nice if Denialists understood their own advice enough to actually adhere to it? After all, if a simple correlation between temperature and CO2, documented throughout the geologic record, does not in and of itself prove causation, then why should the ~800 year lag in the Pleistocene ice record necessarily disprove it? The 'bottom line' is that a valid understanding of the interrelationship between temperature and CO2 requires a more complex understanding of the processes affecting the system, although once these processes are understood, a primary forcing on temperature by CO2 emerges. Our current understanding of what happens to atmospheric CO2 remains incomplete even in regards to contemporary proesses, and we have a great deal more to learn regarding the geochemical cyclicity of CO2 in the atmosphere, hydrosphere, and lithosphere on a geologic time scale, but while we're still studying and learning, it is important to interpret the presently available data without bias or agenda. If AGW is wrong, it's not because of the ~800 year "lag". So, true skeptics: Keep looking for legitimate weaknesses in AGW. It's your right and duty; And denialists, could we please move on? This argument is getting a bit threadbare. -
Argus at 02:35 AM on 19 May 2010Species extinctions happening before our eyes
#64 Ned, My apologies! I should have phrased my remark differently (or withheld it). My native language is not English, so maybe that made it come out even worse. But looking through the 100+ different topics or posts, I have a hard time finding one that is not based on the effects of an increasing percentage of CO2 in the atmosphere. But as you point out, that is the subject of this website (for which I am grateful). -
Phila at 01:54 AM on 19 May 2010Species extinctions happening before our eyes
#58 "Some of the science is over my head, but I appreciate and enjoy reading it never the less." When science is over my head, as it often is, I refrain from assuming that it's the scientists who are getting things wrong. I assume there's a failure of understanding on my part, not theirs. "Oh well LOL" isn't a coherent counterargument. "the author stated that he didn't consider Australia a continent, but an island." Australia is normally considered to be a continent, in both geological and geographical terms. The author you cite seems to calling it an island in order to discard inconvenient data. That should raise some red flags, I think. -
Steve L at 01:53 AM on 19 May 2010The significance of the CO2 lag
The data in 1b do not look linearly related to me. -
Spencer Weart at 00:48 AM on 19 May 2010The significance of the CO2 lag
Full citation is Scheffer et al., Geophys. Res. Lett.,33,L10702,doi:10.1029/2005GL025044,2006 online here -
VoxRat at 00:41 AM on 19 May 2010The significance of the CO2 lag
WAG: What's the one exception? -
WAG at 00:25 AM on 19 May 2010The significance of the CO2 lag
The real problem with this argument is that it is simply illogical. Just because CO2 lags temperature does not prima fascia rule out the possibility that CO2 can also cause temperature to increase. That's the beauty of global warming skeptics - of all the skeptic arguments, all of them except for one are not just scientifically wrong: they are simply logical fallacies. -
Ned at 00:18 AM on 19 May 2010Species extinctions happening before our eyes
Argus writes: [...] whereas this site blames everything on CO2 [...] Please let's be careful in our use of language. Yes, the article at the top of this thread focuses on climate change and doesn't discuss land use, invasive species, or other non-climate stresses on species. But I don't think anyone here is ignorant of or dismissive of the effects of those stresses. We mostly talk about climate change here because that's the subject of the website. Certainly, invasive species and land use change will exacerbate the problems of climate change for many species. -
Argus at 23:55 PM on 18 May 2010Species extinctions happening before our eyes
Thank you, Tom Dayton (#35) for the comprehensive and patient answer. I have also listened to the radio program, where they spent around 10 minutes on the problem, so I now have a much better understanding of the lizard problem. It seemed that, apart from endless presentations over and over again of all the titles of the professors present, most of the podcast was about other problems affecting flora and fauna than AGW, such as drought, urban development, and farming (whereas this site blames everything on CO2). Interesting aspects. Actually two listeners, calling, seemed to have interesting questions that promised to shed even more light on the topic of extinction, but they were cut off before they were allowed to get to the point (and falsely promised to be back after 'the break'). Disappointing practise! -
Ned at 23:51 PM on 18 May 2010The significance of the CO2 lag
Mythago, the details of this are very complicated, but the big picture isn't too bad. There is an equilibrium between CO2 in the atmosphere and CO2 in the ocean that shifts as a function of temperature. If you kept the total CO2 in the system constant but heated the ocean, CO2 would move from the ocean to the atmosphere (if you cooled the ocean, the opposite would happen). But we're not keeping CO2 constant, we're adding CO2 to the atmosphere at a rapid rate. This pushes it higher than the equilibrium value, so some of it gets taken up by the ocean (see below for references). But as it gets warmer, less gets taken up by the ocean than would happen if it were cooler. So, when CO2 was only a feedback rather than a forcing, the ocean would behave as described in the first paragraph of the article at the top of this thread (giving off CO2 when the ocean warmed). But now that CO2 is both a feedback and forcing, the ocean is "forced" to take up some CO2 even though it's warming, because there's so much going directly into the atmosphere. The other complicating factor here is the slow mixing time of the deep ocean. Originally (pre-1970s) most people weren't concerned about AGW because it was assumed that the deep oceans would take up more CO2 than we could ever emit. But from the 1950s to the 1970s evidence began to accumulate that this was incorrect. Because the surface layer takes a long time to mix with the deep ocean, the surface layer becomes saturated with CO2 much more rapidly, and its uptake is limited. Both of these factors mean that if you add a lot of CO2 to the atmosphere, the following chain of events will occur: (1) CO2 very rapidly increases in the atmosphere. (2) CO2 rapidly increases in the surface ocean, leading to a decrease in pH. (3) Because of (1), the atmosphere and surface ocean warm. (4) Because of (3), the surface ocean takes up less CO2, leading to a further increase in (1). (5) On long time scales (centuries to millennia) the CO2, warming, and low pH signal all propagate slowly into the deep ocean. Once you stop adding CO2 to the atmosphere, the following occur: (6) The atmosphere and surface ocean fairly rapidly come into equilibrium. (7) CO2 and temperature of the atmosphere and surface ocean very slowly decrease, and pH correspondingly slowly begins to return to normal. (8) The long memory of the deep ocean spreads out the process of returning to normal conditions over a timescale of millennia. A couple of useful papers (taken from our list here): Climatological mean and decadal change in surface ocean pCO2, and net sea–air CO2 flux over the global oceans (Takahashi et al. 2009) The Oceanic Sink for Anthropogenic CO2 (Sabine et al. 2004) I hope this helps. It is indeed a very confusing subject. When I was in grad school in the 1990s we had a lecture & lab exercise on ocean/atmosphere CO2 exchange and the oceanic carbon cycle, and we had to reprise them twice over because the professor (former director of a world-class climate science research institute) kept discovering essential details that he'd left out of the previous, simpler version. All of us students had nightmares about that part of the course! -
JMurphy at 23:39 PM on 18 May 2010Species extinctions happening before our eyes
nofreewind, you state that some of the science is over your head but also that you don't believe that "a one to two degree change in temperature, from 92 to 94F say, is wiping out these lizards" because it doesn't make "common sense" to you. This would suggest that the science behind this particular thread is not over your head, i.e. you understand it and have come to the decision that it is wrong. But when you also say it doesn't make 'common sense' to you, that suggests that your view isn't based on the science but on, rather, something else - this 'common sense'. Could you provide the science you have used to determine your view or state what the 'common sense' is ? -
Arkadiusz Semczyszak at 23:24 PM on 18 May 2010Species extinctions happening before our eyes
With many of the speeches on abrupt climate change - short and long past - the survivors now living species (not only lizards) - I chose two, but one author: Richard Seager ... - "The Little Ice Age" (film): "In the early 14th century cooled off in just 10 years. The temperature was about 2 degrees lower than today. Change in solar activity was low and we need to find out why it had so great influence on the climate. " - in presentation to the New York Academy of Sciences: "These abrupt changes - the Dansgaard-Oeschger events of the last ice age and the Younger Dryas cold reversal of the last deglaciation - are well recorded in the Greenland ice core and Europe and involved changes in winter temperature of as much as thirty degrees C!" -
michael sweet at 23:07 PM on 18 May 2010The significance of the CO2 lag
Mythago: The answer to your question is that in the past the temperature was forced (changed) by some other cause (like solar variation). CO2 was released by the ocean as temperatures increased. In the current situation, CO2 is being released by humans. This CO2 causes (forces)the temperature to rise. The ocean absorbs CO2 from the atmosphere now, changing ocean pH (and decreasing temperature rise). It is not yet known how long the oceans will continue to absorb CO2, or how much will be absorbed. Because the change in temperature is caused by a different forcing, the CO2 response (release, absorbtion) in the ocean is different. The CO2 lead/lag is also caused by the difference in the forcing. -
Ned at 22:58 PM on 18 May 2010Species extinctions happening before our eyes
nofreewind writes: This is the only blog that I would bother to read regarding the warmers point of view. Some of the science is over my head, but I appreciate and enjoy reading it never the less. I'm not sure what a "warmer" is. But if you like this site, you might also check out the thread about Science of Doom. I just added a comment that lists a few other useful and less well known climate science blogs. -
Ned at 22:51 PM on 18 May 2010Woody Guthrie award to The Science of Doom
I too am a fan of the Science of Doom blog. For those who are interested, here are a few more climate science related websites that I like. I'm omitting ones that are already widely known (RealClimate, Tamino) and those that focus more on policy, politics, etc., in favor of less-well-known sites that focus on the data and the science: Climate Change (Chris Colose's blog) Climate Charts & Graphs (Kelly O'Day's blog) The Whiteboard (Ron Broberg's blog) moyhu (Nick Barnes's blog) Clear Climate Code I would add these to the list of links, but that seems to be more intended for people to submit their own blogs as links ... -
Tom Dayton at 22:43 PM on 18 May 2010Species extinctions happening before our eyes
Nofreewind, the Science article that this post is about, is behind a paywall. But a huge number of libraries have that journal. If you're unwilling to get to a copy of the journal, you should at least listen to the radio interview I linked to in my earlier comment. As John explained in his post, the lizards can't forage sufficiently while they are sitting quietly in the shade. Also, they can't find mates. -
Ned at 22:23 PM on 18 May 2010CO2 measurements are suspect
Okay, one last comment. I wrote "Of course, the trends are actually increasing exponentially, but over short periods of time they don't diverge much from a linear trend." To be precise, the CO2 curves are actually increasing faster than an exponential trend. -
Ned at 22:18 PM on 18 May 2010CO2 measurements are suspect
FYI, here are the linear trends in CO2 concentration, 1990-2008, at the stations shown in the above graph:
Of course, the trends are actually increasing exponentially, but over short periods of time they don't diverge much from a linear trend. There are lots of additional stations all over the world that show the same thing. Anyone who still claims that the Keeling Curve is somehow contaminated by proximity to a volcano and unrepresentative of the rest of the world needs to explain why every other non-urban site shows the same pattern.Mauna Loa, Hawaii: +1.79 ppmv/year Barrow, Alaska: +1.78 Cape Ferguson, Australia: +1.79 Halley Bay, Antarctica: +1.78 Key Biscayne, Florida: +1.78 Ocean Station M, Norway: +1.78 Niwot Ridge, Colorado: +1.79 -
Ned at 22:00 PM on 18 May 2010CO2 measurements are suspect
As Tom Dayton suggests, if the question is whether CO2 has a short residence time, that should be discussed in the thread CO2 has a short residence time. If anyone is still uncertain about how consistent CO2 measurements are globally, please go to the World Data Center for Greenhouse Gases, search for CO2 data from various stations, and look at them yourself. Here are some examples of graphs. These data haven't been "normalized" or "fixed" to match each other; they're completely independent data sets. Some are from the polar regions, some from the tropics, some from the northern hemisphere, some from the southern, some from ocean sites, and some from inland sites.
[BW 2015-08-22 - link to graphic on imageshack (co2stnsfull.png) no longer valid]
Here's an enlargement showing 1990 to the present:
[BW 2015-08-22 - link to graphic on imageshack (co2stnspost1990.png) no longer valid]
Note how consistent the following are: the actual value, the upward trend, and the seasonal cycle.
Moderator Response:[BW 2015-08-22 - embedded graphics deleted as no longer showing valid content (were showing advertisments instead) and were breaking page formatting]
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nofreewind at 21:59 PM on 18 May 2010Species extinctions happening before our eyes
Quokka: >There is only so much WUWT I can take in one sitting. I could say the same about here, but I won't. This is the only blog that I would bother to read regarding the warmers point of view. Some of the science is over my head, but I appreciate and enjoy reading it never the less. But when I see the majority of you completely accept the premise that global warming in Mexico is making these lizards go locally extinct, what I can say but Oh Well, LOL. You mean, that a one to two degree change in temperature, from 92 to 94F say, is wiping out these lizards, I am supposed to believe that is the conclusion?? Sorry, but it just doesn't make any what I call, "common sense" to me. Could someone point me in the direction of the Mexico temperature data. -
nofreewind at 21:54 PM on 18 May 2010Species extinctions happening before our eyes
Quokka: >I didn't get past the abstract. the author stated that he didn't consider Australia a continent, but an island. -
Arkadiusz Semczyszak at 21:46 PM on 18 May 2010Species extinctions happening before our eyes
and ... "... and continually hark back to 12 year old papers ..." - The UNEP Climate Change Science Compendium 2009, on page 5, first version ... -
neilrieck at 21:33 PM on 18 May 2010The significance of the CO2 lag
During previous interglacial periods, natural warming (initially caused by Milankovitch Cycles) cause the oceans to release CO2 into the atmosphere. Milankovitch Cycles are base upon sine-waves but feedback processes (from CO2, water vapor, albedo, etc) change the sine-waves into a resultant saw-tooth wave. See the second graphic on this page: www.southwestclimatechange.org/climate/global/past-present The problem with the current interglacial (which started 11,700 years ago) is that industrial humans have precharged the atmosphere with industrial CO2. As the oceans continue to warm, dissolved CO2 will fizz out then add to the CO2 we have already released. Humanity will be hit with a double whammy. Scientists "have speculated" that our oceans hold 50 CO2 molecules for every CO2 molecule in the atmosphere. Let's hope the warming oceans are able to retain some of it. -
sleepership at 21:22 PM on 18 May 2010The significance of the CO2 lag
So what does this mean in our present time frame? In the current decade- 2010-2020? Would we see a global rise of around .3 degree F? Most climate models see this decade warming as much as the period of 1970-2010. -
boba10960 at 21:21 PM on 18 May 2010The significance of the CO2 lag
John, Thanks for reminding everyone that CO served as a feedback in past climate change and therefore MUST follow the initial climate forcing (e.g., the warming at the end of an ice age). However, temperature is not the main factor causing CO2 to change. The temperature dependence of CO2 solubility in seawater is well known. On glacial time scales the combined effects of changes in the temperature and salinity of seawater could have accounted for only about a fifth of the observed changes in atmospheric CO2 (e.g., W.S. Broecker, Glacial to interglacial changes in ocean chemistry, Progress in Oceanography 2(1982) 151-197). Over the time period covered by the ice core CO2 record the primary factors regulating atmospheric CO2 involved changes in ocean and atmospheric circulation that determine the amount of CO2 stored in the deep ocean, as shown by a number of recent studies. See for example: Anderson et al., Science 323(2009) 1443-1448, and the related Perspective by Toggweiler (same issue, p. 1434). Skinner et al., to appear in Science next week, and the related perspective. George Denton and coworkers have a review (in press) in Science that documents the complete sequence of conditions and events at the end of the last ice age, including the ocean and atmospheric processes that caused CO2 to rise. They emphasize and the importance of CO2 as a feedback to complete the termination of the last ice age. The science is certainly not settled on this issue, and competing hypotheses warrant further examination. But it’s an exciting time to see so many new insights concerning the links between past climate change and CO2. -
Arkadiusz Semczyszak at 21:17 PM on 18 May 2010Species extinctions happening before our eyes
# 50 Chris NOAA Paleoclimatology: "Imagine that over the course of a decade or two, the long, snowy winters of northern New England were replaced by the milder winters of a place like Washington, D.C. Or that a sharp decrease in rainfall turned the short-grass prairie of the western Great Plains into a desert landscape like you would see in Arizona. Changes of this sort would obviously have important impacts on humans, affecting the crops we grow, the availability of water, and our energy usage. These scenarios are not science fiction. Paleoclimate records indicate that climate changes of this size and speed have occurred at many times in the past. Past human civilizations were sometimes successful in adapting to the climate changes and at other times they were not. Because they occur relatively rapidly, these sorts of climate change are called abrupt climate change. Our understanding of past abrupt climate changes and their causes is still in its infancy; most of the research on this topic has been completed since the early 1990s. Scientists have made significant progress, however, in identifying and describing various abrupt events of the past and forming hypotheses about their causes. This paleo perspective will describe the evidence for past abrupt climate change and explore some of the possible causes." (2004,2008) - sorry for so long a quotation -
Mythago at 20:23 PM on 18 May 2010The significance of the CO2 lag
Okay I almost fully understand the principles of CO2 temperature lag but there is still another aspect which suddenly doesn't seem to fit, unless it is an effect that occurs during the time lag period which still doesn't seem to fit. I am referring to Ocean acidification which is (stating the obvious I know) the absorption of CO2. Now you say that the oceans releases CO2 as the temperature rises(first paragraph). So where does CO2 get absorbed into the oceans in this great cycle of events to bring about all this acidification that the oceanographers are screaming about? Are they simply getting jealous about the atmospheric scientists getting all the publicity? :-0) Only joking honest! I know acidification does destroy coral reefs but there seems to be a contradiction here. Has anyone done any research as to this aspect other than to say 'oceans get more acidic and this leads to the destruction of corals etc'? It happens to be a very pertinent point which if a mere amateur like me can spot it then I am sure the idiots who insist its all a scam will no doubt have spotted it too and be busy refuting climate science as another excuse to increase taxes (well here in the UK at least). So can you point me in the direction of some very simple research that will allow me to get my head around that sequence of events so that I can then set the record straight if anyone starts arguing the point. Specifically how CO2 gets absorbed by the oceans, yet is released by the oceans when the temperature increases. Yet there is a temperature lag from increased CO2 in the atmosphere, but the oceans are getting more acidic as atmospheric CO2 increases. But the increased atmospheric CO2 increases atmospheric temperature which increases ocean emissions of CO2. Which surely must reducer oceanic CO2 concentrations which must in turn reduce the acidification unless there is something that I have missed which says that CO2 is absorbed by the oceans from some other third party source. But which source would that be or by which mechanism does this occur? Its one of those silly niggling points that will bug me all day now.:-0) Any help with that would be very gratefully appreciated. -
Arkadiusz Semczyszak at 20:15 PM on 18 May 2010The significance of the CO2 lag
"However, this is complicated by the fact that different carbon cycle processes operate on different time scales." ... and it is very important: the essence - the heart of the matter. There is a huge range of uncertainty as "... Carbon Cycle Processes Operate On Different time scales ..." react (respond) to the temperature rise. For example, land. 11 the computer models, gave for 2,100 years (as projected in different p.CO2 for 2100 - 730 - 1020 ppm) results differ by up to circa 20 GtC/yr ! (Fig 1. (e), (f) - Climate–Carbon Cycle Feedback Analysis: Results from the C4MIP Model Intercomparison, Friedlingstein P. et al., 2006). # 2. MarkR It would be worth on this issue, once again to discuss (on this website) Segalstad's these words: "The IPCC postulates an atmospheric doubling of CO2, meaning that the oceans would need to receive 50 times more CO2 to obtain chemical equilibrium ..." According to me about the amount of CO2 in the atmosphere does not decide the ocean. That soil. I am currently working hypothesis - the scheme: the beginning of warming = increase soil respiration = increase of CO2 in the atmosphere. Remember that, with the highest content of soil humus, there are a temperate climate - warmer version (ie 4% of northern Ukraine, southern 7% humus in the soil). There synthesizing microbes humic acids dominate. The proposal - in the long term warming stimulates the synthesis of humus. Warming (especially tundra) = first increases respiration (p.CO2 increase in the atmosphere), then the succession of microbial groups, biocoenoses synthesize humus (final result: taiga) = increase in humus content = decrease of CO2 in the atmosphere. Delay (tens of years), is due to the fact that there is no simultaneous microbial succession of the whole team. Different species move at different speeds with the progressive warming. I recommend a very interesting publication: Temperature-associated increases in the global soil respiration record. Bond-Lamberty B, Thomson A, Nature. 2010. -
chris at 20:08 PM on 18 May 2010The significance of the CO2 lag
This paper should also be included in this discussion. Like Scheffer et al, Frank et al (2010) analyse pre-industrial Holocone temperature/CO2 relationships to extract a range of likely [CO2] feedback response to temperature change. They consider high values to be rather unlikely. So probably not quite so scary as the numbers in the top article might imply tadzio! That's not to say that there won't be nasty surprises ahead, since these analyses are for relatively non-perturbed natural environments, and unexpected responses to rapid temperature increases might push us into new regimes where theses analyses don't apply (e.g. heat-stressed rain forest die-back and the accompanying loss of carbon sequestration)..... Also it would be good if we would stop cutting down rainforest.... -
Ned at 19:45 PM on 18 May 2010The significance of the CO2 lag
RSVP writes: "warming causes more CO2 and more CO2 causes warming" Taken to its logical conclusion, this statement implies a runaway effect... (assuming an unlimited supply of CO2). Nope, that's wrong. In addition to Chris's explanation, see this other thread here and the graphs here. A given forcing (of either CO2 or warming) will produce more CO2 and more warming, because of the positive feedbacks. But unless the forcing keeps increasing, both CO2 and temperature will converge on some new, higher value, with no runaway effect (unless you add enough heat or CO2 to cause a regime shift a la Venus). -
Daved Green at 19:32 PM on 18 May 2010The significance of the CO2 lag
does not anyone find this a bit scary ?? -
chris at 18:39 PM on 18 May 2010The significance of the CO2 lag
no it doesn't RSVP let's take the value of a [CO2] response to warming of 15 ppm (equilibium rise in [CO2]) per oC. let's say that during the early Holcene (no human contribution to changes in atmospheric [CO2]) the Earth temperature was suddenly to rise by 1 oC. Atmospheric [CO2] would slowly rise from 270 ppm to 270 +15 = 285 ppm. We can esily calculate the consequent temperature response. Let's assume a climate sensitivity of 3 oC (of Earth surface warming at equilibrium per doubling of [CO2]). The temperature rise is close to 0.23 oC. This will induce a recruitment of more [CO2] (the CO2 response to enhanced temperature). This is 15 ppm x 0.23 = 3.6 ppm. The temperature response from this enhanced [CO2] (285 + 3.6 ppm = 288.6 ppm) is around 0.05 oC. This will recruit an extra 15 ppm x 0.05 = 0.75 ppm of [CO2]... ...and so on. In other words the two feedacks: [CO2] feedback (15 + 3.6 + 0.75 + .....) ppm temperature feedback (0.23 + 0.05 + ...) oC converge to new equilibrium values. i.e. no "runway effect" -
RSVP at 18:03 PM on 18 May 2010The significance of the CO2 lag
"warming causes more CO2 and more CO2 causes warming" Taken to its logical conclusion, this statement implies a runaway effect... (assuming an unlimited supply of CO2). -
MarkR at 18:01 PM on 18 May 2010The significance of the CO2 lag
I don't have time to read the paper yet, but I do wonder: as I understand it, a lo of the feedback is mostly from the oceans. Henry's Law says that both temperature and partial pressure of CO2 control the rate of CO2 dissolving. We now have drastically increased partial pressure by a factor of larger than the temperature change: might this not stop the CO2 feedback? At most, we should just expect a declining percentage of dissolving CO2 and eventually an increasing airborne fraction. -
babelsguy at 17:50 PM on 18 May 2010Increasing CO2 has little to no effect
doug_bostrom, well, that is the interesting thing: He claims that his "study" would avoid all discussion of other issues but just show that CO2 (and the other GHGs) *cannot* be the culprit due to what he calls the energy balance question... -
Riccardo at 17:40 PM on 18 May 2010There's no empirical evidence
PaulK, the heat balance equation can be solved analytically for a forcing linear in time F=b*t (Schwartz 2007); neglecting feedbacks: DT(t) = b*((t-tau)+tau*exp(-t/tau))/l where tau is the response time (=C/l with C heat capacity) and l is the climate sensitivity. For small deviations from equilibrium, i.e. DT<< Te, the increasing thermal radiation E is proportional to DT, E=c1*DT. If the linear forcing is due to an increasing IR absorption (e.g. exponentially increasing CO2 concentration), the total OLR is: OLR(t) = E - F = c1*DT - b*t which, grouping all the constants together for simplicity, can be written as: OLR(t) = c*((t-tau)+tau*exp(-t/tau))-b*t The first term in the equation above is linear for t>>tau and one can write: OLR(t) ~ (c-b)*t - c*tau ; for t>>tau what governs the slope of the OLR is then the term (c-b) which can be positive or negative. For short times, instead, the slope of the OLR is always negative: d OLR/dt = c*(1-exp(-t/tau))-b*t ~ -b*t ; for small t In a few words, with a linear forcing DT will always increase linearly for time much longer than the characteristic response time of the system while OLR may increase or decrease depending on the strength of the forcing. What I (inappropiately) called runaway warming is when you have a continuosly decreasing OLR.
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