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Comments 130501 to 130550:

130501. AnthonySG1 at 20:34 PM on 9 May 2008
        Al Gore got it wrong
        Seems Gore was wrong afterall: http://scienceandpublicpolicy.org/images/stories/papers/monckton/monckton-gores_10_errors_old_and_new.pdf http://www.johnstonsarchive.net/environment/gore.html http://scienceandpublicpolicy.org/monckton/goreerrors.html http://article.nationalreview.com/?q=YmFiZDAyMWFhMGIxNTgwNGIyMjVkZjQ4OGFiZjFlNjc=
130502. AnthonySG1 at 20:25 PM on 9 May 2008
        Antarctica is gaining ice
        OK smarties. If Antarctica is overall losing ice, then how do you explain the data? http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg The Arctic doesn't seem to be doing so bad anymore, also: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
        Response: Note: the rebuttal above has been updated since this comment was posted, incorporating later references and clarifying that sea ice and land ice are two separate phenomena. Antarctica is losing land ice at an accelerating rate. Sea ice around Antarctica is increasing. The reasons for sea ice increasing in a warming Southern Ocean are complex and described in detail above.
130503. rcglinsk at 15:22 PM on 9 May 2008
        Models are unreliable
        Poptech, nice job of trying to help people understand what computer modeling is and what it can do. Folks, if a climate model doesn't predict past data 100% perfectly then it's useless. You can create an infinite number of different mathematical models that will predict any data series 100% perfectly. To deserve any respect these climate models must predict the previous data perfectly as a start, none should even be thought about unless it does that, and then it has to predict the future better than a simple polynomial fit that also perfectly predicts past data. Frankbi, all the facts in Poptech's post are verifiable. I learned them in school. His analysis is spot on.
130504. Quietman at 08:53 AM on 9 May 2008
        Can animals and plants adapt to global warming?
        chris I agree to some extent but feel that CO2 does not play as big a role as you indicate. Its primarily a feedback mechanism and needs something to feedback from, that is why there is a lag to temp increases. Asd you mentioned Milankovitch cycles, these appear to be a major climate driver but not the only one. Then there is the Fairbridge sea level cycles and his last hypothesis about solar (system) cycles, about which Mackey did a paper on after Dr. Fairbridge passed away. AGW is about an artificial CO2 feedback but there is also a very real natural CO2 feedback mechanism. PS - In my original comment "interesting" was in reference to the potential comments opened up by this particular subject which I am much more familiar with than climate science.
130505. gx at 18:19 PM on 8 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        About April anomaly,over land Asian exceptional anomaly has greatly reduced while antarctica interior has been warm this month,oceans are warming slowly despite la nina rapid decline(there is a 2-3 months lag beetwen ocean temps and ENSO) thus do not expect a very warm month as March(neither cold anyway). RSS satellite data are stable due to land cooling compensated by ocean warming but satellite data are more sensitive to tropical SST change and less to land surface anomaly... RSS land and ocean data: MSU Land Temp MSU Ocean Temp And some information about MSU vs tropical SST
130506. paledriver at 08:13 AM on 8 May 2008
        There is no consensus
        #52, Robert S., I don't know where you got 200 climate researchers were there, but there are over 20,000 climate scientists in the U.S. alone according to the AGU, so even there were 200 in attendance, and assuming they were all skeptics, that's still only about 1%. That would qualify as an overwhelming consensus in my book.
130507. gx at 22:50 PM on 7 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        co2 interannual varibility is mostly due to tropical land fluxes,droughts and fire in the Amazon basin and Indonesia during el nino are the main driver not ocean release/absorption: http://www.atmos-chem-phys.org/3/1919/2003/acp-3-1919-2003.html http://cat.inist.fr/?aModele=afficheN&cpsidt=16775977
        Response: Those are both interesting papers, thanks for the links.
130508. Steve L at 12:59 PM on 7 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Responding to the possibility of atmospheric CO2 declining this year ... well, the 1998 El Nino was associated with higher CO2 concentrations (presumably due to the Pacific releasing it or failing to absorb much due to warm surface temperature). Also, after Pinatubo there wasn't much increase in CO2 (despite the volcanic release), I guess because it was colder and the ocean surface absorbed more CO2? I wonder if the size of the economy can be reconstructed from trends in CO2 concentrations? That's presumably another factor that COULD contribute to a lower-than-expected CO2 concentration in 2008, although I greatly doubt it.
130509. tbandrow at 02:13 AM on 7 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        I don't think anyone doubts that global temperatures will continue to rise. After all we're continually enhancing the levels of atmospheric greenhouse gas levels, and temperatures are already on their way up to a new equilibrium level "set" by the enhanced greenhouse gas levels already up there. Some people do have that doubt. So, what I'm trying to do is set up an actual conditions of a simple experiment. John's been super enough to basically describe his view of things and its certainly mainstream enough. La Nina ends, and global temperatures will rise for it through the year. If the temperatures rise, then, yeah for Hansen and friends. current models are more validated and the sunspot people made a prediction that failed. we have a weak solar cycle, low flux and sunspots, and the earth's temperature still goes up. That would pretty much do it. If the temperatures fall, though, then yeesh, there's work to do. If there is some sort of mechanism driving the climate than a lot more science needs to be done. But, at least there is a, double yeah for Hansen and friends because they at least have some software base that will need to be adjusted to reflect new things learned. I am skeptical of global warming per se, but that doesn't mean I oppose the use of computer models as a means of encoding scientific knowledge. Rather, I just think the current models suck. It's been my experience that most experts in some other field are horrible programmers, and I'm a computer programmer. I had a look at Hansen's GCM, and although my FORTRAN is very rusty, what they have in there just seems absurd. Some other climate models seem to use the same sort of analytical and modelling techniques used by the finance industry, and that's been a 200 billion dollar fiasco -so far-. I have a sort of a dream that I'm going to write a GCM that doesn't suck and so this immediate experiment interests me. So, I'm not coming from the perspective of denial because a lot of people of a left wing ilk are pushing it. Rather, I see an opportunity for my capitalist friends to really cash in on climate by offering someday a -better model-. So, to other skeptics, I would say, if you don't like the model that is out there kicking out global warming predictions, make one that is more accurate. If you can't, then get out of the climate business and let the pros do their jobs.
130510. chris at 22:42 PM on 6 May 2008
        Can animals and plants adapt to global warming?
        Quietman We know reasonably well well why ice ages occur. In the general case, major glacial epochs (we're in one now) are associated with low atmospheric CO2 levels. For example the present glacial epoch began during the Miocene. The early Miocene glacial period around 20 million years ago (mya) is associated with the late Oligocene-early Miocene decrease in atmospheric CO2....the middle Miocene climate optimum (so-called) with a rise of atmospheric CO2, and then the late-Miocene expansion of the East Antarctic ice sheet is associated with a drop in atmospheric CO2 around 14 mya [*****] Of course these glacial periods also require other factors...for example the Miocene glaciations that heralded the start of the cool period which we're still in, wouldn't have occurred (or at least not to the same extent) without a land mass in the Antarctic for ice to build up on.... Likewise the earliest glacial epoch on Earth more than 3 billion years ago was likely the result of the evolution of the first photosynthetic organisms that produced oxygen which eventually (after turning enormous amounts of oceanic iron salts into iron oxide) destroyed (oxidised) the high methane concentrations that was then "helping" to warm the early Earth. As for the ice age cycles within the current glacial periods, these are also quite well understood, as I'm sure you know. They result from the slow cyclic variations in the orbital properties of the Earth (google Milankovitch cycles) that result in slow and small variations in the pattern of solar irradiation on the Earth. These cycles have associated variations in greenhouse gas concentrations (especially CO2). I think it's quite clear that we are in an interglacial period which still has quite a few thousand years to "run". [*****]e.g. Kurschner WM et al. (2008) The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of terrestrial ecosystems; Proc. natal. Acad. Sci. USA 105, 449-453. Abstract: "The Miocene is characterized by a series of key climatic events that led to the founding of the late Cenozoic icehouse mode and the dawn of modern biota. The processes that caused these developments, and particularly the role of atmospheric CO2 as a forcing factor, are poorly understood. Here we present a CO2 record based on stomatal frequency data from multiple tree species. Our data show striking CO2 fluctuations of approximate to 600-300 parts per million by volume (ppmv). Periods of low CO2 are contemporaneous with major glaciations, whereas elevated CO2 of 500 ppmv coincides with the climatic optimum in the Miocene. Our data point to a long-term coupling between atmospheric CO2 and climate. Major changes in Miocene terrestrial ecosystems, such as the expansion of grasslands and radiations among terrestrial herbivores such as horses, can be linked to these marked fluctuations in CO2."
130511. John Cross at 11:34 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Chris: some comments about your point (i). The PDO came about from fishery research in Alaska so I suspect that the warm / cool is a local description (and not really a useful one either). My guess is that we will start to see the term positive and negative phase used more and more. Keep in mind the idea of the PDO is only about 10 years old. Regards, John
130512. chris at 05:43 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Some general comments and questions about this thread. There are a number of things that I'm confused about: (i) All of these ocean oscillations (El Nino's, La Nina's and the Pacific Decadal oscillation) act to modulate the global surface temperature through the redistribution of solar energy with respect to the ocean surface and depths. In El Nino years, for example, warm surface waters spread across large parts of the equatorial Pacific with a suppression of cold water upwelling of the West coast of S. America. So the Earth's surface temperature rises a tad during the period of this phenomenon....however the contribution to any long term trend (e.g. drien by greenhouse-warming) is close to zero. However, according to your Figure 2, the warm phase of the PDO seems to be associated with reduced sea surface warmth overall. Apparently the PDO is identified with respect to the pattern of sea surface temperatures near the NW coast of the US and Canada. But this seems a highly localized affair! Unless something untoward is happening on the other half of the globe (hidden in Figure 2), I don't understand what's going on. I actually assumed that you might have mislabelled Figure 2 a and b, but apparently not. It does look a bit odd to me...much larger areas of red and dark red in the "cool" phase of the PDO.. (ii) What are the predictable elements of the PDO in the analysis of Keenlyside et al? I had a quick read through their paper and it doesn't seem obvious to me. In other words what is it about the PDO that is sufficiently predicatble that Keenlyside are basing their projections on its future behaviour? It's not particularly cyclic (see your Figure 1), so what is it? Anybody got a simple explanation? (iii) Keenlyside et al [Nature 453, 84-88, 2008; link in Johns summary at the top of the thread] seems slightly problematic to me. In their Figure 4 (top of page 87), their "hindcast/forecast" shows zero global warming between 1985 and 2000. They consider the latter parts of this period as "verification". I would conclude that their "verification" has failed somewhat! Their "forecast" indicates that the period between 1985 and 2005 should give a temperature increase of around 0.1 oC. That's much smaller than the measured global temperature rise during this period... again that might be taken to indicate that their "forecast" isn't actually that good. (iv) A general point. I wonder whether the efforts at short-medium term "forecasting" are premature, or if not premature, might be being taken out of context. If there are stochastic elements of the climate system that are not well-defined [see point (ii)], aren't these "forecasts" similar to "guesses"? Modelling seems a rather good way of assessing the equilibrium temperature increase in response to various greenhouse gas emission scenarios, and giving us some indication of the time scale of temperature increase and the geographical distribution of excess warmth. But rather detailed forecasts of the Earth's temperature evolution over periods of a few years to decades seems problematic to me. I can understand the value of these efforts in (a) the continuing development of modelling efforts and (b) as a test of our understanding of the various elements of the climate system and their interactions, and so on...but they really need to be understood in those terms I would have thought. I don't think they should be considered as "true forecasts" in the wider sense. They're certainly not "predictions", although unfortunately many will consider them to predictions, and will no doubt be ready to jump on them when the forecasts turn out not to be correct...
130513. chris at 04:58 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        tbandrew, re your comments: ["LaNina ended in April. Are you standing by the assertion that global temperatures will continue to rise now that that has happened? If they do decline, then what is the cause? And, what would you say if the Mauna Loa CO2 measurements for this year actually -decline-."] I don't think anyone doubts that global temperatures will continue to rise. After all we're continually enhancing the levels of atmospheric greenhouse gas levels, and temperatures are already on their way up to a new equilibrium level "set" by the enhanced greenhouse gas levels already up there. The point of this thread is that internal variability in the climate system (El Nino's, La Nina's, and more specifically to this thread, the Pacific Decadal oscillation) might act to counter the greenhouse-induced surface temperature rise for a while. Of course if the sun "decides" to burn a tad cooler or we have a serious bout of volcanic activity, then greenhouse-induced warming will be delayed further....but one cannot massively enhance the concentration of atmospheric greenhouse gases and not expect that the world will warm.. And it's rather unlikely that the atmospheric CO2 levels will decline during 2008. They're already well above 2007 levels. Why should they decline? What's your proposed mechanism whereby addiding CO2 to the atmosphere will result in a decreaed level of atmospheric CO2, particularly as the oceans absorption of CO2 is already becoming somewhat less eficient?? here's the data: http://www.esrl.noaa.gov/gmd/ccgg/trends/ (either view the Mauna Loa data or scroll down the page for the globally averaged sea surface CO2 data).
130514. John Cross at 03:41 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Tbandrow: In regards to the temperatures, I would be surprised if they continued to grow. I am actually expecting a small decline in April's temperature - only because the March temperature was so large. I do not expect them to return to the January / February levels. In regards to the CO2 levels, if there is no annual growth in the CO2 levels then I will be extremely surprised. Regards, John
        Response: The Australian Bureau of Meteorology have updated their Southern Oscillation Index and La Nina continues to subside. So as a broad guesstimate, I expect April's temperatures to be around level to March, possibly slightly higher depending on whether they get Africa's data this month and whether Russia's massive heat wave continues.
130515. Quietman at 02:11 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        tbandrow Good points. But how about the gases and particulates from burning buildings, burning fuel and supply dumps, burning vehicles and ships and the gases from the ammunition of all types expended. Being a combat veteran I am somewhat familiar with the effects of a combat zone and its a dirty place. Just think about the Kuwait conflict where Sadam burned the oil fields. That is a lot of emissions all at once. In WW2 the allies burned a lot of oil fields. But, like I said, its just a thought.
130516. tbandrow at 01:06 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        The reference to WW2 is figure 4. The confilct in Europe began in 1936 and the Pacific conflict slightly earlier. An interesting anomaly that could easily have been AGW due to the wartime industry and the conflict itself. Just a thought. You might have us on climate but your history suffers for it! Fuel demands were much, much lower then. By way of example, the US Army back then used 1/16th of the fuel of the fuel it uses today. Vehicles are heavier today, and faster. Jet engines gobble fuel. There were no helicopters in World War II. http://www.strategypage.com/htmw/htlog/articles/20080404.aspx This isn't to say that the USA fought WWII by itself, but, if anyone gobbled fuel during WWII, it was the USA. The Japanese and Germans both had tremendous fuel problems. Germany couldn't get fighters aloft for lack of fuel, and its own offensives often stalled for the same reason. By the end of the war, Japan was reducing to sending capital ships on suicide missions because they didn't have the fuel to actually operate them. Also, no army was as well mechanized as the US Army was. The German logistical train had a lot of steam engines and horse drawn transport, whereas the USA operated a lot of trucks. The Russians had a big, mechanized army too, and used a fair amount of fuel - but they didn't operate strategic bombers and a giant navy the way the USA did. domestically, the USA rationed gasoline "is this trip really necessary". Most passenger transport was by rail. If you look at most of the rail transport in the USA, you will see a lot of steam locomotives being pressed back into service. In fact, FDR actually forced some loco companies to keep making steam engines rather than diesels (which ultimate lead to their postwar demise), because coal was more available and steam was at least well understood. But locomotives are awefully cheap on CO2 compared to cars. I mean, a big steam engine of the day -might- make about about 2000 horsepower, (the biggest, Big Boy, was about double that), or about the power of 10 of today's car and not even close to the power of a single jet engine on a fighter aircraft. But out of that horsepower, you would pull a rail line that could probably be many, many passenger cars. The UP BigBoys pulled freight trains that were measured in -miles-. Moral of the story is, the cheapest way to go green is to build more rail lines and use more trains.
130517. tbandrow at 00:19 AM on 6 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        That's all well and good, but earlier, you wrote to discredit the sunspot series, and you predicted that: a) the current drop in global temperatures was due to La Nina, AND b) that, once LaNina ended, global temperatures would continue that rise. LaNina ended in April. Are you standing by the assertion that global temperatures will continue to rise now that that has happened? If they do decline, then what is the cause? And, what would you say if the Mauna Loa CO2 measurements for this year actually -decline-.
        Response: My assertion was that the sharp cooling from Jan 2007 to Jan 2008 would reverse when La Nina reverses. I still expect that to occur (in fact, I believe it's currently occuring). If CO2 levels at Mauna Loa fell this year, it would be an interesting result. However, that is one station - if the global average of CO2 levels fell this year, I would be very surprised.
130518. Craig Allen at 17:13 PM on 5 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        How are the forcings in plot 4 estimated?
        Response: The net forcing is the result of combining all the following forcings:
        
        
        
        NASA GISS have links to further resources:
        

        • Well-Mixed Greenhouse Gases
        • Solar Irradiance
        • H₂O
        • Tropospheric Aerosols
        • Stratospheric Aerosols

        You can find out more at their Forcings in GISS Climate Model page.
130519. Quietman at 05:45 AM on 5 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        John Cook Re your response to Steve L.: Deniers love it, the skeptics simply expected it. The trend forcast as 10 years is conservative. I have read that the trend down would last through 2040 and then resume upwards. I have also seen that it will have an inverse peak around 2022. Lets hope they are right as it give us a reprieve.
        Response: The global cooling predictions through to 2040 are usually based on predictions of cooling solar activity. I would treat those with healthy skepticism. I also hope they're right but don't think it likely (or frankly very possible).
130520. Quietman at 05:29 AM on 5 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        John Cross The reference to WW2 is figure 4. The confilct in Europe began in 1936 and the Pacific conflict slightly earlier. An interesting anomaly that could easily have been AGW due to the wartime industry and the conflict itself. Just a thought. In figure 3 the correllation can also be seen to some extent but not in the trend line. It makes it clear that other factors are involved.
130521. Quietman at 02:46 AM on 5 May 2008
        Can animals and plants adapt to global warming?
        chris On cycles and explanations for previous extinctions: I used those 2 articles simply because they were the most recent, not actually the most relavent. As you are aware the idea of extinction cycles is just hypotheses, while the idea of climate cycles has good evidence. In the case of the KT event, some paleontologists have pointed out that the dinosaurs were in decline from about 70 million years ago due to climate stress. The effect of the Deccan Traps and the Yucatan impact seem to be a fatal blow but most likely not within a cyclic extinction (my view). The PT event also involved an impact and the Siberian Traps but did they actually cause the climate change or again were they a coincidence that simply made things worse? The issue of clarity in climate cycles is simply that there are too many of them and not all of them identified as yet. Why do ice ages occur? Of the 4 major iceages why are they of different lengths and what causes their end. Are we now coming out of an ice age of merely within an interglacial? There are definate cycles involved but we still have a long way to go in understanding them. And I agree, Global warming does seem to be directly related to extinctions and I believe that it is the speed not the temperatures that are relavent. The warming slopes are much steeper than the cooling slopes, not allowing enough time for species to adapt. I simply disagree that mankind is the direct cause. But I feel that our mistakes have only made things worse.
130522. Quietman at 02:14 AM on 5 May 2008
        Can animals and plants adapt to global warming?
        chris Thank you for the responses. My personal position is not as extreme as you might believe, in fact its closer to yours than average, I just don't get emotional about it. As I said, we, as a species, have made mistakes by not taking better care of the habitats that we live in and should attempt to correct these mistakes. I am not saying that the answer is to do nothing, but pointing out that our concentration should be on area that needs it the most like the Amazon deforestation issue. What I attempted to point out with polar bears is that they are adaptable, they are not actually in danger of extinction while other species are. With limited resources we should concentrate on the species that are both truely endangered and of greater benefit to both ourselves and out habitats. In doing so we will also be helping less endangered species like the polar bear. Barry Brook is pointing out the endangered areas, of SE Asia. While concerned, I feel we need to look in our own back yards first. By helping the ecology here we can do our small part. This however does not mean that I believe that extinctions over the past 10K years are not natural or that the endangered animals currently under stress were not already under stress, just more so.
130523. chris at 08:07 AM on 4 May 2008
        Can animals and plants adapt to global warming?
        Quietman, On cycles and explanations for previous extinctions: Hunting around for the latest press releases and popular science articles as all-encompassing “explanations” for past events isn’t very helpful or scientific. Scientific explanations require a set of rather more self-consistent data and theoretical frameworks. A very recent paper that indicates that dinosaurs may not have had the genes for generating brown adipose tissues (the article in Science Daily that you urled), does not suddenly become the explanation for the demise of the dinosaurs, let alone the more widespread extinctions associated with the end-Cretaceus events! The possible lack of adipose tissue in dinosaurs certainly wasn’t the cause of end-Cretaceous extinction of ammonites, mosasaurs, plesiosaurs, various birds and mammals, plants and invertebrates, and so on.. In fact, if you read the paper referred to in your popular news article [N. V. Mezentseva et al (2008) “The brown adipocyte differentiation pathway in birds: an evolutionary road not taken”; BMC Biology 6 (17) 21 April 2008], you’ll see that the authors don’t mention dinosaur extinction at all (the words “extinct” or “extinction” don’t appear in their paper). No doubt the popular press article that you urled was “sexed up” by an editor to give it a punchy general appeal. The fact is that the end Cretaceous extinctions were not due to the possible lack of brown adipose tissue in dinosaurs, although that might or might not have contributed to the demise of that particular order. Regarding the dinosaurs, it’s rather more likely that the widescale attenuation of photosynthetic activity for a few years following an extraterrestrial impact was more than sufficient to kill off large herbivores and their predators. For the extinction event overall, the evidence indicates a combination of an extraterrestrial impact with a long term tectonic events associated with the Deccan Traps formation in non-India as the likely causal factors [e,g Beerling et al (2002); Keller (2005); Kelley (2007)]. But was the end-Cretaceous extinction part of a regular “cycle” of extinctions? The evidence isn’t very strong. You describe Wikramsinghe and Napier as indicating a 36 million year (my) cycle of extraterrestrial impacts that relate to passage of the solar system through the galactic plane. That paper isn’t available yet apparently, but a recent similar study by Napier [“evidence for cometary bombardment episodes” Mon. Not. R. Astron. Soc. 366, 977-982 (2006)] doesn’t present that compelling a case for a regularity of impacts. And after all, in the paper you previously cited as evidence of the cyclic nature of extinctions [Rohde and Muller, Nature 434, 208 (2005 )], the extinction “cycle” was supposed to be 62 my. You presumed from that study that we are “presently in one now” (i.e. an extinction, since the period is 62 my, and the last one was around 65 mya). However if the extinctions are actually supposed to “cycle” with a 36 my, then we shouldn’t be in an extinction now at all! So which is it? I suspect the problem relates to the search for “cycles”. The cosmic ray fluxers look at the extinction record and see a 140 my “cycle”; the astrobiologists “see” a 36 my “cycle”; Rohde and Muller “see” a 62 my “cycle”. It’s rather easy to “fit” sinusoidal variations into very sparse data sets (rather few extinction events; rather few impact craters; rather limited fossil record). I don’t have any problem with the possibility that there might be regular variations in the cometary intensity due to passage of the solar system through the plane of the Galaxy. The problem is that the evidence isn't that compelling, and there is really only one extinction event (end-Cretaceous) that has good evidence for a causal impact event. More compelling (to me!) is the data that focuses carefully on the extinction events themselves to identify features of the contemporaneous geological record to determine potential associated geological and environmental effects. When one does this, the most regular correlate of extinctions is tectonic events (doesn’t necessarily indicate causality of course!). A very recent reanalysis of the argon-argon dating “clock” has established, for example, that the massive Permian Triassic extinction correlates with the massive volcanic events associated with the formation of the Serbian Traps (see Science 25th April 2008)]. The end-Cretaceous extinction (dinosaurs et al) correlates with the tectonic events associated with the Deccan Traps formation. The Paleo-Eocene Thermal Maximum extinctions with the tectonic events associated with the opening up of the North Atlantic at a plate boundary. The Triassic-Jurrasic extinction (201.6 mya) associates with the massive volcanic outpourings of the central Atlantic magmatic province…and so on... Are these tectonic events governed by grand “cycles”. There’s no evidence for such a cycle, nor is there evidence for any causal attribute of periodicity in these processes. Actually, when one boils down the essential correlates of extinctions as these are best defined, the evidence indicates that global warming (as the result of the release of greenhouse gases) seems to accompany most extinction events, and that’s one of the compelling reasons for attempting to get to grips with these difficult to study events in the deep history of the Earth! ---------------------------------------------- Beerling DJ et al. (2002) An atmospheric pCO(2) reconstruction across the Cretaceous-Tertiary boundary from leaf megafossils; Proc. Natl. Acad. Sci. USA 99 (12): 7836-7840 Keller G (2005) Impacts, volcanism and mass extinction: random coincidence or cause and effect?; Austral. J. Earth Sci 52 725-757. Kelley S. (2007) The geochronology of large igneous provinces, terrestrial impact craters, and their relationship to mass extinctions on Earth ; Journal of the Geological Society 164, 923-936 etc..
130524. chris at 07:57 AM on 4 May 2008
        Can animals and plants adapt to global warming?
        Quietman, There are two issues here. One is the reality of our present impact on the biosphere and the additional consequences of global warming on a natural world suffering the effects of habitat destruction and fragmentation. That's what Barry Brook's article is about. The second is about the causes of previous extinctions and the possibility of cyclic causal factors. These can be addressed separately, since while past extinctions are clouded in various uncertaintites, the present extinction is not. So I'll address the current extinction in this post and the possibility of cyclic contributions to past extinctions in another. Notice that the possible contributions to past major extinctions are (whether cyclic or not) variously: tectonic events; catastrophic extraterrestrial impacts; changes in greenhouse gas concentrations (CO2; methane) resulting in global warming or cooling that may be associated with tectonic events or impacts; sea level changes; variations in the cosmic ray flux...(we might come up with some others...) NONE of these apply to the current extinction event even 'though the enhanced greenhouse contribution is likely increasingly to do so (that's the subject of this thread if you remember!). The last several thousand years, and especially the last several hundred years has NOT seen extinction-level tectonic events, extraterrestrial impacts, massive sea level changes, very large and persistent changes in the cosmic ray flux; large changes in greenhouse gas levels and so on... So the current extinctions are not a consequence of any of these, nor a consequence of any unspecified grand "cycles". They’re a result of mankind’s impacts on the biosphere, especially habitat destruction and fragmentation. Let's not pretend that we don't know what we do know! The problem with the attempt at passive dissociation from these realities is that it leads to a rather disinterested acceptance of events that might very well be in our control to address. So let's look at these: (i) You consider that our part in these processes (direct extirpation of species by hunting or persecution; habitat destruction and fragmentation; more recently, massive release of greenhouse gases) is a natural one. That certainly applies in the past; however not only is that an unhelpful notion in the present context (it lends to passive acceptance of issues we might otherwise address productively), but at some point that notion breaks down, at the very least at whatever time in our history we start to recognise the wider consequences of our actions, and it’s implications for our futures. So it’s not really “natural” anymore by most generally recognized meanings of the term. But however we might semanticize our present situation ("natural"/"non-natural"), the fact is that we might decide to address the problems since we recognise and understand these. We might choose to address policy that limits destruction of habitats and allows these to extend somewhat; we might take further measures to protect ocean species by setting up protected no-fishing respite zones in the manner that is being undertaken already; we might take measures to limit greenhouse gas emissions, and to curb human population growth...in fact we have to do some of these sooner or later…the only meaningful long term future for mankind is one based on stable populations in societies fueled by renewable energy sources for example, and that future starts rather soon! (ii) you suggest that we shouldn't "help" polar bears since they’re apparently a "competitor to us as a species" and "we share the same habitat" and "eat the same food" and "we should concentrate on saving species that are beneficial to us". Fair enough...but what a dismal philosophy if I may say so. After all why not kill off all species that we can't productively convert into domesticated animals for food, furs, milk, and other bits and pieces? And in what way is the polar bear a "competitor" which "shares or habitat" (Arctic continental margins and sea ice?) and eats the same food (seals?)? Mankind has co-existed pretty comfortably with polar bears and there's no reason why we can't continue to do so. It may be that the polar bear is doomed because its habitat is not going to survive the likely destruction of Arctic sea ice. But let’s recognize that that will be a diminishing prospect for us and the natural world and one that we might take careful note of, especially in relation to more effective protection of wilderness areas. There is a philosophical issue here of which Barry Brook’s article highlights one side and your posts highlight a rather extreme other. On the one hand, we can make mature and rational attempts to inform ourselves about the natural world, our place within it and our impacts, as indicated by careful observations and analysis, and then address these in relation to concerns about our wellbeing and that of our near descendants (who will themselves have to address these issues)… ..or on the other hand, we can sit back and wash our hands of the whole affair, using as justification for our passivity, pseudoscience notions of “natural” “cycles”, which we are apparently helpless to explain and understand.
130525. Steve L at 04:06 AM on 4 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Dear Johns, my immediate impressions follow: First, comments in the links regarding abilities to forecast El Nino, etc, seem a bit optimistic; also, it seems quite early to have any confidence in a forecast of PDO. Second, who named the 'warm' and 'cool' phases of the PDO phenomenon? Must have been North Americans? Third, Pinatubo caused the low forcing in 1992, and I suppose El Chichon caused the downspike in 1983. Google helped me find Agung in 1963 -- is that the cause of the mid-60s downspike? One can go to lots of internet locations to find discussion of the quality of temperature measurements; what's the best place to look to learn about reconstructed estimates of forcing?
        Response: Re the accuracy of the new model's predictions of El Nino, PDO and North Atlantic short term behaviour, this is the most ironic element of the whole situation. These are new models testing new methods - inevitably, they'll be refined and improved over time and there'll be inaccuracies. And yet as they're predicting results the skeptics like (eg - cooling in the short term), the skeptics suddenly have lost their skepticism for climate models - or at least for these results.
        
        Re forcing reconstructions, there are links to papers and people at the NASA GISS page on forcings.
130526. John Cross at 03:47 AM on 4 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Quietman: Are you talking about Figure 4? If so, I see the spot you are talking about. I could also make an argument for an earlier period of say about 1905 to 1925 - but I tend not to trust forcing estimates from that early. NewYorkJ: Thanks for the links. I had a skim through but have booked marked it to go back to and read in more depth when I have the time. Regards, John
130527. NewYorkJ at 03:05 AM on 4 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Regarding the Keenlyside forecast, most media reports are missing a key piece - that the temperature projection converges with the IPCC projection within 20 years. http://climateprogress.org/wp-content/uploads/2008/05/nature5-1.jpg http://climateprogress.org/2008/05/02/nature-article-on-cooling-confuses-revkin...
130528. Quietman at 00:50 AM on 4 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        Johns I see that there is a lack of correllation from the beginning of WW2 through a couple years past its end. Otherwise it appears to be a faily good match.
        Response: Looking at Hansen 2005's model hindcasts, they also show less correlation around the 1940's. I'm guessing it's due to internal variability - possibly strong El Nino at the time? I haven't looked at it in detail yet though (but plan to for a future post on mid-century cooling).
130529. Quietman at 13:53 PM on 3 May 2008
        Can animals and plants adapt to global warming?
        chris Since you chose the KT event as an example, I can addrss that event. The cyclic influences, Sun's Movement Through Milky Way Regularly Sends Comets Hurtling, Coinciding With Mass Life Extinctions *1. This gives a slightly xhorter cycle than the Berkely study. But the dinosaurs were already in decline before the Yucatan impact and before the eruption of the Deccan Traps due to a cooling climate which they could not adapt to. Their problem was that Dinosaurs Probably Lacked Tissue To Generate Heat *2. Vulcanism and the impact pushed them over the edge. There are a lot of forcing cycles for climate change and for extinctions vulcanism and impact cycles also must be included (see Johns PDO title, the solar titles and the volcanos title for just a few). *1 Adapted from materials provided by Cardiff University *2 Adapted from materials provided by New York Medical College
130530. stephen at 13:36 PM on 3 May 2008
        Do 500 scientists refute anthropogenic global warming?
        You guys might have heard about this, but there are some very annoyed scientists around now that they have discovered their names are on the list without permission. They are also very annoyed at having their science twisted around to suit Heartland's purposes e.g. "I am horrified to find my name on such a list. I have spent the last 20 years arguing the opposite." Dr. David Sugden. Professor of Geography, University of Edinburgh"
130531. Quietman at 10:53 AM on 3 May 2008
        Is Pacific Decadal Oscillation the Smoking Gun?
        John Nicely done. A similsr post on the Atlantic long cycle will help complete the picture (I know, more work).
        Response: Not to mention ENSO and the various other oceanic cycles. But the answer is essentially the same - oscillations cause short term internal variability but don't explain the long term trend which is caused by the energy imbalance.
130532. Quietman at 06:45 AM on 3 May 2008
        Human fingerprint on atmospheric CO2
        A chart here shows the percentages
130533. Quietman at 03:24 AM on 3 May 2008
        Misinterpreting a retraction of rising sea level predictions
        John You might be interested in this relevant article: Stay cool about short-term climate forecasts posted Thursday, May 01, 2008.
        Response: This is addressed in Is Pacific Decadal Oscillation the Smoking Gun?
130534. shawnhet at 03:03 AM on 3 May 2008
        Do cosmic rays cause clouds?
        Chris, I haven't read H&S in a while, but I will make a couple of points. "(ii) Harrison and Stephenson make two points in their paper. If one looks at their Figure 2 and associated text, one sees [point ONE] a very weak correlation between the CRF and the diffuse fraction (DF) (cloudiness – presumably dominated by changes in low-level cloudiness), which [point TWO] breaks down when the CRF is higher than 3600 (x100) per hour. Above this level the DF is independent of the CRF." I will agree that this seems to be a pretty good point against a simple relationship btw CRF and cloudiness. I will have to read H&S again to, and think about it, however, the relationship found by H&S is still statistically significant and is consistent in multiple locations. IAC, I think it is a mistake to claim that the relationship btw CRF and clouds is simple, but it is also a mistake to claim that there is no evidence of such a relationship. Cheers, :)
130535. chris at 23:23 PM on 2 May 2008
        Do cosmic rays cause clouds?
        A slight clarification of my long post. When I say (referring to Harrison and Stephenson's data; e.g. see their Figure 2a) that above a CRF count of 3600 (x100) per hour there is no correlation between the CRF and the diffuse fraction (DF), I really should say no correlation between changes in CRF and changes in DF. Above the 3600 (x100) per hour "threshold", the DF remains high, but loses its correlation with the CRF that is marginally apparent at CRF values below the threshold. And similarly, in pointing out that periods in recent history (last 400 years as indicated by the well-characterised sunspot numbers) like the Maunder and Dalton minima can't have had a contribution from the CRF since the CRF was likely well above the 3600 (x100) per hour threshold during these and other large parts of the last 400 years, I really should say that differences between the surface temperature of the Maunder or Dalton minima (say) and the surface temperature during the period between 1975 and 1925 (say) can't have had a significant contribution from any changes in the CRF, since it's likely that the CRF was already above the threshold value [3600 (x100) per hour)] where changes in the CRF don't result in further changes in the DF (cloudiness), during all of these periods. and in point (iv) I meant "persistent cloud effects" rather than "temperature effects" in realtion to the Sloane/Wolfendale analysis of Forbush events!
130536. chris at 21:48 PM on 2 May 2008
        Do cosmic rays cause clouds?
        Shawnet, I decided to have a good read of Harrison and Stephenson this morning, and have come up with as rather long post for which I apologize. I've tried to organize it coherently: Harrison and Stephenson [Proc. Roy. Soc. A 462, 1221–1233 (2006)] is fine. However I don’t think it provides very good evidence of a CRF contribution to climate. As the authors state “Changes in DF and the frequency of overcast days represent changes in the weather and the atmospheric energy balance.”, and there are a number of considerations that need to be addressed if the effect is to be considered a “climate”-influence, rather than a “weather”-influence. Here are some: (i) The first relates to something that we are all aware of. There isn’t any correlation between these processes and the Earth’s temperature evolution during the period in which the CRF has been monitored in detail. After all the CRF was as high in the period 1950-55 as it is now. High CRF should correlate with high low level cloud and low temperatures. However the Earth is clearly a lot warmer now than in the early 1950’s. Now of course, that’s an unfair comparison, since the CRF varies with the solar cycle, and so one doesn’t expect persistent warming/cooling from an oscillating forcing that has no trend. But that just re-emphasises that the there has been no significant solar contribution (CRF included) to the very marked warming of the last 30-odd years. This has been re-emphasised in two detailed analyses just published by Lockwood/Frolich (see bottom of post [***]). (ii) Harrison and Stephenson make two points in their paper. If one looks at their Figure 2 and associated text, one sees [point ONE] a very weak correlation between the CRF and the diffuse fraction (DF) (cloudiness – presumably dominated by changes in low-level cloudiness), which [point TWO] breaks down when the CRF is higher than 3600 (x100) per hour. Above this level the DF is independent of the CRF. Taken at face value, this seems problematic. Examination of Harrison and Stephenson’s Figure 2 indicates that most of the data in their analysis period (1968-1994) lies in this non-responsive region of the CRF/DF “correlation” where the CRF and DF are apparently completely independent (no correlation). If one examines the entire CRF record [http://ulysses.sr.unh.edu/NeutronMonitor/Misc/neutron2.html], that is reinforced. During around 90% of the entire period between the start of the CRF count (1951) to now, the CRF has been higher than 3600 (x100) per hour [if one looks at the climax CRF/sunspot number plot on the page I urled and compares this with the data in the downloadable datasets on that page one can work out that a CRF count of (3600 (x100) per hour corresponds to around the 83% level].Again one might conclude that that’s additional explanation for the complete absence of a detectable CRF (solar) contribution to the marked warming of recent decades. (iii) This leads to an additional problem (it seems to me), which relates to ascribing CRF climate effects to earlier periods. Although we’re in a solar minimum right now with respect to the solar cycle, the sun is in a relatively “strong” state. If one examines the sunspot data going back to 1600 [e.g. here: http://en.wikipedia.org/wiki/Sunspot], this is apparent. Now if the very strong inverse relationship between CRF and sunspot number (see Climax neutron/sunspot data urled above) was maintained in those periods (no reason to think otherwise), then the CRF was likely generally stronger [greater than 3600 (x100) per hour] during periods like the Maunder and Dalton minima. However taking Harrison and Stephenson’s data at face value, the cloudiness as measured by the DF is completely independent of the CRF at values above 3600 (x100) per hour. Therefore the CRF cannot have played a significant role in the cooling during those periods. We could deal with that problem by making some ad hoc assumptions. Perhaps the CRF became decoupled from the other solar parameters during periods with “weak” solar output. Perhaps the thresholds for a CRF-cloud correlation was higher then than it has been for the past 40 years (one might imagine that in periods where the air is rather clear of man made aerosols, the threshold for CRF effects on cloud formation become higher…and so on). But there’s no evidence for any of these ad hoc assumptions. (iv) One may still question whether the apparent correlation between CRF and DF in the CRF range below 3600 (x100) per hour is due to the CRF and not some other solar-related parameter that cycles in step with the CRF. Harrison and Stephenson used Forbush events in an attempt to assign a causal connection. However the useable Forbush events are apparently very rare (31 days in a 50 year period with CRF count reduction greater than 5%), and so the data is not terribly strong; the Forbush events (0.2% of the record) may not be representative of the other 99.8% of the record. (iv) We come back to the point of whether the CRF-cloud “correlations” are significant with respect to “climate” effects as opposed to “weather” effects. Sloane and Wolfendale’s analysis indicates a lack of detectable temperature effects from the Forbush events. We’ve already seen [see point (i)] that there’s no correlation between the CRF and the Earth’s temperature response since the start of the count, although we recognise that the CRF has been trendless, and so will only be represented in the solar cycle which is difficult to “pick out” in the record since it is smoothed by the inertia in the climate system, and is apparently small with respect to other stochastic variations (El Nino’s, volcanos, La Nina’s), and especially with respect to the strong and persistent trend arising from the enhanced greenhouse effect. (vi) A couple of other points need to be established if the CRF-cloud correlations have potential “cloud” implications rather than “weather” implications: (a) Does CRF-mediated cloud formation result in a nett change in the cloudiness over that resulting from other cloud-forming process (currents that mix warm damp air with cold air; all the other atmospheric aerosols; mountains and land masses). I don't think that's been established 'though Harrison and Stephenson's data might support that conclusion? (b) What about the day/night relationships? According to the CRF-cloud theory, cloud effects act during the day. CRF-mediated cloud formation blocks solar irradiance at the surface cooling the Earth. Notice that the greenhouse-mediated warming acts during both day and night, since the effect results from atmospheric “trapping” of IR radiation emitted from the Earth’s surface that occurs during the day and night. This is consistent with the fact that the warming of recent decades is as large or larger for night-time than day-time periods, and is another inconsistency with any potential CRF contribution to recent warming. One possibility is that any CRF-mediated cloud effects roughly cancel between day and night. For cloud effects to act on climate (Earth’s surface temperature), one expects that they need to be persistent at least for some hours. However enhanced cloud formation during the day (cooling effect) that persist into the night will result in a night time warming effect (decreased radiation of surface warmth) and vice versa. Overall Harrison and Stephenson is an interesting paper with what looks like fine data. However it doesn’t negate the very strong evidence for a lack of CRF effect on the very marked warming of recent decades, and if we’re concerned about that, we should focus to rather more well-supported causal factors. Secondly, it doesn’t constitute a very significant case for a CRF-climate link, and in fact tends to dis-favour such a link, at least over time periods in the relatively recent past (since 1600) when there is a reasonably good record of solar outputs (as monitored by sunspot numbers). [***]M. Lockwood & C. Fröhlich (June 2008) Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature. II. Different reconstructions of the total solar irradiance variation and dependence on response time scale Proc. Roy. Soc. 464, 1367-1385. M. Lockwood (June 2008) “Recent changes in solar outputs and the global mean surface temperature. III. Analysis of contributions to global mean air surface temperature rise” Proc. Roy. Soc. 464, 1387–1404.
130537. shawnhet at 05:38 AM on 2 May 2008
        Do cosmic rays cause clouds?
        Chris, A couple of points here regarding the significance argument. No one that I am aware of has challenged Harrison & Stevenson 2006 which found that "Across the UK, on days of high cosmic ray flux (above 3600×102neutron countsh−1, which occur 87% of the time on average) compared with low cosmic ray flux, (i) the chance of an overcast day increases by (19±4) %, and (ii) the diffuse fraction increases by (2±0.3) %. During sudden transient reductions in cosmic rays (e.g. Forbush events), simultaneous decreases occur in the diffuse fraction. The diffuse radiation changes are, therefore, unambiguously due to cosmic rays. Although the statistically significant nonlinear cosmic ray effect is small, it will have a considerably larger aggregate effect on longer timescale (e.g. centennial) climate variations when day-to-day variability averages out." Now, it seems to me that given the above, it is one thing to be skeptical of the significance of the CRF climate link, it is another to say that there is no evidence that it is significant. Cheers, :)
        Response: Actually, I know of two papers that cast doubt on Harrison's result on forbush decreases. One is Sloan's paper, the subject of this post. His paper actually has 3 sections - on latitude dependence, forbush decrease events and LCC lagging CRF. My plan was to do a separate post on each section. However, just over the last few weeks, another study was done on forbush decreases by Jón Egill Kristjánsson who presented his results at a recent AGU conference. He found a similar result to Sloan. I contacted Kristjánsson about the paper but it's still in review. So I'm mulling over whether to wait for the paper to be published before doing the post on forbush events and Harrison's paper. Or maybe I'll just go with Sloan for now. Stay tuned :-)
130538. Quietman at 03:05 AM on 2 May 2008
        Can animals and plants adapt to global warming?
        chris You are asking me to give an answer that that thus far has been unanswerable. I can only give you my philosophical view. For starters, my view of our part in extinctions is a natural one. We are animals struggling for survival. In our struggle we have made many mistakes and to correct them is the obvious thing to do. But because we are a part of nature the term "man made" warming is referring to our mistakes and not outside of nature. The current AGW is the point of contention. Will it cause extinction on its own. No, I do not feel that our errors alone are a cause but they certainly don't help. Should we save the polar bears, No. First, I don't believe that they need any help. Second, they are a competitor to us as a species, we eat the same food and occupy the same habitat. Our duty is to our species, not to a species in competition. The save the bears thing is an emotional issue, not a darwinian issue. We need to concentrate on helping species that are beneficial to us, regardless of the actual cause of their stress. As for the cyclic nature of the universe, that would take a lot more room than John has on this server. We need to stay on a point to point basis, like PDO and the Atlantic cycles, the vulcanism and gravitational pressure that drive them and the solar cycles, each has a place but not in this thread.
130539. Quietman at 02:25 AM on 2 May 2008
        Can animals and plants adapt to global warming?
        John In your comment to chris you mrntion a title change. I think that you chose the better title as AGW may make the event worse but did not start the event which has been going on for a very long time. We, as a species, have only barely survived this event and are in a diversification stage ourselves. My personal belief is that this event is nearing an end and we will be the winners if we get our act together.
130540. chris at 23:28 PM on 1 May 2008
        Can animals and plants adapt to global warming?
        Quietman, I'm going to answer each of your points sequentially: ["I do not disagree that there is a possibility of these extinctions. But I do feel that in most cases diversity must and will occur, just as descibed by Darwin, but that it will be new species that survive, not the parent species."] I think you're being over-theoretical here. If one dissociates oneself from extant reality and views our situation as an interested bystander, no doubt one can conclude that the present extinction period, will in time (we're talking many 100's of 1000's to millions of years), result in a rediversification of life on Earth. All very interersting from a Darwinian perspective no doubt. However if we are interested in our extant reality and that of our descendants over the next decades, 100's and even 1000's of years, then we might want to put those academic considerations aside and focus on the reality. And the reality is that continued habitat degradation exacerbated by continued global warming is going to produce an inpoverished biosphere. Since we're not disinterested bystanders, but are in fact an integral causal part of these processes, we might want to consider doing something to address the problem (which we are, as it happens, since there are many efforts underway to protect wilderness areas, and there are growing efforts to address the problems of man-made global warming). ["Re: "There's no such thing as an "extinction cycle"." That is not a fact. It has not been proven one way or the other. The Berkeley paper is a hypothesis, and if correct, we are in one now. The evidence so far is very good that we indeed are. Are you denying that there are climate cycles as well?"] Fair enough. However one has to be careful here. Let's say that the Berkeley paper [Rohde and Muller, Nature 434, 208 (2005] is correct. You say that means that (referring to extinction "cycles") "...we are in one now. The evidence so far is very good that we indeed are". But that is to take the passive attitude to ridiculous extremes. The natural world is not in the process of undergoing a large-scale extinction because of some ill-defined, uncharacterised "cycle" in which we find ourselves helplessly unlucky enough to find ourselves!. It is in the process of large-scale extinction because of large-scale habitat destruction and the other human practices described in Barry Brook's article at the top of this thread. We're part of it. Now are there extinction cycles? Perhaps there are but the evidence isn't very strong. It's possible that the extinction/diversity events only appear to follow a cycle, but aren't cyclic at all. After all there's rather good evidence that the end-Cretaceous extinction 65.5 million years ago (mya) was due to an extra-terrestrial impact perhaps supplemented by the massive tectonic events which formed the Deccan Traps in now-India. The extinctions at the Paleo-Eocene Thermal Maximum (55 mya) was likely due to the tectonic events (and massive release of methane) associated with opeining up of the North Atlantic plate boundary. The Triassic-Jurrasic extinction (201.6 mya) associates with the massive volcanic outpourings of the central Atlantic magmatic province.....The huge Permian-Triassic extinctions (252.5 mya) appear to coincide with the tectonic events resulting in the Serbiamn Traps formation....and so on. Are these events part of some huge cyclic phenonenon during Earth's history? It seems unlikely. The most "popular" notion of the origin of the 62 my "cycle" is long term cyclic variation of the cosmic ray flux (CRF). But how does that relate to tectonic events on Earth? It's difficult to ascribe any sort of connection. I suspect that the extinction/diversity cycles only appear to be "cyclic". However even if they truly are part of a grand cycle, that obviously doesn't account for the current extinctions. Is the world undergoing massive tectonic processes during the past 200 years? No. Are we being blasted by a massively enhanced CRF all of a sudden. No. We know what is causing the current extinction. It ain't some magical "cycle". It would be foolish to sit back passively and suggest such a thing... ["Are you denying that there are climate cycles as well"] Which "climate cycles"? There is an 11 year solar cycle. There seem to be cycles associated with ocean circulation. There are the climate cycles associated with the slow variations in the orbital properties of the Earth (Milankovitch cycles). But what other cycles are you considering? Again the same argument applies. Whether or not there are "climate cycles", we know that the current very marked warming of the last 30-odd years isn't due to any of the cycles that we know of. It's very likely to be due to man-made enhancement of the Earth's greenhouse effect. By suggesting that everything is "natural" (we're in a "natural extinction cycle"; we're in a "natural warming cycle") we might conveniently absolve ourself from any imperative to address these problems. In fact we know with a very high degree of probability that the current extinctions are not part of some "natural cycle" and the the current warming is not part of some "natural cycle". The evidence is overwhelming on the first and very strong on the second. Clearly if these were "natural" then the must have some explanation in terms of "natural phenomena". So what are these "natural phenomena"?
130541. frankbi at 16:38 PM on 1 May 2008
        Models are unreliable
        Wow Poptech, what a rousing, impassioned, statesman-like speech. Unfortunately, it contains no verifiable concrete facts.
130542. Elanc at 15:58 PM on 1 May 2008
        La Nina watch: March update
        What about this news bulletin from NASA which indicates that we may have a significant cooling effect for the next 20-30 years? La Nina and Pacific Decadal Oscillation Cool the Pacific http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=18012
130543. Quietman at 15:01 PM on 1 May 2008
        Can animals and plants adapt to global warming?
        chris I do not disagree that there is a possibility of these extinctions. But I do feel that in most cases diversity must and will occur, just as descibed by Darwin, but that it will be new species that survive, not the parent species. Re: "There's no such thing as an "extinction cycle"." That is not a fact. It has not been proven one way or the other. The Berkeley paper is a hypothesis, and if correct, we are in one now. The evidence so far is very good that we indeed are. Are you denying that there are climate cycles as well? I agree with your closing statement. We should indeed protect the environment to minimize stress on these animals, but that does not make it less interesting from an evolutionary standpoint. By the way, I am somewhat skeptical about the current causes of climate change. So from my point of view much of this is natural. But that is irrelevant to my statements here, as I am not advocating that we just let them die. So please do not be offended by my scientific curiosity.
130544. Quietman at 14:30 PM on 1 May 2008
        Can animals and plants adapt to global warming?
        Steve L I understand what you are saying, there is more than one definition. I database fossil species primarily so I look at living species from a evolutionary point of view. I see polar bears as speciation in progress, so calling them a species as far as legal terms go, I don't have an issue with and that is not why I used them. I used polar bears because everyone is somewhat familiar with them on an international level. Coyotes are not as well known but are another example of speciation in progress.
130545. chris at 09:52 AM on 1 May 2008
        Do cosmic rays cause clouds?
        shawnet, O.K. now perhaps we are talking past on another!. My very first post on this thread started: ["There are two questions really: (i) do cosmic rays influence clouds formation? (ii) is this effect, if real, significant with respect to the Earth's surface temperature and climates?"]. When I state that most papers don't support the connection, I'm talking about (ii) namely the connection between CRF and climate. There is evidence that the CRF can influence cloud formation. Is this significant with respect to the Earth's surface temperature and climates? There's very little if any evidence in support of that idea. We know that the very marked warming of the last 30-odd years has occurred without a significant contribution from changes in solar outputs. Therefore the CRF has been largely irrelevant during that period. Svensmark has presented his evidence in support of that rather well-supported conclusion. Svensmark's ionization chamber experiments aren't particularly compelling with respect to this (CRF-clouds-climate), and a causal chain needs to address several questions: (i) are the nanometre size nuclei observed in the ionization chamber relevant for cloud nucleation in the real world? (ii) does any CRF-mediated cloud formation significantly alter the cloud cover in a climatically significant manner? After all there are many cloud nucleating species in our atmosphere (particularly in our modern world). Might any clouds produced by CRF be nucleated by other species anyway? (iii) Clouds have short lifetimes (few hours). The nucleation of clouds results in a lower water vapour concentration in that part of the atmosphere (unless or until the condensed water vapourises again). So a cloud that might subsequently have formed may not now do so. Thus the cloud cover in that particular region might be net-neutral averaged over a short period (say a daylight period) whether or not CRF-mediated cloud nucleation occurs... and so on. Note that this isn't quibbling. It is addressing the rather blatant facts that CRF hasn't contributed to the most significant global warming event of the entire Holocene, and the fact that there is no evidence for CRF-mediated cloud nucleating contributions to climate. Thus it is difficult not to be skeptical about the notion. Of course that doesn't mean that it doesn't exist (CRF-mediated cloud nucleating contributions to climate). It just means that there is no evidence for it..
130546. chris at 09:02 AM on 1 May 2008
        Can animals and plants adapt to global warming?
        Quietman, You can't separate adaptation from extinction in the context of global warming. If the title of the thread is "Can animals and plants adapt to global warming?" the answer must contain the probability that for many species the answer will be no. No means extinction. There's rather clear from Barry Brook's analysis and from what we have observed already in relation to habitat destruction and impoverishment. There's no such thing as an "extinction cycle". There are extinction events that have causes (most likely climatic changes in the broadest sense as you indicate). So the Holocene extinction is not part of some grand "cycle", and describing it as such can suggest the notion that it's either inevitable or nothing of much concern (after all it's just another part of the "extinction cycle"!) In fact it's an extinction that relates to man-made destruction and impoverishments of habitats, and it's likely to be exacerbated in a warming world. It is an issue that we can choose to address or not. I don't see your point about diversification in relation to polar and grizzly bears. Of course species have diversified in the past (polar bears likely split from the ancestral species from a couple of 100,000 years ago). The past has seen a glorious diversification of species to give us the richness of the natural world which man-kind has already rather significantly reduced especially during the last couple of centuries. If one considers the fate of bears now and in the future it's not a rosy one. For example, the possibility that polar bears become extinct as their habitat disappears in a warming world is a significant one. Unless wilderness areas are maintained there won't be any bears at all, since bears and mankind are incompatible outside of zoo's and circus's...considering bears overall, extinction is a rather more likely future than diversification... That's really the point. In the deep past speciation/diversification occurred with speciation events likely taking 100's of 1000's of years (much like the polar bear speciation/diversification). Every so often massive climate change (resulting from extraterrestrial impacts or from massive tectonic events, for example) resulted in very widespread extinctions. These events weren't associated with diversification since, in general, most of the species of interest were unable to adapt. They went extinct without diversification. It was only following the recovery to more stable environments that the evolutionary process allowed the recovery of an impoverished post-cataclysmic biosphere, and this recovery, which was associated with rather widespread speciation/diversification as habitats were repopulated took many millions of years. So we need to be clear about where we are. Yes we have seen some speciation/diversification during the Holocene (the evolution of freshwater seals in Finland is a better example, since this is a truly post-glacial event), but we've seen far more extinction. The combination of continued habitat destruction combined with a very rapid warming is very likely to see this trend accelerating into the future. Yes there will be many species that survive and a few may diversify in response to habitat/climatic changes in the coming 100's and 1000's of years. But on the whole the biosphere will continue to become impoverished. If we have 500,000 species of "interesting animals" (say the size of a child's fist and larger!), and we watch 200,000 of these disappear (unable to adapt = extinct), while 100 (say) undergo diversification to new species, I think we would agree that the richness and diversity of the biosphere has become degraded. In recognising where we are, we have the ability to address these issues, since we're very much part of it all. We're not bystanders observing some inevitable "extinction cycle" and 'though we might be enthused by the possibility of P.E.-type diversification within those species that are able to adapt to an impoverished natural world, I would consider that future generations would be rather more enthused by the possibility that we might now be taking steps to minimize the impoverishment of the natural world which they will inherit.
130547. Steve L at 08:04 AM on 1 May 2008
        Can animals and plants adapt to global warming?
        Sorry, I should apologize for the US-centric view assumed in the above comment. I refer there to the ESA of the United States and a decision on polar bears to be made by the US gov't.
130548. Steve L at 08:01 AM on 1 May 2008
        Can animals and plants adapt to global warming?
        Quietman, I have an interest in evolution too and work as a biologist studying salmonids. I say that because I think I disagree with large portions of what you've written, and I don't want you to think it's because of a lack of evolutionary perspective on my part. One place we could start is with polar vs grizzly bears. I pick this one because it's topical wrt an impending decision re ESA listing. (Is that why you chose that example?) First argument: Ursus arctos vs Ursus maritimus -- they are described as distinct species; hybridization is not enough to say they are only subspecies unless you apply a strict "biological species concept" (Mayr). You can search for many articles describing the difficulties in applying that concept. You might like to read this paper, too (I'm a coauthor): http://tinyurl.com/5fdax5 Second argument: under the ESA, distinct population segments can be listed as species. That is, the legal definition of species does not follow the biological species concept.
130549. Quietman at 06:15 AM on 1 May 2008
        Can animals and plants adapt to global warming?
        Re: "we're not going to see diversification" I have to disagree on this point. We have already seen diversification within the Holocene. The same Polar/Grizzly Bear exaample serves. It is one species that we did not recognize as one because they were/are in the process of speciation (Darwin's mutation and variation in isolation). Hybridization is already showing up as their habitats begin to overlap. Hybridization can lead to a new subspecies as well. If subsequently isolated speciation would occur eventually as well. The comparison of the geologically short time that hominids have existed can not be validly compared to the thousands of years prior. If you want to use the past century, it needs to be compared to a similar sized slice of the past. This is a common error when trying to compare trends. The likelyhood of the slope of a single century resembling that of an epoch is extremely low. Its like apples and oranges, they both may be round but there the similarity ends.
130550. frankbi at 04:55 AM on 1 May 2008
        There is no consensus
        Robert S: Well, I couldn't find any concrete mention of any figures above 19... only some mentions of climate inactivists claiming there were "hundreds" of scientists there. Given that there were ~500 people in total, I wonder why they couldn't be more specific. In the meantime, Heartland Institute included a list of climate skeptic "co-authors" which included Mann, Rahmstorf, Keeling, and other well-known global warming theory _proponents_. And many scientists are angry about this: http://tinyurl.com/6zjxy4

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