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Comments 48001 to 48050:

48001. Matt Fitzpatrick at 10:42 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       First time I've seen anyone draw an arbitrary line through a graph (Fig. 3), sprinkle magic stats fairy dust on it, and call it a trend.

       The stats fairy will love and accept any arbitrary line if it's short enough. That's what makes her useless. I could likewise draw an arbitrarily short and steep — dare I say, alarmist? — line, and it would pass the same stats fairy test.

       Even the eyeball test reveals the yellow line as nonsense. 2003-2007 are all near or well under the yellow line; 2008-2012 are all near or well over it.

48002. Brandon Shollenberger at 10:40 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       Sorry for the lack of paragraphs. None of my line breaks are going through, and I have no idea why.
48003. Rob Honeycutt at 10:33 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       

       Brandon @ 20...  Your original post states, "Do you believe McIntyre's post an example of conspiratorial ideation as Mann claims?"  My following post is saying that, yes, McI's post is an example of conspiratorial ideation, per Lew 2013.

       Now your post @20 says, "Michael Mann explicitly stated Steve McIntyre invented a conspiracy involving "[Mann], multiple scientists, the AGU, IPCC, etc." That's a very specific claim, and my point has been it is unfounded."

       This was not in your original post and, in fact, you stated differently in each of the two posts.  Re-reading Mann's FB post, it's quite clear that he is referring to "conspiracy ideation" rather than a specific "conspiracy theory."  

       The overriding point remains, rather than looking for a rational explanation (or even bother to ask direct questions) McI takes it upon himself to create his own story out of whole cloth.

48004. Brandon Shollenberger at 10:33 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       Tom Curtis @19 raises three points. He first claims discussing this example given by Mann "evades the point raised by Cook." This is untrue. Cook promoted this example by favorably commenting, associating his work with it, as well as by promoting it on Twitter. By implicitly agreeing Mann's claim was another example of what his paper found, he made Mann's claim perfectly relevant.Tom Curtis's second claim is McIntyre's post "certainly contains conspiracy theory ideation" because "it consists of attributing to malice what should properly be attributed to laziness, or carelessness." This is a red herring. McIntyre's attribution was not conspiratorial, whether or not it was right. Malice is only one part of such ideation. Moreover, even if one believed attributing malice is inherently engaging in conspiratorial ideation, that is not what Cook referred to. Cook explicitly said McIntyre "lunges towards a conspiratorial explanation of events." There was nothing conspiratorial about McIntyre's explanation.Tom Curtis's third point is just... strange. He says McIntyre suggests connivance between Naomia Oreskes and Michael Mann when he says Oreskes seems "to have [been] wrongfooted." Being wrongfooted requires one be mislead. Curtis's interpretation requires Oreskes be mislead by Mann yet intentionally play along with him. That's impossible. If Oreskes was mislead to believe a point, she was necessarily unaware the point was wrong.Stephen McIntyre alleged Michael Mann made decisions with the intent to deceive. He then argued it appears those decisions mislead Naomi Oreskes into believing untrue things. Right or wrong, that is not conspiratorial.
48005. Brandon Shollenberger at 10:18 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       Tom Curtis @18 is right. Somehow the second link in my post got malformed to have the Skeptical Science URL appended at the beginning. I have no clue how that happened, but you can get the right URL by stripping out the first part (or just following the link Curtis provided).I'm afraid I can't understand the point made by Rob Honeycutt @17. Michael Mann explicitly stated Steve McIntyre invented a conspiracy involving "[Mann], multiple scientists, the AGU, IPCC, etc." That's a very specific claim, and my point has been it is unfounded.
48006. Tom Curtis at 10:08 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       

       Brandon Shollenberger @15,

       1)  John Cook's comment referred to conspiracy theories developed by McIntyre with regard to Lewandowsky's "conspiracy" paper in 2012.  Referring us back to McIntyre's post on Mann's AGU presentation evades the point raised by Cook rather than adressing it.

       2)  As noted by Rob Honeycutt, Lewandowski's theory is about the presence of conspiracy theory ideation, ie, the types of thought patterns typically found in conspiracy theories, rather than the presence of conspiracy theories themselves.  McIntyre's post on Mann's AGU adress certainly contains conspiracy theory ideation, regardless of whether it contains an actual conspiracy theory.  In this case the conspiracy theory ideation consists of attributing to malice what should properly be attributed to laziness, or carelessness.

       On that topic, Mann's AGU presentation should have used updated data.  The updated data is readilly available and should have been replotted to avoid any possibility of accidental deception.  This is particularly the case given the fact that the updated data appears go against Mann's argument.  Further, Mann should not have used the land station only data.  The comparison was to a projection of global temperatures, so a global temperature index should have been used.  If I understand Mann's explanation correctly, he in fact sent a diagram containing both Land station only, and Land-Ocean data to his publishers, who tidied up the graph by removing the later.  Mann should have noticed that the wrong temperature series had been retained, although it is a natural mistake to not have done so.

       3)  McIntyre does not just criticize Mann, but also goes on to criticize Oreskes.  In fact, he does so in terms that suggest connivance between Mann and Oreskes, saying:

       "Mann's AGU Trick appears to have wrongfooted his mini wingman, Naomi Oreskes."

       and

       "Oreskes’ starting point was that models had supposedly under-estimated relative to observations – a starting-point that seems oddly disconnected to the IPCC graphic shown above but, hey, Oreskes is an expert in manufactured disinformation. If Oreskes was not in fact wrongfooted by Mann, then one would like to know the provenance of her assertion that models were “underestimating” observed temperature increases."

       To clarrify, Oreske's is indeed an expert in analysing the manufacture of disinformation by pseudo-skeptics.  McIntyre's (at best) ambiguous phrasing suggests that she manufactures disinformation rather than analyzing that manufactured by others.

       Be that as it may, Shollenberger's claim that McIntyre "... blames everything in that post on Michael Mann", and that "That cannot possibly be talk of a conspiracy" are simply false.  McIntyre has alleged or strongly suggested that both Mann and Oreskes misrepresented data with an intent to decieve; and strongly hinted that they connived to do so.  That is a conspiracy theory, even if not as wide ranging as suggested by Mann.

       It is worthwhile noting that McIntyre completely misrepresents the basis of Oreske's talk.  As pointed out in comments, it was based on this recently published paper.  Contrary to McIntyre's suposition, it was not based on temperature data alone.  It was not based on analyzing Hansen 88.  It was based on clear assessments of earlier reports by later reports.  There is a certain audacity in McIntyre's suggestion that because Hansen 88 scenario B temperatures are running above observations; that therefore they are running above all projections of temperature increase since 88; and that a general claim that climate scientists have erred on the side of caution must be false because they have over estimated temperatures increases (if they have) regardless of how drastically they have underestimated the retreat of Arctic Sea Ice, Greenland melt rates and sea level rise.

48007. Tom Curtis at 09:33 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       

       RH, the "fixed link" now goes to an SkS page.  I think you will find this link is the one you are after:

       http://climateaudit.org/2013/03/02/mikes-agu-trick/

       Moderator Response: [RH] The link I fixed was the one going to the Lew_2013 paper.
48008. scaddenp at 08:58 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       jzk - please read what I actually wrote (and preferrably some of the scientific literature pointed to in Chp6). Globally averaged, the CO2 forcing are around 3W/m2 but note that this applied to all of globe since GHG are well mixed in the atmosphere. Locally (60N), the milankovitch forcing is much higher. Easily enough to locally overwhelm GHG forcing. Ice sheets changes also change sealevel, albedo,  - and GHG. Got an alternative model where the number add up for a synchronous SH glaciation to NH forcing. 

       Now what Roe actually says is "This implies only a secondary role for CO2– variations in which produce a weaker radiative forcing than the orbitally-induced changes in summertime insolation – in driving changes in global ice volume"

       Your quote does not from Roe. Roe is quite correct - CO2 is secondary to NH summertime insolation which does the driving - but its an important feedback that makes it global. You might want to look at Denton et al 2010 as well as my earlier Hansen cite.

48009. Kevin C at 08:50 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Not sure if anyone's answered Kevin's question about what triggers the descent back into a glacial?

       Basically the glacial state is the equilibrium for icehouse earth. The Milakovitch peaks concentrate enough of the (almost constant) solar radiation in the latittude band where most of the land ice is which temporarily shifts the equilibrium, and the feedbacks take over to do the rest. Once the Milankovitch peak is over the feedback alone is not sufficient to maintain the interglacial state, causing a gradual descent back into a glacial.

       That's also why interglacials tend to be shorter than glacials.

48010. Rob Honeycutt at 08:48 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       

       Brandon...  Isn't that a little like asking what the conspiracy was behind the JFK assassination that conspiracy theorists claims?  It's not about the actual conspiracy.  They create a story line out of what they perceive to be inconsistencies.

       The point is the ideation of conspiracies, which is exactly what McIntyre engaged in.  Rather than attempting to look for a logical explanation, or even simply ask Dr Mann any questions, he went off in his own direction connecting dots to form a story line that had no basis in reality.  That's what conspiracy theorist do.  That is what McIntyre did in this case, as well.

48011. Brandon Shollenberger at 08:46 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       Ah, thanks. Sorry about that!
       Moderator Response: [RH] No problem.
48012. Chris Colose at 08:42 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Since my comment #16, there's still confusion of timescales in the discussion of feedbacks and "control knobs."  There's also some misunderstandings of Richard's AGU presentation.  He said himself that CO2 does not explain "everything" and he was looking at the broadest view of climate in a geologic perspective, and telling it as a historian.  That was his choice for giving a ~60 minute presentation on over 4 billion years of climate history, and I think it was a good choice, but obviously it's not fully inclusive.  Rather clearly, CO2 is not the principle driver behind abrupt climate changes, ENSO dynamics, regional climate variability, and it only tells part of the story over glacial-interglacial cycles (a CO2-focused perspective is valuable in the tropics, not so much at higher latitudes where the orbit and cryospheric feedbacks dominate and have a different structure than projected global warming changes).

       On geologic timescales, the weathering feedback being discussed (which by the way goes back at least to Walker and Kasting's paper in 1981) has classically been invoked to be important for long-term CO2 evolution.  This comes back in discussions of the Ordovician climate, the Neoproterozoic snowball deglaciation, the evolution of climate in the last 60 million years, etc...for a recent discussion of the Cretaceous to Cenozoic problem, see e.g.,  this paper.  This mechanism has also worked its way into the planetary science community as a viable mechanism to expand the limits of the habitable zone in the search for extrasolar life, and could conceivably work on any planet with plate tectonics and liquid water.  Keep in mind that this mechanism works on timescales longer than orbital, so you can still get considerable temperature fluctuations on sub-million year timescales, or can have positive carbon cycle feedbacks, operating primarily from the ocean or biosphere (as is evidently the case for the glacial-interglacial problem in the last several million years).

       
       The 'control knob' concept on geologic timescales comes not only from the fact that CO2 is a big player in climate evolution over geologic time, but also because CO2 can interact with the climate through a variety of negative carbon cycle feedbacks (on million year timescales), and positive carbon cycle feedbacks (on glacial-interglacial timescales), and thus inserts its role in climate evolution almost everywhere we can look.  It's only on rather short (decadal) timescales that we usually don't need to think about boundary condition changes from CO2.  For the timescales in which carbon cycle feedbacks tend to be positive, it's not a 'thermostat' anymore, but still a 'control knob.'  And in the case of glacial-interglacial changes, that control knob is very good at communicating the orbitally-paced fluctuations to the equator and globally.

       
       Other mechanisms do not work as a thermostat or control knob because they don't interact with the climate.  The sun, for example, changes independently of the climate. Moreover, solar evolution over geologic time is a one-way street, gradually brightening at ~7-8% per billion years.  On shorter timescales, the changes are usually too small for a lot of purposes.  Volcanic activity displays no to weak dependence on the mean climate state (there might be issues with the ground temperature or ice sheet loading on the crust, but these are probably small).  These things are very important for understanding climate evolution on all timescales.  Volcanic forcing, for example, is very important for the last millennium and there's still some uncertainty in these forcing reconstructions.  But volcanoes don't get up and organize themselves to blow up every year and cause an ice age. 

       
       In the Andrew Lacis worldview, the 'control knob' concept revolves moreso around the fact that CO2 is the most important non-condensing greenhouse in Earth's atmosphere, is very long-lived, and is most capable of changing on anthropogenic warming timescales.  The CO2 in the atmosphere is required to maintain a significant water vapor greenhouse, and any CO2 modifications in the future (likely to be the most dominant forcing over the next century) will set the stage for any water vapor or cloud responses.  Of course, other forcings could offset this tendency, but they tend to either be too small (solar variations), too slow (Milankovitch), or too short-lived (volcanoes, ENSO) to get in the way of making confident projections of late-century climate.  In this case, it's the uncertainty in climate response (sensitivity) and emission scenarios that dominate, rather than minor issues in how forcings are specified or what initial conditions you need to deal with (as in the decadal-projection problem).

48013. Brandon Shollenberger at 08:26 AM on 7 March 2013
       Conspiracy Theorists Respond to Evidence They're Conspiracy Theorists With More Conspiracy Theories
       The proprietor of this blog, John Cook, recently promoted a Facebook post written by Michael Mann via Twitter. The post claimed this post by Steve McIntyre contained talked of conspiracies, saying McIntyre:

       chose to invent an entire conspiracy theory involving not just me, but multiple scientists, the AGU, IPCC, etc.

       John Cook also favorably commented on the post, saying:

       I find it interesting that Steve McIntyre automatically lunges towards a conspiratorial explanation of events. Stephan Lewandowsky published a paper last year showing a significant association between climate denial and conspiratorial thinking. The response to the research from climate deniers was a host of new conspiracy theories. We document the originators of these conspiracy theories in the paper Recursive fury: Conspiracist ideation in the blogosphere in response to research on conspiracist ideation: Lewandowsky_2013. The chief originator of conspiracy theories? Steve McIntyre.

       This associated the paper this post is about with Mann's claims, and that leads to an important question. What conspiracy did McIntyre supposedly allege? As far as I can see, he blames everything in that post on Michael Mann. That cannot possibly be talk of a conspiracy.Do you believe McIntyre's post an example of conspiratorial ideation as Mann claims? If so, what conspiracy did he discuss?
       Moderator Response: [RH] Fixed link that was breaking page format.
48014. Rob Honeycutt at 08:10 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       jzk...  Except that Lindzen stands virtually alone in such statements regarding glacial-interglacial cycles.  

       And you also managed to completely dodge my point that the direct radiative effects of CO2 are well accepted.  Please read my following post @61 about the properties of CO2.

48015. jzk at 08:04 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Rob Honeycutt,

       Actually when presented with that very issue, that CO2 is necessary to drive interglacials and glacials, Richard Lindzen said "I don't think there is any case to be made for that."  He has further cited Roe's "In Defense of Milankovitch" which states "Thus, the relatively small amplitude of the CO2 radiative forcing and the absence of a lead over dV/dt both suggest that CO2 variations play a relatively weak role in driving changes in global ice volume compared to insolation variations."

48016. Rob Honeycutt at 08:01 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       jzk...   What you also don't seem to yet understand is that it's not the radiative effects of CO2 alone that are what makes CO2 the biggest control knob.  The direct radiative forcing of CO2 is not that much greater than Milankovitch cycles (AFAIK).  But it's the other properties of CO2 that make it important.  The fact that it's a long lived, well-mixed, non-condensing atmospheric gas is what makes it the control knob that it is.

48017. Rob Honeycutt at 07:56 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       jzk...  As has been pointed out in this thread many times now, the most recent research suggests that there may not be a lag.  And even if there is a lag, that doesn't in any way disprove the relationship between CO2 levels and global temperature.

48018. Rob Honeycutt at 07:51 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       BillEverett @52...  If I understand Dr Alley's work (specifically his "Biggest Control Knob" lecture), the CO2 rock weathering thermostat idea comes from Dana Royer's work.  And then there is also Andrew Lacis' work on the CO2 thermostat that describes the mechanism on shorter time scales.

       I'm quibbling over the "main" vs "biggest" exactly because of the semantics issue that Kevin seems to be misunderstanding.  The problem seems to arise from how the thermostat changes.  

       Kevin seems to be saying, if the temp goes up before the thermostat (CO2), then CO2 can't be the thermostat.  Where he's getting it wrong is, he's not comprehending the forcing and feedback aspects of the thermostat, and I think that's where quibbling over phrasing becomes important.

48019. jzk at 07:41 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       scaddenp,

       During the last 400,000 years, when temperature levels were highest, CO2 levels were also at their highest (of the cycle so far) and the reusultant forcing from the CO2 was at its highest.  Yet, that, very powerful forcing, according to AGW theory, is not enough to overcome the forcing from all else because temperature starts dropping and CO2 levels continue to rise.  If CO2 forcing is stronger than everything else, how can that be? 

48020. Rob Honeycutt at 07:28 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       jzk...   Actually, the forcing from Milankovitch cycles and the direct radiative effects of atmospheric are very well understood and calculated.  Not even the Richard Lindzen's and Roy Spencer's of the world dispute these figures.

       I would suggest that if you're not getting a satisfactory answer, then maybe you aren't reading or comprehending the research.

48021. scaddenp at 07:20 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       jzk. On a global scale milankovich forcing vary solar by 1/m2 but at high latitudes the forcing very much higher. (40 I think??) It easily can force high latitude change to albedo. However, albedo feedback alone is insufficient to create the global change. (Ie what you see is a change in forcing in NH affecting climate in SH where the forcing is the in the opposite way). However, there is no problem explaining the global change when you factor in the changes to GHG that are forced by the milankovich changes eg see Hansen et al 2012 and see how closely albedo + GHG does at reproducing the ice age cycle, assymetry and all. As always, not a bad idea to read the appropriate chapter in IPCC WG1 (chp 6).

48022. Greg54 at 07:08 AM on 7 March 2013
       George Will - Still Recycling Classic Climate Change Myths for The Washington Post
       

       Will's column was carried in our newspaper (the Holland, MI Sentinel), and I wrote a letter to the editor in reply before seeing this section of scepticalscience.com : http://www.hollandsentinel.com/opinions/x171156157/LETTER-George-Will-perpetuates-myth-about-science

       I wish I had seen the article here beforehand, so that I could have included a link to it.  I think it's really important to address the climate change denials that misrepresent science, scientists, and their motivations in even small newspapers every time we see them.  There are lots of folks who still get most of their news from such sources, and who are more likely to take a challenge from within their own community more seriously than one that originates from elsewhere.

48023. shoyemore at 06:47 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       Don9000,

       I spent some time today explaining to some deniers that you cannot just cherry-pick a reference value of zero, do a statistical test with your data for a significant difference in your mean value from the reference value (of 0), and then say that the "true" mean value "must be 0" if there is no significant difference.

       A perfect example of the "begging the question" fallacy, assuming the result you want to prove as part of your "proof". The "reference value " of 0 has no justification in the data, but these guys were agog at the genius of Anthony Watts, who had given them their heart's desire.

       I think my efforts will be in vain, because the main people these deniers want to fool is themselves. And they wll keep going back to the Watts' and McIntyres for re-assurance.

48024. Don9000 at 06:47 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       Oops. I see I changed Eschenbach into Eschenberg in the second to last paragraph above. Mea culpa.

48025. Andy Skuce at 06:45 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Can anybody explain where all the water went during the low sea levels in the Miocene? Figure 2a shows Miocene sea levels (green squares) that, mostly, are less or much less than pre-industrial sea levels, some of them comparable to the low-stands during Pleistocene glacial maxima. Miocene climates are generally thought to be warmer than today, with no major northern hemisphere ice sheets and Antarctic ice volumes that fluctuated but were less than today's. RealClimate article on the Miocene

       Moderator Response: (Rob P) Most likely into ephemeral ice sheets in the Northern Hemisphere. The early Miocene period was very warm and is the interval under discussion at Real Climate. The ice sheets most likely formed in the latter part of the Miocene. See below from Zachos(2001):

       

       See also the site linked to in the green box at the bottom of the post. Still lots of research to be to be done to sort out some of the disparities.
48026. Don9000 at 06:43 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       As a literary scholar I find the other side's analysis is often as rich in verbal silliness as it is in scientific gobblygook. Here's a pithy verbal pearl of wisdom from Willis Eschenbach's guest post on WUWT, which was posted in response to the Watts post linked to above:

       "the ocean is huge beyond belief"

       The quote can be found here:

       wattsupwiththat.com/2013/02/25/ocean-temperature-and-heat-content/

       Eschenbach makes this profound point in an attempt to back up his notion--or maybe it's a scientific hunch?--that the data on the ocean's heat content or average temperature he is working with is suspect. Here is his complete sentence (the ellipsis is Eschenbach's):

       "I find the claim that we know the average temperature of the upper ocean with an error of only one hundredth of a degree to be very unlikely … the ocean is huge beyond belief."

       In other words, followers of WUWT should have faith in Eschenbach's idea that the temperature rise he's taken the trouble to graph is of no real signficance because the ocean is really, really, really big to the point where Eschenbach, who has possibly thunk about it hard and long, simply can't wrap his mind around the volume of water involved.

       Okay. Fine. I grasp that Eschenbach is trying to imply that there aren't enough sampling points in the vastness of the briny deep to have faith in the stated accuracy of the data, but that is of course exactly the kind of thing scientists take into account when they do their work and present that data. And unlike those scientists, Eschenbach has provided no evidence to back up his claim beyond the aforementioned pearl of wisdom.

       Oddly enough, if we accept that the ocean is so huge that even someone as talented as Eschenberg cannot believe how large it is, and we accept that the data is accurate to the degree scientists say it is, then it should occur to Eschenberg and others that the seemingly trifling increases in temperature he has graphed translate into vast increases in heat content over a short period of time.

       As this is a very scary conclusion and I hate for people to actually worry about such scary things, I take a modicum of comfort from my own belief that it will not trouble the sleep of regular readers of WUWT.

        

48027. jzk at 06:41 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin,

       I have also asked your question of many, and so far have not received a satisfactory answer either.  It is said that the Milankovitch cycle is not "strong" enough to force an ice age or an interglacial, yet it sure seems to be able to reverse a warming trend just as CO2 is higher than at any time in that cycle and continuing to rise.  If that is the case, the Milankovitch forcing must be stronger than the forcing from the CO2 at its peak.  Otherwise, the system would continue to rise and run away.  And it hasn't.

48028. scaddenp at 06:38 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Just a quick point on assymmetry. I dont see that symmetry should be expected. At least two processes are not. Firstly ice sheet/shelf/glacier development versus break up is assymetrical largely because of calving. eg a glacier retreats much faster than it advances. Also affecting albedo is vegetation loss/recovery. The second one is methane (which becomes CO2) from swamps and possibly clathrate though isotope studies suggest swamps are most important. Accumulation is slow process, release very fast.

48029. BillEverett at 06:28 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Rob Honeycutt@8, "biggest" versus "main" is quibbling. I know "biggest" was used in the title of Ally's lecture. I also know he wasn't addressing the general public at the fall 2009 AGU meeting. But Ш used "main" above because that was the word being used here. My point is the greenhouse gases do serve as a thermostat for the climate in the sense that ordinary people understand in their daily lives, and CO₂ is the main greenhouse gas because it has a very long residency. For example, many cooking recipes begin "Preheat the oven to..." Why? Because there is a noticeable time delay between setting the desired temperature and the oven finally reaching that temperature. Using the term "thermostat" or "main thermostat" for the atmospheric CO₂ concentration would make it easier for non-scientists to grasp the fact that the current increased global temperature DOES NOT correspond to the "setting" on the global thermostat any more than the temperature in your oven one or two minutes after you turn it on corresponds to the setting of its thermostat. Depending on the oven and what temperature you set, it might take ten or twenty minutes or even longer to reach the equilibrium temperature. One estimate of the relaxation time for the earth temperature-CO₂ equilibrium is about 700 years (roughly half the turnover time of the thermohaline circulation).
       
       Kevin@38, "removal of CO₂ from the atmosphere is a worthwhile endeavor because the decline in temp is the same as the incline has been." Yes and no. If we reduced today's 394 ppm to 350 ppm CO₂, then the temperature would continue to increase for several hundred years because we are still far from the equilibrium temperature for 350 ppm. If you look at the graph, 350 ppm is about 15% higher than the highest peak in the last 800 thousand years. Getting the CO₂ down to 300 ppm might stop the temperature increase. Might. Getting it down to 250 ppm would most likely start a slow cooling. So, yes, reducing the CO₂ level would be good. No, it won't cause a temperature decline UNLESS the reduction in CO₂ is sufficiently large.
       
       In summary, greenhouse gases are the thermostat for the temperature of the earth climate. No greenhouse gases, which is impossible for our planet because there would undoubtedly be a small amount of water vapor in the atmosphere, means a snowball earth with little or no life as we know it. Life, as we know it, has a rather narrow range of tolerable temperatures. In the past different natural factors changed the thermostat setting, rapidly in some cases, where rapidly typically means a time scale of a century or millenium, and slowly in other cases, where slowly typically means a time scale of ten or a hundred millenia or even a million years. If you don't like atmospheric CO₂ "controlling" the temperature of the earth's climate, then you are free to think that whatever it is at a given time that changes the setting of the CO₂ thermostat is what is really controlling the the temperature (via the CO₂ concentration). Currently, humans are cranking the thermostat up and up and up. So, you can say, "No, CO₂ is not 'causing' the climate to heat up. People are 'causing' the climate to heat up by putting more CO₂ in the atmosphere."

48030. Composer99 at 05:28 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       From the department of redundancy department...

48031. Don9000 at 05:28 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       I'm still having fun with Watts' quote: "Sure looks like a pause to me, especially after steep rises in OHC from 1997-2003. Note the highlighted period in yellow:"

       Parsing this brief passage, I note that Watts has used the word "rises" to characterize the already brief 1997 to 2003 period. I suspect he did so because the data shows, if we use his vague concept of "a pause," that from 1999 to 2001 there was a similar "pause." And before 1997 there were arguably similar pauses from 1993 through 1999, as anyone with a yellow highlighter could show a la Figure 1.

       
       Of course, by subdividing a graph that is alreadly a subdivision in a sense (as it excludes the data for deeper water) into shorter cherry-picked segments, Watts is able to hide or obfuscate the larger trend even as he leaves room for faux sceptics to point to short periods of decline or even short periods of lower rates of increase as evidence that a longer duration trend has reversed or paused.

       I wonder if this kind of manipulation is not in some way linked to a kind of intellectual Attention Deficit Disorder where Watts' followers are concerned. Don't we see the same kind of deluded excitement from the Watts crowd every autumn when the Arctic starts to refreeze?

48032. Composer99 at 05:27 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       I have the feeling that, if and when we deploy satisfactory instrumentation to measure heat content in the deeper ocean (below 2,000 m) we won't like the results.

       Previous discussion on deep ocean behaviour has been discussed at Skeptical Science here.

48033. Roger D at 05:26 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       Well, sure, if you're gonna be such a stickler as to "consider all the available data".

       (nice post - thanks)

48034. Don9000 at 04:48 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       It took a few minutes, but I read through the various links. I have to say that Anthony Watts' post is not exactly a model of scientific rigor. I really love that he sums up on his site this post's Figure 3 in this especially rigorous way:

       
       "Sure looks like a pause to me, especially after steep rises in OHC from 1997-2003. Note the highlighted period in yellow:"

       And then Watts shortly goes on to write the following to underline his highly-rigorous scientific claim by quoting that highly regarded genuine faux physicist and bonifide television character "Dr. Sheldon Cooper":

       "As Dr. Sheldon Cooper would say: 'Bazinga!'"

       The delicious irony I find in Watts' choice to use this line from The Big Bang Theory is derived from the fact that it is used in the television comedy when the character has told a joke or pulled off a prank and is letting his friends know they've been played upon. Should anyone wish to fact check me, there is actually a website devoted to the character's use of the term:

       www.sheldonfan.com/origin-sheldon-coopers-bazinga.html

       Ironically, Watts wrongly seems to think "Bazinga!" is used by the character when he has made a valid scientific point.

       
       I'd say Watts has exercised the same telling degree of intellectual rigor in using the bazinga quote as he's used in presenting his graphic with a yellow line (which, ahem, he only used to highlight the region, don't you know).

48035. Doug Bostrom at 04:47 AM on 7 March 2013
       Arctic sea ice has recovered
       

       Yes, quite striking. Far be it from my place to criticize (because I'm way too ignorant) but the pattern of the last handful of years makes me wonder if we're overestimating the volume of ice left in the Arctic ocean. Those excursions just leap out at the eye. 

48036. Rob Honeycutt at 04:44 AM on 7 March 2013
       Cherrypicking to Deny Continued Ocean and Global Warming
       

       What's continually amazing to me is how the (fake) skeptics will give Anthony Watts a pass on such a blantant error, but turn around and scream all day long about nuances of the statistical significance of trends.  

       It just boggles the mind.

48037. BBD at 04:41 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       James Hansen, Makiko Sato, Gary Russell and Pushker Kharecha have a draft paper Climate Sensitivity, Sea Level, and Atmospheric CO2 which contains the following succinct description of the geological carbon cycle and temperature change over the Cenozoic (65Ma - present):
       
       
       Carbon dioxide is involved in climate change throughout the Cenozoic era, both as a climate forcing and as a climate feedback. Long-term Cenozoic temperature trends, the warming up to about 50 Myr BP (before present) and subsequent long-term cooling, must be primarily a result of the changing natural source of atmospheric CO2, which is volcanic emissions that occur mainly at continental margins due to plate tectonics (popularly "continental drift"). This CO2 source grew from 60 to 50 My BP as India subducted carbonate-rich ocean crust while moving through the present Indian Ocean prior to its collision with Asia about 50 Myr BP (Kent and Muttoni, 2008), causing atmospheric CO2 to reach levels of the order of 1000 ppm (parts per million) at 50 Myr BP (Beerling & Royer, 2011). Since then, atmospheric CO2 declined as the Indian and Atlantic Oceans have been major depocenters for carbonate and organic sediments while subduction of carbonate-rich crust has been limited mainly to small regions near Indonesia and Central America (Edmond and Huh, 2003), thus allowing CO2 to decline to levels as low as 170 ppm during recent glacial periods (Petit et al., 1999). Climate forcing due to CO2 change from 1000 ppm to 170 ppm is more than 10 W/m2, which compares with forcings of the order of 1 W/m2 for competing climate forcings during the Cenozoic (Hansen et al., 2008), specifically long-term change of solar irradiance and change of planetary albedo (reflectance) due to the overall minor displacement of continents in that era.

48038. BBD at 04:40 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin @ 38

       Looking at the graphs in fig 1a, I would argue that is not accurate.  If the rise and fall of the temps and CO2 is from the CO2 feedback loops, then why is the fall so different then the rise?  Clearly, there is a different mechanism at play.

       Please see 37. Perhaps slowing down and reading some of the responses and links might be a good idea at this point.
       

48039. 10in10Diet.com at 04:37 AM on 7 March 2013
       Living in Denial in Canada
       

       Thanks, BobLoblaw, for the link to the article about where we Canadians are getting our oil. I've been pretty obsessively watching climate science for ten years and although I walk the walk in my vegetarian lifestyle, I have no illusion that this individual action does anything but make me feel a bit righteous. However, I certainly have had my head in the sand regarding the sources of our fossil fuels. It's a tricky thing to argue. We live in a country where just about all of us live in homes that use at least $1000 a year in fossil fuel or electricity for heating. Vaclav Smil points out that we could make the biggest difference if we stopped eating so much meat and if we stopped burning fossil fuel to generate electricity. He believes we could transition to very efficient motor vehicles over one decade, if that efficiency were legislated. He's all for well-insulated buildings, but it's unimaginable that we could retrofit every one.

48040. Rob Honeycutt at 04:33 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin @ 46...  This is exactly what I'm talking about with regards to the semantics.  You are interpretting this to mean that CO2 has been a forcing over the past 40my.  No one is making that claim.  

       What is being said is that CO2 is the biggest "control knob."  That doesn't mean that CO2 is controling global temperature.  It means that it is the mechanism that causes the biggest amplification on forcing.

48041. BBD at 04:31 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin @ 38

       Looking at the graphs in fig 1a, I would argue that is not accurate.  If the rise and fall of the temps and CO2 is from the CO2 feedback loops, then why is the fall so different then the rise?  Clearly, there is a different mechanism at play.

       Please see 37. Perhaps slowing down and reading some of the responses and links might be a good idea at this point.
       

48042. BBD at 04:27 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin @ 43

       
       It is widely accepted that the gradual reduction in CO2 levels over the ~50Ma since the Eocene Optimum caused a very gradual cooling *within which* many different climate states occurred (Zachos et al. 2008).

       
       This is how CO2 and sea levels can broadly correlate over the last ~40Ma.

        

48043. Kevin8233 at 04:24 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Sorry, but you are just engaging in pedantry as far as I can see.

        

       ( snipped)

       I did not make any claims as to the last 100 years.  This article is talking about the past 40 million, so any discussion about anthropogenic CO2 is off topic.

       Moderator Response: (Rob P) - sloganeering snipped.
48044. Rob Honeycutt at 04:23 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin said... " If temp leads CO2, clearly, CO2 can't be dominate control of temp!"

       This is absolutely wrong.  I think you're getting twisted up in the semantics of the analogies and thus missing the point of the actual published research.

       Think of it as gears.  CO2 is the cog in the system that causes the greatest amplification on a given forcing.  It doesn't matter if there is a delay in the response or not.    

       What we are doing by burning fossil fuels is taking what is normally a CO2 response, and we're turning into a forcing.

48045. Don9000 at 04:13 AM on 7 March 2013
       Arctic sea ice has recovered
       

       

48046. Dikran Marsupial at 04:13 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin, there have been other occasions where CO2 has led temperature changes (e.g. uplift of Appalacians leading to increased chemical weathering, reduction of atmospheric CO2 and cooling temperatures), and there is also the fact that if CO2 is released by anthropogenic emissions then obviously any temperature change will lag emissions.  Sorry, but you are just engaging in pedantry as far as I can see.  Viewing CO2 as a thermostat is misleading as it can also be a forcing, calling it a control knob likewise doesn't tell the whole story as it often acts as a feedback.  This pedantry seems to be aimed at avoiding the key point of the story, which is that our anthropogenic emissions are twisting the control knob on the thermostat, and paleoclimate tells us that there is good reason to expect that to have a significant effect.

48047. Don9000 at 04:10 AM on 7 March 2013
       Arctic sea ice has recovered
       

       The most recent PIOMAS current ice volume anomaly graphic (31 January 2013) suggests to me that the Arctic Ocean is beginning to behave much more like a seasonally frozen lake or pond than a permanently frozen large expanse of ocean that melts around the edges. Note in particular the annual pattern in the graphed data from the 2010 maximum to the end of January, 2013:

        http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.png?%3C?php%20echo%20time%28%29%20?

48048. Kevin8233 at 04:02 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Composer99,

       First, I should like to draw your attention to the fact that the graph in figure 1(a) goes backwards in time as you go from left to right. So what you are actually seeing is that CO2 and sea levels are dropping very gradually, with brief interludes and irregularities, and then rise very drastically.

       Thanks, I am used to seeing this the other way around, and did think it looked odd.  But that doesn't counter my points.

       

       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years

       Just pointing out that the title of this article can't be accurate.  As I pointed out, and everybody agrees, CO2 didn't start or end any of the ice ages.  I also pointed out 1 paper for, and yes, someone pointed out one against, temp leading CO2.  If temp leads CO2, clearly, CO2 can't be dominate control of temp!

       Sorry about the multiple points, but they are all so closely related.

       Moderator Response: [RH] Fixed image width.
48049. Rob Honeycutt at 03:33 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       Kevin...  Just to be completely clear here, even if CO2 does lag (noting the most recent research suggesting there is no lag), that doesn't in any way cast doubt on the role of CO2 as a greenhouse gases, nor does it cast doubt on the warming effects of man-made CO2 from burning FF's.  It's a complete non-issue with regards to published research.

48050. grindupBaker at 03:31 AM on 7 March 2013
       Carbon Dioxide the Dominant Control on Global Temperature and Sea Level Over the Last 40 Million Years
       

       @1.Kevin "..do they just happen to go up and down together, perhaps each caused by something else..". It's known as hard physics that CO2x2 will force back ~3.5Wm-2 (skeptic Lindzen says 3.4). By simple math that power would raise ocean temp. to full depth by 1 C in 147 years with no other factors. Ocean mixing to depth takes ~1,000 years so it will be less than 147 years for top, say, 1000m. So you ask whether something known to be enough to melt massive ice was simply a coincidence in time with some mysterious other thing never seen (that you cannot suggest yourself) that does precisely the same. I'm sure not. What think you ? 

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