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Comments 99551 to 99600:

99551. Phila at 03:38 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       gallopingcamel: I have a general objection to "Climate Science". Frankly, this statement strongly suggests that you are someone who should not be taken seriously. The way to overcome this impression is not to continue posting witless conspiracy theories and snide generalities about "science," but to read articles like Anne-Marie's more carefully, educate yourself where necessary, and offer logical, evidence-based rebuttals to specific points instead of slandering an entire scientific discipline. In short, don't proceed from the assumption that everyone's wrong and proving it is a simple matter of throwing enough mud at strangers. Instead, please consider the far more likely possibility that it is you, rather than the world's climate scientists, who are failing to make an intelligent, informed assessment of the evidence. Doing so will put you in a better position to make thoughtful counterarguments to specific claims, or to debate the proper course of action. Wallowing in situational ad hominem, as you've been doing here, simply makes you look like a fool.
99552. caerbannog at 03:29 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       gallopingcamel at 17:09 PM on 5 January, 2011 The tortured logic by Ms. Blackburn and Jeffrey Severinghaus are good examples of the nonsense that surrounds CAGW dogma. Jeff Severinghaus is a full professor at the Scripps Institution of Oceanography. He is one of Scripps' leading scientists. The Scripps Institution of Oceanography, BTW, is that little place that was recently rated as first in quality nationwide for doctoral programs in meteorology, oceanography, and atmospheric science by no less than the National Academy of Science (linky here: http://scrippsnews.ucsd.edu/Releases/?releaseID=1114, doubters are free to track down the original NAS/NRC report with a bit of googling). Someone who dismisses Dr. Severinhaus' work as "tortured logic" and "nonsense that surrounds AGW dogma" truly is taking Dunning-Kruger to the next level.
99553. Bob Lacatena at 03:19 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       36, garythompson,

       ...maybe it is my ignorance...

       As I said to Lurgee, this isn't acceptable. You can accept what the experts say, or you can study it enough to know the difference. It's unacceptable to simply say "I don't know myself, but I think they might be wrong." One of the things that bugs me to no end is the presumption that scientists are stupid, that a layman sort of wandering around a blog in "just thinking things through, using, you know, common sense" is going to come up with all of these ideas that were maybe missed by scientists who studied for decades to earn their degree of knowledge and proficiency, and who now as a profession focus on the topic for eight or more hours a day, five or more days a week.

       ...if anyone has a good source for that i'd enjoy reading that.

       Now that's the right attitude! Simple place to start is here, at Skeptical Science -- Tree Ring Proxies. If you have the time and the background, you can get a lot more detail from this study. In general, though, the Internet is a vast and intriguing place. A little bit of searching will find a lot of information -- as long as you're smart enough not to take it at face value, and to realize that any old schmuck can publish his opinions as fact on the Internet. Be wary of sneering skeptics, and always check the quality of the source information. If possible, look for independent confirmation (which is not the same as just finding the same lie repeated over and over on the multiple sites with an agenda to push). But it's all there to be had, right at your fingertips.
99554. Alec Cowan at 03:11 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       @gallopingcamel #24 So you had a speech to give. That speech includes truisms like "causes precedes effects", pseudo-categorical assertions about truisms like "in matters of science, cause precedes effect" and an absurd intent of malicious propaganda on your part like "I persist in my minority (at least on this blog) view that in matters of science, cause precedes effect." which implies that the majority here think something along "effect precedes causes" or "I don't care" or "I dunno". This propaganda is a ridiculous pursue, as this is written -you seem to have forgotten that- and everybody's comments -and backgrounds- are here to see. You have just written something that -said perhaps aloud with projected voice and in the absence of recorders- may have an effect on audiences sensible to those kind of verbal sedatives. Contrary to most people here, I don't think you are willing to follow any argumentation and provide proper critic. You have some designed messages to sow (they don't get money ... in comparison, Stalin was Mother Theresa) and nothing but such kind of messages to sow.
99555. Bob Lacatena at 03:07 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       38, apiratelookat50,

       (too many to list)

       Well, not really... :) See post 37.
99556. apiratelooksat50 at 02:52 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       So, Sphaerica @ #34, I think we agree. Orbital changes can initiate global cooling or warming, but other complex factors (too many to list) affect the rate, intensity and duration of these changes.
99557. Bob Lacatena at 02:51 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       #35, les,

       ...rather than simple "cause precedes effect" type changes?

       Let's have some fun, and look at all of the causes and effects:
       • Multiple orbital changes (orbital shape and inclination, axial tilt and precession, apsidal precession) occur in just the right combinations.
       • These alter the length/strength of the northern hemisphere summer past a tipping point.
       • Winter snow/ice cover on the northern continents does not melt back far enough during the summer.
       • The northern hemisphere albedo changes, reflecting more sunlight back into space, cooling the planet.
       • Atmospheric CO₂ is absorbed by the cooling ocean, reducing the GHG effect, and cooling the planet.
       • The snow/ice melts even less.
       • The albedo increases further, and the planet cools more.
       • Even more CO₂ is absorbed by the ocean (and, I've always presumed, more vegetation is covered with snow/ice without a chance to decay and return to the atmosphere), cooling the planet even more.
       • With the drop in global temperatures, atmospheric H₂O also drops, further reducing the GHG effect.
       • The planet cools even more.
       • The cycle continues -- cooling -- more ice, higher albedo, less CO₂, less H₂O -- more cooling.
       • Eventually, the expanding snow/ice extent reaches a latitude where summers are simply too long/warm for it to remain, and the process halts -- in a new glacial period that will last until the orbital forcings alter again, to run the entire "program" in reverse.
       How very simple!

       Well I'll be!

       :)
99558. garythompson at 02:37 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       thanks so much to many for your replies to my questions in #12. to reply to Marcus #19, let me clarify by what i meant by 'temps stable'. i'm not attempting to go OT here and talk about weather stations, GISS data, etc. i was sticking to the graph in figure 1 of this post. if you look at the temperature line, for about the last 10,000 years our temperatures have seemed to be in a noisy region and while it is oscillating, it appears to be flat and uncharacteristic of anything else over the past 400,000 years of this ice core data. why is that? to me, it's the most obvious feature of this graph and everytime i see it i ask that same question. oh, one more. the temperature axis is in units of temperature change (C). What is the base period that it uses for the zero change? and i second some of the comments stating that ice core data might have some issues with accuracy. i have the same reservations with tree ring data as well. maybe it is my ignorance in how these tree rings and ice cores are extracted, measured and then how these measurements are translated into degrees C and ppm CO2. if anyone has a good source for that i'd enjoy reading that.
99559. les at 02:33 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       #34 Are you saying that changes, like entering or exiting ice-ages, are kind of interlocking auto-catalytic & feed-back loops, rather than simple "cause precedes effect" type changes? Well I'll be!
99560. birdbrainscan at 02:25 AM on 6 January 2011
       An online resource for the IPCC 4th Assessment Report
       I also like the search by author, and the preset example for Schneider, e.g. It is evident that keying on author name as cited breaks up a single person into several entries, one for each way of abbreviating, even whether the initials are followed by dots or not. As for paper citations, it looks like you already matched them up to their unique DOI. If the citations are keyed on DOI, that would readily show up all the many cases of the same paper cited in subtely different ways. you could display a list of unique DOIs, and under each one show different cites to it, though I think only people like you and I would be very interested in how the citations vary internally... have you looked at linking back to the places in the body of the AR where the works are cited? That would be really powerful for research if it could be done. I guess it might require reverse engineering either the HTML or the PDF of the reports, to follow the footnote numbering.
99561. Bob Lacatena at 02:19 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       apiratelooksat50

       Why can't the cooling phase be initated by changes in orbital cycles?

       I'm not sure what your point is. This statement is of course true. The glacials (cold) and interglacials (warm) are both initiated by changes in orbital forcings. Those orbital changes are not, however, enough to cause the changes seen. Something else (CO2) needs to play a major role. Interestingly, too, contrary to the overly simplistic view that most people take, the orbital change isn't one of "warmer" or "cooler" for the planet as a whole. That is fairly constant. What actually happens to initiate a glacial period is that northern hemisphere summers change in a way to become cooler and shorter, so that the previous winter's snow and ice extent (in the northern hemisphere) doesn't have the time or energy to melt back. This changes the planet's albedo, reflecting back more sunlight, and that is what makes the planet cooler. But not enough to actually cause a glacial. For that, something else has to happen.
99562. birdbrainscan at 02:17 AM on 6 January 2011
       An online resource for the IPCC 4th Assessment Report
       Fantastic site, Mila -great work! i really like the list of cited journals ranked by citation counts. Do you happen to have a number for the total of unique journal papers cited for the whole AR4? it should just be the sum of all the counts for different journals listed. On mobile safari on iPad I cannot view the pop-ups for the journal name links, even after i unchecked "block pop ups" in Safari prefs. On Windows Chrome they work fine of course.
99563. Eric (skeptic) at 01:41 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       #24 gallopingcamel, I'm not sure what you are accomplishing here. You apologized for being rude, but then proceeded to another completely off-topic generalization (research money). You did not support your cause-effect claim in any way, just repeated it. You appear to be ignoring the simple fact that nobody here disagrees that warming causes increases in CO2.
99564. apiratelooksat50 at 01:41 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       I teach environmental science and my students long ago picked up on the CO2 lag. (I know we are talking about high school kids, but oftentimes a simpler, uncluttered insight is valuable. Kind of like Occam's Razor). When they initially saw the chart, their consensus was "that something else is affecting both". Now that this article supports the initiation of the warming phase by changes in orbital cycles, their next question is: "Why can't the cooling phase be initated by changes in orbital cycles?" This is not skepticism on their part, but inquiry.
99565. apiratelooksat50 at 01:33 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       Rob Painting @ 21: I'm not supporting anyone's stance, but it should be pointed out that there is a difference between BIODIVERSITY and BIOMASS. Biodiversity refers to number of species. Biomass refers to the total mass of living biological organisms at any given time and place. I don't have a clue about the biomass at that time, but your chart is not applicable.
99566. Bob Lacatena at 01:31 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       lugree,

       I'm a rank amateur, but I'd question the accuracy of the ice core...

       The subject of interpreting ice cores (or any such proxy data) is far more complex than your brief description implies. More importantly, the people that work with them are very, very, very smart, and have spent much of their professional careers dedicated to the subject, not just a few minutes while reading a blog. So you have two choices. You can just accept what the experts say, or you can study intently to understand what you are talking about. The third alternative, which is to simply say "I'm a rank amateur, but..." is not an option. That's a cop out. You can't have a strong opinion about something that you admittedly don't understand. A very simple starting point: Wikipedia Unless and until you at least get through that, you are unjustified in casting aspersions on the validity of the data.
99567. Bob Lacatena at 01:18 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       gallopingcamel,

       cause precedes effect

       Of course it does. Do you also insist that every effect can have exactly one and only one cause? Do you also insist that every cause can produce exactly one and only one effect? Do you also insist that a cause can never be the effect of something else, and an effect can never cause anything else? Or is it possible that the world is a complex place, and that to resolve situations one must use intelligence and difficult thought, and consider more intricate processes than the merely childishly simplistic? Part of what I take from your comments is that you either did not bother to read or simply did not understand the original post. You need to go back and try again, with a skeptical point of view (i.e. not with the mindset of one who already knows that what he hasn't read is wrong, and therefore has no need to focus on what is actually written). Your own logic equates to "my father died of cancer, therefore I will die of cancer, therefore I am invincible to everything but cancer." You need to study the situation much more intensely if you are to have a viable opinion on the subject.
99568. Arkadiusz Semczyszak at 01:14 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       @lurgee ... it's doubtful how accurately thousands of years of variation can be recorded in a few metres of ice ... You're right - it actually can be a problem. I recommend the discussion here. I warn You - it is very long. CO2 is not correlated with the temperature - at the time - also in the Holocene and the Historic Time (Anno Domini). It was found from 50 (Frank et al., 2010.: “... with a 50-year CO2 response lag—such timing is consistent with modelled CO2 response to a temperature step change.”); to 250 years difference.
99569. Anne-Marie Blackburn at 01:04 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       gallopingcamel

       That said, I persist in my minority (at least on this blog) view that in matters of science, cause precedes effect. Therefore, the hypothesis that rising temperatures cause CO2 concentrations in the atmosphere to rise is more plausible than the reverse over the periods covered by ice core data.

       Unless I'm mistaken and missing your point, this is what I said in my OP. I then took it a step further by saying that increasing CO2 levels cause further warming which again releases more CO2 - i.e. increasing CO2 levels become the cause and effect of further warming.

       I have a general objection to "Climate Science". Researchers with hypotheses linking climate catastrophe to the actions of mankind are likely to be showered with money by governments around the world. Scientists who have opposing views are marginalized and de-funded. I call this the "New Lysenkoism" and it is more dangerous than Stalin's version.

       Do you have any evidence to support this? Any evidence that sceptic scientists have lost funding? How do you then explain contrarians such as Lindzen, Spencer and Soon publishing in the scientific literature?
99570. muoncounter at 00:48 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       #13: "Cause precedes effect." Anyone who's argument lives by this, dies by this. Cause: burning fossil fuels. Effect: increased atmospheric GHG and the resultant warming.
99571. JMurphy at 00:32 AM on 6 January 2011
       Not So Cool Predictions
       I can't keep up with those in denial about AGW, the latest hypocrisy being a made-up consensus...from the same people who have always railed against consensus because it allows them to favour the individuals whom they can then compare to Galileo, etc. Or, rather, because they had to dismiss the views of the majority of science and scientists because they didn't agree with what they were saying. Now, their made-up consensus is, apparently, the true sign of scientific thinking ! And what are they basing their made-up consensus on, if it's not temperature readings - those same temperature readings that were previously so unbelievable that they had to come up with all sorts of strange criticisms, ranging from urban heat, to fraud, to conspiracy. Now, though, those temperature readings are being abused to try to give them what they want to see. But which temperature readings do they trust these days ? It used to be Spencer and Christy's satellites but now, because they are showing too much heat for the so-called skeptics' liking, they are falling back on CRU's figures - the ones that were previously accused of fraud, etc - because they don't include the warm regions of the Arctic...and are therefore more likely to show lower temperatures. Possibly. Can anyone actually keep up with these people anymore ?
99572. Eric (skeptic) at 00:24 AM on 6 January 2011
       Understanding the CO2 lag in past climate change
       The complexity of the climate system actually makes it simple: CO2 increases have less ultimate temperature feedback than during the glacial to interglacial time. IOW, as the temperate zones thaw, the earth warms through both CO2 -> temperature and temperature -> WV -> temperature. The effect of more CO2 in the current climate is CO2 -> temperature (with temperature -> WV being much weaker now than during glacial periods).
99573. Arkadiusz Semczyszak at 23:19 PM on 5 January 2011
       A Positive Outlook For Clouds
       Global warming due to increasing absorbed solar radiation, Trenberth and Fasullo, 2009.: “While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts.” “Sake of completeness.” Low clouds (especially in high latitudes) may also have a positive RF - Observational and Model Evidence for Positive Low-Level Cloud Feedback, Clement, and Burgman, 2010., (cited in paper A.D.) with these caveats: Comment on “Observational and Model Evidence for Positive Low-Level Cloud Feedback”, Broccoli and Klein, 2010. : „... using more complete model output, indicates better agreement with observations, suggesting that more detailed analysis of climate model simulations is necessary.” Another problem is that aerosols and clouds: Europe. Decline of fog, mist and haze in Europe over the past 30, Vautard , Yiou & van Oldenborgh, 2009.: “These variations presumably result from changes in aerosol burden and clouds ...” “Over Europe, the marked solar radiation increase since the 1980s is thought to have contributed to the observed large continental warming ...”, “This decline is spatially and temporally correlated with trends in sulphur dioxide emissions, suggesting a significant contribution of air-quality improvements.” “Statistically linking local visibility changes with temperature variations, we estimate that the reduction in low-visibility conditions could have contributed on average to about 10–20 % of Europe's recent daytime warming and to about 50 % of eastern European warming.” Years of 80th, however, the volcanic eruption of El Chichon. Globally, however, there is no simple correlation between aerosols and clouds - Consistency of global satellite-derived aerosol and cloud data sets with recent brightening observations., Cermak et al., 2010.: “In a period from the mid-1980s to the mid-2000s, aerosol optical depth is found to have started declining in the early 1990s [Mt. Pinatubo], while cloud data sets do not agree on trends.” Because not everyone aerosol increases the amount of clouds (as well as DSM). Can aerosol decrease cloud lifetime?, Small et al., 2009.: “... (ii) the “lifetime effect” whereby anthropogenic aerosol suppresses precipitation and results in clouds with more liquid water, higher fractional cloudiness, and longer lifetimes. Based on new observations presented here, and supported by previous fine-scale modeling studies, we suggest that the balance of evidence shows that non-precipitating cumulus clouds can experience an evaporation-entrainment feedback, and respond to aerosol perturbations in a manner inconsistent with the traditional “lifetime effect.” This is confirmed by other regional examples: Significant decadal brightening of downwelling shortwave in the continental United States, Long et al., 2009.: “We show that widespread brightening has occurred over the continental United States as represented by these measurements over the 12 years of the study, averaging about 8 W m −2 /decade for the all‐sky shortwave and 5 W m −2 /decade for the clear‐sky shortwave. This all‐sky increase is substantially greater than the 2 W m −2 /decade previously reported over much more of the globe as represented by data from the Global Energy Balance Archive spanning 1986–2000 and is more than twice the magnitude of the corresponding 1986–2000 2–3 W m −2 /decade increase in downwelling longwave.” Global Brightening over the Continental US, NASA, 2008.: “Brightening is commonly attributed to decreasing aerosol optical depth. However, these new results show that reductions in dry aerosols and/or direct aerosol effects alone cannot explain even half of the brightening. Changes in cloudiness play the dominant role. And the subtropics: Subtropical Low Cloud Response to a Warmer Climate in an Superparameterized Climate Model, Wyant, Bretherton and Blossey, 2009.: “Intriguingly, SP-CAM shows substantial low cloud increases over the subtropical oceans in the warmer climate.” Regional changes in cloud cover (such as the above) can be ignored by global models - and can affect (is significant) on the balance of RF cloudiness.
99574. Bart Verheggen at 21:11 PM on 5 January 2011
       A retrospective of the Climategate retrospectives
       After my rant about what a distasteful act this was, I tried to balance that out by also looking at what we could possibly learn from this affair (or what came into clearer focus): http://ourchangingclimate.wordpress.com/2010/11/23/climategate-lessons-learned/ - There’s no strong relation between knowledge/information and people’s perceptions: Just the facts won’t do. - Values and ideals clash in public climate discussions, and this greatly affects the perception and communication of the science. - The animosity towards climate science is even greater and more widespread than we thought it was. - There are many other aspects besides science that influence one’s policy preferences. - The need for increased transparency and openness of data and code is now widely shared. - Citizen science has taken off over the last year. - Don’t let your anger or frustration shine through in your communication. It doesn’t go over well (except with people who share your PoV). - We should rethink our communication strategy (which one? exactly.) Even when we get more angry because of such events, I think we should try to minimize our venging of anger (note to self: me too). As difficult at it is, we should probably try to be more respectful to those who are critical of the science for whatever reason, even if they don't pay us that respect. A very difficult cookie to swallow, but I think it's the only way to have science regain its deserved credibility. Going full attack mode as some favour will beakfire, as "climategate" has shown.
99575. cynicus at 20:38 PM on 5 January 2011
       Not So Cool Predictions
       Potholer54 also has a nice video on the "Gulf stream has stoppe, a new Ice Age is imminent" media story.
99576. Paul D at 20:01 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       galloping camel@13 said: "Cause precedes effect. Get used to it." However complexity and time, can create different causes and switch a cause around to an effect and visa versa. It is naive to assume that a cause at one point in time, will still be a cause at another point in time. Ironically it is usually skeptics that emphasise the fact that we have a complex system to analyse, yet bury that philosophy when wanting a simple answer that fits their perspective. In fact, the change in materials and processes from causing an effect, to being the effect of a cause is probably employed in many inventions that benefit humanity. The cycle of the internal combustion engine comes to mind, or a jet engine, they both depend on a cycle in which a cause, produces an effect which then becomes a cause for the next effect and so on until the original cause finally becomes an effect. When a problem occurs in the cycle of causes and effects, the machines operation changes or stops completely. In a simple world, you have a cause and that produces an effect, end of story. We don't live in a simple world.
99577. Rob Painting at 19:57 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Polar Bear @ 9 Shimkus of Illinois............I think in the age of the dinosaurs, where we had most flora and fauna...... Well perhaps not. Where does he (Shimkus) get these ideas?? I have a hypothesis, but the comments policy precludes me from elaborating further.
99578. Alec Cowan at 19:22 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       @galloping camel #13 Really? Sure, the patient didn't die from gangrene because he rotted mostly after he had died.
99579. Marcus at 18:57 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Gary Thompson, to the best of my knowledge, the next glacial period isn't due for several *thousand* years, possibly even more than 10,000 years-so your claim is without foundation. As others have already pointed out, why do people like yourself still running around claiming temperatures are "stable", when even a brief analysis shows that they're rising with unprecedented speeds (+0.12 degrees per decade since 1950, & +0.16 degrees per decade since 1980)-with no indication of a slowdown. I do wish people would try & get their *basic* facts right before posting on these boards.
99580. Marcus at 18:52 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Of course, Congressman Shimkus ignores a few critical issues. First is that that, when CO2 levels were at their highest, the bulk of all fauna & flora was still *Beneath* the Ocean. Second, the plant & animal life that did exist on land during these eras had evolved-over *millions* of years to be able to thrive in a higher CO2, higher temperature paradigm. Third, that the shape of our land-masses & oceans was significantly different to those today-& that must be taken into account when considering whether high CO2 levels today will have a damaging impact on our planet. Still, good to see the usual flimsy "logic" coming out of the so-called skeptic camp.
99581. Glenn Tamblyn at 18:41 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       garythompson See some of my comments to TIS. The behaviour at different stages of a glacial cycle can be complex and differ from cycle to cycle. For example, starting at the bottom of a cycle, ice sheet retreat is an important factor, replacing reflective ice with darker land and ocean. However retreat for huge ice sheets takes a long and depends on the extent of the ice sheets in different parts of the world, the underlying topography as they retreat etc. So ice sheet retreat is likely to be a slow, lagging forcing. Conversely, coming out of an Inter-Glacial, as things start to cool, a wider extent of snow fall can also have a big impact - a thin layer of snow has similar reflectivity to a massive ice sheet. So as some cooling progresses, expansion of snow cover can be a rapid cooling forcing, not a slo lagging one. So the behaviour of ice is potentially a major factor in the difference between the warming and cooling cycles.
99582. Glenn Tamblyn at 18:33 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       The Inconvenient Skeptic #1 & #6 John Sorry to have not continued our discussion recently - technology problems have kept me off the air. Currently I am sitting in a cafe writing this. "If CO2 isn't a significant factor, the concentration that is 400ppm instead of 270 ppm doesn't really matter.....According to the Vostok record the temperature dropped 6C while CO2 levels were stable. If elevated CO2 levels caused the warming, then the Earth would not have cooled." We have had this discussion before John and I pointed out the fallacy of your reasoning then. You are comparing ppm levels and using language like 'significant factor', 'CO2 levels caused the warming'. Your argument is based on imprecise use of language and failing to compare forcings quantitatively. Multiple factors influence the progression through Ice Age cycles - Orbital changes, Methane, CO2, Albedo change due to ice sheet variations, Albedo change due to changes in vegetation patterns etc Many of these factors can be estimated and quantified and they support this general understanding. CO2 is one factor that mattered then, but not the only one. As I have pointed out in an early discussion we had, when there are multiple factors, not all of them may be forcing in the same direction. As I pointed out to you, during the Holocene CO2 levels only varied by about 20 ppm until recent times. Milankovitch was stronger. How NET forcing varies depends on the sum of all of them. CO2 can remain stable, or even rise somewhat such as during the Holocene, but if other forcings are working against it then they can dominate. Not because CO2's impact is small, period. But because it's impact is only one part of all the impacts in THAT context. In a different context such as today, its percentage contribution is different. Understand CO2's quantitative impact in one context so we can calculate its quantitaive impact in a different context. You mention the Eemian, the exit from an inter-glacial before our current one. We have also discussed the behaviour over the Holocene. If you want to argue about what 'the data' tells us then you need to provide the data that matters. Not simply the temp vs atmospheric level figures for CO2. Rather the Temp vs Forcing data for multiple factors. The relative forcing associated with these various factors and thus their relative significance. Not every Milankovitch cycle is the same so the magnitude of the forcing variation varies from cycle to cycle. Similarly you aren't discussing changes in Methane levels. Also, look at the first figure shown by Anne Marie. The CO2-Temp relationship is different for each one. Because each cycle has different particular circumstances. In your posts you are also repeating something I have pointed out to you before, a failure to distinguish between the significance of what a 'level' means, and the significance of what a 'change of level' means. This comment 'If elevated CO2 levels caused the warming, then the Earth would not have cooled.'! Whether they are elevated or not isn't the point. It is change in the level that matters in producuing a forcing. And even then this goes into the mix of other factors that can all produce forcings. If CO2 behaved in the past in ways consistant with our understanding of its behaviour, then we can project that behaviour onto what we expect to see today. If you feel that the Ice Core record casts doubt on this, show us the calculations. Show us some calculations of forcing changes over the Ice Core record for Milankovitch, CO2, Methane, Albedo etc. Show that CO2's behaviour from that record is inconsistent with what we expect from current radiative physics. You are an engineer John, but much of what you have argued here and on your blog uses qualitative arguments. Put some meat on the bones of your argument. Do the math. Show us how the forcings change and that CO2's contribution doesn't match expectations "Or are you simply using strawman as a method of avoiding the data from the end of the Eemian?" No John, they pointed out the strawman in your claim which is fundamentally a mis-statement of what CO2's effect is 'expected' to be. A Strawman Argument is about creating a false expectation that can then be 'knocked down'.
99583. archiesteel at 18:15 PM on 5 January 2011
       Scientists tried to 'hide the decline' in global temperature
       I like the part where Fred Staples completely ignores counter-arguments in order to repost a variation of his original (incorrect) statement. Contrarians are like broken records.
99584. lurgee at 17:53 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       @ Garythompson "and why did temps decrease around 130k years ago while CO2 remiained high?" I'm a rank amateur, but I'd question the accuracy of the ice core on that point. They measure CO2 levels from air bubbles trapped in ice. There's always going to be a margin of error in that, because the air bubbles will be formed in older snow, and it's doubtful how accurately thousands of years of variation can be recorded in a few metres of ice. Also, looking at a single ice core is a bit like looking at a single thermometer - you can't really be sure how much is local variation, how much is global, and how much is just confusion and noise.
99585. Daniel Bailey at 17:11 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Re: garythompson (12) "...why are our temps stable?" They are not. They are rising. "Is the excess CO2 preventing the next glacial?" Looks that way. See here. "Over the past 400k years we've seen a periodic steep increase in temps followed by a steep temp decrease (glacial) but we have avoided that somehow. why?" Interglacial length/duration does have some variably associated with it, but all signs were pointing to a long (on a human scale, not a geologic scale), slow decline into a resumption of the current ice age. Until mankind intervened with its fossil fuel CO2 emissions. "Why did temps decrease around 130k years ago while CO2 remiained high?" In times previous to our civilization, CO2 acted as a feedback to temps. When orbital conditions caused a warming of temps, warming oceans outgassed more CO2, enhancing the natural warming going on (hence the quick rise out of glacial conditions into interglacials). Then, as orbital conditions changed, temperatures fell. CO2 lagged behind temps because sequestration of CO2 is a slow process, requiring tens of thousands of years. CO2 concentrations now have risen so quickly that CO2 is acting as a forcing to climate, causing the global temps to rise, which in turn cause other feedbacks to kick in, which in turn causes CO2 levels to rise further. Manmade CO2 concentrations are the big driver here, though. Gross 30 billion tons, of which the environment manages to do with about half (causing other issues, like ocean acidification), for a net increase of about 15 billion tons per year. Or about a 2 PPM yearly increase in atmospheric concentrations (the rate of increase itself is also increasing). Hope this helps, The Yooper
99586. gallopingcamel at 17:09 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       The tortured logic by Ms. Blackburn and Jeffrey Severinghaus are good examples of the nonsense that surrounds CAGW dogma. Cause precedes effect. Get used to it.
       Moderator Response: [Daniel Bailey] Respectfully, GC, you are quite wrong on the "cause precedes effect" trolling comment you made. We know why conditions were the way they were in the past. Just as we know why conditions are different today, with CO2 acting as a forcing instead of its usual feedback to temps. But being wrong doesn't give you leave to be rude. Find a way to respectfully disagree. Or...
99587. kdkd at 17:02 PM on 5 January 2011
       Scientists tried to 'hide the decline' in global temperature
       KL #2 "We know what 'the decline' is. It is the decline in tree ring proxy temperatures after about 1960." No it is not. It's the decline in reliability of the tree ring proxy temperatures when compared to the instrumental record after about 1960.
99588. garythompson at 16:51 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       i am very familiar with this vostok ice core graph and i've always wondered why the 'noise' in our present time appears. i.e. we appear to be stabilized between an interglacial and a glacial and while the chart 'predicts' a glacial we are hovering around our current level of global temperatures. CO2 is continuing to rise as is evidenced by the mauna loa readings but why are our temps stable? is the excess CO2 preventing the next glacial? over the past 400k years we've seen a periodic steep increase in temps followed by a steep temp decrease (glacial) but we have avoided that somehow. why? and why did temps decrease around 130k years ago while CO2 remiained high?
99589. hfranzen at 16:13 PM on 5 January 2011
       The Physical Chemistry of Carbon Dioxide Absorption
       An addition to my response to #29: I certainly agree that I am not in any way capable of considering how the GHG energy is distributed over the earth, and I say that in everything I write. I report the forcing temperature increase because that is the conventional way these results are reported, but for the earth-year average that is just one way of giving the net energy increase. You are complettly correct that I should leave to others the question of the effects of the energy on different areas of the earth. and I do.
99590. hfranzen at 16:06 PM on 5 January 2011
       The Physical Chemistry of Carbon Dioxide Absorption
       Response to #31: The number that I get (.014 K/yr)is what comes out of the calculation. I do not know where your 1.25ln(1.78)/ln2 comes from so I cannot make a comparison. I do know that my number comes from a quite accurate calculation of the broad-band, diffuse, transmittance and that it is directly related to the GHG flux at the earth's surface. I have seen numbers very similar to 0.014 K/yr quoted for the CO2 forcing, but I don't rememeber where. If you think that your formula is an improvement on the basic science I have presented I would very much like to see how it is developed. On the other hand, I think the two results for CO2 forcing (1 degree and 1.4 degree) are both indicative of a serious warming.
99591. hfranzen at 15:46 PM on 5 January 2011
       The Physical Chemistry of Carbon Dioxide Absorption
       Response to #29: The last steps of GWPPT6 are based upon a steady state for the earth-year average: energy in equals energy out. If, over the earth and over a year, more energy is coming in to the earth (which is the case because of the increase in CO2 in the atmosphere and the GHG effect)more energy must go out. The energy that goes out increases as the fourth power of the temperature. Therefore the increased temperature from year to year is directly calculable from the increased GHG effect for the earth-year average. The temperarure effects you mention (wind, waves, phase transitions) are irrelevant to the total energy in-energy out for the total earth.
99592. iana at 15:45 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Hi In the first graph, what year is 'present'?
       Moderator Response: [Daniel Bailey] It's my understanding that the ice core record graphics typically use 1950 for their "year zero" baseline unless otherwise specified. See the response in comment 3 above for a somewhat updated version.
99593. dhogaza at 15:40 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       "The Inconvenient Skeptic" is simply repeating the stupidity that climate science presumes that *only* CO2 affects climate, and changes in solar insolation does not. TIS: climate science doesn't claim that. What you are doing is known as making a "strawman argument". The difference between now and the prehistorical times you mention is very simple: Back then, fossil fuel wasn't being burned in ever increasing quantities. It's so tiring to hear people claim, in essence, that if one burns hydrocarbons, the resulting CO2 doesn't end up in the atmosphere. Where do you think it ends up? ( -edit- )
       Moderator Response: [Daniel Bailey] Be nice. No need for a tactical nuke when a 2x4 will suffice.
99594. Polar Bear at 15:00 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Democracy Now reported Congressman Shimkus of Illinois will be the head of the subcommittee on environment and economy.He said in 2009:Today we have about 388 parts per million in the atmosphere. I think in the age of the dinosaurs, where we had most flora and fauna, we were probably at 4,000 parts per million. There is a theological debate that this is a carbon-starved planet—not too much carbon. Where does he get these ideas??
99595. pdt at 14:54 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       #6 The Inconvenient Skeptic: Is it possible that more than one thing can cause the earth to warm or cool? Is it possible that something else changed while the CO2 concentration was stable during a period when the earth cooled?
99596. muoncounter at 14:54 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       #6: "If CO2 isn't a significant factor... " If you've reached that conclusion, you haven't been paying attention. Read the paragraph under Fig. 1 above again. "elevated CO2 levels in the past ... " The strawman is by your choice of one aspect in a complicated story. Elevated? compared to today, no. Elevated while the earth cooled because of a change in orbital parameters that initially overwhelmed the effect of atmospheric CO2. "If elevated CO2 levels caused the warming ... " In #1, you asked us to discount the glacial terminations, now here they are as part of your argument. Bad choice, as the literature doesn't support you: The overall correlation between our CO2 and CH4 records and the Antarctic isotopic temperature is remarkable (r^2 = 0.71 and 0.73 for CO2 and CH4, respectively). This high correlation indicates that CO2 and CH4 may have contributed to the glacial–interglacial changes over this entire period by amplifying the orbital forcing...
99597. The Inconvenient Skeptic at 14:08 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       All, If CO2 isn't a significant factor, the concentration that is 400ppm instead of 270 ppm doesn't really matter. Phila, Is it strawman to point out that elevated CO2 levels in the past existed while the Earth dramatically cooled? According to the Vostok record the temperature dropped 6C while CO2 levels were stable. If elevated CO2 levels caused the warming, then the Earth would not have cooled. Or are you simply using strawman as a method of avoiding the data from the end of the Eemian?
99598. Miriam O'Brien (Sou) at 13:52 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       Thanks, Daniel. Would you give me permission to use that image elsewhere (with credit to you and skepticalscience.com)? It's a very stark reminder of what we're doing.
       Response: [Daniel Bailey] Not mine to give permission for. However, the SkS version is here. See the Creative Commons language there for fair usage. Thanks!
       
       [John Cook] I've added CO2 History to our list of Climate Graphics. It's under a Creative Commons licence so you're free to use it elsewhere:
       
       
99599. muoncounter at 13:34 PM on 5 January 2011
       Scientists tried to 'hide the decline' in global temperature
       #6: "the relentless propaganda... " If quotes from 1999 and 2004 are all you've got to show relentless propaganda, you don't have much. FYI, relentless means (of pace or intensity) sustained; unremitting. Meanwhile, nothing about these 'tricks' changed any of the basic facts. See, for example, Did global warming stop in 1998? and the more recent Did global warming stop in ____fill in the blank with year of your choice___? If it's propaganda in today's world you want, look here. The lead article has tropical cyclone activity reaching a new low (ask our friends in Queensland how that's working out). Even better, look here. Dr. Singer is at it again: “the number of skeptical qualified scientists has been growing steadily; I would guess it is about 40% now.”
99600. Phila at 13:33 PM on 5 January 2011
       Understanding the CO2 lag in past climate change
       TIS says: the forcing effect of CO2 is not the critical factor in the glacial cycles. Anne-Marie says: The only conclusion that can be reached from the observed lag between CO2 and temperatures in the past 400,000 years is that CO2 did not initiate the shifts towards interglacials. Is it my imagination, or has yet another "skeptic" erected yet another strawman?

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