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This Week

Filed under: — mike @ 4 May 2007 - (Türkçe)

There are a few minor items this week worthy of mention:

1. The CO2 rise. Who dunnit?

Here at RealClimate, we have been (naively, apparently) operating under the assumption that climate change contrarians had long ago moved on from the untenable position that humans are not even responsible for the observed increase in CO2 concentrations over the past two centuries. The dubious paper by Ernst Beck we commented on the other day indicates that there is indeed still a rear guard attack being waged. As if to drive the point home further, pundit Alexander Cockburn, known generally for his progressive views, has perplexingly disputed the existence of any link between CO2 emissions and rising CO2 concentrations in the atmosphere in a screed he penned this week for the online journal “Counterpunch” (also printed in The Nation). It’s hard to know where to start, since his piece is so over the top and gets just about everything so thoroughly wrong, it’s almost comical. So we’ll just hit the low points: (a) Cockburn claims that there is zero empirical evidence that anthropogenic production of CO2 is making any measurable contribution to the world’s present warming trend, despite the fact that not even such strident climate change contrarians as Pat Michaels dispute that there is a measurable influence of anthropogenic greenhouse gases on global temperature. Plus there’s all the empirical evidence of course (see the new IPCC report). (b) Going further, Cockburn brazenly opines that ‘it is impossible to assert that the increase in atmospheric CO2 stems from human burning of fossil fuels’ despite the fact that there is an isotopic smoking gun for this connection. He then (c) fails to understand that water vapor is a feedback not a forcing, and citing ‘expert’ Dr. Martin Hertzberg, quite remarkably states that ‘It is the warming of the earth that is causing the increase of carbon dioxide and not the reverse.’ Never mind that isotopic evidence proves otherwise. Upon what evidence does he base this assertion?

Since no anti-global warming op-ed these days is complete without it, Cockburn (d) resorts to the usual misrepresentation of lag/lead relationships between CO2 and temperatures during glacial/interglacial cycles as if they disprove the causal relationship between greenhouse gas concentrations and surface temperatures (see our most recent debunking of this favorite contrarian talking point here). Oh dear.

2. The other (Glenn) Beck–Even Worse!

CNN gave their resident shock-jock Glenn Beck a forum for spreading more disinformation on global warming in an hour-long segment entitled Exposed: The Climate of Fear (see also this discussion by “Media Matters”). We could pick apart his (rather thin) arguments, which constitute the usual cocktail of long debunked contrarian talking points. Suffice it to say, however, that the moment a rhetorician invokes Hitler, Nazi Germany, and Eugenics, it is the moment they are no longer worthy of being listened to (cf Godwin’s Law of usenet debates). We don’t seem to be alone in our opinion here. Beck’s performance earned him the dubious title of “worst person in the world” from analyst Keith Olbermann.

However, there was one amusing moment: Beck asked Christopher ‘Incorrect’ Horner what the key thing to google was that would show that Al Gore was wrong. Horner suggested the lag between CO2 and temperature in the ice cores. Of course, if you do Google that, the first hit is the RealClimate debunking of the issue. Thanks!

3. Nature’s new blog

Nature has started a new blog called “Climate Feedback”, which says of itself ‘Climate Feedback is a blog hosted by Nature Reports: Climate Change to facilitate lively and informative discussion on the science and wider implications of global warming. The blog aims to be an informal forum for debate and commentary on climate science in our journals and others, in the news, and in the world at large.’

We wish it well, remembering their welcome for RealClimate, though early reviews based on the first few posts are decidedly mixed.


280 Responses to “This Week”

  1. 51

    Gavin, from this just past story:

    http://www.cbc.ca/canada/north/story/2007/05/01/climate-arctic.html

    Has there been a correlation made between sea ice models not matching ice shrinkage and current Arctic atmospheric temperatures which seem to be very much like Polar amplification some 20 years from now? The models seem correct, all be out of sync only if you look at their projections 20 years ahead. What goes with the Polar Ice also goes for the atmosphere right above. As an example, March just past very cold temps on the North American sector continue to have an impact, and particularly a footprint : http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/arctic.jpg

    which is acts as cooling feedback.

  2. 52
    Dana says:

    Regarding #32
    Thankyou Michael for that information.It’s way over my head but the gist of it is we have a way for industry to measure and make effective changes.

    Regarding #36 Right, the ambient co2 is the net difference between emissions and sinks per the bathtub?
    Now on the rising co2 levels recorded in the late 20′s thru the 30′s does this represent the result of emissions from 50 years up to 100yrs before the late 20′s? So the current ambient co2 represents the emissions from the mid 50′s on back to 1900?

    Thanks for all the great replies,Dana

  3. 53
    Marion Delgado says:

    The Peak Oil scenarios and models are too simplistic, I think. Probably in a chicken little way, but the precautionary principle applies there, too. Something to be said for acting as if they’re close to correct. Especially since (I think, this is all from memory) we’re already applying fairly serious extraction technology that, had it been all in place from the start of extraction in the US, might have shifted Hubbard’s peak in the US ahead a few years.

    On the other hand, for certain there will gradually be de facto surcharges, if you want to call it that, The difference is like the difference between tariffs and a foreign importer simply jacking up prices. In the case of tariffs and energy taxes, you have money available to take actions that free market agents won’t or can’t. The de facto surcharges leave you with less ability to adapt to them, and definitely encourage bad alternatives like, say, more coal for instance. Or completely eliminating wilderness set=asides and cashing them in for (now-profitable) reserves.

    It’s always better to encourage conservation up front. For one thing, since you know conservation measures are coming, one way or another, the industries, companies and countries that jump on them will eventually have market, political and stability advantages over others that will offset current short-term profits lost by retooling.

  4. 54
    Marion Delgado says:

    According to Maxine, apparently from Nature publishing, that blog doesn’t represent Nature, the magazine.

  5. 55
    Leonard Evens says:

    I finally tracked down actual data for the period Cockburn is talking about. I must say that even if you don’t know anything about the intricacies of the Carbon Cycle, provided you have some minimal experience with thinking about scientific issues, you will find his argument underwhelming.

    The figures for CO2 production are at

    cdiac.ornl.gov/ftp/ndp030/global.1751_2003.ems

    You see that production dropped about 26 percent from a high in 1929 to a low in 1932, but it was back up to the 1929 level by 1936.

    Ice core estimates for atmospheric CO2 concentration can be found at

    cdiac.ornl.gov/trends/co2/graphics/lawdome.smooth20.gif

    The graph shows the trend averaged over 20 years. There is too much year to year variation not to so average. The trend is definitely upward during the 30s, but it levels off for about 10 years in about 1940. Given the averaging and the possiblity of a time lag, that should not be too surprising, even if you accept the validy of such an argument. An unbiased person looking at the data would conclude that perhaps something interesting was going on there, but that it would be best to leave it to experts to interpret.

    Presumably Cockburn didn’t dream this argument up himself. Does anyone know where it came from originally?

  6. 56
    Hank Roberts says:

    Chuck, that part of the analogy is not overlooked; that’s covered at the same site, in the followup to the original John Sununu post. Worth reading the original.

  7. 57
    Bob Reiland says:

    After reading this latest report at RealClimate, I thought of a response that is similar to what Thomas, #6, wrote. My version of it is that, when those opposed to dealing with anthropogenic global climate change started anticipating the latest IPCC reports, they became so worried that they might lose the PR battle about climate to those scientists who know what�s going on that they started to produce their own version of the �Surge.�

    Suddenly there was a glut of articles attacking everything about climate science and the IPCC. It has been intense, but it has even less chance of working than does the surge in Iraq. It is too frantic and too noisy, and it comes as the general public has become very worried about climate change. Polls show that this public is rapidly moving away from the positions of climate change skeptics.

    A week ago I presented a 15 minute paper on some of the very basic features of the physics of climate change at a meeting of about 40 high school and college physics teachers. No one suggested that what I said was wrong and many asked me additional questions during the morning break and during lunch. This was a group of well-educated teachers who know that there is a problem. Yet many of them lacked fairly basic knowledge about climate change. The important thing is that they were very receptive. In addition many of the other teachers and the students at my school are asking me for more information. It seems that people are becoming more interested in knowing what is going on with climates and less interested in opinion pieces on the subject.

    In general I�ve found that there is a relatively small group that is totally against doing anything about actions destructive to the Earth as a whole. Yet the members of this group write and talk so prolifically that they seem to be a much larger group. They are now desperate because they are loosing the information battle, and they will continue to lose now that the effects of climate change are becoming apparent and groups of scientists such as those in the IPCC and in RealClimate keep presenting good science.

  8. 58
    Steve Bloom says:

    Re #48: In the past it’s been found difficult to explain the recent glacial cycles using this sort of idea since an overall stabilizing feedback would have to keep things from getting colder as well. There’s also the fact that the glacial cycles are triggered by insolation changes (due to Milankovitch orbital wobbles) that by themselves require substantial positive feedbacks to result in the climate changes observed in the ice core records.

  9. 59
    Richard Vermillion says:

    Please excuse the question if this has been answered before, but I’m interested in the logic on “the isotopic smoking gun”. While I don’t personally doubt that a large portion of the recent CO2 increase is driven by man-made fossil fuel combustion, I’m not sure I understand why the isotopic evidence is a smoking gun.

    To make my point of confusion clearer, here’s a thought experiment: Imagine you have a bucket with two spigots leading into it, one labeled A and one B. Both spigots deliver water (but with different isotopes of oxygen, say) to the bucket. Spigot A is running at a given rate and the bucket has filled up. Spigot B is off. The bucket is overflowing at a certain rate (that must equal the rate of spigot A flow). If you were to turn on Spigot B a small amount, it might have a negligible effect on the overall flow into and out of the bucket, but you would still expect the water in the bucket to grow (from zero) in the concentration of B isotopes over A. This would be true even if the flow from spigot A was increasing (or decreasing) according to other cycles, or even if the bucket was growing or shrinking.

    Yes there would be a limit to how much B you would expect based on the comparative flow rates of A and B, the extent of mixing that occurred, and the rate of change of bucket size. But it’s a complicated relationship and it doesn’t seem to follow that just because concentration of B isotope is increasing that we therefore know that the flow from the B spigot dominates the overall growth.

    Hopefully the analogy to natural (A) and anthropogenic (B) CO2 production is clear. Can someone help me understand why an increasing fossil fuel isotopic ratio necessarily entails that the total increase in CO2 is driven by fossil fuels? Wouldn’t you expect the concentration of the isotope found in fossil fuels to go up because you’re burning fossil fuels, even if the increase in the total CO2 was driven by other natural factors?

    Thanks,

    -rv

    [Response:The CO2 release from fossil fuels is already double the atmospheric rise, the difference due to uptake by the oceans and land biosphere. What need is there for a heretofore undetected natural source? David]

  10. 60
    ray ladbury says:

    Re: Cockburn. Neither the left nor the right has a monopoly on anti-science stupidity. The left has its Cockburns and Feyerabends and countless liberal arts academics who want to shut down science and engineering departments because they are sexist or racist, the right its Crichtons, Monktons and 3 Presidential candidates who say they don’t believe in Evolution. It is not that centrists by their nature are any more reasonble. The center is just the only place where reasonable people from right or left can come together when they get tired of the idiots who are on their side.

  11. 61
    Edo River says:

    Hugh thanks for the link. I am slowly trying to digest the 26 pages
    I hate to ask this and sound dumb but I am wondering about other links mentioned here as well,http://www.benfieldhrc.org/activities/issues/issues3.pdf
    is there some reason I can’t save this link? The Adobe reader won’t let me save it.

  12. 62
    Hugh says:

    #61 Edo

    Sorry Edo I’m not quite sure I understand the problem you’re having but all BHRC publications are available here:
    http://www.benfieldhrc.org/activities/publications.htm

    Regarding the 26 pages. Yes, sorry I said ‘quick resume’ didn’t I? I should have said ‘good’. Sometimes reading a paragraph just can’t get all the information across :)

  13. 63
    ray ladbury says:

    Richard, Your thought experiment would be better phrased as having the initial state of the bucket with spigot A on being one of equilibrium–flow in equals flow out. We know this because ice cores tell us that CO2 content of the atmosphere fluctuated about some equilibrium value in the 200-289 range up to the industrial revolution. So, we’ve got a long record of observation that says we have more or less a stasis–despite occasional perturbations such as volcanic eruptions etc. Now WE turn on spigot B, and lo and behold, the bucket begins to overflow and due to the isotopic composition from B, we have our smoking gun. What is more, we have no way of regulating A, really (unless you can think of a way to control the decay of vegetation, or the exchange of carbon between atmosphere and ocean, etc.), so it makes sense to throttle back on B, while at the same time, perhaps finding ways of sequestering what’s already in the bucket (A+B). Does that make sense?
    The situation ante 1750 was a quasistable equilibrium, which we perturbed beyond its ability to compensate.

  14. 64
    ray ladbury says:

    Re 44. Rod B. Yes, and the helmsman on duty when the Titanic sank did more to avoid the ice berg than any previous helmsman.
    The histories of W’s and Clinton’s efforts on climate change reflect the weaknesses of their respective administrations. Clinton et al. really did a pretty good job of imposing a market viewpoint onto Kyoto. Prior to the US effort, the approach was more regulatory than market. Where Clinton failed (well, other than morally) was in not getting China, India and Brazil on board and in not mustering support among the American people, and particularly in the Senate. That was where we needed someone like LBJ who would (literally) kick you in the shin if you voted against him. The China-India-Brazil thing is probably understandable–it was during the Asian Financial Crisis, so it looked like growth would take a hiatus. The failure in the senate was pure Clinton–not having the courage to fight for his convictions.
    This is not a failing one would ever accuse W of. The problem with the current administration seems to be a conviction that you can spin reality–whether that reality is the degree of opposition an invading army will face or atmospheric physics. It really is a pity, because a lot of the solutions I see being posed to the issue seem to be trying to spin the laws of economics. These are just as immutable as the laws of physics and it seems that the input of businessmen and economists would be more valuable on the economics of climate change than it would on the physics.

  15. 65
    pat n says:

    Re: 7.

    Dear climate alarmist,

    To be or not to be, that is the question.

    Nature’s carbon ‘sink’ smaller than expected
    Earth in 2100 could be up to 2.7 degrees F. hotter than previously predicted, studies say.

    http://www.csmonitor.com/2007/0503/p01s02-wogi.html?page=1

  16. 66
    Ellis says:

    #2
    So to ask questions clouds the issues and makes me an idiot. This is an excellent position for scientific discovery. Unfortunately, I missed the chance to ask my questions because I did not really get into the “debate” until ipcc4 summary came out in February. I guess the early bird really does get the worm. And yet when I look at the about page here at RC I find-
    “RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists. We aim to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary. The discussion here is restricted to scientific topics and will not get involved in any political or economic implications of the science.”

    Perhaps, they could change that last sentence to “…The discussion here is restricted to our point of view only.”

    A few unthreaded questions I have regarding the science, If the addition of CO2 is algorithmic, does this not mean that the more CO2 in the atmosphere the less effect each molecule has on IR radiation, what is the saturation point whereby adding more CO2 will have no effect on the energy budget?

    [Response:I don't know if there is a concentration at which temperature loses all sensitivity to CO2. Venus, as Hank Roberts notes below, has 70 atmospheres of CO2, and I think increasing CO2 still further would heat the planet up even more. David]

    If the troposphere is warming and the stratosphere is cooling does this not point to a zero sum equation?

    [Response:Perhaps to some extent but we live in the troposphere. David]

    How could less ozone in the stratosphere possibly be a negative forcing on the troposphere, as more UV radiation is making it to the surface, should this not be a positive forcing?(I know this will be covered in the coming weeks as RC delves into ipcc4).

    [Response:Ozone is a greenhouse gas.]

    Speaking of the IPCC, why can’t they just release the scientific report and then the summary of conclusions?
    (I am pretty sure this is no big deal, in terms of the science released, but wouldn’t it be just as easy to do things the right way?)

    [Response:I agree, it would be better to release it all at once. David]

    Anyway, I am sure all of this has been covered, but I am to much of an idiot to know for sure.

  17. 67
    Steve says:

    I’ve been reading The Nation for quite some time and while I find Cockburn’s writings to be entertaining, they are not always illuminating. I suspect many of his rather dyspeptic screeds are written (a) because he’s on a deadline and has to write something to fill is space and (b) because he just likes the extra ink he gets in the letters column the week after wherein he is allowed to bloviate at length in reply to his critics.

    For a long time I figured that at some point, like Christopher Hitchens before him, he’d eventually go stomping off in a huff over some slight, real or imagined, but I’ve come to believe that he just delights in stirring the pot and taking combative stances on the pages of The Nation in order to provoke comment on his writing and feed what seems to be an enormous ego.

  18. 68
    beyondtool says:

    Not sure if this has appeared here before, but a climate skeptic pointed me to this article from 21stcenturysciencetech magazine which suggests the levels of C02 in the atmosphere have been higher prior to the 1950s :
    http://21stcenturysciencetech.com/Articles%202007/True_CO2_Record.pdf

    Would anyone care to pick this article apart?

    [Response: Georg Hoffman already did in this previous RC post (the record shown is Beck's record). - mike]

  19. 69
    Hank Roberts says:

    Ellis, unthreaded

    > algorithmic
    What? I think you’ve read a joke somewhere and thought it was a science term, or you’re trying to joke.
    Assuming you’re serious: It appears you’re asking what happens if all the available carbon is burned. It won’t be a Venus-type atmosphere, but it wouldn’t be like Earth’s is either. Search “Venus” in the Search box.

    > troposphere warming, stratosphere cooling, zero sum?
    No. See the AIP History (first link in the list of other science sources, right side of main page)

    >less ozone/forcings
    Ozone is a greenhouse gas, that may be what’s involved, but I don’t know where you’re reading that.

    >summary
    The summary is negotiated by the representatives from each country involved, as a way to publish what their policy-makers are willing to accept, before the science is released. The scientists released their final draft so you can compare that to what the politicians did revising it; ideas unacceptable to various countries were taken out. You can look this up.
    Otto von Bismarck: If you love sausage and the law, never watch either being made.

    I’m just another reader here; people who know more will, I trust, correct me and add pointers to sources.
    Hope that helps.

  20. 70
    Chuck Booth says:

    Re # 64. Ray,
    That would have been a good analogy, but the Titanic was on its maiden voyage. So, there was no previous helmsman to share the blame. Had he survived, perhaps the Titanic’s Captain, Edward John Smith, could have blamed the unseen iceburg on global warming?

  21. 71
    William Astley says:

    In reply #58 Bloom “There’s also the fact that the glacial cycles are triggered by insolation changes (due to Milankovitch orbital wobbles) that by themselves require substantial positive feedbacks to result in the climate changes observed in the ice core records.”

    The data from the paper discussed in the attached link appears to question Milankovitch’s theory. What are your thoughts?

    http://www.news.wisc.edu/9557.html

    What’s more, the group found evidence that the last major glacial period prior to the last ice age, from a time dating to 150,000 years ago, mirrored North American climate for the same period.

    “During the last two times in Earth’s history when glaciation occurred in North America, the Andes also had major glacial periods,” says Kaplan.

    The results address a major debate in the scientific community, according to Singer and Kaplan, because they seem to undermine a widely held idea that global redistribution of heat through the oceans is the primary mechanism that drove major climate shifts of the past. The implications of the new work, say the authors of the study, support a different hypothesis: that rapid cooling of the Earth’s atmosphere synchronized climate change around the globe during each of the last two glacial epochs.

    “Because the Earth is oriented in space in such a way that the hemispheres are out of phase in terms of the amount of solar radiation they receive, it is surprising to find that the climate in the Southern Hemisphere cooled off repeatedly during a period when it received its largest dose of solar radiation,” says Singer. “Moreover, this rapid synchronization of atmospheric temperature between the polar hemispheres appears to have occurred during both of the last major ice ages that gripped the Earth.”

    The data from the paper referenced in the attached link provides evidence that contradicts Milankovitch’s hypothesis. The data shows that a planet wide forcing function is simultaneously affecting both Northern and Southern Hemisphere. The Northern and Southern hemisphere glacial and interglacial cycle are synchronized. (i.e. The Northern hemisphere and Southern Hemisphere cool and warm at the same time.) The Milankovitch orbital change mechanism is not capable of simultaneously affecting both the Northern and Southern Hemispheres. The insolation changes due to the orbital changes are symmetrically opposite from North to South Hemisphere. i.e. If summers are warmer in the Northern hemisphere due to orbital changes they are colder in Southern hemisphere.

  22. 72
    ray ladbury says:

    Ellis, You will note that the restriction is to scientific discussion. Since denialists have yet to bring any science to the discussion, I see no problem with smacking them down when they seek to cloud the issue. I think you mean to say that the addition of CO2 is “logarithmic” rather than “algorithmic”. Yes, the next 100 ppm will have less greenhouse effectiveness than the previous 100, but this does not take into account feedback mechanisms. It may well be that the next 100 ppm could take us to the point of no return, where the ocean, permafrost, etc. contribute their ghgs as well.
    As to the ozone, a quick look at the solar spectrum shows why this is not a significant effect–there’s simply not a lot of energy in the UV. Moreover, we can measure the energy from the Sun, and it can’t account for the effects and trends seen.
    If you care to learn rather than pontificate, you will find a lot of answers on this site. The editors of this site have literally a couple of centuries of combined experience in climate matters.

  23. 73
    William Astley says:

    Re: #63 Landbury

    “We know this because ice cores tell us that CO2 content of the atmosphere fluctuated about some equilibrium value in the 200-289 range up to the industrial revolution.”

    Hi Ray, this paper indicates that CO2 levels have been as high as 326 ppm during warm periods and dropped to 271 ppm during the 8200 year BP cooling event. (See Table 1, in the paper and figure 1.) Someone in this forum suggested that changes in CO2 levels in part could be due to changes in the surface temperature of the ocean.

    That is to say when the surface temperature changes there is a step response change in CO2 level. Over time the step increase or decrease of CO2 levels due to ocean surface temperature changes, will be mitigated as the CO2 level reaches equilibrium with the CO2 level in the deep ocean.

    How can the CO2 isotope data and analysis, be used to determine what is the expected CO2 equilibrium level?

    http://www.pnas.org/cgi/reprint/99/19/12011?ck=nck

    Excerpt from the above paper:

    “It should be noted that early Holocene records from Greenland ice cores have repeatedly indicated rapidly fluctuating CO2 levels including values > 300 ppmv (36, 37). At present, the Antarctic record is usually considered to be reliable, so that discrepancies are ascribed to CO2 enrichment within the Greenland ice (38, 39). However, there is evidence that in polar ice also postdepositional CO2 depletion could occur, but underlying chemical processes of this potential source of error have not yet been investigated in detail (38, 39). The documented coupling between CO2 fluctuations and the 8.2-ka-B.P. cooling implies a distinctive involvement of the oceans, where short-term perturbations of sea-surface temperature and_or salinity allow rapid CO2 transfer between the atmosphere and surface waters.”

  24. 74
    FurryCatHerder says:

    The Peak Oil scenarios are far from Chicken Little. Cost of bringing in a barrel per day of production continues to increase. My understanding, and I re-read the article yesterday and can find it if anyone objects, is that it costs $5,000 per barrel per day of production (so, that’s 365 barrels per year, etc.) to develop Saudi oil, and $10,000 to $15,000 to develop the same outside of Saudi Arabia.

    The “Peak Oil Contrarians” (people, like myself, who reject the IPCC projections because we believe rising fossil fuel costs will price fossil fuels out of the market, while favoring the development of renewables) argue that the cost difference is what will drive carbon reduction. If you look at organizations like NativeEnergy, they are aiding in the development of energy projects that are 100% renewable, produce 0% carbon, and have fixed costs relative to rising fossil fuel costs.

    While I think oil sands and stripper wells will continue to provide heavy petrochemicals into the 22nd, 23rd, 24th centuries (and beyond!), relying on centralized, fossil-based energy supplies, and cheap petrochemicals for transportation, is an idea whose time seems to be coming to a close. I’m not fond of the Algore, but his PowerPoint chart showing the decline of the leading non-hybrid vehicle makers along with the ascent of hybrid makers (and average gasoline prices) signals a sea-change in attitudes. The hobbyists have already begun attacking the pluggable hybrid problem, and if the history of hobbyists and computers is any indication, Toyota, Honda, and the other major hybrid players will begin offering them soon.

  25. 75
    ks says:

    Re: 66

    “If the addition of CO2 is algorithmic, does this not mean that the more CO2 in the atmosphere the less effect each molecule has on IR radiation, what is the saturation point whereby adding more CO2 will have no effect on the energy budget?”

    CO2 addition is logarithmic. What it means is that you cannot assume linearity in adding CO2. As a result, we discuss the impact of doubling CO2 (increase temp by 3C). Since pre-industrial CO2 levels were at 290 ppm, if we increase to 580 ppm we will see close to a 3C increase (given everything else is equal). It would require another doubling to 1160 ppm to increase temp another 3 C. So far as I have seen, there is no suggestion that the saturation point could be reached while the Earth was still habitable by anything except bacteria.

    “If the troposphere is warming and the stratosphere is cooling does this not point to a zero sum equation?”

    as the troposphere warms, it expands (as all gases do). this pushes the stratosphere further out in to space, causing cooling. I’m not sure how the two layers interact, but if they stay segregated to any degree, you would not see a zero sum equation, but two isolated events. Furthermore, stratosphere cooling has not had an impact on the surface of the Earth (where humans live).

    “Speaking of the IPCC, why can’t they just release the scientific report and then the summary of conclusions?
    (I am pretty sure this is no big deal, in terms of the science released, but wouldn’t it be just as easy to do things the right way?)”

    I’m not sure what “the right way” would entail, but I don’t believe releasing the summary after the report is the best way. Simultaneous release might be nice, but the current way is similar to a trial when the lawyers make introductory statements summarizing their position before diving into the evidence. Evidence before summary seems backwards to me.

  26. 76
    tamino says:

    Re: #73 (William Astley)

    Wagner has been trying for years to contradict ice core CO2 records with estimates of past CO2 levels based on leaf stomatal density. I dealt with this at length on my blog.

  27. 77
    Ellis says:

    Ray and Hank thank you for your responses. Yes, logarithmic is the word (I guess spell check can only help the appearance of intelligence to a point.) And, I am pretty sure that by asking questions implies I want to learn, as I stated above, I am sure every question has been asked a thousand times before, however, since I was not privy to the answers, in order for me to learn, I need to ask so then I’ll be in the know.

    Ray, I asked a simple question about whether the saturation point of CO2 in the atmosphere is known. I am not suggesting that we ever want to reach this level or that approaching it will not bring us to the tipping point, I just wanted to know what the level is, if this is known.

    As to ozone, I suppose it is all a matter of perspective, yes we know the amount of energy hitting the top of the atmosphere from the sun, however, a change in the amount of UV in the troposphere due to a decrease in ozone, would still be a positive forcing, not to mention the feedback from tropospheric ozone as more UV is available to be absorbed. My question was not can ozone describe all of the effects and trends seen, but simply how could a decrease in stratospheric ozone be a negative forcing.(ipcc 4 has a complete listing of forcings).

    I will leave the pontifications to those that are disgusted that us idiots exist.

  28. 78
    Rod B says:

    Ray (64), I think your assessment of the political situation and personalties are right on; I agree, but have one quibble: I probably wouldn’t call the laws of physics immutable, though they’re pretty close and not worth an argument. But, the laws of economics are definitely a long ways from immutable, though we stumble across things that work out occasionally. Economists don’t fully understad it; and, btw, climate scientists probably don’t have a clue, which is why I chuckle when some of the RC posters describe in clear detail how draconian carbon controls will be enormously great for the entire world’s economy. Maybe it will; maybe it won’t. Nobody knows .

  29. 79
    Leonard Evens says:

    Re 59 and the isoptoppic “smoking gun”:

    I’ve tried to make this argument before, but no one ever takes me up on it.

    In my own specialty in mathematics, I often find that other mathematicians, even in closely allied fields, misunderstand certain crucial points about my area. Also, when I enter a new field, even with quite a lot of background, I often find that the first five ideas I have about it are wrong. That has led me to respect experts who have the requisite knowledge and have actually taken the time to investigate an idea. This is particularly true where the reasoning involves a mathematical model. It may not be possible to explain the subtlties in words. So I am releuctant to question a general scientific consensus unless I have done some homework and have a strong reason to do so.

    So my advice to Richard is to consider the possibility that his conceptual model is just too simple minded to catch the reality of what is going on. It is good to ask such questions as a beginning in developing an understanding, but one shouldn’t take one’s own initial ideas seriously. In such circumstances, it is best to assume first that you are wrong and the experts are right.

  30. 80
    Rod B says:

    Ellis (66): a brief partial input/answer: mathematically the log of something never goes to zero, but gets there practically sometime. Also bear in mind that the models assume a log relationship to the 5th+ power of the CO2 concentration.

  31. 81
    ray ladbury says:

    Ellis, type “ozone” into the search box at the top of the page, and you’ll have about a week’s worth of reading. Realclimate is a tremendous resource, but don’t expect things to be simple.

  32. 82
    Bob Reiland says:

    Re: #77: See the response to #1 in the RealClimate post http://www.realclimate.org/index.php/archives/2006/11/broadly-misleading/ .

    Basically saturation of infrared CO2 bands is not expected to ever occur on Earth.

  33. 83
    Leonard Evens says:

    Re: “the log of something never goes to zero, but gets there practically sometime.”

    I presume you mean the rate of change of the log function. Of course, log(x) goes to infinity as x does. Its derivative varies inversely with x and goes to zero as x goes to infinity.

  34. 84
    William Astley says:

    Re: #76 Thanks for the information Tamino. The following are my comments.

    I believe you have not disproved Wagner’s hypothesis that there has in the past been fairly rapid step changes in atmospheric CO2 due to changes in ocean surface temperatures. The step changes in atmospheric CO2 are in response to the sudden coolings and then a return to “normal” temperatures, such as the 8200 kyr ago cooling event. Your blog notes that the step atmospheric CO2 changes, that Wagner determines by studing leaf stomatal density in fossils, is not recorded in the Antarctic ice core data.

    The Antarctic ice core gas data is, however, smoothed due to the following process (From Paleoclimatology, Second Edition, Raymond Bradley, Page 167):

    “A fundamental problem in constructing a paleo-record of trace gas concentrations from ice cores is the fact that the air in ice bubbles is always younger than the age of the surrounding ice (Schander and Strauffer, 1984)”

    The problem is the ice continues to breath and hence is an integration of atmospheric air rather than a spot sample. In your blog you state that the Taylor dome ice tracks current atmospheric changes in CO2, which it may, however it will also track changes a hundred years from now and will integrate the change. (i.e. As the ice “breathes” the ice core air is a mixture of atmospheric air over a long period of time rather than a spot sample.) Hence if CO2 levels increase 25 ppm and then decrease 25 ppm and then return to the original 280 ppm, in a relatively short period of time, the Antarctic ice core will have 280 ppm trace CO2 which is the average over time.

    Continuing from “Paleoclimatology”, Second Edition: “Pore close-off varies with accumulation rate, ranging from approx. 100 yr at high accumulation sites such as Dye-3 in Greenlandâ�¦ to as much as 2600 yr at very low accumulation sites such as East Antarctic.”

  35. 85
    Ike Solem says:

    The basic level of background information required to grasp climate change is actually pretty high – but it is very available. The best way to get up to speed on the topic is, of the books I’ve seen, “The Discovery of Global Warming” and its associated website, http://www.aip.org/history/climate/index.html

    There, you can quickly learn about the history of the scientific investigation into the appearance of fossil fuel-sourced CO2 in the atmosphere:

    None of this work met the argument that the oceans would promptly absorb nearly all the CO2 humanity might emit. Plass had estimated that gas added to the atmosphere would stay there for a thousand years. Equally plausible estimates suggested that the surface waters of the oceans would absorb it in a matter of days.(29) Fortunately, scientists could now track the movements of carbon with a new tool – the radioactive isotope carbon-14. This isotope is created by cosmic rays in the upper atmosphere and then decays over millennia. The carbon in ancient coal and oil is so old that it entirely lacks the radioactive isotope. In 1955, the chemist Hans Suess reported that he had detected this fossil carbon in the atmosphere.

    The amount that Suess measured in the atmosphere was barely one percent, a fraction so low that he concluded that the oceans were indeed taking up most of the carbon that came from burning fossil fuels. A decade would pass before he reported more accurate studies, which showed a far higher fraction of fossil carbon. Yet already in 1955 it was evident that Suess’s data were preliminary and insecure. The important thing he had demonstrated was that fossil carbon really was showing up in the atmosphere. More work on carbon-14 should tell just what was happening to the fossil carbon.(30)

    It will take a bit of time, but for Dana et al, reading the book and checking the website (which takes some time and effort!) should answer many questions. It should also be required reading for all science journalists who cover this issue. It’s very surprising to see how many of the ‘skeptical arguments’ are recycled from 50+ years ago… at a time when the science was not nearly as well understood (you can find references to ‘the discredited theory of plate tectonics’ in geology textbooks from the 50s, as well)

  36. 86
    tamino says:

    Re: #84 (William Astley)

    Your blog notes that the step atmospheric CO2 changes, that Wagner determines by studing leaf stomatal density in fossils, is not recorded in the Antarctic ice core data.

    I established a lot more than that. For one thing, that according to other scientists working in the same field, Wagner’s methodology is questionable on a number of grounds. For another thing, that leaf stomatal estimates of CO2 don’t give the precision necessary to support the results he claims. For yet another thing, that the large fluctuations on decadal timescales — which according to his studies are the rule rather than the exception — are simply not possible in light of the remarkable smoothness of the modern instrumental record, which (despite Beck’s protestations) is unimpeachable, and has better time resolution than any paleo record.

    Wagner’s claims are pretty well busted. And you’re on thin ice.

  37. 87
    Stu says:

    Re #55 – Leonard, I went searching around for the data that Cockburn is talking about and came to similar conclusions on my blog. I thought his description of how smoothly the CO2 kept increasing was the giveaway that he was looking at smoothed data. As far as I know, there aren’t any measurements from that era to resolve trends to the sort of accuracy he is talking about – though perhaps the experts here can correct me if I’m wrong.

  38. 88
    pat n says:

    Reid Bryson, founding chairman of the University of Wisconsin Department of Meteorology, when asked on how much outward radiation is absorbed by carbon dioxide, answered:

    Eight hundredths of one percent. One one-thousandth as important as water vapor. You can go outside and spit and have the same effect as doubling carbon dioxide.

    This begs questions about the widely publicized mathematical models researchers run through supercomputers to generate climate scenarios 50 or 100 years in the future. Bryson says the data fed into the computers overemphasizes carbon dioxide and accounts poorly for the effects of clouds�water vapor.

    http://www.wecnmagazine.com/2007issues/may/may07.html

    The response on the Cockburn claims (above article) should work for Bryson, I assume.

  39. 89
    James says:

    Re #74: [The "Peak Oil Contrarians" (people, like myself, who reject the IPCC projections because we believe rising fossil fuel costs will price fossil fuels out of the market...]

    You’re overlooking a couple of things. First, assuming your peak oil arguments are correct, you’re still overlooking the fact that oil is responsible for only a fraction of CO2 generation. A big chunk comes from coal, and I seem to recall projections of a several century supply. Rising oil prices won’t affect this at all.

    Second, there is still plenty of room for oil prices to rise before they start making significant cuts in demand. US gasoline prices have about doubled in the last few years without noticably cutting consumption, or creating any general demand for fuel-efficient vehicles. European prices are roughly double US ones, but likewise have had little effect. That seems to suggest that even if peak oil is reached soon (or has been already), consumer demand will go on supporting higher prices for a long time to come.

  40. 90
    Hank Roberts says:

    >Bryson
    Curious article; I emailed the editor asking if there’s a chance for a followup (it’s a monthly) to ask Dr. Bryson to give his sources and cites so people can read the material on which he bases his opinion.

    The two opinions that stood out to me were his statement that warming continues for this period, long after the rapid rise that ended the ice age, and that that’s typical — it doesn’t show up in what I’ve seen, so I’m curious what he relies on for that.

    I’ve seen this and the footnotes to it: http://www.globalwarmingart.com/images/thumb/b/bb/Holocene_Temperature_Variations_Rev.png/350px-Holocene_Temperature_Variations_Rev.png

    The other point that stood out was his belief that the industrial age hadn’t started in 1800, and that human activity couldn’t increase warming or CO2 before that. I understood coal was being used as a fuel well before that time, and Dr. Ruddiman’s work on agriculture and climate looks at changes for thousands of years before the present. Again I’m hoping they are willing to provide cites and footnotes to the statements.

    Opinions are entertaining curiousities. Sources and cites are the making of an educational experience.

  41. 91
    Richard Ordway says:

    #88 [We ask about that evidence, but Bryson says itâ??s second-tier stuff. â??Donâ??t talk about proxies,â?? he says. â??We have written evidence, eyeball evidence. When Eric the Red went to Greenland, how did he get there? Itâ??s all written down.â??]]

    If Bryson thinks that he can prove AGW is a normal trend, then there is an *open* way for him to debate his views for veracity…in the peer-review journals.

    If he has evidence, it will be evaluated by the whole world in the court of the world…not sneaking his views in through the rear and beating his chest claiming that everyone else is wrong, everyone should listen to him and national policy should be based on his findings.

    Can you imagine science without the open peer-review journal process-even as slow and imperfect as it is?

    Tobacco-paid PHDs pushing that cigarettes are good for you and laws should be passed to ensure that teens use it for medicinal reasons in high school.

    Environmental groups’ paid scientists stating that the wild sabretooth cat is endangered (“they have had actual living examples…but they died”) and the whole USA must become a preserve with no individual property rights.

    Oil companies’ paid scientists stating that they have definitive evidence that burning oil, coal and gas keeps the climate stable, so we have to burn all we can.

    Religious-sponsored scientists stating that all MD doctors should be outlawed because they can prove that more people die with doctors then without them.

    John Doe, a newly minted PHD research scientist “finds” that an asteroid is going to hit the Earth in five years and the USA has to dedicate 90% of our total resources to combat it in the next five years.

    Without the peer-review process, science does not work.

    Errrrr…get the point?

  42. 92

    [[A few unthreaded questions I have regarding the science, If the addition of CO2 is algorithmic, does this not mean that the more CO2 in the atmosphere the less effect each molecule has on IR radiation, what is the saturation point whereby adding more CO2 will have no effect on the energy budget? ]]

    Logarithmic. Yes, it becomes less effective with each additional molecule. But as far as I know there’s no limit at which it stops. We know it can get at least as bad as on Venus, where the greenhouse effect — due primarily to the planet’s 96.5% CO2 atmosphere — has raised the surface temperature from 232 to 735 K.

    [[If the troposphere is warming and the stratosphere is cooling does this not point to a zero sum equation?]]

    No. The troposphere is much more massive than the stratosphere. Also, we live in the troposphere.

    [[How could less ozone in the stratosphere possibly be a negative forcing on the troposphere, as more UV radiation is making it to the surface, should this not be a positive forcing?(I know this will be covered in the coming weeks as RC delves into ipcc4).]]

    Darned if I know. Anyone…?

  43. 93

    [[The "Peak Oil Contrarians" (people, like myself, who reject the IPCC projections because we believe rising fossil fuel costs will price fossil fuels out of the market, while favoring the development of renewables) argue that the cost difference is what will drive carbon reduction.]]

    Coal is still cheap.

  44. 94

    [[I believe you have not disproved Wagner's hypothesis that there has in the past been fairly rapid step changes in atmospheric CO2 due to changes in ocean surface temperatures.]]

    Skeptics have not disproved MUFON’s hypothesis that the unexplained events in UFO incident compilations were caused by alien starships.

    It’s not up to climatologists to disprove Wagner’s hypothesis. It’s up to Wagner to prove it. The burden of proof is on the affirmative.

  45. 95
    Ray Ladbury says:

    You know, it is absolutely amazing to me that someone who is trained in the sciences can look at the changes we are seeing and say: “It’s all a natural trend.” Look, if temperatures are rising, if ice is melting, then you are adding energy to the system. WHERE is that energy coming from? CLUE TO DENIALISTS: Energy does not just happen. It does not just increase naturally. It has to come from somewhere. The pathetic attempts to claim that this is just a continuation of warming from the last ice age are reminiscent of a 4 year old standing over a brokek vase and saying, “It just happened!”

  46. 96
    pete best says:

    Re #94 – King Coal and fossil fuels

    humandkind has enough fossil fuels reserves to blast out business as usual scenarios for at least 50 years even if Peak Oil and Peak Gas come into effect because although economically it might be disasterous the falloff in use and affordability is gradual and hence coal reserves can sustain humandkinds level of carbon output for some time to come even if peak oil was 2018 and peak gas 2020/2040 time lines.

    No, we are in a warmer world reality, 2 degrees minimum or 0.2 degrees per annum for another 50 years adding to the 0.6 already here makes 1.6 and we are expecting another 0.5 from the oceans making 2.1 degrees C.

    By 2030 my country the UK can expect relatively speaking temps to hit 40 C during some summers. Rain concentrations and amount will also alter. It could makes things much more difficult for us and increase costs of everything to.

  47. 97
    pat n says:

    Re: 90

    As the population in Britain increased, the need for fuel supplies also increased, wood became scarce as great tracts of forest were felled for both fuel and building materials.

    By 1683, some of the bigger mines were using timber to support the roof, this enabled coal to be mined much further away from the mine entrance.

    http://www.pitwork.net/history1.htm

  48. 98
    Lynn Vincentnathan says:

    Luckily I don’t have cable and no time to read other blogs, so I just check in here now & then. Unfortunately an influential person I know seems to be checking in somewhere else, where all they do is complain that their (denialist) theories are not given fair coverage and consideration in the media, and he thinks that’s unfair, that all ideas should be given a fair chance. I think I’ll send him this entry.

    But it’s sort of weird that people think the media and their consumers should be the arbitrars of science; I thought scientists were supposed to be.

    Pretty soon the people may wrest science back from the scientists and we’ll know for sure that the sun goes around the earth and not vice versa. Any idiot can stand outside & see that it rises in the east, heads westward during the day, and set in the west. And the earth certainly is not moving. Do you feel it moving? Hunh? Now where the sun goes at night is anyone’s guess. A Chinese myth has it that the fire bird flies through the sky during the day and goes to the underworld and sleeps on a tree at night. But since I’m from California, I say it sinks into the ocean and get extinguished, then a new sun comes up each dawn.

    Hey, I think I solved it. Global warming. It’s all those suns sinking in the ocean that’s warming the earth. And there’s even evidence the ocean is warming.

  49. 99
    tom says:

    Can somebody explain how global warming morphed into ‘climate change’?

    Climate change seems to me a useless term as: A> the climate always changes and B> ‘change’ implies that the globe could be cooling.

  50. 100
    Paul Dietz says:

    How could less ozone in the stratosphere possibly be a negative forcing on the troposphere, as more UV radiation is making it to the surface, should this not be a positive forcing?

    As I understand it, ozone also has absorption features in the infrared, so independent of its effects on UV it can act as a greenhouse gas.


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