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Cold Case vs. CSI

Filed under: — gavin @ 14 February 2007 - (Slovenčina)

If you are a follower of TV crime shows, it is likely that you’ve come across one of the CSI offshoots (CSI stands for Crime Scene Investigation) and a slightly less well known show called ‘Cold Case‘. In both these shows, difficult crimes (usually murders) are solved using the most up-to-date forensic methods and incredible detective work. However, it will be obvious to even the most jaded TV watcher that the CSI crew get to have a lot more fun with the latest gadgets and methodologies. The reason for that is clear: with a fresh crime scene there is a lot more evidence around and a lot more techniques that can be brought to bear on the problem. In a ‘Cold Case’ (where the incident happened years before), options are much more limited.

Why bring this up here? Well it illustrates nicely how paleo-climate research fits in to our understanding of current changes. Let me explain….

For the last 30 years or so, the amount of information we have about the planet has gone up by a couple of orders of magnitude – mainly due to satellite information on atmospheric (radiation, temperature, humidty, rainfall, cloudiness, composition etc.), ocean surface (temperature, ice cover, windiness) and land properties (land cover, albedo) etc. Below the surface, we are now measuring much more of the ocean changes in heat content and carbon. This data, while still imperfect, has transformed our view of the climate such that the scientists studying it can seriously discuss details of problems that twenty years ago were not even thought of as issues. “CSI – Planet Earth” if you like.

Comparatively, the amount of information we have for any period in the past is less – hundreds (in some cases a few thousand) of records of climate ‘proxy’ data (i.e. records that are related to climate, such as tree rings ot isotope ratios, but that aren’t direct thermometers or rain gauges) that are not necessarily optimally spaced, nor necessarily well-dated, nor uncontaminated by non-climate influences. However, there is the great advantage of a much longer time period to work with, as well as a greater variety of changes to investigate. Think of the people that work on that as the ‘Cold Case’ crew.

The most prevalent reasonably scientific question about current climate changes is ‘how do we know that this isn’t natural variability?’. A number of versions of that question came up in the House hearing last week (a nice report from the proceedings can be found here). Some of those comments were serious, some were ridiculous, but all essentially pointed to the same issue. Kevin Trenberth and Richard Alley answered it best when they pointed out that the causes of ‘natural variability’ – whether the sun, volcanoes or ocean changes – should be detectable (but haven’t been), and that the anthropogenic ‘hypothesis’ should have consequences that are also detectable (which have). Add in the modelling studies which indicate that current conditions can’t be explained without including greenhouse gases and you have a pretty solid case that what is happening is in large part anthropogenic.

A rather more specious comment heard often (including at this hearing) is that ‘if it was warmer before, then the current warming must be natural’ or alternatively ‘if you can’t explain all of the past changes, how can you explain anything now?’. First of all, there are many periods in Earth history that are unequivocally accepted to be warmer than the present – the Pliocene (3 million years ago), the Eocene (50 million years ago) and the mid-Cretaceous (100 million years ago) for instance. Less clearly, the Eemian interglacial period or the Early Holocene may have been slightly warmer than today. Thus, if that logic were appropriate, no-one should bother worrying about climate change until sea levels start to approach mid-Cretaceous levels (about 100m above today’s level!).

However, the logic is fatally flawed. It is akin to a defense lawyer arguing that their client can’t possibly have committed a particular murder because other murders have happened in the past that were nothing to do with them. That would get short shrift in a courtroom, and the analgous point gets short shrift in the scientific community too. Of course, it is possible that our suspect was involved in previous murders too – but obviously the further back you go, the harder it is to pin it on them. And clearly, there will be past murders where they have a clear alibi.

A better tactic for the defense is obviously to try and pin it on someone else – and if that someone else has a record – then all the better. Therefore, ‘the sun did it’ is a frequent accusation, but as we have discussed here quite often, this time around the sun has an alibi and there are reliable witnesses to back him up.

Given the better information and resources available for the CSI crew, it is natural that their assessment of the current case will generally hold sway. Cold Cases (or paleo-climate) are of course of paramount interest: they provide a much wider set of conditions that set the stage for the modern analyses and provide plenty of test cases for us to hone our techniques (such as climate modelling). However arguments from paleo are extremely unlikely to trump the modern analyses – whether they refer to the medieval warm period or the Phanerozoic.

So to summarise, CSI-Planet Earth have a good case for pinning the latest warming on greenhouse gases. Cold Case has evidence that they were involved in some previous cases (the last glacial period for instance), though they’ve definitely ruled our suspect out for a few others (e.g. the 8.2kyr event). It would be hard to argue that our suspect should be acquitted because there have been some crimes they didn’t commit!

Update: I should have linked to this Newsday piece: Hot on their global trail by Bryn Nelson where I first tried out this analogy.


168 Responses to “Cold Case vs. CSI”

  1. 101
    John D. says:

    Here is a model to set up if any skeptic really wishes to know if climate change is imminent and just how soon and catastophic it will be. You don’t have to be a scientist and it is really quite accurate. Here’s how it works. The U.S. Military and Area 51 personnel know more than anyone, the actual state of the planet at any given moment and will never tell anyone what’s really going on. If you keep an eye on those that have “above top secret” clearance and find out who have sold their beachfront properties around the world in the last few years and where they are investing in new properties, it will give you some answers.

    I’d bet it’s high ground in Wyoming, Idaho, Northern British Columbia and Northern Ontario. Most of these locations are not real targets for anything, are fairly inconspicuous and socially deemed safe zones. Get this model going (if you dare) and let us know your conclusions.

  2. 102
    Hank Roberts says:

    Lynn, you’re creating more scenarios in words and imagination than are likely in reality, I think.
    Occam’s razor — entities should not be multiplied beyond necessity. You’re imagining options that don’t occur.

    There is no ‘linear’ option, and no immediate off switch even if we stopped adding CO2 now — that’s what people imagine and wish were the case.

    Continued warming in excess of what biology and chemistry can handle in real time is our situation. We’re well beyond whenever it was last true that biogeochemical cycles had enough slack to reuse what we added on a year to year basis.

    Donella Meadows was teaching this years ago; her whole archive is still I think better for analogies and images than anything I’ve come across since:
    http://www.sustainer.org/dhm_archive/search.php/?display_article=vn348bathtubed
    http://www.developerdotstar.com/mag/articles/places_intervene_system.html

    Global warming _is_ following a curve — an increase, committed warming, beyond what we have now, because the planet keeps heating up — and an eventual peak and decrease again once what we put in no longer exceeds what nature can handle.

  3. 103
    Ed G. says:

    Re: #64

    I understand what you are saying but note that H. S. Kheshgi coauthored several (I think really good) papers in the late 1990′s with one David Archer of RealClimate. I take that to be a vote of confidence in the man’s competence. Moreover, the papers show results that Exxon PR would rather not be encumbered with. Check them out at http://geosci.uchicago.edu/~archer/reprints/

  4. 104
    Mark Drasdo says:

    I have seen a number of references to sea levels during the most recent interglacials being some 6 metres above present levels. I understand that the previous peak in CO2 levels prior to the present high was at an estimated level of 299 parts per million some 325,000 years ago.

    We are now of course way above that figure and yet I have seen little comment as to why we are not therefore already committed to an equally significant sea level rise. Therefore I presume that there are fundamental differences between this and those previous interglacials-can anyway briefly explain for me what those differences are?

  5. 105

    [[many things can go wrong when your facts are mostly statistical]]

    CO2 in the atmosphere warming the ground isn’t statistical, it’s well-validated physics.

    [[ and direct experimental validation of a hypothesis is difficult if not impossible.]]

    Experimental validation no, empirical validation yes. The AGW theory has made several predictions now which have panned out — global warming at about 0.2 K per decade, troposphere warming while stratosphere cools, greater warming toward the poles, etc.

  6. 106

    [[ Galileo also dispensed with the notion of retrograde motion introduced by Ptolemy and others to account for the observed behavior of the planets; he showed that if you put the sun at the center than there was no need to invoke backwards motions of the planets.]]

    This is incorrect. Copernicus’s system still had epicycles, and heliocentric solar systems need them as long as you stick with circular orbits. Kepler tried to show Galileo that orbits were actually ellipses, but Galileo dismissed it on the understandable grounds that much of what Kepler produced was so nutty (planetary distances from nesting the regular solids, notes of the music of the spheres influencing life, astrology, etc.).

  7. 107
    Nick Gotts says:

    Re #97 I agree that methane capture, and measures to reduce methane and nitrous oxide production in agriculture should have more prominence, but even if your estimate of the effect of reducing short-term GHGs and relaxing sulphate control measures on climate is correct, there is also the “other CO2 emissions problem”: ocean acidification. See “The Acid Ocean â�� the Other Problem with CO2 Emission” on this site; the June 2005 report from the Royal Society of London at http://www.royalsoc.ac.uk/displaypagedoc.asp?id=13314;
    Nature 437, 681-686 (29 September 2005)
    Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms; and a 2006 NSF/NOAA/USGS 2006 workshop report at http://www.ucar.edu/communications/Final_acidification.pdf.

  8. 108
    Sashka says:

    Re: 82, 94

    It is a rather unusual turn of events when an ordinarily hostile reader is more helpful and polite than one of the founders.

    Yes, Ray, I am a former research scientist so I could figure out a lot of answers on my own. However I don’t work at the university anymore and I don’t have access to library and, most importantly, I don’t have much free time. I didn’t mean to tax your valueable time to any significant extent. My understanding was (correct me if I’m wrong) that the group collectively has pretty much complete expertise in climate science so any “basic” question could be answered without trouble. Moreover, I thought it was your mission to educate public about these difficult matters like this. Am I wrong again? Further, even if I am capable of doing it on my own, most people here certainly are not. By answering me you would educate everyone at the same time. Why not stand up to the occation? It’s not like I’m asking dumb questions.

    Finally, even if I decided to do the calculation, I wouldn’t know how to estimate porosity. Porosity would certainly depend on depth and probably on age and temperature. I’m not sure this is such a trivial calculation as you are implying. Since you are teaching this subject I would assume that you should be able to answer it easily if somebody raised it in your class, no?

  9. 109
    Sashka says:

    Re: 94

    I was able to access only the abstract and it doesn’t say much. In the references, however, there is a link to another abstract which actually has the 22 years number.

    http://www.nature.com/nature/journal/v311/n5981/abs/311045a0.html

    The age of the entrapped air is, however, not the same as that of the surrounding ice because air bubbles only become isolated from the atmosphere during the transition from firn to ice. Typically the age of the ice at this transition is between 100 and 3,000 yr, depending mainly on firn temperature and snow accumulation rate.

    So my guess in 108 was correct.

    The mean age difference between ice and enclosed air, as well as the age distribution width for a given sample, are especially important for the investigation of the anthropogenic increase of CO2 and trace gases in the atmosphere over the last centuries, and for the comparison of climatic parameters recorded in the ice with parameters recorded in the bubbles. For Siple Station (Antarctica), this age difference and age distribution width were deduced from the bubble volume measured as a function of depth. The values are 95 yr and 22 yr respectively.

    This would be an answer to the question except they must have assumed something about porosity during transition period. They also had to assume something about accumulation rates in the past vs today. Sorry for the nitpicking.

  10. 110
    GAW says:

    #80 Sorry for the delay, I only get 1 or 2 chances to visit this site during the day. I took a look at your suggestion – sorry, didnt really help.

    When you install perfectly good physics in a finite element model you are making a lot of serious assumptions on how your linear approximation of the continuum is held together. I haven’t bothered to educate myself on the physics involved, but I would be much surprised if a lot of the glue holding all your elements together wasn’t based on some sort of diffusion equation. That turns your finite element universe into a maze of boundary value problems to a very poorly behaved class of differential equations. With such a system, even the simplest assumption of how the representation scales is suspect. Even worse is the assumption that a finite element model of something like steady state temperature distribution to meets expectations can accurately represent a dynamic system.

    In short, I wonder how much physics is left after you have assembled your model. I also really wonder how you have any confidence that common features that appear out of an ensemble of solutions to such an ill formed system are anything other than artifacts of the respresentation.

    A very long time ago, I was given the task of investigating the migration the FAA airport noise model from a Cray to a minicomputer. The basic calculation was a nuts an bolts sum that attempted to account for topography, flight path, plane characteristics, and traffic schedule to draw noise contours at various times of the day. The problem was that the engine noise model was represented by an exponential with a liberal mix of transcendentals in the exponent. I did a standard error analysis on the formula and even the loss of 2 bits of floating point precision (quad precision on a mini) reduced accuracy to order of magnitude. That was enough to kill the project. PS, the model lives on, though it now seems they use some sort of lookup to provide different engine profiles – the planet may go belly up but Fortran never dies!

    Moral: Be very suspicious of complex systems they often don’t work the way you think they do.

  11. 111
    Lynn Vincentnathan says:

    #102, you’re probably right just to stick with “global warming” and include this hysteresis (251 & 55 mya scenarios) as part of its total package.

    However, as I understand it (acknowledging the lag time or “already in the pipes warming”) there are 2 possibilities (and many between): (1) we reduce our GHG emissions to the point at which the earth can reaborb them and the warming slows, ceases, or even reverses (harm is done, but not as extreme as #2); and (2) we reach a point in the warming mainly caused by our GHGs at which even if we reduce our emissions to zero, the warming will cause nature to emit more GHGs (methane clathrates, etc), causing more warming, causing more of nature’s emissions until we get to a much hotter world than with only our own human emissions, and it stays that way a lot longer, thousands of years, and kills off much of life on earth. Then there are many paths between these two, and I think we are already witnessing some of nature’s net emissions due to our initial AGW, but that might be too early to tell, and it does not mean we’ve reached that “tipping point” (but who knows).

    I sort of think that most people only have the 1st case in mind, and have no or little idea about the 2nd. So the attitude is that eventually we’ll get around to reducing our GHGs, and maybe there’re be some more harm and damage, but once we really get serious about reducing, then it’s just a matter of decades or perhaps a century, and we’ll be back to “normal.”

    I also understand that the triggering point for the #2 scenario could be about 6C, which is the upper projection for 2100, and is perhaps more probable for 2200 or 2300. It’s not highly likely that we’ll reach that level of warming, but it’s likely enough to have people understand what might happen (#2) if we get there, and distinguish it from “regular” AGW that could be reduced more easily, albeit with a long lag time for warming already in the pipes.

    Climate scientists, please feel free to jump in here if I’m wrong.

  12. 112
    PeakEngineer says:

    Nice article! We could be looking at a prelude to the arguments at the upcoming U.S. Supreme Court case on global warming: http://www.msnbc.msn.com/id/13554243/

    And imagine if they actually made a CSI episode about global warming…that might get the message through to people.

  13. 113
    SecularAnimist says:

    Lynn Vincentnathan wrote: “I also understand that the triggering point for the #2 scenario could be about 6C …”

    Or the triggering point may be much lower than that, and we may have already reached it, since there is evidence that self-reinforcing feedbacks (reduced albedo, increased GHG emissions from warming soils and thawing permafrost, die-off of phytoplankton, etc.) have already started and may be irreversible; plus there is evidence suggesting that natural carbon sinks that have been absorbing as much as half of the anthropogenic carbon emissions are becoming saturated.

  14. 114
    Mark A. York says:

    Well Steve latham, “Consider the hysteria over Cholesterol.”

    This doesn’t exactly lend credence to what followed. Any heart surgeon wouldn’t agree with this caveat, but doesn’t this sound like global warming alarmist to you? It’s a false analogy and fallacious on its face and that’s why I was heavy-handed as I surely can be, sometimes even unjustly so. I’m working on that one though.

  15. 115
    Climate Fan says:

    Well, in the end, does it matter if evidence is ‘statistical’ or ‘causative’? The consequences are so serious in this case that good statistical correlation and evidence warrants action as much as ‘causative’ evidence does.

  16. 116
    Rod B. says:

    113 says “…there is evidence suggesting that natural carbon sinks that have been absorbing as much as half of the anthropogenic carbon emissions are becoming saturated.”

    But the CO2 absorption of infrared (and its resulting AGW) has not???

  17. 117
    Wang Dang says:

    Re #65

    Lynn, I am a huge fan of science fiction. That is why I read the realclimate comment section. Lots of science, lots of fiction, and sometimes science fiction. I agree with Steve Bloom in #23, reader beware.

  18. 118
    Hank Roberts says:

    You understand the difference in the two uses of the word ‘absorb’ there? Just checking.

  19. 119
    Ray Ladbury says:

    “Reductionism is an extremely difficult discipline and many things can go wrong when your facts are mostly statistical and direct experimental validation of a hypothesis is difficult if not impossible.”

    Ah, spoken like a man without a good understanding of statistics. Contrary to the contentions of Disraeli and Mark Twain, any fool can lie with statistics, but a skillful statistician uses them to tell the truth. In the end, most scientific evidence winds up being statistical, and the result is just as compelling and just as cogent as a reading on a dial. Statistics is not a way of coming to stronger conclusions than are warranted by the data, but rather moderating our conclusions so that we are safe to a degree (e.g. a confidence level) in making a statement about them.
    Anthropogenic causation is the predominant hypothesis precisely because of its explanatory power. No other mechanism is even on the map.

  20. 120
    Marco Parigi says:

    Re #107 Re #97 I agree that methane capture, and measures to reduce methane and nitrous oxide production in agriculture should have more prominence

    Well I expect.. no, I demand that the next Realclimate article be titled “The case for complete bans on methane and Nitrous oxide” – are you listening Gavin?

    See “The Acid Ocean – the Other Problem with CO2 Emission” on this site; the June 2005 report from the Royal Society of London at…

    Now although there is consensus on GW being anthropogenic, you show me where this acidification problem has consensus among the scientists in the latest UN report! If we can get temperatures stabilised or down with CH4 and N2O elimination, that should stabilise or knock back the positive feedbacks in play. In the meantime, maybe we can quantify the oceanic carbon and thermal cycles which are still so poorly understood (as far as net energy is concerned) that little should be concluded as far as policy is concerned just on the acidification factor.

  21. 121
    Hank Roberts says:

    Marco, the change in pH of the surface ocean water is simple chemistry, well understood as soon as anyone noticed it happening. The IPCC is studying atmospheric physics.

    Did you read any part of the reference on ocean pH change that was provided? Which part isn’t clear to you? Have you searched at all in the science journals on this subject and found anything contradicting it?

    Asking smart questions is hard. A less than smart question gives the impression that “I did not bother looking this up, I want service not education” — or that one’s political or religious beliefs preclude considering the science.

    Encouraging experts is our job, if we want them to feel some reward for bothering to try to explain this difficult, evolving subject. Showing a best effort — “show your work, how did you get to your conclusion” — is one of the first lessons any student needs to learn, to keep the attention of someone who’s volunteering time to teach.

  22. 122
    Rod B. says:

    re 116 (mine) and 118 (Roberts):

    Yes, I understand the difference in the physical processes: on one hand the actual carbon/CO2 is absorbed by water, earth, plants, etc and pretty much sequestered. The other, CO2 is absorbing (capturing?) infrared radiation and its energy/heat content to, likely, re-radiate (some of) the “heat” back to earth. But the effect of my question is none-the-less valid: There is a total refutation from the consensus that infrared absorbtion by CO2 is saturated despite some indications that it could be, at least in some of its wavelength bands. (Though the refutation is tempered by the assumption that CO2′s continuing absorption is logarithmic with an even looser assumption of what the constant logarithmic factor is — though those two tandem assumptions get absolutely hardened and forgotten in the modeling process.) On the other hand, the ease with which carbon absorbtion saturation on the sink end is accepted, despite it being a more complex and unknown process, strikes me as more religious than scientific.

  23. 123
    Hank Roberts says:

    > There is a total refutation from the consensus that infrared absorbtion by CO2 is
    > saturated despite some indications that it could be, at least in some of its wavelength bands.

    Says who? This is well explained in the AIP history; it depends on air pressure/altitude; the idea that the bands were saturated was based on sea level pressure experiments done decades ago, not recent work.

    > carbon absorbtion saturation on the sink end is accepted, despite it being a more complex

    We know the amount of coal and petroleum burned; we know the CO2 increase in the atmosphere; we do the math, and say the rest is going into ‘sinks’; we know biomass change totals fairly well; we know solubility quite well; we’re learning about ocean mixing depth and rate. We can’t assume carbon ‘sunk’ is permanently out of circulation. Carbon in plants and topsoil is released when those die, unless they’re buried to make more coal, eh? And the ocean chemistry is going toward increasing solubility of carbonate and aragonite in surface waters, so the organisms that had been producing the sediments containing those materials become less effective at removing carbon this century.

  24. 124
    Hank Roberts says:

    A question for the stratigraphy students — has anyone got a few words on the ways carbon gets taken out longterm? What’s easier and faster, geologically speaking, sediment that with time becomes chalk or coal?

  25. 125
    Dave D says:

    Re ice core time resolution
    (#28 #44 #45 #67), (#94 #108, #109).

    Seeing Sahska’s link which says 100 too 3000(!) years for bubble trapping, has me thinking this issue is not laid to rest yet. In fact, there can be no universal number for the trap time since it depends so much on accumulation rate. The main characteristics of the bubble-record are set by length scales: ~60 to 80m to trap, and 3000m to crush the bubbles. The actual timeline depends on the accumulation rate.

    The abstract from the Siple station work (#109) only talks about going ~200 years back, with a 200m ice core. That is why the trapping is so fast, they get meters of snow per year.

    I am looking for the primary references on Vostok now. Since it is so much older, the accumulation rate must be slower. 3000m/600000y = 0.5 cm/y (ok the ice gets packed denser than the original snow fall). This would imply about 60m / (0.005m/y) = 12000 y to trap. This is an extreme overestimation, since snow is more fluffy that the ice layer it eventually forms, but I am interested in order of magnitude, here. This is waaay longer than atmopsheric CO2 lifetime.

    Like I said, I am trying to find the orignal sources on these long timeline cores. I will not have an issue with whatever values they state for the trap time, they are way more expert than me! I just want to see if they even considered a number for the write time of their ice-memory.

    It is difficult for us lay people to do more than either blindly accept or reject the mass of information on global warming. Original papers cost money, $10 to $15 a pop to download, and if you are asking a question slightly askew of the paper’s intent, you may not even get an answer. That is why this site is so valuable. I do appreciate the knowledgeable people who take the time to deal with these questions. Lord knows they probably have more important things to do. Thanks.

  26. 126
    Marco Parigi says:

    Re #121 (Ocean acidification)

    This from a friend who is a chemistry professor:

    * The arguments about the ocean heating up and outgassing carbon dioxide, and the ocean becoming acidic, ignore the fact that the ocean is a very thin warm bit on top of a very thick cold bit. It is the mixing of these bits that is important. I found some US Geological Survey data of ships sailing here, there, and everywhere and measuring the carbon dioxide concentration in the water. There was a very broad range in carbon dioxide concentrations. The concentration in the water was often higher than atmospheric concentration. There wasnâ??t any trend to less carbon dioxide in warmer water. Why is this? Well,

    * When I was last in (Sydney)I went to a talk by a physical chemist from New Zealand who talked about how mass and heat transport are coupled: you canâ??t calculate the flux of carbon dioxide from water to atmosphere and vice versa just by looking at the concentrations, you need to know the relative temperatures too. I worked out his equations in Excel, and a gas will move against a pressure gradient if it is moving with a temperature gradient: i.e., if the air is hotter than the water, the concentration of carbon dioxide in the water will be higher than in the air. He wrote two papers on this in 1991-1992 in the climate scientistsâ?? journal of record, Geophysical Research Letters. They have each been cited exactly four (4!) times. I found a paper from 2003 by a collection of climate scientist chaps from Princeton and other places, who estimated carbon uptake in various places and come to the conclusion: â??there is more carbon dioxide uptake at low latitudes, and less at high latitudes, than the models predict.â?? Well, this is because the physics in those models is wrong.

    Can a scientist refute this statement please?

  27. 127
    Rod B. says:

    re 123 by Roberts, et al

    A simple equivalent spectograph of the infrared radiation leaving the upper atmosphere shows virtually none in a couple of the major CO2 bands (notably the 15 micrometer band which is near the peak of the radiation spectrum) — implying that maybe the current CO2 is already absorbing 100% of the infrared in those bands. True, as some experimentation shows, maybe more can still could be absorbed in the fringes as the density of CO2 increases; and the models properly account for that by increasing the forcing by the logarithm of the concentration increase (though the concentration ratio is nimbly taken to about the 6th power first!) But it sure isn’t intuitively obvious that the CO2 absorption is not maxed out.

    That was a helpful description of the carbon sink process. But, given its complexity and a few uncertainties as you describe, it’s still a big leap of faith to claim prima facia that it is maxed out. Granted SecularAnimist only says “there is evidence suggesting …. carbon sink saturation”. I could correctly say the same thing for CO2 absorbtiopn of infrared.

    [Response: Of course it's not intuitively obvious. That's why we have textbooks. It's well understood, and if you want to understand it you should just read the CO2 section of Goody and Yung, or Chapter 4 of the draft of my own book (follow the ClimateBook link on my
    web site. --raypierre]

  28. 128
    Hank Roberts says:

    NOAA’s Pacific Marine Environmental Laboratory Carbon Dioxide Program
    http://www.pmel.noaa.gov/co2/co2-home.html

  29. 129

    [[113 says "...there is evidence suggesting that natural carbon sinks that have been absorbing as much as half of the anthropogenic carbon emissions are becoming saturated."

    But the CO2 absorption of infrared (and its resulting AGW) has not??? ]]

    No. Saturation of the CO2 absorption bands was the prevailing theory from about 1900 to 1950. Turns out it’s not correct. Even when the central absorption lines are saturated, the lines in the wings are not, so adding CO2 keeps adding absorption, though at a slower and slower rate. It’s a logarithmic relationship — dF = 5.3 ln (C/C0) where dF is change in forcing in watts per square meter, C is CO2 concentration and C0 is initial CO2 concentration, usually taken as 280 ppmv for 1750.

  30. 130

    [[there is more carbon dioxide uptake at low latitudes, and less at high latitudes, than the models predict.â?? Well, this is because the physics in those models is wrong.]]

    I’m not a scientist, but I play one on TV.

    The poles are smaller than the equator. Even if cold water absorbs more CO2, there’s a lot more warm water.

  31. 131
    Lynn Vincentnathan says:

    #RE 47 & 117, Mr. Dang, you’ve got me pegged pretty good: I’m a bore at parties and a nincumpoop re climate science.

    So I guess you’ll not accept my argument that science is conservative in its avoiding false positives, avoiding making claims about global warming when they are false (which is necessary so scientists can protect their repution & not become the boy who cried wolf). And OTOH, policy-makers, in charge of making sure things are all right in the world, and persons living in the world, who would like to see it flourish rather than decline, would be interested in avoiding false negatives (you’d think). That is, avoiding a situation in which some great harm is happening or impending and we do nothing to mitigate it. Their focus logically/morally/emotionally should be on the high end projections; like creating all sorts of safeguards against pushing that red button.

    Just because our policy-makers-that-be don’t understand their responsibility and are on the conservative side of conservative science, does not make that position correct or moral.

    And you needn’t come back with arguments that mitigating global warming might be harmful to the economy or our political freedoms, because that is just a big science fiction STATE OF FEAR untruth, and amounts to greater alarmism than what moral/concerned persons are proposing — like “save money while saving the earth,” or my “little way of environmental healing” based on St. Therese’s little way of spiritual childhood.

  32. 132
    Chuck Booth says:

    RE #131 “you needn’t come back with arguments that mitigating global warming might be harmful to the economy or our political freedoms,…”

    From Friday’s Hartford (CT) Courant:

    Economists Debate Climate Change

    Panel Members Question Findings On The Costs Of Damage From Global Warming

    By DAVID FUNKHOUSER
    Courant Staff Writer

    February 16 2007

    NEW HAVEN — Yale welcomed Sir Nicholas Stern, the British economist whose team offered an urgent warning last fall on the worldwide economic impact of climate change, and then gave him a good grilling Thursday.

    A panel of top economists questioned many of the assumptions loaded into the economic models used by Stern’s team. But the overriding response was that the climate science behind the report is sound, that the world must act, and that the solutions will require raising the price of carbon – the element at the center of the global warming dilemma.

    “The review provides enough information to make an economic case for immediate action,” Wesleyan economics Professor Gary Yohe said…

    Stern, head of Britain’s government economic services and a former chief economist at the World Bank, advised the audience of a few hundred students, faculty and interested citizens gathered for the daylong symposium Thursday not to take his report’s models “too literally.”

    “On the whole, the models are conservative,” he said. “And I believe the damage will likely be greater” than predicted. “The case for the urgency of action is very powerful.”

    Figuring out what it will cost to cut emissions enough to meet Stern’s goal – and whether that goal is worth meeting – involves some complicated calculations of costs vs. benefits.

    The Stern Review predicts that the risks from climate change could cost from 5 percent to 20 percent of global gross domestic product if no action is taken. But the report contends the cost of combating the problem can be limited to about 1 percent of GDP.

    Yale economics Professor William Nordhaus argued that the review overstates the case for urgent action and criticized Stern for failing to subject the report to peer review, a practice he said is “fundamental to good science and sound economics.”

    He [Nordhaus] and the other panelists proceeded to offer such a review in public, their critiques tightly woven with the language of economic theory and modeling. Nordhaus criticized key factors used in the review’s modeling, which he said led him to question the costs of damage from climate change and the efforts to abate it.

    He [Nordhaus] said most economists agree that the science behind global warming is sound, and that the issue needs to be addressed, almost certainly by raising the market price of carbon.

    In other words, put a price on fossil fuels and CO2 emissions that will begin to reflect their environmental impact. One way to do that is through “cap and trade” systems for carbon dioxide emissions similar to the one already in place in Europe and now being organized in Connecticut and several other northeastern states. Such systems put a price on every ton of carbon emissions and allow “credits” for these emissions to be traded.

    **************
    Hmmm….it seems the economists get it. Why can’t the AGW skeptics accept the science (and economic impact), too?

    [Response: Indeed, and remember that the economists agree with the need for action, even on the basis of their own rather limited methodology. In particular, the standard methodology of economics requires a discount rate for future harms, and most of the argument between Nordhaus and Stern comes down to the choice of discount rate. For distant harms, there is no one right answer, and any choice of discount rate severely distorts something. Nordhaus is right in that a too-low discount rate means a trivial harm forever (one more mosquito bite) looms large, but Stern is also right in that a catastrophic harm in the distant future appears trivial in Nordhaus' view. Discounting, and indeed traditional cost-benefit is a broken methodology for such problems. For example, there is no really satisfactory way to put a cost on non-market harms like extinction of polar bears. The fact that -- even within the narrow traditional economic view of the problem -- economists agree on the need for action, only underscores how strong the case for action really is. --raypierre]

  33. 133
    Zeke Hausfather says:

    Having attended that eight hour conference with Sir. Nicholas, Nordhaus, Jeff Sachs, etc. last week, I can attest to the veracity of that news report. In general, while there were serious discussions about how strong action needs to be (with Stern and Sachs on the strong side, and Mendelson and Nordhaus on the weaker side), there was universal agreement that some action needs to be taken immediately.

    At the end of the event, Jeff Sachs made a prediction so optimistic that it may disqualify him from claiming to be a practitioner of the dismal science. Namely, he said he was confident that by 2010 there will be a future successor to the Kyoto Protocol with widespread international participation and binding reduction targets or taxes. I’m not sure I’m quite so optimistic, but as Nordhaus quipped, Sachs has a habit of being right about these things.

  34. 134
    James says:

    Re #132: “Hmmm….it seems the economists get it.” Maybe, but I’m not entirely convinced. Else why do they seem to favor a system (cap & trade) which is at best cumbersome (but which does offer job opportunities for a new cadre of bureaucrats :-)); at worst serves to legitimize continuing CO2 emissions; and in any case is at least one level removed from the general public? Seems to me that it would be far simpler and much more effective to replace some existing tax, such as sales tax or VAT, with a carbon tax collecting the same amount of money. That would give everyone a direct and personal incentive to reduce their emissions.

  35. 135
    Rod B. says:

    re 131: Lynn says “… policy-makers…. would be interested in avoiding false negatives (you’d think). That is, avoiding a situation in which some great harm is happening or impending and we do nothing to mitigate it…. ”

    That’s all well and true, but not necessarily so high-minded as HL Mencken (sp?) pointed out (as did Michael Douglas in Mr. President ). The entire purpose of elected leaders is to find some ill, evil, or hobgoblins — real or not, that they can scare the people with and convince the people to re-elect them to save humanity.

    re 132: I think it obligatory to assess the economic costs and impacts of both scenarios with the current accepted methodology to get a rough idea of what could happen. However (truth in lending: I’m a skeptic), raypierre makes a major and salient point. First, economic analyses can be wrong, like science sometimes, though the errors of economics makes the science errors look puny. More importantly, some things simply transcend the “business case” in the final analysis. I’m not sure what the business case was for WWII or the Cold War, but, while important to know, it was just a small piece of the policy making.

  36. 136
    Joseph O'Sullivan says:

    #131 Lynn Vincentnathan – #133 Zeke Hausfather

    A standard talking point against regulatory action in the climate change debate is that it will be too expensive and will ruin the economy. This is an old and incorrect assertion. Opponents of environmental regulation have been using this argument for decades and have been wrong. Its from industry scions like Lee Iacocca and politicians like president Bush, not just people on the fringe.

    Pollution control regulation has economic benefits and there have been studies that demonstrate this. For example the NAS looked at air pollution laws in the US and stated that there were costs, but the economic benefits substantially outweighed these costs.

    One thing that always surprises me is when contrarians say that global warming is just more environmentalist gloom and doom and environmentalist’s dire prediction have always been wrong. Its really people who have opposed environmental regulation who have made predictions of disaster and have been wrong.

  37. 137
    Zeke Hausfather says:

    Re: 134
    I’ve yet to meet an environmental economist who favors a tradable permit system over a tax (see Weitzman’s seminal “Prices vs. Quantities”, http://ideas.repec.org/a/bla/restud/v41y1974i4p477-91.html ; Ian Parry’s “Are Tradable Permits a Good Idea?” http://www.rff.org/Documents/RFF-IB-02-33.pdf ; or Pizer’s “Combining price and quantity controls to mitigate global climate change” http://ideas.repec.org/a/eee/pubeco/v85y2002i3p409-434.html ). In fact, a number of the economists at last week’s panel took Stern to task for not being aggressive enough in advocating taxes over tradable permits.

    However, I’ve also yet to meet a politician who favors carbon taxes of grandfathered permits. And guess who decides policy?

  38. 138

    Re comment 134,

    That [increased fossil fuel tax] would give everyone a direct and personal incentive to reduce their emissions.

    No. It would give everyone who pays the tax an incentive to reduce his or her emissions, but many people work for government, and are net collectors, not payers, of taxes. Increased fossil carbon taxation gives these people a direct and personal incentive to interfere with taxpayers’ attempts to reduce their carbon emissions.

    Re comment 137, politicians have to balance the interests of the economists who hope to gain by increased fossil fuel taxation and the general public who will be required to pay it, and impeded by government in attempts to reduce their emissions.

  39. 139
    Steve Reynolds says:

    Re 132:
    raypierre’s response> …economists agree on the need for action, only underscores how strong the case for action really is. –raypierre]

    The peer-reviewed published median consensus of economists was a carbon cost of about $14/ton which is about the same as current US taxes on gasoline. Adding that tax to coal would have some effect, but does not seem to “underscore how strong the case for action really is”.

  40. 140
    Marco Parigi says:

    Re #121Marco, the change in pH of the surface ocean water is simple chemistry, well understood as soon as anyone noticed it happening. The IPCC is studying atmospheric physics. Did you read any part of the reference on ocean pH change that was provided? Which part isn’t clear to you? Have you searched at all in the science journals on this subject and found anything contradicting it? Asking smart questions is hard. A less than smart question gives the impression that “I did not bother looking this up, I want service not education” — or that one’s political or religious beliefs preclude considering the science. Encouraging experts is our job, if we want them to feel some reward for bothering to try to explain this difficult, evolving subject. Showing a best effort — “show your work, how did you get to your conclusion” — is one of the first lessons any student needs to learn, to keep the attention of someone who’s volunteering time to teach.

    My question was, essentially, would we take action purely on the basis of acidification of the oceans, if we could stabilise temperatures by removing GHG’s other than CO2 quickly. The economic and environmental harm of less alkaline oceans is less well talked about than that of higher surface temperatures. Is there any “Cold Case” evidence for mass extinctions due to less alkaline oceans? Is there any “CSI” evidence of present-day extinctions due to less alkaline oceans?
    Thank you for your link – The other ones didn’t work for me, frustrating my attempts at clarifying my questions.

  41. 141
    James says:

    Re #138: “…but many people work for government, and are net collectors, not payers, of taxes. Increased fossil carbon taxation gives these people a direct and personal incentive to interfere with taxpayers’ attempts to reduce their carbon emissions.”

    I don’t quite see the point you’re trying to make. If it’s that people getting money from the government wouldn’t bother to reduce their emissions, how so? They’d have the same incentive as anyone else: no matter what the source of their income, if they reduce the outgo, they have more left for themselves.

    If, OTOH, you’re suggesting that they’d discourage emission reductions in order to keep the revenue stream flowing… Well, maybe, but consider the lengths people will go to to avoid paying other taxes. Besides, it would be so much simpler, and beneficial for CO2 reduction, just to keep raising the rate each year. As more people find ways to reduce their emissions, the burden (and hence the incentive) on the rest keeps growing – which, now that I think on it, is a nice example of forcing creating feedback :-)

  42. 142
    Chuck Booth says:

    Re # 140 Marco, I think you’ll find the answer to your question in the following references:

    Royal Society (UK) (2005) Ocean Acidification Due to Increasing Atmospheric Carbon Dioxide. http://www.royalsoc.ac.uk/displaypagedoc.asp?id=13539
    Seibel, B.A. and P.J. Walsh (2001) Potential Impacts of CO2 Injection on Deep-Sea Biota. Science Vol. 294. no. 5541, pp. 319 â?? 320 (12 October).
    http://www.sciencemag.org/cgi/content/full/294/5541/319 (subscription required)
    Feely, R.A. et al. (2004) Impact of Anthropogenic CO2 on the CaCO3 System in the Oceans. Science â?¨Vol. 305. no. 5682, pp. 362 â?? 366 (16 July) http://www.sciencemag.org/cgi/content/abstract/305/5682/362
    Orr, J.C. et al. (2005) Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681-686 (29 September)

    The National Research Council of the National Academies of Science published a report on ocean acidiciation a decade ago:
    http://www.nap.edu/catalog/6238.html

    As I recall, the NAS came out with another report on ocean acidification last summer, but I can’t find the reference. Regardless, the 2005 report by the Royal Society has as clear a review of the subject as there is.

  43. 143
  44. 144
    Zeke Hausfather says:

    Re: 141
    Ideally you would tie a tax to the social cost of carbon, which would increase over time as the marginal cost of a ton of carbon (flow) is a function of the size of the existing stock. Also, any good carbon tax would be revenue neutral, e.g. all revenues would be used to progressively cut income and payroll taxes, for example.

    Re: 139
    That price of carbon seems a bit low. Might be the mean price per ton of carbon dioxide (which has a significantly higher molecular weight than simple carbon). In terms of carbon prices, I’ve heard a range from Nordhaus’s ~$30 per ton to Stern’s ~$300 per ton.

  45. 145
    Lynn Vincentnathan says:

    As for (neo)classical economics, I’m a complete skeptic-denialist-contrarian. It probably works somewhat okay in a steady-state world (that exists for a bleep in geological time).

    First of all, taxes only push money around from one place to another & do not in & of themselves harm the economy.

    Second, by making carbon emissions a scarce & costly resource, such artificial mechanisms will not automatically harm the economy either. The greatest inventions, such as ship-building in ancient Greece capable of taking people across the Atlantic, came about precisely because of resource (wood, labor) shortages (though Native Americans might say that was a terrible invention). The archaeological record is replete with examples of how resource shortages spurred greater technological innovation. In fact, if we do not tax carbon to death, we’d be complicit in haulting technological progress AND in causing GW catastrophe.

    As I’ve mentioned before, read NATURAL CAPITALISM ( http://www.natcap.org ). In a few years (assuming we make carbon a very scarce resource by artificial means) this book will be sorely outdated, replaced by the new paradigm that we can reduce GHG by 80%+ while improving the economy.

    I have much more faith in the human spirit, ingenuity, inventiveness, courage, and humanity, than I have in neoclassical economics, which mainly measures the monetization of the economy and not true productivity or well-being (“bads” are counted as “goods”), & certainly not those very important intangibles.

  46. 146

    [[First of all, taxes only push money around from one place to another & do not in & of themselves harm the economy.]]

    There is considerable empirical evidence that tax rates can affect the growth rate of a modern industrial economy. The Coolidge/Mellon tax cuts of the 1920s, the JFK tax cuts of the early ’60s and the Reagan tax cuts of the ’80s all resulted in higher growth rates.

  47. 147
    Ray Ladbury says:

    Re 146 The Kennedy and Reagan tax cuts both resulted in increased deficits. In effect, this artifically increased the money supply, so some of the increased growth may have been due to that. Moreover, I think you could argue that during the past 27 years, we have had a deficit in infrastructure investment–that also diverts money into the sectors of the economy where “growth” is measured. I wonder how much growth would be left if you factored in these considerations. Certainly, basic research, on which future growth depends, has been neglected. I wonder if what we have done is simply to borrow growth from the future US economy.

    [Response: Please no more discusison of general economics. -gavin]

  48. 148
    Chuck Booth says:

    RE #140 and my response to #142

    The ocean acidification report from last summer was issued jointly by the NSF, NOAA, and the USGS: Impact of ocean acidification on coral reefs and other marine calcifiers.
    The report is available as a PDF from
    http://www.pmel.noaa.gov/co2 ( scroll down the page to the link on the left side)

    By the way, this just in:

    http://www.noaa.gov
    Monday, Feb. 19, 2007
    GLOBAL AVERAGE TEMPERATURE FOR JANUARY HIGHEST ON RECORD, U.S. TEMPERATURE NEAR AVERAGE FOR MONTH
    The combined global land and ocean surface temperature was the highest for any January on record, according to scientists at the NOAA National Climatic Data Center in Asheville, N.C. The most unusually warm conditions were in the mid- and high-latitude land areas of the Northern Hemisphere. In the contiguous United States, the monthly mean temperature was near average in January. A moderate El Niño episode that began in September 2006 continued into January but weakened during the month. The presence of El Niño, along with the continuing global warming trend, contributed to the record warm January. Monthly mean temperatures more than 8 degrees F above average covered large parts of Eastern Europe and much of Russia, and temperatures more than 5 degrees F above average were widespread in Canada. The unusually warm conditions contributed to the 2nd lowest January snow cover extent on record for the Eurasian continent.

  49. 149
    Lynn Vincentnathan says:

    I think it’s important to get the relationship between the environment & the economy straight, though. The environment is fundamental; without it we have no food, water, air to breathe, shelter, “resources,” “natural capital.” The economy is contingent. So the first principle is ensuring we have a bounteous and healthy (or at least subsistence-providing) environment; second we can think about the economy, that is, who produces what, who gets things, how we exchange & divvie up things, how we arrange the deck chairs on the Titanic.

    When I took Economy 101, I presented the prof with a diagram: in the center was a small 2-dimensional oval with business/households, goods/services, government; and this rested on a huge mountain, representing the enviornment; and above this was a broken-lined upside-down mountain, representing the socio-cultural-psychological dimensions of the human condition.

    Don’t be swayed by “it’s the economy, stupid,” because “it’s the environment, first and foremost” — the ground we walk on, but take for granted.

    When GW has diminished our life-supporting environment, maybe then we will understand and mourn the loss.

  50. 150
    Marco Parigi says:

    Re #148:The ocean acidification report from last summer was issued jointly by the NSF, NOAA, and the USGS: Impact of ocean acidification on coral reefs and other marine calcifiers. The report is available as a PDF from

    The report mentions this is the most abrupt change in PH in 650,000 years. It did not mention whether it caused mass extinction or other visible results at that time. I can only assume that they don’t know or the evidence doesn’t show this. The report mentioned probable loss of species, but no actual evidence of any lost in the last 200 years due to de-alkalinisation. The site seemed to be sponsored by environmental groups. It seemed to be light on the facts and figures, but quite heavy on the environmental propaganda. I am sure that authentic scientists worked on this research, but I am more concerned for what it fails to mention, eg. the range of PH which oceans have been in the last few million years (the absolute value is also important as well as the rate of change). If in the last 100,000 years the Earth’s oceans have been unusually alkaline, there may be little to worry about. If the opposite is true, we would have way more to worry about. Maybe if there were some impartial scientific websites?


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