Cold Case vs. CSI

A partial translation of this article in Slovak is available here (courtesy Alexander Ač).

168 comments on this post.
  1. Arvella Oliver:

    Dr. Schmidt, this must be why you get the big bucks! ;) This post is genius. I hope you don’t mind if I quote from this in my next Climate Project presentation.

    I deeply appreciate the time you and your colleagues have dedicated to this site. It’s obviously a labor of love, for both the science and the planet. You’ve all become role models for my kids, and, I’m sure, for the children of other people like me who check in regularly to RealClimate. Scientists are officially “very cool dudes” to my 14 yr old son and his friends. Thank you so much.

  2. David Wilson:

    ‘anthropogenic’ is all very well, ‘man-made’ is about the same, no? but that is a mere quibble – I do welcome essays on your site aimed at people who are not scientists, and which help me (at least) make sense of it

    a point brought to me by Leonardo Boff is that the coming changes will involve as many opportunities as potential horrors, there is a hope at least that we can change our ways for the better

    thanks again and be well.

  3. tamino:

    Likewise, once the case goes to trial the defense may try everything possible to sow doubt in the minds of the jury members, suggesting that the evidence itself is tainted (urban-heat-island effects), that my client only assualted the victim (earth has only warmed a fraction of what is claimed), that the evidence is only circumstantial (computer models can’t be trusted), that any deviation from the simplest possible interpretation is proof of innocence (the steady rise of CO2 isn’t matched by the rise-fall-rise pattern of 20th-century temperature), that the victim was killed by roving gangs of “terrists” on a jihad (galactic cosmic rays), that the victim died of natural causes (solar variation). If Johnny Cochran (Fred Lindzen) anchors the defense, that lends it all the more credibility.

    To this juror, the prosecution’s case is true beyond a reasonable doubt. Guilty!

  4. Jeremy Kenyon:

    The big difference between a murder investigation and climate change is that it isn’t a past killing – it’s more akin to an ongoing genocide, and our concern perhaps should be more about stopping the crime than finding out who to blame.

    Perhaps the approach to persuading the sceptics is wrong. Contrarians can always try to say it is natural, not human. By climate scientists saying it is human just puts up a case to defend (one I agree with, but a case to defend nevertheless).

    The best way to answer someone who says it is natural is to ask them what they intend to do about it. After all, if the cost of dealing with sea level and temperature rises is huge human suffering and costs in the trillions, it is still going to hurt even if it is natural.

    Also, a sceptic could quite validly say that the climate has been much hotter and sea levels 100m higher, so there is nothing wrong with that because it is natural – all we are doing is making it happen a bit sooner.

    The only problem is that we depend on the climate being what it is – we have built society around the current (give or take a bit) sea levels and temperatures. We can adapt to 100m higher sea levels, but it will take centuries of determined effort.

    It’s like driving a bulldozer through a piece of land. If the land is empty, it is not a crime. But if there is a house on the land, with a family living in it, it becomes a crime. Climate change with nobody in the way would be OK, but the majority of the worlds population are in the way right now, along with the rest of the inhabitants of the earth…

    The question becomes ‘what can we do to slow or prevent climate change, whatever the cause’, and the answer will include ‘reduce carbon emissions’. At the very least, it will give us more time to prepare for the ‘crime’.

    Still leaves the problem of those who insist there is no change happening at all though…

  5. Leonard Evens:

    The contrarians often seem to be engaged in an ‘anything but greenhouse gases’ expedition. As you note, the argument is that it may be possible to explain current warming by some other mechanism, so that excludes greenhouse gases as the culprit. There are obvious difficulties with such reasoning. It doesn’t suffice to show that solar forcing for example may explain a large part of observed warming. You also need to show why greenhouse gas forcing doesn’t work as an explanation. Indeed, contrarians often come up with an abundance of different explanation which in total would overexplain observed warming. It appears that the ‘consensus’ climate scientists are the only ones who realy take seriously all possible explanations and who are bothered by such inconsistencies.

    A similar thing happened with supposed tropospheric decadal cooling/warming trends. Contrarians kept quoting it as evidence that no warming was taking place but never seemed particularly concerned with the diparity from surface data. The serious climate siceentists saw it instead as a puzzle demadning solution, eventually obtained through better analysis of the microwave sounding data.

  6. Taylor:

    Thank you for such a very graspable metaphor–and for continually informative posts.

  7. mike:

    It is helpful now and then to air our minor differences of viewpoint here at RC, and I present this comment in that spirit. It is certainly the case that paleoclimate evidence is just one line of evidence in support of the case for anthropogenic impacts on climate. We’ve said as much several times before (see e.g. here and here) of course. However, the targets provided by paleoclimate information are important for far more than simply “honing our techniques”. They are essential for independently testing the models, and determining whether or not they can be relied upon outside of the relatively narrow range of modern observation that informs the parameterizations of unresolved physical processes in the models. We probably would have relatively little faith in current generation climate model predictions if not for the fact that they seem to be able to describe some important changes in the past reasonably well (e.g. the LGM cooling). However, until we can solve e.g. the equable climate problem (the fact that climate models cannot reproduce the apparent greatly reduced equator-to-pole temperature gradient of e.g. the Eocene), we have to take some pause in fully trusting them to make accurate predictions of possible future climate change. The paleoclimate evidence suggests the possibility that models may underestimate future changes, and we ignore this evidence at our peril. This is particularly true with respect to certain phenomena (e.g. El Nino). We can’t yet trust the global coupled models to be getting El Nino (and changes therein) right as long as certain known deficiencies (e.g. the “split ITCZ problem” in the Pacific) persist in the models. The modern record of El Nino is simply too short to determine the natural variability of El Nino, no matter how spatially or temporarily dense our modern measurements are. Paleoclimate observations provide our best hope to get a handle on this, and help us determine when we’ve probably got El Nino right in the models. This isn’t a trivial issue. Until we are sure how climate change impacts El Nino, regional climate change forecasts over most regions of the world are likely to remain of somewhat limited utility. Its important to keep all of this in perspective.

  8. Ed G.:

    Great article!
    Minor typo: In the next to last line of the next to last paragraph I think you mean “unlikely to trump the modern analyses”

  9. Pat Cochran:

    I’m not sure I agree with the analogy. So climate murder has been committed and there are several suspects. Some of them have been convicted of climate murder in the past ( volcanoes, solar events, etc). They are natural. Civilization has never been convicted of climate murder in the past but because there are no clues pointing to the naturals, we use circumstanial evidence to convict civilization. So we find them guilty and go about reforming them so they can’t do it again. That’s all well and good.
    What I can’t understand is why we think we can control the climate in the future. We don’t know what natural forces will be in play even a year from now.
    Can anyone here explain how we know that we can control the climate? What if the climate started cooling for natural reasons? How would we stop that? Would cooling be good since we’re so warm now? How long would we let the cooling go on? Till it was as cool as in 1850? If this warming were found to be natural should we interfere with a natural process?
    I think there are two things certain, we have no clue as to what the future holds, we have no way to control the massive forces of nature.

    [Response: Unfortunately for civilisation, it's more than just circumstantial. They were seen leaving the scene of the crime, their fingerprints are all over the murder weapon and while motive is still in doubt, there was plenty of opportunity. However, the issue is not whether we can 'control' the climate. I don't think we can (hence my scepticism over geo-engineering efforts). But it's precisely because we can't predict precisely where our current course will lead that makes me wary of pushing the system much further. - gavin]

  10. John Gribbin:

    It is also worth emphasising that the pace of change now is greater than during previous “natural” warming events. Ecosystems that adapt to a change of a couple of degrees in 10 kyr find it impossible to cope with two degrees every fifty years!

    [Response: Yes, this is really the key point. Arguably, if we had been firmly within the grip of glacial period during the pre-industrial period and had adapted to that state over tens of thousdands of years, and Co2 increases were taken us towards an 'anthropogenic' state resembling, say, the Little Ice Age, we'd be in much greater trouble. We'd be facing much greater sea level increases and coastal flooding. Its not the absolute state as much as the rate of change, which presents the real challenges and threats. -mike]

  11. RBH:

    I’m nowhere near a climate scientist (I do evolutionary modeling in an applied context), but I read RC fairly often. I’ve noticed that it has begun to suffer from creeping acronymism which makes it less and less accessible and comprehensible to the lay reader. For example, in Mike’s comment above there’s a reference to “the LGM cooling”. Try as I might, I find no prior referent for that acronym in the main post or other comments, and can construct no plausible interpretation (“Little Green Men cooling”?). It’s a great help to non-specialist readers if on first use, folks give the full phrase with the acronym in parentheses, so those of us not in the in-group can follow along. While I appreciate that many of the posters are professionals debating among themselves, a fair proportion of your readers are not professionals, are not conversant with every acronym, and appreciate it when the professionals remember they’re also in a teaching mode on RC.

    [Response: Last Glacial Maximum - around 20,000 years ago. Sorry about that - we will try harder in future. - gavin]

    [Response: This is defined in past RC posts. But in most cases, as here, just stick "LGM" in our search window, and you'll get an answer instantly. Unfortunately, our glossary is still a bit sparse. This should have been in there. -mike]

  12. SecularAnimist:

    gavin wrote: “… there are many periods in Earth history that are unequivocablely accepted to be warmer than the present …”

    The word you want there is “unequivocally“, from “unequivocal” meaning unambiguous; clear; having only one possible meaning or interpretation; absolute; unqualified; not subject to conditions or exceptions.

    [Response: whoops. thanks. -gavin]

    gavin wrote: “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 [...] it illustrates nicely how paleo-climate research fits in to our understanding of current changes.”

    Hmmm. Consider the insights into climate research and the global warming policy debates that might be revealed by extending this metaphor to include Law And Order, Without A Trace and The Closer.

  13. Mike:

    I’m pleased to see that your articles seem to be more frequent. A daily fix would be most appreciated. Ps – that’s not how you spell comparatively or unequivocally!

    Keep up the good work


    [Response:You are unequivocally correct. -gavin]

  14. teacher ocean:

    They made a big deal about AGW on Boston Legal last night and the lead character’s argument before the jury was that AGW is not only real but a big problem and we should all, on an individual basis, do something to minimize our impact. The story line and evidence were meant to be humorous and has no scientific relevance because Boston Legal is mostly a comedy, but it was good.

  15. Lynn Vincentnathan:

    RE how the contrarians trot out past warming as evidence AGW is not happening (even if GW may be happening), I’ve learned to jump the gun on them at social gatherings.

    I trot out past warmings first, as evidence that it’s happened in the past, with 90% of life dying 251 mya, and it could happen again, only this time we’re triggering it & faster — esp if we get to the 6C increase (upper projection for 2100, but who knows for 2200 or 2300).

    Then before they can even criticize Gore’s AIT, I criticize it for being too conservative and not including the possibility of limited runaway warming (hysteresis), in which our AGW triggers nature to emit more GHGs, causing more warming, causing more GHGs, and so on, all the way to oblivion for a large chunk of life on earth.

    I’ve learned to get in and out fast at various social gatherings…moving on to a more benign conversation, before the contrarians can sicken me ad nauseum with their usual criticisms. I leave the contrarians with, “Just check out; they’re top climate scientists, and they have all the refutations to your issues.”

  16. raypierre:

    To carry further Gavin’s fine analogy, let’s extend it to the fact that the most viable theory for Cretaceous warming, and for a large part of glacial-interglacial warming, is also CO2 change — though not CO2 change caused by humans. I have some ideas how the storyline would go for that, but instead of writing down my own analogy, I thought I’d toss it out to the crowd to play around with. Just as a way to remind us that CO2 has indeed been implicated in past climate changes, and that the role of CO2 in past climate changes tells us something about the present, even though this time around it’s humans that are causing the CO2 increase.

  17. Benny:


    I thought all you New Yorkers were too busy going to museums and attending art openings to waste time on commercial television…..Good grief. You probably watch Stephen Colbert.

    [Response: Actually, I never watch TV - I'm just trying to get with the zeitgeist. (The good Colbert clips can be found on though.... - gavin]

  18. Ray:

    My class and I reviewed paleoclimate over the last two weeks and the “lightbulb” moment was when we took the derivative of the Vostok ice core record in the Holocene to the last glacial (+1.95 degC every 1000 years). That is 0.2 deg/century. When you are talking about 1.5 deg C per century it’s dimes and dollars.

  19. Philippe Chantreau:

    A Seattle PI blogger mentioned a study apparently published yesterday about glaciers, whose title suggest the melting trend is not as clear cut as was accepted. Do you know anyting about it?

    These were the references provided:
    Title:Glaciers Not on Simple, Upward Trend of Melting
    Author: University of Washington
    Published on Feb 13, 2007, 06:42
    Published Online February 8, 2007
    Science DOI: 10.1126/science.1138478

  20. tamino:

    Re: #18

    Don’t forget, that the Vostok ice core measurements indicate temperature in the Antarctic region; that’s why the net change glacial-to-interglacial is so high (about 10 deg.C). The global change is less than that, about 5 deg.C. So, the indicated Antarctic rate, 0.2 deg.C/century, translates to a global rate of only about 0.1 deg.C/century. The modern rate (using the latest version of HADCRUT3 from 1975 to the present) is nearly 1.9 deg.C/century. So, it’s not dimes and dollars, it’s nickels and dollars.

  21. Lynn Vincentnathan:

    #16, here’s one. People walking through the woods sometimes eat poisonous mushrooms and die (past GW & mass extinctions). However, Mrs. Smith wanted to bump off her husband, so she fed him poisonous mushrooms (our GHG emissions & GW now). The defense tried to claim it was his accidental eating of these natural fungi growing in the wild. But the detectives found the stems in her Mrs. Smith’s garbage can and forensics detected trace amounts of poisonous mushroom on the dirty dishes, and on Mrs. Smith’s knife and hands. Furthermore, Mr. Smith had not been near that woods for the past week, according to witnesses, but Mrs. had been.

    The problem with this legal analogy is that policy-makers and we (as mini-policy-makers) do not have to establish “beyond reasonable doubt” or even “preponderance of evidence” (civil standard) to take AGW seriously and address it; the amount of evidence & certainty Bush had for WMDs in Iraq would be more than enough to dig in and mitigate GW.

    Wouldn’t it have been great if instead of spending all that money on the Iraqi war, we would have plowed even a tenth of that into GW mitigation measures, most of which pay for themselves & go on to save…like investments. And we could have used those savings to give even greater help to the poor of the world. Then the whole world would have become our ally. Even terrorists may possibly have started thinking, we can’t attack such good people, bad PR for our cause.

  22. Sashka:

    Re: 18

    It would be another lightbulb moment if somebody took trouble answering questions about diffusion of gases within ice cores.

  23. Steve Bloom:

    Re #11: As a sort of consumer warning, be aware that the bulk of the comments made on RC are not from climate scientists. There are some climate scientists who comment, a rather larger number of non-climate scientists, and a yet larger number of laypeople who have made a serious (albeit amateur) study of climate science (I’m one of those), but all of these taken together are probably no more than half of the total comments. As well, bear in mind that you can’t rely on there being a refuting comment to every single contrarian claim that gets made here. So, while you can rely on the main posts and the highlighted responses, everything else should be taken with a grain of salt.

    Note to RC authors: When you post individual comments, please highlight them as Mike did in #7 above. Regulars know who you are (most of the time, but was that possibly Ray Bradley in #18?), but nobody else does. Thanks.

  24. Bill:

    Well argued sir. I had the pleasure of listening to Dr. Pachrui (head guy at IPCC) speak not long ago. Thankfully this group’s model is so comprehensive and conservative it isolates the climate change denies into a tiny indefensible pocket.
    For those who want to carry the banner forward & get involved:
    I work for the American Council On Renewable Energy ACORE and we have a package deal for young professionals who are already working in the field. The largest all-renewables trade show is 3 weeks off and we have a special offer for RE professionals in their 30′s and early 40′s. It’s great opportunity to network and see the latest technology. The show is Power-GEN Renewable Energy & Fuels and it’s in Las Vegas.
    Here�s the link:

  25. coby:

    ‘if you can’t explain all of the past changes, how can you explain anything now?’.

    This illogic is the subject of one of my “How To Talk To a Sceptic” articles:

    A very common attack.

  26. Hank Roberts:

    > 19, P. Chantreau.
    This is sad. A new NYT blogger–not a science writer– got this ball rolling recently.

    Best response so far I think was this one there:

  27. SecularAnimist:

    Lynn Vincentnathan wrote: “Wouldn’t it have been great if instead of spending all that money on the Iraqi war, we would have plowed even a tenth of that into GW mitigation measures, most of which pay for themselves & go on to save…like investments. And we could have used those savings to give even greater help to the poor of the world.”

    The governments of the world spend around ONE TRILLION DOLLARS per year on the military — on weapons and other means for human beings to kill each other — and more than half of that is the US military budget.

    Imagine what those many, many billions of dollars might accomplish — what they might long ago have accomplished — towards developing and deploying appropriate technologies for a sustainable human civilization living respectfully of all life and within the carrying capacity of the Earth’s biosphere, providing the means for health, happiness, peace and prosperity for all human beings everywhere. It is almost painful to think about it.

    Many critics of taking action to reduce fossil fuel related GHG emissions to mitigate anthropogenic global warming and climate change complain about the supposed “high cost” of doing so. A trillion dollars a year would go a long way towards addressing the problem. But we humans — or at least a number of humans who are in the positions of power to direct such vast resources — prefer to spend that amount on building weapons and killing each other.

    Perhaps the reason the SETI project has been unable to detect signals from any technogically advanced civilizations on planets in other star systems is that all technologically advanced civilizations inevitably follow the same course that we are on, and thus they only have very short periods of time (decades) when they are sufficiently advanced to generate such signals, before they destroy the capacity of their planets to support life, and themselves with it.

    [Response: The NYT had an interesting series in the business section a few weeks ago called basically "What could you do with a trillion dollars." They had lots of good examples, but unfortunately they left out climate stabilization. In a recent talk at Chicago, Steve Pacala estimated that a gross cost of about US$100 per ton of carbon would be enough to stabilize US emissions at a climatically acceptable rate, using present technologies only. Net cost would be lower, since if you used a carbon tax some of that spending would get plowed back, and even without a carbon tax, there's the contribution to GDP from people working in carbon sequestration, photovoltaic factories, etc. I think the same numbers can be gotten from Pacala and Sokolow's paper here but it was stated a bit more transparently in the talk. That would mean a gross cost of 168 billion per year to stabilize the US carbon emissions, given our current emission rate. (about $550 annually per person, gross cost, less if you rebated some carbon tax as income tax rebate). Not something to break the bank. You can compare that $168 billion with your favorite government spending number. --raypierre]

  28. Dave D:

    Someone was making a point about time resolution of ice-cores in another thread on this site the other day. I think his question is relevant here, and I didn’t see an answer, so I will give my dumbed-down understanding of it, and ask for an expert to help.

    The time constant for a perturbation of CO2 concentration to decay is about 100 to 150 years (currently). Is this about correct?

    How long does it take a snow layer to be compressed to hermetically trap air bubbles? One website I found said snow is compressed to ice at about 80 meters down. How far back in time is that, say, for Vostok? Ice cores come from up to 3000 m down. Beyond that the bubble collapse under pressure(?). How long ago is that?(600,000 yr?).

    It seems like the trap rate is much slower that the CO2 sink rate. Doesn’t this low-pass filter the CO2 time-signal? For instance, hypothetically, in 1 year a volcano could quadruple CO2. This excess CO2 would drain out over 100 to 200 years. If it takes 1000 years to trap, you would almost totally miss this excursion ( in concetration and temperature from isoptope analysis).

    These numbers are just examples. What is the time resolution of ice cores? Should’nt we be careful saying CO2 concentration is higher now than in any time in past 600,000? Our instantaneous Co2 concentration is higher now than the highest time averaged CO2 over XXXX (?) years , seen in the past 600,000 years.

    Also, does CO2 follow ocean temperature ( outgassing) or lead it?

    Thanks. This is a great site.

  29. Daniel Goodwin:

    One problem with this paleoclimatic crime scene, for purposes of figuring out where we’re headed, seems to be that the most recent precedents for current or impending CO2 levels may only be viewed as pre-icecore fuzzy daguerreotypes. Perhaps scientists have a technical definition of planetary disequilibrium, but today seems close to such a state, and that’s a significant problem: disequilibrium is grossly chaotic, thus nearly impossible to reliably predict. The current lag of the models behind what the splendid GRACE data is saying about the ice sheets is an example of a reality fatigue which will persist in studies of an Earth in a continuing state of disequilibrium.

  30. Steve Bloom:

    Re #22: Couldn’t stay away, eh, Sashka? Actually the issue you raise has been discussed here before, so a search should locate the information. It happens that Eric Steig, one of the RC co-authors, is an expert on such matters.

  31. Ray Ladbury:

    Excellent post–and the analog between the denialist camp (yes I’ll continue to us this word) and the defense is appropriate, as all defense views it’s sole duty to sew doubt, not to reach the truth. However, for someone who truly takes a scientific view, it is not sufficient to say “It’s all natural variation.” We are witnessing changes, and changes do not occur without an underlying driver. Thus far, they have advanced no credible candidate mechanism for the changes we are seeing, while the anthropogenic greenhouse mechanism explains what we are seeing very well and is physically reasonable. To demand that we drop the best candidate mechanism without advancing a credible scientific alternative is anti-science, every bit as much as demanding Darwin not be taught in biology class is anti-science.
    Re 22: Given that diffusion is controlled by molecular size and pressure, it would be expected to occur differentially for different molecules. Moreover, the deuterium/hydrogen ratio does not even depend on the gas, but rather on the water/ice. The expectation if diffusion were a significant issue would be chaos (indeed that is what is seen for very old ice), not a self-consistent body of evidence that favored climate change. That is indeed a lightbulb moment if you understand it.

  32. Alexander Ac:

    Good post, as always ;-)

    Though, the comment is slightly off-topic, but I miss one point. We are talking about (inevitable??) reduction of CO2 emissions.

    Let’s consider the Japan, which is country with very high energy use efficiency, on the other hand, “they can’t afford the Kyoto”. Why? Because they are so developed, that they use so much energy and the ONLY way, how to significantly reduce the emissions is simply to use it LESS.
    But is it even possible in practise, to start use LESS energy without any APPARENT reason? On the other hand, everybody wants to be like Japan. Highly efficient and highly developed.

    P.S. For those who don’t know, Chzech president Vaclav Klaus is the new defender of climate and environmental truth ;-)

    of course, backed-up by Sen. Inhofe and Vaclav Klaus chzech fan Lubos Motl…

  33. Eli Rabett:

    Perhaps this is a good thread for a question I have had for a long time. Multiproxy reconstructions appear to underestimate climate sensistivity. Was this an artifact from early reconstructions or a sign that preinstrumental forcings have been overestimated?

    [Response: Don't know why you would think that. Hegerl et al (Nature, 2006) did a reasonable job on the implications for climate sensitivity in the paleo-reconstructions and find a range that is similar to that inferred elsewhere - given the uncertainties in both the forcings and the response. Did you have some other study in mind? - gavin]

  34. Marco Parigi:

    Ok, great so you’ve proven Humans guilty beyond reasonable doubt… Stunning. Now for the punishment – I vote we just let the Global warming take its course as a suitable punishment for our collective sins. The Easter Islanders were greedy and cut down all their trees and as a punishment they lost their Island paradise. That’s fair. However bad things get, or what actions we take, the punishment will be proportional to our collective stupidity.

  35. Blair Dowden:

    I am wondering how Cretaceous sea level could be 100 meters higher than today when there is only about 70 m worth of water in the remaining ice caps. Is there 30 m of thermal expansion? And how can you compare sea level when the paleogeography (arrangement and size of the continents) was completely different?

  36. Marco Parigi:

    Instead of beating the drum on AGW, why not get a little perspective on the range of GHG’s. After all, there is plenty of damning evidence against CH4, CFC’s etc. (This is a serious question by the way) Is it plausible that ALL (>90%) of the recent temperature increases can be attributable to GHG’s other than CO2? This would be reasonably hard to prove/disprove as all GHG’s have risen sharply in previous decades, and all have demonstrated mechanisms of warming. This would have immense policy implications don’t you think?

  37. Jim Crabtree:

    Re #27: Raypierre’s response

    I think your number for $168 billion may be off by a couple orders of magnitude when you consider that the US has about 5% of the world’s population and produces about 25% of the worlds CO2. Even if we cut our CO2 production to zero, that leaves the other 75% out there, most of it being produced by third world countries where most of the population is in survival mode or slightly better. They are going to need LOTS of foreign aid to cut their CO2 which will be needed to stablize the CO2.


  38. Jim Crabtree:

    Correction on #34

    I should not have indicated that this was Raypierre’s number, but that of Pacala and Sokolow’s.


  39. Gene Hawkridge:

    Re 19: I think a couple of the things about glaciers that confuse some folks are that warming might actually result, sometimes, in glacial surges – meaning that the glacier rapidly advances rather than retreating(and thinning at the same time – which may not be as obvious). As I understand the theory behind this, melt water under the glacier provides lubrication, thereby accelerating glacial advance. The other aspect of this issue is that precipitation increases could actually add to glaciation in some cases – precipitation increases that perhaps are due to warming, due to increased evaporation rates. Denialists will latch onto these counterintuitive effects and reach possibly erroneous conclusions – but it is more complicated than just pointing to retreating glaciers.

  40. Craig Allen:

    May I make a suggestion for your website:

    Given the very broad range of subscribers to this site and the quantity of jargon and acronyms that are necessarily used, it would be very helpful if you could add a readily accessible glossary. I think I’ve seen on a site somewhere a button that hovers at the bottom right of the screen that maintains it’s position independent of page scrolling. If this were to open a popup window with an alphabet menu at the top, it would be a very useful resource for us all.

  41. Charles Muller:

    Let’s fill the analogy…

    All warming, past or present, is a collective crime (in French we say crime en réunion, i.e. several authors for one murder, I don’t know the American terminology). Here, the crimes are approx. 0,75 K for 1850-2005 (CSI). Or approx. 5 K for LGM-midHolocene, for example (Cold Case).

    I notice that the first crime is not so… criminal – because of course, CSI never investigate on putative future crime, so far there’s no crime scene for exerting their precious forensic methods. The problem for CSI experts is to carefully look for and analyze the clues, in order to confound one culprit, and prove the others innocent.

    For Climate Scene Investigation, the big problem (limits of analogy, maybe) is the collective nature of the crime. Suspects are numerous, here, and few think they are totally innocent. Intrinsic variability, sun, aerosols, land-use, GHGs of course are all under suspicion to have some responsibility for the horrible offense of 0,75 K on 150 yrs. And some detectives even look for exotic-but-still-under-exam clues like GCR. The case in even more complicated so far the usual suspect (CO2) is a hopeless murderer, needing the help of pernicious and elusive accomplices (e.g. water vapour, nebulosity, lapse rate).

    What is at stake for CSI ? Not to point out one culprit and expose him/it to public condemnation. But to precisely adress (quantify here) its responsability in the past, present (and eventual) future collective crimes of warming. Not an easy job. And much more complex than rough controversies “all-solar” vs “all-GHGs” so appreciated by popular jury.

  42. Gareth:

    I’d suggest that the paleo guys are a bit more like Midsomer Murders (Mike Mann as Barnaby, of course) – dead bodies all over the place, all connected in some sort of obscure way, solvable by the application of detective skill. Perhaps those working on current climate areThe Bill?

    Which actually leads to what I hope is a sensible point. The paleo data is used to validate modelling work by constraining the way that models represent known climate events. However, we have currently booted the planet into a set of conditions not seen in the paleo record: interglacial, high CO2, major deforestation etc. It seems to me that the paleo record is relevant to a climate system operating within its normal bounds, but may not be much help when it’s operating way out of its design parameters. We’re into the “unknown unknowns”, and there’s a danger that the models can’t help much here…

  43. Eli Rabett:

    No. I was thinking more of a comment in von Storch and Zorita, but I have seen the comment elsewhere also. What do you get as the sensitivity from say MBH 98 when you make reasonable assumptions about the forcings.

    [Response: This is getting off topic. There is a whole slew of papers by Hegerl et al, Crowley, and others looking at this, using all of the different reconstructions. You can find the references in the Hegerl et al Nature article. The bottom line is that you get sensitivities in the range of 1.5-4.5C for all reconstructions, including MBH98 and all the others. However, one point that is poorly appreciated in many discussions is that random uncertainties in the forcing estimates will necessarily act to systematically underestimate the sensitivity, because of the way sensitivity is defined: as the covariance between forcing and response divided by the sqrt(forcing variance). The random uncertainties in the forcing therefore lead to inflation of the denominator, even if they have no impact on the covariance term (which one would expect for random uncertainties). There is a detailed discussion of this in the appendix to Waple et al (2002). Incidentally, the von Storch et al stuff (and problems therein) has been discussed on site previously here and here. We'll leave it at that. -mike]

  44. mark s:

    Re #28,

    I think Steve(#30) and Ray(#31)’s replies to the ever-dependable Sashka apply to your questions, Dave.

    For a minute i thought your ‘dumbed-down’ understanding, might have had the IPCC on the ropes. Phew, close shave on that one.

    Maybe next time, eh! :-)

  45. Steve Bloom:

    Re #28 (Dave D): “For instance, hypothetically, in 1 year a volcano could quadruple CO2.” Let’s hope it stays hypothetical, as few of us could hope to survive such an event. For fun, you might look up “Siberian Traps” and “Deccan Traps.” But the short answer is that volcanos emit very little CO2 in global terms (although lots of dust in the case of big eruptions). Regarding the ice cores, bear in mind that while there is a degree of smoothing, rates of global CO2 change are so slight that it’s not a problem. Even with a really sharp change (much sharper than the record rate of change happening now), I doubt that there would be enough of a smoothing effect to hide such an event (even ignoring the fact that anything of the sort would leave plenty of other evidence). But I’m no expert, so see this RC post for details, and in particular look in the comments for some remarks by Eric Steig.

  46. Wang Dang:

    Back to the main topic of popular TV shows, science and climate change. My wife loves these shows but she hates watching them with me, because I am an analytical chemist and I understand and have hands on experience with many of the techniques and instrumentation frequently presented on the CSI type shows. They feed in the sample, and out pops the answer. The never have to deal with sample matrix issues, extraction, recovery, interferences, misleading results, etc. Also, the lead detective is always full of obscure information directly related to the case at hand.
    I also like it when the detectives are wearing leather pants and high heels in the lab, and they they drive a Hummer too, very realistic for science nerds. I’m guessing that the RC climatologists are the similar, leather pants, disco shirt, carefully messed hair, but instead of a hummer they drive a $90,000 Tesla all electric sports car. (Am I right?)
    My favorite GW moments on TV have been when Al Gore was on SNL and during the news segment he showed an old picture of some barren frozen glacial wasteland followed by the current mountian lake that it had become and he debated with Amy Pohlar, his position, that this was a bad thing, and her position was that the new lake looked awesome.
    South Park has also done some shows on GW (taking the skeptical side). One with GW related to human flatulance, another ridiculing (an rightfully so) that horrible pile of garbage movie “Day After Tomorrow”, and another mocking Gore.

  47. Wang Dang:

    Re #15
    Wow Lynn sounds like you’re a real barrel of fun at the evening cocktail party. Have you ever seen the SNL bit about Debbie Downer, you should. By the way, you may be contradicting yourself if you are calling Gore’s AIT conservative and talking about a runaway greenhouse effect and then citing RC as your source.

  48. Jon Ellis:

    Re 32: Japan has most definitely grow it’s GDP with considerably less growth in energy consumption than other economies.

    However, as someone who has spent the last 5+ years living around Tokyo, there is still a huge amount of wasted energy.

    Programs like Cool biz are an encouraging sign, but there is much more than can be done to further reduce energy use in Japan.

  49. Paul M:

    I enjoyed reading that article, If I were to give it a grade, it would be an A.

  50. John D.:

    One should never equate spending war chest money on trying one global problem to make peoples lives better and achieve peace on earth and goodwill. There are a multitude of problems associated with why there are wars such as Religious and social differences, race, borders, greed, tyranny, world banks, oil, nasty neighbors, Taliban, terror cells, government structuring, ignorance, to name a few. There will always be a group that will be pissed bacause they did not get as much as their neighbor when the pie is being divided.

    Unfortunately, the only solution to a warless planet is to have one world religion, run by that religion and it would have to be a total tyranny that subdues it’s subjects with fear. Then you would not need to spend on wars but you would still require an army to police it.

  51. Jane Kloeckner:

    Hello, Lovely analogy! Here’s another point of view about the analogy between criminal law and environmental risks. A risk avoidance theory for Environmental Law is different than risk avoidance in criminal law.

    “In environmental risk situations, the cost of a false negative – deciding that the benign hypothesis is true when it is not – is much higher than the cost of a false positive – deciding that the catastrophic hypothesis is true when it is not .. Catastrophic results more than offset the modest benefits of erroneously accepting the benign hypothesis ….
    [Therefore,] when the potential adverse effects of an environmental risk are many times greater than the potential benefits, a proper standard of proof of danger … may be that there is only ‘at least a reasonable doubt’ that the adverse effect will occur, rather than requiring a greater probability, such as ‘more likely than not’ that the effect will occur.” See Plater, Environmental Law & Policy (2005) at 14, citing to Professor Page, 7 Ecology Law Quarterly 207 (1978).

    Criminal law has an opposite goal, limit false positives, e.g., limit the chance of a false conviction because it’s better to let hundred criminals go free than convict an innocent man. So, criminal law prosecution uses the “beyond a reasonable doubt” standard of proof, which is an inappropriate standard for avoiding environmental risks.

    We do not need to prove GHG or other anthropomorphic forcings are causing GW beyond a reasonable doubt, like the CSI or the Cold Case investigators. It’s the wrong standard. Climate scientist can convince lay people that the environmental risk must be mitigated by showing “at least a reasonable doubt” that the problem is anthropomorphic.

    The IPCC, SPM 4AR, Feb. 2, 2007, finds climate risks exceed the “at least a reasonable doubt” standard of proof of danger, e.g., some risks are very likely, see page 4-18, fn 6, and some are just “more likely than not”, see Table SPM-2. In general, the SPM provides adequate evidence for reasonably prudent persons to find that governments and businesses have a duty to mitigate climate change within their abilities. It’s also clear that we need to study climate change more thoroughly to find solutions and decided on mitigating actions, regionally and globally.

    It’s fun to participate in this forum. I’m learning so much from this blog<3 It’s great.

    FYI: On Thur., 2-15, 6:30 PM Central time, Prof. Jimmie Adegoke, who teaches at UMKC, is giving a lecture via OPAL, on Midwest climate change.

  52. Mike:

    Re#13 – Thanks and I’ll try and watch my spelling as well. Here’s the smoking gun themselves i.e. Exxon and a link to their peer reviewed work on climate research (!!??). As my prosecution lawyer what’s your assessment of these articles? Their overall tone?

    Keep up the good work

  53. Alexander Ac:

    Re 45:

    Well, that is optimistic ;-). If Japan wastes energy, what to say about US… :-)

  54. Ray Ladbury:

    Re 37: It is a common misconception that developing countries contribute a large proportion of the CO2 from burning wood/forests, agricultural waste, etc. This simply is not true. See

    Even in those developing countries with high emissions (mainly China, but to a lesser extent, India, Iran and Brazil), the emissions come from the urban/industrial sector, not the underdeveloped sector. Thus we can have a significant effect if we rebalance the energy sources for these and our own economies. Look at France–a developed country but contributing only 1.6% of CO2 emissions.
    As to the “punishment” for the “crime” some are discussing, I might note that it is the sons who are being punished for the sins of their fathers, so it might be more in the spirit of justice to reform our own ways so that our progeny have the benefits of a functioning civilization.

  55. Barton Paul Levenson:

    [[The governments of the world spend around ONE TRILLION DOLLARS per year on the military -- on weapons and other means for human beings to kill each other -- and more than half of that is the US military budget.

    Imagine what those many, many billions of dollars might accomplish -- what they might long ago have accomplished -- towards developing and deploying appropriate technologies for a sustainable human civilization living respectfully of all life and within the carrying capacity of the Earth's biosphere, providing the means for health, happiness, peace and prosperity for all human beings everywhere. It is almost painful to think about it.]]

    Futile, too. Like it or not, countries attack other countries, and any even minimally responsible government will either spend money on a defense establishment of its own or ally itself with a big power that spends it. Suddenly stopping military expenditures in the US, for instance, would leave us vulnerable to attack from the large number of countries around the world that hate our guts. Cuba, for instance, might want to annex Florida. Without a military, how would we stop them? Response from the well-armed citizen militia? Don’t make me laugh.

  56. Dano:

    I just read this entry. This is a good way to use analogy.

    And I must expand on #3:

    ‘If the curves don’t fit, then you must acquit!’



  57. Sashka:

    Re: 54

    With all due respect, Wikipedia is not an ultimate source of truth. In one of the recent threads I linked a NYT article where it quoted research indicating that burning in Indonesia alone amounted to 8% of global CO2 emissions.

    [Response: One does need to take care to distinguish peak emissions in a few years and the long term emission. After all, one can only go on so long before there isn't any forest left to burn, or peat bog left to drain. But that's somewhat beside the point. There is no question that tropical deforestation -- and let's not forget Indonesian peat bogs -- is an important contributor to global CO2 emissions. Anything that helps to bring this under control has got to be a good thing, with lots of benefits for biodiversity as well as for global warming. What's to dispute about that? --raypierre]

  58. Jeffrey Davis:

    Tangent Rejoinder

    Easter Islanders certainly degraded their island’s resources to a dangerous degree, but it was hardly an island paradise to begin with. However, we don’t have to restrict our imaginations to the false dichotomy of paradise vs. death. Our present hyper abundance and ease might fade with time, but barring runaway catastrophe we’re not going to go back to subsistence farming and such.

    [Response: Precisely why I took the risk of mentioning some dollar cost figures for the US. The economic-alarmism argument that carbon controls will drive us back to subsistence farming sets up a false dichotomy. To solve the US problem, we're talking about $550 per person annually gross cost (less in net terms). That's not going to drive us back to the stone age. It's not even going to put much of a dent in our present hyper-abundance. The burden on the poor can easily be handled by something like the Earned Income Tax Credit, which would still leave plenty of incentives in the system for companies to build IGCC coal with carbon sequestration, or wind farms instead of pulverized coal plants. Forgive me please for pushing the limits of our comment policy by injecting these numbers into the discussion, but I justify the indulgence because the estimates link to the technical feasibility arguments in Pacala and Sokolow, which are indisputably a matter of science. --raypierre]

  59. Lynn Vincentnathan:

    Re #9, Gavin, I think the motive is more or less the same as the robber who holds up a gas station, one who doesn’t really intend to kill anyone. He just wants to get the money so he can live a rich and high life. Then in the heat of the moment he kills the person, without really thinking.

    Same way we want to live a rich and high life. We don’t really intend to kill anyone to get that (at least the vast majority of us don’t want to do so). But something happens in the process. People get killed or hurt, their property destroyed.

    And contrarians plead innocent until proven guilty by a bunch of uneducated juror peers who can easily be swayed by the swagger of a couple of contrarian scientists and big name novelists. Even the judge is coaxing them to return a “not guilty.” And since the jurors are also guilty of the same crime, they surely don’t want to set any precedence that will go against them (even if the victims are their own progeny).

    The problem is its sort of like shooting bullets up into the air (which they do around here on New Years), and some people get hurt. Everyone’s doing it, and you don’t know who’s going to get hurt. The bullets we shoot today will be up in the air a very long time, causing untold harm…but most of it decades, centuries, millennia from now. Doesn’t make for a good crime show or court case.

  60. Hank Roberts:

    Ray, you may want to update the Wikipedia article if it’s not been done. Google News found these.
    Note this is a change, any ‘percent’ estimate has to include the time span to be useful information.

    Global Warming Is Being Seriously Underestimated, India – Feb 2, 2007
    This then emits about 65 tonnes of CO2 per hectare per year. Currently, millions of hectares of peatlands are drained and are decomposing in Indonesia and …

    Once a dream fuel, palm oil may be an eco-nightmare
    Taipei Times, Taiwan – Feb 2, 2007
    “These emissions generated by peat drainage in Indonesia were not counted before,” Kaat said. “It was a totally ignored problem.” …

  61. Hank Roberts:

    Finishing the digression, I hope; this is definitely off topic. The sources for the peat/CO2 story are here:

  62. Marcus:

    re: 54: Ray Ladbury, your Wikipedia page does not include land-use change emissions, for which estimates range from 3 GtCO2/year (deFries, PNAS, 2002) to 8 GtCO2/year (Houghton, Tellus, 2003) (compared to 24 GtCO2/year from fossil fuel + cement emissions which is what is reported in the Wikipedia table)

    (Though I do share your disagreement with #37 in terms of how hard it will be to stabilize emissions)

  63. Henry:

    I like it. Television fiction as metaphor for paleoclimate research. Of course the reality is that Project Innocence has proven hundreds of mistakes in the criminal justice system. Granted they haven’t proven a single mistake in CSI or Cold Case.

  64. tamino:

    Re: #52

    I checked out the page of “ExxonMobil Contributed Papers on Climate Science.” They list 41 papers. All but 4 of them (!!!) are “attributable” to ExxonMobil because of the participation of a single author: H. S. Kheshgi. The one I find most ironic is this one:

    28. Kheshgi, H. S. (Contributing Author), 2001. “Technical Summary,” In (J. T. Houghton, and D. Yihui eds.) Climate Change 2001: The Scientific Basis: Contribution of WGI to the Third Assessment Report of the IPCC, Cambridge University Press, New York, 21-83.

    This isn’t the only IPCC report on which Kheshgi contributed, and all of them are listed as “ExxonMobil Contributed Papers on Climate Science.” In other words, ExxonMobil is trying to take credit for the IPCC reports!

    This is “padding the resume” to the extreme — I’ve never even imagined anything like it. I think it shows, quite effectively, just how hollow are ExxonMobil’s claims that their position on global warming has been “misunderstood.”

  65. Lynn Vincentnathan:

    #46 & 47, Wang Dang, you obviously are not a sci fi freak, like me. I was okay with DAT, knowing it was sci fi, but I liked THE ARRIVAL better (aliens trying to accelerate global warming to meet their comfort level). The only problem was my disbelief became unsuspended when the ice started chasing the people — as it did in SUPERMAN when Superman flew around the earth opposite the spin & turned back time. I also didn’t like that much water in WATERWORLD, but would have been okay if it had been explained at coming from both global warming & some aliens shipping in oceans of water to drown us out to make it habitable for them.

    And I have no problem with Venusians who have caused runaway warming on Venus, escaping to earth, but they crash on the moon. Eons later our moon expedition finds their remains & their plans to get to earth in their space pod, and their history on Venus, how they triggered runaway warming. Of course we earthlings are freaking out, thinking maybe some Venusians made it to earth and are living among us, drowning out the voices calling for mitigation of global warming…If I ever get time, I’ll write that up as a screenplay. It’d make a great movie…

    Yeh, I’m no fun at parties. But out of politeness to my hosts, I make my points hard and fast, then move on before it comes to blows. Sorry, but I’m a defender of life on earth, warring against the thanatos drive in the Darth Vaders who would destroy the world.

  66. Lynn Vincentnathan:

    #55, Don’t worry, Barton, once we get through with Florida, no one will want it. My place, too, which is not too far above sea level and in a hurricane area — as we moved down we saw the signs pointing in the opposite direction, “Hurricane evacuation route.”

  67. Dave D:

    Thanks to mark s and Steve Bloom for responses to my post (#28).
    I found the answer to the time resolution of the ice cores in the link Steve (#45) provided. The answer is 22 years for bubble trapping,
    so the cores have enough “bandwidth” to follow CO2 accurately.

    (Neftel, A., E. Moor, H. Oeschger, and B. Stauffer. 1985.
    Evidence from polar ice cores for the increase in atmospheric CO2 in the past two centuries. Nature 315:45-47.)

  68. Jerry:

    Another kind of “cold case” related to climate reconstruction is an article from The Economist, which I excerpt and attach. My edit, ellipsis to omit non-climate related material.

    from: Economist, 10 February 2007
    Better Spatlese than never
    How German wine makers are responding to climate change

    Just as Rheingau Reisling was making its mark again as one of the world’s finest wines, it has come under threat from an unexpected source: climate change. The special quality of Rhine Reisling relies on a mix of cool nights and warm days for slow ripening….

    …But warmer average temperatures are threatening to redraw the wine map. Red grape varieties such as cabernet sauvignon and merlot, traditionally grown in the south, will migrate northward by 200-400km and up hillsides bu 100-150 meters, says Hans Schultz of the Research Institute at Geisenheim in the Rheingau. Bu 2040, cabernet sauvignon will flourish where Reisling does now.

    The impact has already been felt in the past few years. Eiswein, a delicious dessert wine made from grapes which are picked frozen on the vine at a temperature of minus 7C or below, is becoming even rarer. This season the local growers had only two chances – December 27th and January 26th – to pick grapes frozen enough. “That was our latest harvest ever for Eiswein”, says Arno Schales, whose family has grown Reisling since 1783 and has made Eiswein for the past 50 years. His Eiswein this year, a crop of 200 bottles instead of the usual 1,000-2,000, came from pinot noir grapes, which survived the late warm weather without rotting…

    …Mr Schultz, who has written several papers on the subject, notes that the Geisenheim vines are developing shoots seven days earlier, blossoming ten days earlier and starting to ripen 12 days earlier than the 40 year average; they are especially affected by the warmer nights. “Reisling is very sensitive to the soil and the climate,” echoes Ernst Buscher of the German Wine Institute, across the river in Mainz…

  69. SecularAnimism:

    Barton Paul Levenson wrote: “Like it or not, countries attack other countries, and any even minimally responsible government will either spend money on a defense establishment of its own or ally itself with a big power that spends it.”

    Indeed, I surely expect that as accelerating anthropogenic global warming, combined with the other ongoing damage that humanity is inflicting on the Earth’s biosphere (e.g. see the UN’s Millennium Ecosystem Assessment), reduces the capacity of the Earth to support life, while at the same time supplies of the cheap fossil fuel energy upon which industrial civilization is totally dependent peak and then rapidly decline, that the main response of the nations of the world will be to increase military spending, the better to fight with each other over the dwindling resources.

    BPL wrote: “Suddenly stopping military expenditures in the US, for instance, would leave us vulnerable to attack from the large number of countries around the world that hate our guts.”

    The US spends more on its military than the entire rest of the world combined; most of the rest of the military spending is by US allies; and only a small fraction of those US expenditures have anything to do with actually protecting the US from attack. Surely there is some room for adjustments, between a half trillion dollars a year in military expeditures and “Suddenly stopping military expenditures in the US”.

    [Response: Military policy and prospects for doing without military expenditure are decidely off topic here. It came up only as a way of putting the costs of CO2 mitigation into perspective, showing that the expenditures involved do not seem too alarming in light of other things governments routinely spend money on. Let's leave it at that, shall we? My apologies if I myself contributed to stimulating this digression. ---raypierre]

  70. Ray Ladbury:

    Since some object to Wikipedia on principle, I will note that the source of the data was the UN. Here’s another one.

    Fuel use of fossil fuels still dominates the sources of CO2. The industrialized countries still dominate the burning of fossil fuel. I do not think it is reasonable to blame the average Brazilian (or Indonesian) farmer for the fix we are in. Could they be part of the solution? Certainly. The point is: If you really want to impact CO2 emissions, you have to change the energy sources used by industry.

  71. Mike:

    Re #52/64
    Great work I’m sure Tamino. My apologies for not knowing who’s who in climatology. Maybe they didn’t think people would investigate their claims as carefully as their pals scrutinise the good folk’s work.

    Back to the CSI track – Exxon’s dream team (pun intended) just need to insert reasonable doubt. (Doubt is their product?). Reminds me of the lawyer in the movie “Scarface” who said he was an expert at raising reasonable doubt but “when you’ve got a million three of undeclared dollars staring into a videotape camera, honey baby, it’s hard to convince a jury you found it in a Taxi Cab.”

    Oh to be a juror in an Exxon mass tort claim! (Been reading too many Grishams).

    Keep the good work.

  72. Climate Fan:

    I have a silly question, but I need to ask it. The CO2 level that we have now has been unprecedented for 600,000 years. What if someone asks, “Yes, but maybe if you look further back, you WILL find there is a period which has similar CO2 levels”. I know that that is a silly objection; if it were accepted, then no number of statistical studies will be enough. But what is the best way to answer such a question when someone says, “You have not looked long back enough, and perhaps there is a time when we had climate/CO2 levels etc. such as we have today. Hence, this is a natural cycle…”?
    If this question has been answered before, I will appreciate it if you can provide a link.

  73. coby:

    Re 72,

    Have a look at this:

    There may be a couple of other appropriate articles there too…
    for example.

  74. John L. McCormick:

    RE # 72

    IPCC AR4 will help you understand global temperature has increased since 1900 and CO2 increased about 100 ppm since then. World population in 1900 was 1.6 billion. In 8000 BC it was about 5 million. 600,000 years ago is your guess but likely less than a million.

    So. raising atmospheric CO2 concentration 35 percent in about 100 years and increasing population four-fold in that same time period makes the matter of earlier CO2 concentrations meaningless (to your discussion perhaps). Whatever the concentration and impact on climate then, the earth was unpopulated.

    Ask that someone to look ahead.

  75. Joel Shore:

    Re #36: (Regarding the complicity of other GHGs besides CO2.) While there may be a fair bit of uncertainty regarding the sensitivity of climate to GHGs, I believe there is much less uncertainty in regards to the relative sensitivity of climate to the different GHGs. I.e., it is straightforward to determine from the way they absorb radiation what their relative contribution to warming should be. And, in fact, agreements like the Kyoto Protocol have incorporated these other GHGs into the emission reduction requirements using their relative warming potentials.

    It is worth adding, however, that the warming potentials are not the only things that matter, since the lifetime is also important. And, in this regard, I think CO2 has the other “suspects” beat because it has a much longer lifetime in the atmosphere (at least in comparison to the second most potent GHG, methane). So, while lowering methane emissions may actually be a very good short-term strategy to get a lot of bang-for-the-buck (since this could quite quickly lower its concentration due to its short lifetime), eventually you have to deal with “the elephant in the room”, which is CO2…destined to be the dominant player by virtue of its hanging around so long.

  76. Hank Roberts:

    Ray L. — yes, but — note the problem with peat in Indonesia is caused by a Dutch “biofuel” project — unintended consequences!

  77. GAW:

    I wouldn’t push the CSI analogy too far, most of the wiz-bang technology on display is patently fake.

    A better analogy is between AGWism and epidemiology. Consider the hysteria over Cholesterol. Evidence links Cholesterol to heart disease so the “scientific conclusion” is to put half the populace on Statins – a solution that lowers Cholesterol levels but is not only economically wasteful but probably ineffective in reducing heart disease to boot. In reality, the low fat, high carbohydrate diet recommended by the “medical consensus” is probably largest contributing factor to both the Cholesterol problem and the recent epidemic of obesity. But you certainly won’t hear that from the medical establishment or the for-profit industry that has grown up around the Cholesterol ‘problem’.

    You may or may not agree with my assessment of the Cholesterol problem, but I think you are kidding yourself if you don’t think that “climate science” is subject to many of the same limitations as “medical science”. 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. Both medical and climate sciences face concerns about data quality in the face of bewildering complexity. Both are long on causality and past predictions and short on control and future predictions. Both hide their machinery behind a wall of technology that is impenetrable to the layman. Both come to conclusions that deserve a large does of skepticism.

    My fear is that AGWism, like much of modern medicine, will waste a lot of resources that could be better spent elsewhere. My personal feeling (I am a conservationist) that same effort spent on combating the environmental effects of world poverty would do more towards sustaining what is left of our poor planet’s environment than anything the comes out of AGWism. I don’t have any proof of that, but it is pretty much the same feeling I have towards the effect of modern medicine. Those opinions come more from a deep appreciation of our cultural conceit than any skepticism of our engineering might.

  78. Mark A. York:

    “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.”

    And that is exactly why your argument fails. It’s based on unsubtantiated opinion and no facts at all.

  79. Steve Latham:

    Mark, I think you’re being heavy-handed. GAW basically says that we often think we know something when in fact we don’t know it so well. GAW also says the layperson has a difficult time ‘seeing’ evidence for him/herself. I agree with GAW that more controlled experiments would be a real benefit to both climate and medical science. Nothing there to get one’s back up. If there’s one thing in comment 77 I disagree most with, it’s the insinnuendo about profit. There will be inertia if/when the ‘climate consensus’ changes, but it won’t have much to do with profiteering by the scientists.

  80. Dick Veldkamp:

    Re #78 AGWism

    GAW, I think what you argue here is a false dichotomy. Surely we could spend 1% of GDP or something (according to Stern) on mitigating the CO2-problem AND tackle other problems at the same time. Also it would appear that conserving nature becomes very much harder if temperature rises as fast as we think it will – so the problems are really connected.

    You seem to imply with your cholesterol argument that evidence for AGW is rather flimsy. Please take a look at Raypierre’s reply #120 under “Nigel Calder”, that sums up the evidence in a few lines. If that does not satisfy you, what better advice can I give you than to read some more of th4 stuff on this site?

  81. Sashka:

    Re: 57

    Anything that helps to bring this under control has got to be a good thing, with lots of benefits for biodiversity as well as for global warming. What’s to dispute about that?

    To dispute is the Kyoto approach regarding the means and ways whereby the developing countries are assumed to be just a small part of the problem. To dispute also are the well-intentioned government initiatives that lead to the Indonesian fiasco in the first place.

    [Response: So Kyoto doesn't solve all the world's environmental problems. Agreed. So now what do you want to do about it? How does dropping the only mechanism currently available for dealing with a big part of the problem (i.e. developed world CO2 emissions) help solve the Indonesian problem? Anyway, I'm glad you agree something should be done. Kyoto's not my favorite either, and there are a lot of things I'd do differently if I were the emperor of the world, but I'm not. International negotiations are messy. I think you'll have a hard time arguing that what's going on in Indonesia has much to do with anything other than good old fashioned greed and good old fashioned lax environmental regulations. --raypierre]

  82. Sashka:

    Re: 30, 45

    I don’t doubt Eric’s credentials for a minute. Unfortunately, in the RC article that you linked he never mentioned diffusion even once. The only relevant to my inquery bit came from a reader (Georg Hoffmann). However I’m not sure that the paper that he’s referring to discusses diffusion on long time scale.

    [Response: Sashka, we're getting tired of doing your literature searches for you. You are surely perfectly capable of looking up the diffusivity of gas in ice, and combining that with the porosity of densified ice to get the number you're asking for. Our conversation with you, if you can call it that, struck me as familiar, and suddenly I figured out why. When my children were quite small, they figured out that, their parents being professors and having a natural reflex to answer questions, they could be kept going almost indefinitely on any topic by simple utterances of "why?" and "how come?" without even needing to listen to the answer. Sometimes it was amusing (to them, always, actually), but not a great way to make any progress on learning things. At some point we instituted the idea of the "question buzzer." After a certain number of "whys" and "how comes" the question buzzer would go off and no more questions would be answered untill the kiddies had reflected on the previous answer and shown some progress in understanding. I should add that they grew out of the mechanical "whys" and "how come" stage by the time they got to first grade. Draw your own conclusions about what I'm getting at here. --raypierre]

  83. SecularAnimist:

    Every episode of Law & Order begins with this voiceover:

    In the criminal justice system, the people are represented by two separate yet equally important groups – the police who investigate crimes, and the district attorneys who prosecute the offenders. These are their stories.

    With apologies to Dick Wolf:

    In dealing with anthropogenic global warming, the people are represented by two separate yet equally important groups – the climate scientists who investigate the scientific facts of global warming and climate change, and the environmental advocates who work to educate the public and policy makers and press for change to reduce the harmful consequences. These are their stories.

  84. Steve Bloom:

    Re #79: GAW, I would urge you (and anyone else who hasn’t) to read the Discovery of Global Warming on-line book and the new IPCC Report (both linked through the right bar). Also, I think your analogy to medicine is really quite apt, except that climate science is in the role of simply making the diagnosis. In terms of solutions, I suspect most climate scientists would suggest prevention as the first and best course of action now that the diagnosis has been made. The analogy in the case of high cholesterol would be to utilizing appropriate diet and exercise to first stabilize and then reduce the problem. Drug intervention is comparable to various geo-engineering schemes that seek to avoid addressing the causes.

    Regarding your concerns about conservation, speaking as a long-time Sierra Club leader I would point out that there are reasons why world poverty isn’t getting sufficient attention now, and that those reasons have nothing to do with a desire to devote resources to dealing with global warming. Besides, things like increasing drought associated with climate chnage are not likely to be very kind to the Third World.

  85. Craig Allen:

    Re #76: Actually CO2 release in Indonesia (and particularly in the peat forests of north-east Sumatra, Kalimantan-Borneo and perhaps also Irian Jaya (East Papua) is caused by a combination of burning, the creation of vast networks of drainage channels that dry out the peat and wetlands and conversion to farmland and plantations. This is being done by both farmers (massive settlement transmigration settlement programs have been underway for decades) and by forestry companies. Dutch companies and others may be there, but both Indonesia and Malaysian companies are notorious for these practices both there and elsewhere in South-east Asia and the Pacific Region. Go for a tour on Google Earth – it’s really scary.

    Having said that, I was traveling in the Tarkine region of North West Tasmania (Australia) last week and I came across landscape scale areas of temperate rainforest and mixed eucalyptus forest on peat soils that are rapidly being converted to monoculture blue-gum plantations (again it is clear as day on Google Earth). Then we came across an area where from horizon to horizon the rainforest has been so fiercely/repeatedly burnt that all that is left is a depauporate grassland-heath on a skeletal chalky substrate.

    Mind you, much of the timber is used to provide the cheap chipboard, skirting and and just about anything else wooden in our luxury western homes. We’re all implicated in this.

  86. Steve Bloom:

    Re #82: Well, there may be another post that addresses it, so try searching the site. Alternatively, Google Scholar is your friend. Offhand, though, what makes you think it’s a problem at all? Finding literature that simply proves a negative can be difficult. In any case, trying to think the issue through, diffusion could have only a smoothing effect, and if it was suspected that it was somehow masking CO2 excursions (which I think would imply greater climate sensitivity) I’m confident we would have heard a great deal about it.

  87. Sashka:

    Re: 78

    I’m curious what sort of facts would you like to see in support of the opinion expressed in 76? Do you think that direct experimental validation of a hypothesis is easy? If it’s so easy how come hundreds of scientists are working on it so hard?

    What I find wrong about GW “debate” is that positions of the sides are not falsifiable. The denialist wouldn’t agree that the observed trend is out bounds of natural variablilty. Or they would look for other than CO2 reasons. No need for me to bash them: there is a hundred people here who specialize in this sport.

    My problem with “mainstream” is over-reliance on models. Is there something that would signal that the models are wrong? I’m not claiming (just suspecting) there is but the hypothesis that the models are right must be falsifiable. What is the criterion? Is there anything that should happen with climate such that the modeling community would admit that the models don’t have sufficient predictive ability to forecast 100 years forward even with the horrible variance that the current generation displays?

    Correct me if I’m wrong: I don’t believe there is anything that would shutter the confidence. Say, mean global temp in 2007 goes down 1 degree C vs 2006 (no volcanoes, no major La Nina etc.) Does anybody foresee this? No. Would it change anything? I guess not. Free variablity. Noise in the system. Perhaps. All I’m saying that model verification process must include a possibility of falsification. Otherwise there is just one possible outcome. In which case we move to the domain of religion instead of science.

  88. Sashka:

    Re: 87

    In my mind, stack of snow is a porous medium which could allow the air bubble to diffuse through the column until it solidifies completely. I don’t know how long the complete solidification might take, not even down to an order of magnitude.

    The smoothing could obscure sharp CO2 changes in the past. Not that it changes anything about human-made CO2 trend but still I’d like Ray’s lightbulb moment to be taken in the right perspective. Perhaps there’s nothing wron with the argument at all. I’m just asking.

  89. S. Molnar:

    Gavin, I love the new multiple choice search function. If you need me to be your straight man for anything else, don’t hesitate to ask.

    [Response: No problem. You inspired some kindly reader to help me out - I will use you again in future if necessary! Thanks. - gavin]

  90. Jeffrey Davis:

    Kyoto was supposed to be a baby step in global cooperation in global warming. Criticism that it doesn’t solve the world’s problems is like ragging on a toddler for not winning the Olympic 100 meter dash.

  91. tamino:

    Re: #82

    Sashka, if you study the data carefully you’ll discover that for at least the last 700,000 years or so (the time period covered by EPICA dome C), diffusion (even long-term) cannot be a big factor in these measurements.

    That’s because the pattern of CO2 changes from one glaciation to the next are so similar. Diffusion could only smooth the data, but in fact they show no sign of any reduction in variance from one to another glaciation/deglaciation.

    You remind me of the “skeptics” who suggested that the moons of Jupiter discovered by Galileo were actually internal reflections caused by imperfections of the optics. Galileo wondered how it would be possible to construct optical imperfections that would perfectly mimic four separate satellites proceeding in regular orbits around the planet! And when Galileo set up his telescope so the skeptics could actually see them … they refused to look.

  92. Jim Crabtree:

    Ray L:

    I still stand by my numbers in #37. China (a third world country) is rapidly approaching us for producing CO2 and is expected to overtake us in the near future. India is moving up rapidly. I wonder if the UN man-made emissions numbers for Brazil include the transformation of the Amazon from a carbon sink to a carbon source. As for the people – look at how many working poor we have in this country (and we are a rich country). Many of them are living just a paycheck or so away from going under (I call that barely surviving). Most drive cars that get poor gas mileage and live in homes that don’t have energy efficient appliances and live in poorly insulated homes. Now look at China, India, and Brazil and see how many working poor there are. China is bringing online a new coal fired plant at about 1 a week. Think about how much it will cost to retrofit all of the these plants (and other facilities – they most likely won’t shut them down). Most of the workers in Chinese factories are working poor. On a per capita basis, their carbon foot print is small, but their populations are large. What percentage of these people can afford to cut their carbon footprint? The poor slash and burn farmer in Brazil has one objective – to feed his wife and 7 kids today and he is not too worried about something a few years down the road.


  93. tamino:

    Re: diffusion in snow

    Take a look at Etheridge et al. (1996, J. Geophysical Res., 101, 4115), which describes in detail the analysis of the Law Dome ice core. They study the effect of diffusion in the snow (actually firn) by sampling the air in the snow itself down to the “bubble closure” depth (about 72m). This corresponds to ice only 10 years old, but the low value for Law Dome is due to the very high rate of snow accumulation at that site.

  94. Steve Bloom:

    Re #87: Sashka, Dave D. was able to find the answer in the post I linked; see #67 above. 22 years to seal the bubbles clearly presents no problem given the rate of CO2 change being reflected, especially since the diffusion rate would be dropping to zero during that period (and so each bubble effectively would reflect rather less than 22 years of mixing). As for diffusion afterwards, I can imagine there being a small amount, but given the lengths of time we’re concerned with it would have to be a large effect indeed and even so would only tend to make deglaciations look a little less abrupt. But as Raypierre noted, the calculation shouldn’t be that tough. If it turns out to be too hard, of course somebody somewhere has aleady done it (probably lots of somebodies), but if you can’t find anything via Google Scholar email Eric and ask him who would be likely to have such a thing at their fingertips. If he doesn’t know, try NSIDC; I think they have a budget for PR. Good luck with that.

  95. Lynn Vincentnathan:

    RE #83, or:

    In dealing with anthropogenic global warming, the people are represented by two separate yet equally important groups – the climate scientists who investigate the scientific facts of global warming and climate change, and the policy-makers who don’t do much about it and let the environment and society go to ruin (as district attorneys would if they refused to prosecute criminal cases, but let offenders off scott-free). These are their stories.

    The environmentalists would then be like Mothers Against Drunk Drivers, and they’re hopping MADD at the inaction.

  96. Lynn Vincentnathan:

    So now that we’re thick into analogies, how about it if climate scientists expand their concept “runaway warming” to include as a special case the more limited type of runaway scenario, in which the climate eventually rebounds to the initial conditions at the start of the process, as happened after the end-Permian and PETM warming episodes?

    “Runaway” is an analogy (a concept that should not be reified), based presumably on runaway horses or cars that get out of our human control, then eventually stop. So we could have type I runaway warming that stays (relatively) permanently in a new hotter state, as on Venus, or on Earth billions of years from now when the sun greatly heats up. And then we could have type II runaway (or hysteresis runaway), like a bell curve, in which the climate heats up for thousands of years, but then returns to its cooler starting point. A situation in which we may heat the world initially by our GHGs, but that warming causes nature to net emit more GHGs, leading to more warming and more of nature’s emissions, and so only, spirally well beyond anything we could do much about, even if we reduce to zero emissions.

    We really do need a word for this that distinguishes it from linear GW, which presumably in this instance we could halt by halting our GHG emissions, after a lag time. I know from a scientific point of view, GHGs are GHGs whether from human emissions or from nature, but from a policy POV, the distinction is important.

    And BTW, horses that run away, usually return to the stable later of their own accord to get their meal.

  97. Marco Parigi:

    Re: #75(Regarding the complicity of other GHGs besides CO2.) While there may be a fair bit of uncertainty regarding the sensitivity of climate to GHGs, I believe there is much less uncertainty in regards to the relative sensitivity of climate to the different GHGs

    This doesn’t make sense – If there is uncertainty in the sensitivity in climate to GHG’s in general, and the mechanisms via which extra net radiation gets absorbed is different for each individual GHG, and because most GHG’s have been rising since industrialisation, there is almost certainly more uncertainty in the relative sensitivities than in the net.

    in fact, agreements like the Kyoto Protocol have incorporated these other GHGs into the emission reduction requirements using their relative warming potentials.

    In fact methane capture projects seem to be the only ones that have been financed just on the basis of their GHG reduction by Kyoto. Yet, you find me a scientist that will push for methane capture over wind farms. Why is nobody pushing for a reduction of methane emmissions by 75% within 10 years.

    And, in this regard, I think CO2 has the other “suspects” beat because it has a much longer lifetime in the atmosphere

    CFC’s also have a very long lifetime – In fact, the atmospheric concentration is yet to peak, years after emmissions have dropped substantially. It is still plausible that eliminating all short term GHG’s and relaxing our emmissions standards for sulphates could get temperatures dropping again. That would buy us heaps of time to concentrate on the Elephant, and to tease out more accurate relative sensitivities through regression analysis of climate data.

  98. Steve Latham:

    Hi Lynn,
    Here’s a happy link about things actually getting done. Not science, though, so no need to discuss these things here.

  99. James:

    Re #92: You say “…look at how many working poor we have in this country (and we are a rich country). Many of them are living just a paycheck or so away from going under…”

    And why is that, I ask? At the simplest level, not only does it cost _nothing_ to do things like turn off unused lights (particularly outdoor ones left burning all night), or lower thermostats, it leaves money in your pocket. Similarly, if all you can afford is a 20 year old clunker, there are a lot of (comparatively) fuel-efficient Hondas and Toyotas of that vintage. No one _has_ to drive a gas-guzzler, and again, choosing not to do so leaves money in your pocket.

    The problem, in a lot of cases, is not lack of money per se, but the attitude that you’re supposed to spend every cent you get, even if it’s on things you don’t particularly want. That attitude goes across all levels of society: I know people with 6-figure incomes who are likewise just a paycheck or two away from going under.

    Indeed, the fear of losing this sacred “lifestyle” seems to be at the root of most of the denialists’ frantic search for alternative theories. They’re not worried about starving if/when climate change causes massive crop failures, because things like that are totally outside their experience. They’ve gotten used to a society where even the poor – perhaps especially the poor – are obese.

  100. Ike Solem:

    RE#91, 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.

    Assuming that we are heading for the Pliocene-type conditions (3mya), paleoclimatology can tell us something about that world. In 1997, the picture looked like – for a 2004 update, see :

    “Relative to today, the Pliocene warm period was characterized by: 3C higher global surface temperatures, 10-20m higher sea level, enhanced thermohaline circulation, slightly reduced Antarctic ice sheets, emerging but small Northern Hemisphere ice coverage, and slightly (30%) higher atmospheric carbon dioxide concentrations. A small decrease in carbon dioxide concentration could explain the cooling at the end of the warm period if coupled with positive feedbacks, as suggested for the onset of significant Antarctic glaciation.”

    When you consider the massive proportion of people who live in coastal areas, combined with the fact that low-lying countries of 40 million (Bangladesh) are expected to mostly vanish, what you have is a catastrophe, except that you can’t be sure how fast the changes will come. Current rates of fossil fuel CO2 emissions, as well as current rates of CO2 accumulation in the atmosphere, appear to be accelerating – not an encouraging phenomenon.

    Obviously, the thing to do is to 1) keep monitoring the land-ocean-atmosphere-ice system and 2) stop burning fossil fuels, especially coal. Since it doesn’t do much good if only half the world stops burning fossil fuels, we need treaties like Kyoto just to get a forum for international agreements. The incidence of heat waves and intense storms is almost certainly going to increase over historical averages – which is where most of the initial damage can be expected.

    How do you define “damages due to extreme weather?”

    It turns out that the NWS and the NOAA’s use of the 1971-2000 time period (as compared to the 1961-1990 time period) as a baseline has some effect on the ‘weather risk insurance industry’. Their explanation for their change of baseline can be found at – not knowing exactly how ‘extreme weather event insurance’ works, I hesitate to speculate too much on the underlying rationale, other than to note that redefining “normal” is an unusual method of limiting risk. NOAA has also determined that global warming is not connected to any increase in hurricane intensity:

    “According to Vice Admiral Conrad Lautenbacher, head of NOAA, we are entering a cyclical period of extreme weather in the Atlantic that could last another 30 years. “I don’t look at that as the end of civilization or our ability to ensure the core of our economy,” he says. “But we are in a period of higher risk right now.” Six hurricanes made landfall in the U.S. in 2004–the most since 1985–and nine of the hottest years on recent record were in the past decade, according to insurance giant Swiss Re.

    The economic toll is dramatic. Last season’s hurricanes caused $56 billion in damages. The European heat wave of 2003 cost economies there roughly $20 billion. And 2004 was the most expensive year ever for the insurance industry; it will pay out roughly $39 billion in claims related to natural disasters globally.”

    The Atlantic Multidecadal Oscillation is in retrograde, and there is no proof that CO2 plays any major driving role in the climate system…and a moderate El Nino caused the record warmth this winter… except that in Moscow, it was the North Atlantic Oscillation… and in the Artic, it was the Arctic oscillation…you see, all this is due to the various climate epicycles lining up just so, in order to create this (undoubtedly) temporary climate fluctuation.

  101. John D.:

    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.

  102. Hank Roberts:

    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:

    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.

  103. Ed G.:

    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

  104. Mark Drasdo:

    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?

  105. Barton Paul Levenson:

    [[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.

  106. Barton Paul Levenson:

    [[ 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.).

  107. Nick Gotts:

    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;
    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

  108. Sashka:

    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?

  109. Sashka:

    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.

    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.

  110. GAW:

    #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.

  111. Lynn Vincentnathan:

    #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.

  112. PeakEngineer:

    Nice article! We could be looking at a prelude to the arguments at the upcoming U.S. Supreme Court case on global warming:

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

  113. SecularAnimist:

    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.

  114. Mark A. York:

    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.

  115. Climate Fan:

    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.

  116. Rod B.:

    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???

  117. Wang Dang:

    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.

  118. Hank Roberts:

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

  119. Ray Ladbury:

    “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.

  120. Marco Parigi:

    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.

  121. Hank Roberts:

    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.

  122. Rod B.:

    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.

  123. Hank Roberts:

    > 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.

  124. Hank Roberts:

    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?

  125. Dave D:

    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.

  126. Marco Parigi:

    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?

  127. Rod B.:

    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]

  128. Hank Roberts:

    NOAA’s Pacific Marine Environmental Laboratory Carbon Dioxide Program

  129. Barton Paul Levenson:

    [[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.

  130. Barton Paul Levenson:

    [[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.

  131. Lynn Vincentnathan:

    #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.

  132. Chuck Booth:

    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

    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]

  133. Zeke Hausfather:

    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.

  134. James:

    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.

  135. Rod B.:

    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.

  136. Joseph O'Sullivan:

    #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.

  137. Zeke Hausfather:

    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”, ; Ian Parry’s “Are Tradable Permits a Good Idea?” ; or Pizer’s “Combining price and quantity controls to mitigate global climate change” ). 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?

  138. Burn boron in pure O2 for car power:

    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.

  139. Steve Reynolds:

    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”.

  140. Marco Parigi:

    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.

  141. James:

    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 :-)

  142. Chuck Booth:

    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.
    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). (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)
    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:

    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.

  143. Hank Roberts:

    > any ‘cold case’ evidence …?
    You read this?

  144. Zeke Hausfather:

    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.

  145. Lynn Vincentnathan:

    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 ( ). 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.

  146. Barton Paul Levenson:

    [[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.

  147. Ray Ladbury:

    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]

  148. Chuck Booth:

    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 ( scroll down the page to the link on the left side)

    By the way, this just in:
    Monday, Feb. 19, 2007
    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.

  149. Lynn Vincentnathan:

    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.

  150. Marco Parigi:

    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?

  151. Kobayashi Maru:

    False analogy. If either show used computer models to predict murder patterns 100 years in the future they would be broadcast on the Sci Fi channel.

  152. Hank Roberts:

    Marco, 650,000 years is the record for ice core data. You write “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.”

    Well, okay.

  153. Steve Bloom:

    Re #125: Dave D, you may already know about this, but go here and look at the several papers relating to ice bubbles. Who knows, it might even have what Sashka wants.

    Re #150: “The site seemed to be sponsored by environmental groups.” PMEL? Marco, that’s a NOAA lab. And you say a report issued by NSF, NOAA and USGS is “quite heavy on the environmental propaganda.” Do you have any idea what those organizations are? Maybe you should look then up. And if I were you I’d consider cutting back on those “X Files” reruns.

  154. Hank Roberts:

    Geology; March 2003; v. 31; no. 3; p. 211-214

    Missing molluscs: Field testing taphonomic loss in the Mesozoic through early large-scale aragonite dissolution
    Paul Wright*,1, Lesley Cherns*,1 and Peter Hodges*,2

    1 Department of Earth Sciences, Cardiff University, Cardiff CF10 3YE, UK
    2 Department of Geology, National Museum of Wales, Cardiff CF10 3NP, UK

    It appears that major aragonite dissolution normally distorted both apparent diversity (65% decrease in bivalve diversity) and the trophic structure of the offshore facies, providing aragonite that probably sourced the diagenetic carbonates. We suggest that aragonitic shells were selectively dissolved in the upper sediment column in lower-energy settings, where high organic contents favored microbial decay and acidity; such early dissolution was absent from the higher-energy facies that originally had low organic contents. Taphonomic loss through early skeletal aragonite dissolution was an equally important process in Mesozoic offshore shelf environments, and although still leaving depleted molluscan-dominated faunas, resulted in a massive distortion of diversity.

  155. Lynn Vincentnathan:

    RE #151, well, actually the analogy breaks into reality at that point, because that’s what we’re doing through anthropogenic global warming & its harms, killing future people. That’s the whole point.

    And I don’t base my predictions using computer models, but from looking at past GW events, such as those 55 & 215 mya. Only this time, we’re the ones triggering this major extinction level event, with nature due to take over in emitting GHGs (& failing to absorb) in response to the warming we are now causing, on top of the reducing albedo effect. It’s a tough pill to swallow. Makes one want to believe the denialists, rather than own up to it and take responsibility.

    I also don’t need the denialists’ 99% certainty or the scientists’ 95% certainty to reduce my GHGs (which I started doing in 1990). The paradigm for thinking about this, 1st proposed by the father of statistics, Pascal, is: If GW is happening and we do nothing to mitigate it, we may be headed for a hellish world. If GW is not happening, and we reduce our GHGs thinking it is happening, we are headed for a much more efficient and productive economy.

    So what do you say? Come help us mitigate AGW. Reduce, reuse, recycle, use alternative energy when feasible. Every little bit helps. The future peoples will greatly thank you.

  156. Joseph O'Sullivan:

    #16 Raypierre, your analogy is very interesting. It reminds me of how evidence is admitted into court.

    Normally past crimes can not be mentioned to a jury. Once the jury hears that the accused is a convicted criminal they tend to jump to the conclusion that he must also be guilty of the crime he is charged with now. To properly decide the jury must look at the evidence of the crime in question and not be misled or prejudiced.

    There is an exception to this rule. If there is a pattern that fits the current crime, a jury can hear about a prior conviction, but there has to be consistent pattern. Someone might have multiple convictions for drunk driving, but this is not a pattern that would show this same person is likely to be a bank robber. If the accused has multiple convictions for robbing banks it is telling if he is being charged with another bank robbery. There is a shown past pattern that can help answer the question at hand.

    For the comments discussing ocean acidification, there was a symposium on the effects of ocean acidification this past summer. The take-home message seemed to be that there is not enough known to draw firm conclusions, but the early evidence does not look good for the oceans.

    In the recently passed bill reauthorizing the Magnuson act, there is a directive for the National Research Council to examine the effects of ocean acidification. From the bill: NOAA will “request the National Research Council to conduct a study of the acidification of the oceans and how this process affects the United States”.

  157. Dave D:

    Re #153 Thanks Steve. This is a great source. I’ll read more, but it does seem that the trap time can be long in low accumulation rate sites.

    In fact, I think the lag of CO2 concentration behind the temperature record is due to this integration time.
    Temperature is determined by hydrogen/deuterium ratio of the ice itself. This is instantaneous (delta function impulse response), as opposed to the air which is a running average (integrator). Think about how a running average responds to a small step function, then consider the real input CO2 signal as made of a bunch of small steps. You get a lag of the integration time.

    Someone has probably already thought of all this, but I have seen some discussions going back and forth on what the lag means for climate dynamics (CO2 vs. Temp … chicken or the egg). Maybe its a perfectly reasonable artifact of the system functions of the two processes.

  158. Hank Roberts:

    > The take-home message seemed to be that there is not enough known to
    > draw firm conclusions, but the early evidence does not look good for the oceans.

    No, no, no. Great paper, but I disagree with the summary. Quoting a bit:

    “While much work remains toward answering the fundamental question: ‘How will marine calcification rates respond to increasing atmospheric CO2 concentrations,’ we need to begin investigations that look forward to answering the question: ‘What are the consequences of reduced calcification in both planktonic and benthic calcifying communities and ecosystems?’ We should not wait until we answer the former question before tackling the latter.

    “This report is intended as a guide to program managers and researchers toward designing research projects that address these important questions.”

    This is the _research_ proposal guide. It focuses on where research is needed. They know the situation overall:

    “There is clear evidence that the carbonate equilibrium of the oceans is shifting in response to increasing
    atmospheric CO2 concentrations….. dissolution rates of carbonates will increase in response to CO2 forcing. Even small changes in CO2 concentrations in surface waters may have large negative impacts on marine calcifiers and natural biogeochemical cycles of the ocean …

    “… example, a rapid volcanogenic increase in pCO2 at the Triassic-Jurassic boundary (Palfy, 2003)
    coincides with a major extinction event, a worldwide interruption of carbonate sedimentation, and an evolutionary replacement of aragonite with calcite (Palfy, 2003; Hautmann, 2004). Furthermore, there is evidence that groups of calcifying organisms have become more or less dominant over geologic time, depending on CO2 levels, and is likely linked to their utilization of dominant carbonate species in the ocean. For example, comparison of atmospheric CO2 fluctuation from the Cambrian through the Cenozoic, to dominance trends for cyanobacterial and algal calcifiers, demonstrate that cyanobacteria dominate during periods of high CO2 …”

    This is the issue: the species we rely on for cycling ocean CO2 can’t form their shells at ocean pH levels sure to occur in large parts of the oceans by 2100 — within this century the pteropods and other calcite- and aragonite-shell-forming species that currently dominate the oceans will be replaced. Question is, how?

    They go methodically through the denials:

    Misconception 1. Increasing atmospheric CO2 will increase rather than decrease pH of marine waters. This argument is based on an incorrect assumption …..
    “Misconception 2. CO2 fertilization of zooxanthellae will lead to an increase in coral calcification ….

    “Misconception 4. The effect of global warming on calcification will outweigh the effects of decreased saturation state…..”

    It’s a very good paper, I’m glad you point to it. I just don’t agree with your simple one line summary.

    The take-home message is — lacking research as proposed — we can only hope evolution may operate fast enough in selecting among marine plankton species that something will replace the pteropods.

    My one sentence summary:
    Right now we have only faith-based planning — a faith that some plankton species will promptly take over removing CO2 from the ocean this century — a faith that evolution is our friend, and will protect us.
    Seriously, read this paper. Don’t rely on any one line summary, look at their sources (cited in earlier posts here too).

  159. Chuck Booth:

    Re #150 “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.”

    Umm…Marco, which site are you talking about? Look at the URL ( better yet, visit the site and actually read the text: The site is maintained by the NOAA Pacific Marine Environmental Laboratory (pmel) in Seattle and highlights its Carbon Dioxide Program, which “conducts ocean carbon cycle research from ships and moorings in all of the major ocean basins in collaboration with AOML’s CO2 Program” (AOML = NOAA’s Atlantic Oceanographic and Meteorological Laboratory). The report was sponsored jointly by the U.S. National Science Foundation, the National Oceanic and Atmospheric Administration, and the U.S. Geological Survey. The scientists who authored the report are listed in the document. If you want to discredit the science, or the scientists, you are free to do so, but how about doing it based on scientific grounds – your comments quoted above make you look foolish.

    Moreover, you initial question misses the important point – there well may be no documented extinctions yet – that is beside the point: There is strong evidence that several taxa of marine calcifiers are at risk of extinction due to changes in carbonate solubilities with acidification- this is clearly explained in several of the reports I cited in my initial post (#142), and in those cited by Hank Roberts.

  160. Joseph O'Sullivan:

    #158 Hank Roberts

    My understanding of the ocean acidification issue is that its harder to figure out what the effects will be than climate change. Short term changes like el nino are temperature changes that give clues to what a warmer ocean will do to ecology, but we have no recent change in ocean chemistry to compare the recent ocean acidification to.

    Yes, no one should accept my one sentence summary without doing more reading.

  161. Vincent:

    So what does that mean, murders and global warming are both good for science & technology? This is a kind of James Glick ignorance of fundamental physics and thermodynamics. So institutional scientists use ever diminishing and accelerating methodological & technical means to try and understand ever increasing disorders and instability.

  162. Roger William Chamberlin:

    I think that concentrating on whether global warming is man-made or natural is to miss the point completely… the facts appear to show that BOTH effects are combining and it matters not which is greater [although perhaps it is becoming clear that men are the major cause] …

    What matters to life on earth is how rapidly it changes and what is the peak … there is now substantial evidence that the RATE of change is too high for species to move North to be able to live at their optimal conditions , as much a four times too fast a change … we simply cannot afford to allow nature to die off in this fashion in the name of making our lives more ‘convenient’ for a while [because they will become very seriously inconvenient rather quickly as our food supply fails]

    There is equally rather obvious danger in letting the temperature go too high, people are already dying worldwide and having their way of life destroyed by climate change and teh CO” in teh atmosphere continues its work for centuries … there is a delay between taking action and the temperature stopping rising and we have not even begun to act to stop our insane adding to the problem for people and life in general in the future… the peak temperature is critical to the extent to which life survives on this earth, billions of human lives are at stake besides much of the ecosystem itself… and evry day we delay pushes the final peak critically higher besides increasing the rate… and the rate of rise is still increasing!

    It is time mankind came to its senses if it can express them at all, we need to stop the way we are living in teh West and sttop exporting it to the East too… that is a massive task that needs to start now if we are to have any hope of saving at lest some of life on this planet … we ahve walked blindly into a TRAP because of the insidiousness of the onset of the problem and the fact that even when te problem becomes obvious it takes many decades to even start addressing it and centuries for te world to recover…

  163. Marco Parigi:

    re #158If you want to discredit the science, or the scientists, you are free to do so, but how about doing it based on scientific grounds – your comments quoted above make you look foolish.

    Well, I don’t really have a defence, but I was very frustrated by only being able to get the abstracts, and requiring subscription to get anymore. The homepage I was looking at appeared to my eyes as very propaganda-ish and biased. I have no qualms at pushing buttons. Thanks for the good links, and especially for the overviews and your own unbiased views.

  164. Hank Roberts:

    > we have no recent change in ocean chemistry to compare

    Um, except what’s described in the literature. Some experiments you do not want to do outside a lab, because you can see in the geological strata what happens to your nice planet when you do them.

  165. Joseph O'Sulivan:

    Me #156 The take-home message seemed to be that there is not enough known to draw firm conclusions, but the early evidence does not look good for the oceans
    Hank Roberts #158 No, no, no

    I will try to explain one more time, one more time, one more time ;) Hopefully the third time will be the charm.

    I have surveyed the literature on ocean acidification. For the effects on ecosystems and individual organisms the literature is light on the effects, both in lab experiments and open ocean measurements. The summary of the symposium about the effects of acidification on organisms and ecology sections stated repeatedly that early results of the few studies done on this show that there could be serious negative effects, but there is little specific data to go on. The big picture is that ocean acidification is bad, even catastrophic, but there are details that need to be worked out.

    Climate-induced changes in carbonate chemistry could diminish the abundance of microscopic open-ocean plants and animals that build calcium
    carbonate structures. Some of these highly abundant organisms influence ocean-atmosphere interactions, but our knowledge of this influence and these interactions is rudimentary, making it difficult to predict the consequences of any chemical changes.
    -Coastal and Marine Ecosystems and Global Climate Change p.51 Pew Center for Climate Change Aug. 2002

    Potential biological impacts of both passive invasion of anthropogenic CO2 into the surface ocean and active sequestration of carbon in the ocean are only poorly known.
    -The Ocean in a High CO2 World; Oceanography Sept. 2004

    Weakness of Royal Society report The report was weak on biology because very few relevant experiments have been conducted.
    We do not know what changing ocean chemistry will do to marine biota (other than some calcifiers) and especially we do not know what the long-term chronic effects will be on ecosystems
    -Ken Caldeira Comment #41 The Acid Ocean RC post

    Resonse to my comment (#39) World Wide Glacier Retreat post
    Response: You may also be interested in the article by Richard Feely and colleagues, Impact of Anthropogenic CO2 on the CaCO3 System in the Oceans arguing that quite apart from any climate impact from atmospheric CO2, there is a much more direct impact from the dissolution of CO2 in the world’s oceans. Richard has said that the scientific community has dropped the ball on this one, and we should have been warning the public about this particular catastrophe a long time ago, when it was first suspected. Unfortunately, and despite the name calling we get, we scientists tend not to raise alarms until we are very sure. I think Richard is now very sure

    I will add that not enough research has been done by the scientists to warn the pubic.

  166. Lynn Vincentnathan:

    #162, “I think that concentrating on whether global warming is man-made or natural is to miss the point completely… the facts appear to show that BOTH effects are combining and it matters not which is greater…”

    The way I look at it is that we humans only have some control over our own GHG emissions, not directly over nature’s emissions, so I take an anthropocentric approach (though climate scientists may tend to take your more geocentric view).

    Nature’s GHG emissions that can be attributed to the warming which we humans have caused by our GHG emissions, should also be attributed to humans, even though we did not directly emit them. Or, the total warming that our emissions cause should also include this positive feedback of warming-nature’s emissions-extra warming, to get a more accurate assessment of the ultimate warming & ultimate harms (& some benefits) our emissions cause — their direct & indirect consequences.

    While this may be near impossible to quantify due to lots of uncertainties and unknowns, esp into the long-term future (some of our CO2 may be in the atmosphere up to 100,000 years), at least we should have the model in our minds….that there’s more bang per bucket of our daily emissions than we’ve been assuming.

    And conversely our reductions will have a much greater positive impact (or avoidance of negative impacts) than we currently realize under a more linear, time-constrainted, positive-feeback-lacking mental model.

  167. Lynn Vincentnathan:

    Re #156 & 158, I guess the view we as nonscientists-concerned-about-the-world and proactive-policy makers should probably take is not whether the science on ocean acidification is in beyond a reasonable doubt, but the actions that produce our GHG emissions have many negative impacts, which is all the more reason to reduce: GW, ocean acidification, acid rain (from SO2 & NOx), local pollution, wars to secure oil (and perhaps some 50+ other negative impacts, and 1,000+ negative reverberations from those negative impact, including farmer suicides due to droughts).

    Perhaps the analogy should shift to responsible parents taking the chemistry set away from Jr, when they come to know he’s building bombs. We don’t know if he really has the capability to do that, but we need to stop his experiment, to be on the safe side. Likewise we need to halt this ocean acidification & global warming experiment on the oceans and earth BEFORE the dangerous results can be confirmed at 95% confidence (or even 50% confidence).

    Let’s just never find out!

  168. Joseph O'Sullivan:

    There has been a recent development in the news regarding ocean acidification. An environmental group, the Center for Biological Diversity (CBD) has petitioned (sued) to have CO2 listed as a pollutant under the Clean Water Act.

    This is different than the recent Supreme Court case which was about listing CO2 as a regulated pollutant under the Clean Air Act. Getting CO2 emissions regulated and reduced under the Clean Water Act may be easier, but in some ways may be harder. If there were more studies specifically about acidification’s effect on ecosystems there would be a stronger case.

    The Center for Biological Diversity was a participant in the recent petition to get polar bears review for endangered status and the petition getting corals in the Caribbean listed as endangered. For both anthropogenic climate change is a major threat.

    Here’s a news story and a press release:

    Yes this is off topic, but my comments on RealClimate usually are off topic.