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Bush on “The Fundamental Debate”

Filed under: — group @ 31 March 2006

The President of the United States, George W. Bush, recently voiced his opinions on the science of climate change:

We — first of all, there is — the globe is warming. The fundamental debate: Is it manmade or natural. Put that aside.

The first part is the silver lining: despite receiving novelist Michael Crichton in the White House recently, Bush obviously has not bought his theory that the globe is in fact not warming. Crichton is one of the last trend sceptics who deny the warming trend is real.

Rather, Bush adopts an attribution sceptic position: warming yes, but is it caused by humans? This position is equally out of step with science, where the debate over this question has also now been settled.

Data show that carbon dioxide levels are rising, they are now 30% higher than at any time during at least the past 650,000 years, and likely even the past several million years. This rise is caused entirely by human activities. This is also demonstrated beyond any reasonable doubt by data – for a start, we know how much CO2 we have emitted, and the observed rise is equal to 57% of this (the rest has been taken up by ocean and biosphere). That carbon dioxide acts as a greenhouse gas, trapping longwave radiation, is also a measured fact and well-established physics since the 19th Century. For a doubling of CO2 concentration, this amounts to a radiative forcing of 3.7 Watts per square meter, which in equilibrium would cause a warming of around 3 ºC (that’s the climate sensitivity discussed by us here). The rise of CO2, plus some other gases like methane, is already causing a forcing of 2.7 Watts per square meter. In equilibrium, you therefore expect a warming of 2 ºC based solely on the human-caused rise in greenhouse gas concentration. But there’s a time lag due to ocean heat uptake (“thermal intertia”), so that up to half the expected warming would still be in the pipeline and not here yet (this is shown by models and confirmed by oceanographic data, Hansen et al. 2005). That means: this rough calculation shows that the human-caused increase in greenhouse gases can explain at least 1 ºC of global warming. The observed warming is 0.8 ºC – this is less than what would be expected from greenhouse gases alone, because greenhouse gases are of course not the only factor that affects climate – there is a cooling effect by aerosols which counteracts part of the warming.

What about a “natural” explanation for the observed global warming? There is none. Indicators and measurements of solar activity show no increasing trend over the past 60 years. The orbital cycles, which cause the ice ages, would currently tend towards cooling, if anything. There is no remotely feasible alternative explanation for the observed warming published in the scientific literature. The “fundamental debate” postulated by Bush is a media phenomenon – to use the words of ABC News, a “con job” by special interest groups. It is not a debate that is ongoing in the scientific community. The numerous, often hair-raising arguments that have been brought forward as part of this “con job” have been thoroughly refuted many times.

In summary, the following scientific findings can no longer credibly be argued to be in dispute:
(1) The observed large-scale warming of the atmosphere and ocean is an entirely expected, and in fact well-predicted, consequence of the human-caused accumulation of greenhouse gases in the atmosphere.
(2) There is no other reasonable scientific explanation for the observed warming.

Bush would be more informed if he listened to what his close ally British Prime Minister Tony Blair has to say about the topic, or perhaps (why not try science?) the scientific Academies.

71 Responses to “Bush on “The Fundamental Debate””

  1. 1
    Roger Pielke Jr. says:

    Just a point for your clarification:

    The IPCC TAR SPM stated in 2001 that:

    “In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.”

    It defines “likely” as 66%-90%, which presumably leaves some room for scientifically honest disagreement. I am no fan of President Bush, but reading the IPCC would suggest some small room for valid disagreement on this issue, and that his statement was not inconsistent with the latest IPCC.

    Is it your contention that since 2001 that the 66% to 90% in this phrase is now 100%?


    [Response: Attribution has been a pretty heavily researched topic since the TAR, and it’s all gone one way. So this is one area where the TAR is out of date. But… you are perfectly well aware of that. You (and presumably Prez Bush’s science advisors) must have read the AR4 draft, no? -William]

    [Response: Nothing is ever 100% – but decisions are often made on the basis of beyond reasonable doubt (or even weaker levels of certainty). Attribution is now ‘beyond reasonable doubt’ – I’ll leave it to the IPCC authors to give a % certainty to that. – gavin]

  2. 2
    Coby says:

    While I’m afraid the content of this site may be over GWB’s head, I did write an article that he should be able to grok. To bad he is not very familiar with “the internets”, what with it being a democratic invention and all ;)

  3. 3
    Andre Bijkerk says:

    The science about the reason of the current warming of the last two decades could have been settled if we were looking at a valid physical process. But greenhouse gas effect is hardly that if we look at it’s minimum relative effect here (based on Modtran runs):

    or without logarithmic distortion here:

    So what caused the GHG effect? Albedo change, if the computatiuons of Palle et al 2006 (EOS Vol. 87, No 4, pp, 37,43, January 24) are right

    The variation of 10% albedo change is good for 2.8 degrees black body temperature change (Stefan Boltzman law). The real world change was only 0.6 degees, showing a robust negative feedback, which would raise eyebrows at the claimed strong positive feedback for greenhouse warming.

    Palle et al could have seen the correlation with surface temperature (R2 = 0,575) if they just had tried:

    Lack of clouds is causing global warming. Why more discussion?

    Shadow post here:

    [Response: Sorry, but you are just not interpreting MODTRAN correctly. And see for some discussion on what is wrong with your albedo theory. -gavin]

  4. 4
    Paul says:

    Roger, a small army of oncologists tells you that there’s a 66-90% chance that the tumor you’ve got in your brain will metastasize within the next year.

    Would you opt for a medical response, or sit out on the sidelines because a lawyer told you that the tumor is benign?

  5. 5
    pete best says:

    Science can be right on GW, however does it offer a solution that is economical and politically sane ? I would say that science, economics and politics has its own latency, namely that of a suitable replacement to fossil fuels for a 9 billion population whilst not losing to much if any of what they current have or desire to have, namely material wealth and fun exciting lives.

    Fusion is years off if at all, renewables are part of the solution, fission also has a case as does other solutions in the longer term but at the present time nothing will replace fossil fuels entirely and hence we can only slowly diminish our fossil fuel dependency in the hope of a suitable replacement being invented.

    [Response: It’s not necessarily a matter of stringent sacrifice. It’s a matter of wealth taking forms that are less energy intensive. Are you that much less wealthy if auto technology goes into fuel efficiency rather than better acceleration? If you live closer to public transit and go to blues clubs, baseball games or the opera instead of taking long drives to the mall? If you pay 20% more for electricity but your power company burns their coal in a non polluting IGCC plant that can be eventually retrofitted for carbon sequestration? As an example, you could live like the French (not a bad life, I’ve tried it) and emit only a quarter of the CO2 as the typical American. –raypierre]

  6. 6
    Dano says:

    Re 3:

    But Paul, what’s the medical cost of surgery vs the cost of going about your business? Surely the medical cost is very high and likely more than you can expect to make in your lifetime.

    Therefore, you should do nothing. ;o)



  7. 7

    You dare to say: “This position is equally out of step with science, where the debate over this question has also now been settled.”

    It has been settled only inside IPCC headquarters and other politically motivated organizations. If there is something that has not been settled is climate science, but you will never acknowledge this. It would ruin your business.

    I agree that the AGW issue is settled in the pages of Science, Nature, Scientific American, and other similar publications grinding an axe as political as it can be imagined. But science is absent from those journals, at least when it comes to climatic reporting.

    When you mention CO2 levels and record levels you bypass the information that CO2 levels during some periods as the Cretaceous ranging between 6000 and 2600 ppm were contemporaneous with temperatures only 2º C above today’s temperatures. But you already know that.

    You also bypass the information presented by Monnin et al. (2000) and many others about the fact that CO2 levels increases lag temperature increase by 600-800 years during Glacial Termination III, and other periods of Earth’s history. And you also already knew that. As you already know many things that contradicts your loved hypothesis of catastrophic AGW but will always look to the other side and try to keep them hidden and out of reach from the general public and the media. It is not good for the “business as usual” of asking funds for climatic research.

    The way you present your case is abominable misinformation, mixing assumptions with real data, and presenting it as facts. Science has been knocked out by you.

    Eduardo Ferreyra
    President of FAEC
    Argentinean Foundation for a Scientific Ecology

    [Response: Oh please… You are wrong about the Cretaceous (but note that sea level was about 100m higher than today, and alligators lived on Ellesmere Island), you are wrong about the significance of the ice-core CO2-temperature lag (discussed here), you are wrong about the funding, and you know what, I wish you were right about AGW being mis-information… but, you are wrong about that as well. – gavin]

  8. 8
    Roger Hill says:

    Just the fact we a debating whether the earth is flat or round at this point is utterly depressing.

  9. 9
    Paul Dougherty says:

    Your logic certainly leads to the inescapable conclusion that GW is man-made. But I continue to have difficulty in blaming all of this on carbon dioxide. Two NASA papers attribute probably over 50% of Arctic warming to carbon soot and ozone. Other greenhouse gases are contributing significantly to GW, aerosols are being fingered in cloud formation, and more is being reported on land use affecting climate.

    I understand that the science cannot produce a list of quantities attributed to the various man-made causes but it is important to attempt it. Suppose that George II has an epiphany and orders a war on CO2 and then time shows that the thermostat did not reset as low as hoped. Suppose also that in the meantime further research demonstrates that the other man-made causes were greater than first expected. I can see a huge loss in credibility.

    Would you address the issues and possible quantification of other man-made causes of GW and how they stand up to carbon dioxide? Also is not CO2 in reality the long range monster while the other sources are more immediate?

    [Response: We are not saying that it is all CO2 – look at the ‘forcings‘ bar chart for an idea of how the other factors compare. However, CO2 has a very long lifetime compared to soot or CH4 and so has the greatest potential for causing serious problems in the future. Reductions in soot and CH4 could be very beneficial and allow for a slower rate of growth in the net forcings, and thus ‘buy a little time’, but they can’t be a substitute for thinking about CO2. – gavin]

  10. 10
    Daniel Kirk-Davidoff says:

    Actually, I thought the most interesting part of his answer was this line:
    “And so I guess I should have started differently when I first became President, and said, we will invest in new technologies that will enable us to use fossil fuels in a much wiser way.” That may be the closest I’ve ever heard our President come to admitting an error. It may be significant if it’s an indication that the White House feels like it needs to reasses its position.

  11. 11
    grundt says:

    Re#7 Maybe Eduardo Fereyra,Ud. tenga razon en algunas de sus apreciaciones… Pero, anyway, the chemistry of our planet is quite different from any past one.

    Thousands of man-made compounds which will stay for a non-known number of years, contribute to things taking place not naturally. Like the POPs (persisting organic pollutants), like so many volatile solvents, like HCFC besides CFC, etc.

    Aunque parezca que algunas cantidades son insignificantes, pueden tener efectos extraordinariamente amplificados, tipo catalizador (los catalizadores son necesarios en cantidades mi­nimas en algunos casos).

    Climate Science is extremely difficult. Why neglect its Science status? You see, just recently it has been discovered that neutrinos have mass… Oh… it means Physics texts must be rewritten ASAP. Would you dare to say that Physics is not Science…(?)

    Has the work of Science to stop because you do not discover something still to be discovered and you ignore your ignorance?

    Sorry, I am no climate scientist. I would like to be, because so many scientists should be involved in such a most complicated field of Earth Sciences.

    BTW, I have also been involved in a a kind of Scientific Ecology… maybe not with your status. Nor are we receiving funds.. Does your organization receive funds, or are you volunteers?
    Sorry to be rude today..

  12. 12
    David B. Benson says:

    “Beyond a reasonable doubt” — Translating this to a percentage depend upon what is at stake. At 95% there is presumably 1 chance in 20 that one is wrong. However, in many areas of life sciences, including agriculture, 95% suffices for action. At another extreme, the designers of large airplanes aim for 99.9999% reliability and are able to achieve this.

    I suppose each of us could attempt an estimate of a percentage. I doubt it matters in that climatologists have established, beyond a reasonable doubt, that GW is occuring — and that ought to suffice for action.

  13. 13
    Roger Pielke Jr. says:

    Re: Responses to #1

    Gavin, William, Thanks.

    Yes, you know and I know what is ongoing within the IPCC. (And an aside, I have frequently written that the science has been long good enough for action.) But what seems to be missed here is that you are taking GWB to task for making a statement that is consistent with the latest IPCC reports. So long as these types assessments are produced every 5 years it either provides political cover for politicians to rely on old science or a lag in the connection of science and decision makers.

    I would not expect Bush or his administration to be on top of the inner workings of the AR4 draft. So your criticism of Bush’s understanding may well be correct, but please also recognize that your criticism also implicates the fundamental assesment processes that are relied on to inform policy makers. Another way to read this post is:

    “GWB is relying on the science in 2001 TAR SPM, therefore he must be an idiot or willfully denying the science.”


    [Response: No. Bush’s comment is not consistent with the latest IPCC report, the TAR. With the FAR, perhaps. You know that. Suggesting, as Bush does, that the issue of attribution is completely undecided is nonsense. But in addition, why are you expecting Bush to be basing his science evaluation on the TAR? He has all the science done since then, and the AR4 drafts to summarise it, available too. I don’t understand your excuse-making for Bush, it’s weird – William]

    [Response: And just to add to that, I disagree that his statement is consistent with TAR. TAR established that a significant portion of the warming was likely to be anthropogenic. Assuming that this implies that there is a significant probability that the manmade component is zero is a misreading. Had he said instead that the exact attribution is uncertain, that would have been more valid. (NB. Please do not put words into our mouths – I generally consider what I say here quite carefully and do not wish to be associated with comments that are likely to be construed as offensive.) – gavin]

  14. 14
    JohnLopresti says:

    orbital cycles, which cause the ice ages, would currently tend towards cooling, if anything
    I take the excerpt from the above is saying, ‘we are warming now when in what would otherwise be a cooling cycle (orbital)’. While we problem solve now, before the tipping point which we are defining as probably within ten years before transiting a region of progressively more impossible capability to reverse or slow the effects of GW, it would be an interesting contrast to define the timespan before which the ordinary warming would begin (based on orbital cycles).
    That is to say, how far into the cooling are we before orbital cycles begin the planetary ordinary warming cycle? I am sure if I read more in the RealClimate archive I will find the timeline, and I shall do that. Where are we…15kY years or 60 kY until warming begins for REAL?
    In a reasonable sense, besides the Hansen defined tipping point zone, it might be useful to regard the wake effect: what does it look like for the planet trying to emerge from its own orbital-cycle-based warming given accreted anthropogenic warming; i.e., adding such a depiction might increment impact of the model going in, reinforcing the warnings clear in the tipping point zone lemma.

    [Response: We are already in a warm phase of the glacial cycles (in the Holocene interglacial), so expect no further warming from orbital cycles. The next thing the orbital cycles will do to us is start a new Ice Age – but that’s at least 30,000 years away. -stefan]

  15. 15
    Roger Pielke Jr. says:

    William- Thanks. You write:

    “He has all the science done since then, and the AR4 drafts to summarise it, available too. I don’t understand your excuse-making for Bush, it’s weird”

    Yes the IPCC TAR does in fact give considerable room for “attribution skeptics” to assert that “most of the warming in the last 50 years is not due to increased greenhouse gases, with a 10%-34% certainty.” That is simply the complement to what it actually says, and that I quoted before from the Summary for Policy Makers. Not much ambiguity there.

    More importantly, does the Bush Administration have access to the AR4 drafts and have they read them? I don’t know, but given the experience with hurricane Katrina, I’d suggest that they do have a serious information management problem. From this experience, I’d doubt that they have much of a clue about the AR4.

    My point is not to defend Bush, I’ll be happy to see him go, but rather to suggest to you good folks at Real Climate that there might be more going on here than a “con job” as you suggest, involving Michael Crichton and other evil characters.

    For instance, it could be that the very assessment process that has been adopted to link science and policy works too slow, to inefficiently, and too disconnected with policy.

    [Response: Perhaps you can point us to a scientific publication that proposes a serious alternative explanation for the observed warming, worthy of our discussion? -stefan]

  16. 16
    llewelly says:

    Roger, do you think it would be helpful for the IPCC to produce assessment reports more frequently, such as every 2 years? (by helpful, I mean, would the benefit outweigh the cost?)

  17. 17
    Roger Pielke Jr. says:

    A further question for you guys:

    When the IPCC says “likely” meaning 64%-90% certainty, should I interpret this to mean that:

    a) between 64%-90% of scientists believe this statement 100% and between 10%-36% believe it 0%

    b) every participating scientist’s view can be found within the range of 64%-90%

    c) Some somehow-otherwise formally weighted measure of central tendency hat allows for legitimate views outside of this range

    d) The subjectively negotiated result among participants that everyone agreed to without any quantitative process for weighing views

    e) Other?

    What does it mean? Thanks!

    [Response: f) None of the Above. -gavin]

  18. 18
    Roger Pielke Jr. says:

    llewelly- (#15)

    Yes I do. The IPCC could do two things that would dramatically improve its role in policy:

    1. Explicitly discuss policy options
    2. Issue updates as needed on a continuous basis when scientific results lead to important changes related to #1, and policy makers cound assume the status quo ante unless told otherwise.

    The parts of WGs II and III are very much oriented around the Kyoto Protocol which I would expect will be very much moot when the AR4 comes out, thus making much of the IPCC irrelevant. This will have the undesirable effect of further pushing the political debate onto WG I.

  19. 19
    Roger Pielke Jr. says:

    Gavin- (Response to #17)

    The correct answer is of course (d)! From the IPCC guidelines:

    “Be prepared to make expert judgments and explain those by providing a traceable account of the steps used to arrive at estimates of uncertainty or confidence for key findings – e.g. an agreed hierarchy of information, standards of evidence applied, approaches to combining or reconciling multiple lines of evidence, and explanation of critical factors.”

    If there is a specific quantitative process, it is not explained by the IPCC. Thanks!

  20. 20
    Ike Solem says:

    I think the IPCC has quite enough on its plate without having to suggest policy options; that is a somewhat different question. The IPCC should stick to providing accurate data and reliable analysis.

    The largest sources of carbon dioxide are coal-fired electricity generation and petroleum-fueled transportation systems.

    If electricity generation is switched to wind and solar power coupled to reliable energy storage systems, the need for coal-fired electricity is eliminated.

    Transportation is a thornier problem because it seems that liquid fuels are among the best options. Biofuels are currently produced using energy-intensive agricultural practices (at least in this country). Low-energy agricultural production is thus a necessity for climate-friendly biofuel production.

    Thus, the greatest uncertainty in future CO2 emission profiles is human behavior. Methane effects may also play a role (melting permafrost/ice hydrate issues). The net effect of CO2 + CH4 (and others) on climate variables is the question that the IPCC should stick to.

    The residence time of CO2 in the atmosphere is ~100 yrs. So, we have to engage in long-range planning – certainly longer then the next election cycle, or the next economic cycle.

    So, the question of what to do? need not be answered by climate scientists; rather policy makers should pass the question on to energy scientists and engineers. How about an IPRE? An International Panel on Renewable Energy? The IPCC is certainly a good model for how that might work.

  21. 21
    Eli Rabett says:

    Solem, it is my understanding that a primary purpose of the IPCC is to present and evaluate (in economic and social terms) a range of policy options. That is, indeed the WGIII’s primary job. However, choice among the policy options is the job of governments. In this forum, we often identify the IPCC with the work of WGI whose job it is to do a critical evaluation of the science. WGII is there to evaluate the possible effects, for good or ill. (see

    Roger, to suggest that the President of the United States does NOT have the drafts of AR4 available to him with experts available to discuss the matter is insulting. That he might not have the interest or the time to do so is another matter. That he might prefer to shoot from the hip is yet another.

    However, the whole thing is a hoot. In the 70s we had tragedy, today we have a farce.

  22. 22
    Saint says:

    Talk about a con job! I wonder how “the group” (all 11 of them) could have missed the statement President Bush made during an interview with ITV in the United Kingdom on 29 June 2005 shortly before the G8 talks(and available on the White House web page). When asked if he accepted that climate change is manmade, he replied: “To a certain extent it is, obviously. I mean, if fossil fuels create greenhouse gases, we’re burning fossil fuel, as is a lot of other countries.”

    One would be excused for thinking that the good folks at RealClimate would have noticed this–it was in all the papers. If the group posted on this, I missed it. But I think we all know, instinctively, that it did not.

    Further, the group spends a considerable space in its post arguing the point that anthropogenic greenhouse gases emissions are the cause of the observed increase in greenhouse gas concentrations in the atmosphere, suggesting implicitly that the President has questioned this fact. Not so. In his 11 June 2001 speech on climate change, the President said: “Concentrations of greenhouse gases, especially CO2, have increased substantially since the beginning of the industrial revolution. And the National Academy of Sciences indicates that the increase is due in large part to human activity.”

    And in the same speech, he recognizes the cooling effect of aerosols, which was also noted in the group’s post.

    If the group has any collective sense of fair play, it should withdraw this post, not because it is a political hit job – which regular readers of RealClimate have come to expect – but because it is a particularly poor one.

    [Response: I will readily concede that his set speeches on the matter are much better crafted than his off-the-cuff remarks here. And there is no shortage of people in the administration who have a very good grasp of the issues. Maybe you could see this post as a mere corrective… -gavin]

  23. 23
    llewelly says:

    Saint, do you have an explanation for the contrast between Bush’s recent speech, and the 11 June 2001 speech you refer to?

    This RC article is about a speech which is more recent than either of the quotes you mention.

  24. 24
    John Baltutis says:

    You state: carbon dioxide levels… are now 30% higher than at any time during at least the past 650,000 years,. Really? Based on your detailed and accurate measurements over that period or on the suppositions you’ve obtained from modeling constructs or selective data mining?

    [Response: Based on the highly replicated and well understood data from the Vostok and Dome-C ice cores actually. -gavin]

  25. 25
    Steve Latham says:

    Regarding Eduardo’s #7,
    I’m always amazed at how contradictory “the sceptic argument” is (or seems to be). In #7 we are told that we know the temperature of the Earth was 2C higher back in the Cretaceous (with some values of CO2 conc.). Elsewhere you can find sceptics saying we can’t know within one degree what the temperature was just 1000 years ago. Then you find some people who say that model confirmation via comparisons to history is impossible due to circularity as the models just have the data built into them, while some other people say that the models don’t predict x or y that occurred five or forty years ago. That these various people rarely seem to argue amongst themselves is evidence that their ‘side’ is politically-based. There are several sceptic arguments, but I can only imagine that their reason for not working it out and coming up with one or two coherent arguments is because they see anything anti-GW as being an ally. If they were really interested learning/teaching ‘truth’ then there would be no tolerance for these contradictions.

    Same goes for the anti-GWB people, but that’s another story.

  26. 26
    Paul says:

    I think I finally understand why Roger is such a creature of interest to journalist. He is always around to make a bombastic statement and then ignore or glibly glide across any rational response.

    You just don’t find people like that every day. So I guess he does serve a purpose.

  27. 27
    Eli Rabett says:

    Would Saint point to a posting here where it was stated that Bush denied that anthropogenic greenhouse gases emissions are the cause of the observed increase in greenhouse gas concentrations in the atmosphere. OTOH, I bet you could find several where it was questioned if he believed this lead to global climate change and warming, and rightly so. Let us quote from GWBush’s 11 June 2001 speech

    ” There is a natural greenhouse effect that contributes to warming. Greenhouse gases trap heat, and thus warm the earth because they prevent a significant proportion of infrared radiation from escaping into space. Concentration of greenhouse gases, especially CO2, have increased substantially since the beginning of the industrial revolution. And the National Academy of Sciences indicate that the increase is due in large part to human activity.

    Yet, the Academy’s report tells us that we do not know how much effect natural fluctuations in climate may have had on warming. We do not know how much our climate could, or will change in the future. We do not know how fast change will occur, or even how some of our actions could impact it. ”

    I await your answer.

  28. 28
    John Greifendorff says:

    It seems that american science has become a tool of political expediency. That is much more serious than global warming. President Bush’s opinions matter, but they have no effect on the evidence.

    I would hate to make a call that would affect my entire nation on the basis of this level of discussion. So would the President I expect.

    Fortunately, scientists will never make social policy because their incompetence in the political realm is equal to a politician’s incompetence in a scientific field, like, say, meteorology.

  29. 29
    Mark A. York says:

    Roger would make a good prototype for a character in a novel.

  30. 30
    John Baltutis says:

    #24. Gavin, your response isn’t held by all. See

    [Response: You are going to have to be more specific. I don’t see anything contradictory on that site. – gavin]

  31. 31
    llewelly says:

    Mr Greifendorff, the level discussion on which policy makers are expected to decide, is here. Please read it. Note President Bush has access to drafts of the upcoming IPCC 4th Assessment report, and experts of many political backgrounds.

  32. 32
    llewelly says:

    I assume this is the original NICL graph, or produced from the same data. Please note it was made in 1999, and the figure of 365 ppm in the graph is from 1999. The source linked on the page you link to is broken. Since 1999, CO2 has risen to about 380 ppm. The highest point on that graph is at about 295 or 300 ppm. 380 divided by 300 is about 1.267 or 26.7% higher (alternatively, 380 / 295 is about 1.289, or 28.9% higher). Rounding this to one significant figure results in 30%, as Gavin said. In 1999, when the graph was made, 20% would have been a reasonable approximation; 365 / 300 ~= 1.22, or about 22% higher.

  33. 33
    John Baltutis says:

    #30/32. My error. Erroneous example; just ignore my comment.

  34. 34
    Alan says:

    Re: #28 “Fortunately, scientists will never make social policy because their incompetence in the political realm is equal to a politician’s incompetence in a scientific field”

    Do the names Ben Franklin, Thomas Jefferson, John Adams, ring any bells? These are some of the interesting people in a book that rips apart many a preconcived pigeonhole. For some reason the wizard of Oz also springs to mind.

  35. 35
    Pascal says:

    hello Gavin

    what do you think about this graph and particularly about the Moberg05 reconstruction (found in Wikipedia).
    I’m very surprised with the green curve of Moberg05 in the medieval period.
    Sceptic people use this type of curve to deny actual anthropogenic warming.

    [Response:Why are you looking at some cr*ppy wiki-mirror instead of wikipedia? The wiki original is That graph, though, was constructed by an unreliable source unable to even spell “IPCC”. A somewhat better version is at But those graphs are only of interest for historical reasons: ]

    And finally… to answer your question… the green in your pic isn’t Moberg – William]

    [P.S.: You will find my own version – comparing Mann et al., Moberg et al, Oerlemans, observed data and IPCC projections – as figure 2.6 in the pdf of chapter 2 of our new book. Text is in German, but graph is self-explanatory. -stefan]

  36. 36
    Saint says:


    First, the recent “speech” wasn’t a speech at all but a statement in response to a reporter’s question (“off-the-cuff”, as Dr. Schmidt notes, if only belatedly). Second, if you read the entire response the President gave, you will find that it is consistent with his earlier speeches and statements. There is nothing new here.

    Eli Rabett:

    You haven’t been paying attention. I said the group’s post “suggest[s] implicitly” that the President doubts that human activities have caused the observed increase in CO2 concentration. The post begins by accusing Bush of adopting a position as an “attribution sceptic”, and it then launches into a discussion of the growth in the CO2 level, pointing out that this is caused by human activities “beyond any reasonable doubt”, as if this were an area if disagreement. This is a common rhetorical trick, the purpose of which is to pretend a controversy exists where it does not.

    As to those passages from the President’s 11 June speech, what’s the issue? He captured the uncertainties identified in the 2001 National Academies report quite accurately and succinctly. (I find that this is one those reports that is widely cited but only rarely read.) It doesn’t get more “consensus” than the National Academies.

  37. 37
    Lynn Vincentnathan says:

    Re standards for action, we don’t need evidence that humans are causing GW “beyond a reasonable doubt” (though we now have that). Even “preponderance of evidence” (roughly 51% chance) is too high a bar on such a threat.

    It seems to me the important point is that WE CANNOT DO ANYTHING ABOUT NATURAL CAUSES OF GW, but we can do something about human causes, so even a vague idea that AGW may be happening is enough for me to jump into action to reduce it — which I started doing in 1990, well before the first study reached 95% certainty of AGW back in 1995.

    I was hoping all along the evidence would go in the opposite direction — but even if it had, I was going to continue reducing my GHGs, since it was saving me money. I guess the rich have the privilege of profligacy.

    This is the way the human world works: whatever the powerful want to do, they do. Some show that they indeed know right from wrong, by socially constructing the situation and their actions as within ethical bounds. So the king of the world can say, “There is no AGW, and it’s perfectly all right that I continued promoting GHG emissions.” And he can keep saying that indefinitely and acting as he pleases, no matter what the evidence. Because he’s king, and no one’s around to depose him.

    How often have we heard our superiors say, “There’s nothing I can do about it” (& we know darn well there is plenty that can be done about it).

  38. 38
    Almuth Ernsting says:

    And even if there is still one percent or however little uncertainty about CO2 emissions making global warming worse: I understand that there is absolutely no uncertainty with regard to ocean acidification. See here, for example: . It is happening, and I understand that the chemistry behind it is relatively simple and not disputed.

    Surely, the looming destruction of much of the marine food-web and massive changes to the chemistry of the oceans are reasons enough for burning less fossil fuels?

  39. 39
    llewelly says:

    From the June 11 2001 speech:

    There is a natural greenhouse effect that contributes to warming. Greenhouse gases trap heat, and thus warm the earth because they prevent a significant proportion of infrared radiation from escaping into space. Concentration of greenhouse gases, especially CO2, have increased substantially since the beginning of the industrial revolution. And the National Academy of Sciences indicate that the increase is due in large part to human activity.

    From the new ‘off-the-cuff remark’:

    the globe is warming. The fundamental debate: Is it manmade or natural. Put that aside.

    When I first read these two statements, I figured they were nearly equivalent, with the differences being due to lack of preparation. William pointed out to me that while functionally equivalent, the old speech is stronger, in that the role of GHGs emitted by people is explicit. After re-reading both the old speech and the new off-the-cuff remark, I felt somewhat different.

    You claim ‘There is nothing new here’ . That is precisely the problem! The contrast, as I called it, is in the context.

    It has been nearly 5 years, and in that time, scientific understanding of climate disruption has increased dramatically, and scientific confidence that human-emitted GHGs are the primary cause, has also increased. What President Bush called ‘The fundamental debate’ was nearly resolved when he spoke in 2001, and is now as completely resolved as any science ever gets. The counter-arguments have gone from being scientifically reasonable, but later disproved notions, to bizarre arguments that seem poorly informed, and often self-contradictory.

    I hope, for all our sakes, that ‘Put that aside’, and what follows, means that the ‘fundamental debate’ must end, as it is resolved, and action must began. But given past failures to prepare for, and adapt to, dangers already present in the climate we live in, some clear confirmation of this would be helpful. I can find no such clarity.

  40. 40
    Henry Molvar says:

    Although this comment is not about science, some RealClimate readers may find it entertaining today. See:

  41. 41
    Aaron says:

    [As an example, you could live like the French (not a bad life, I’ve tried it) and emit only a quarter of the CO2 as the typical American. –raypierre]

    Of course, 76% of our energy will have to be derived from nuclear power for that to be the case.

    [Response: Are you assuming I would necessarily object to this? Nuclear isn’t a panacea, but a case can be made that it’s easier to solve the problem of nuclear waste than the problem of burning coal safely. It should be an option on the table. By the way, for the French, it’s 75% of electricity, not 75% of all energy, last time I checked. –raypierre]

  42. 42
    John Finn says:

    Re: #7

    Gavin regarding your response to Eduardo Ferreya. i.e.

    you are wrong about the significance of the ice-core CO2-temperature lag (discussed here)

    Your link does not provide a reason for the CO2-temperature lag. It simply argues that although the CO2 was not responsible for the initial increase in temperature it might have been responsible (or partly) for the remainder. To be honest I don’t find the argument in this article terribly convincing.

  43. 43
    Pat Neuman says:

    re: 39

    From a few conversations I had recently, there is no reason for me to believe that people will change their fuel dependent living styles out of any concern from global warming. For example, conversation #1. … Sharing a table with a stranger at a ski resort in Colorado. After learning that the person was from Colorado Springs, I asked if she was familiar with Florissant Fossils National Monument (between Colorado Springs and Breckenridge CO). She told me that she had seen the fossil redwood tree stumps at the Nat. Mon. a few years ago, and said to me that few people are aware that Colorado had a tropics like environment many millions of years ago. I mentioned that fossil skeletons of primates which were found in CO and WY can be seen at the National History Museum in Denver … although humans had evolved from some of the primates found in Africa. She then informed me of her Creationist beliefs. I said I believed God created the environment for life to evolved in. I said global warming is harming the planet, and I believe it’s sinful to destroy the environment which God created. She informed me that there is no man made global warming, and that one or two volcanoes put more emissions into the atmosphere than all the emissions from humans combined, going on to say that government funded scientists, the same who said 30 years ago there was an ice age coming, were spreading gloom and doom information on global warming in order to get more money for their “research”. Then the 10-12 people she was waiting for arrived, so I moved to another table. I doubt anyone here at RC would be that interested in my conversations with others while I was visiting family in Colorado, or would you?

  44. 44
    llewelly says:

    Pat, unfortunately, I have had many similar conversations with friends, relatives, nieghbors, and co-workers. None of them live in Colorado. Most live in Utah, like me.

    Troublingly, of the few whose minds have changed, most believe hurricanes are caused by global warming, despite my best efforts.

    These conversations – nearly all with staunch Republicans – make it extremely difficult for me to interpret ambiguous statements, like those of President Bush, or lack of action, as other than negative. I have been told that I should not allow such things to influence my view of politicians. I try to keep in mind that there are Republicans who realize the seriousness of the problem. Nonetheless, I find the situtation quite upsetting.

  45. 45

    I don’t know as describing the confusion among the general public will get us very far. I think all of us have experienced it. I can’t resist my favorite anecdote, though. Through a peculiar set of circumstances I found myself at a large luncheon group in rural Poplarville MS. (It’s a long way from Cote St Luc, QC!) They asked me what I did, and I asserted that I was a climatologist. After a brief, awkward silence, a socially adept woman volunteered “ohh… that must be… lucrative”.

    The point that the obfuscators are having success obfuscating hardly needs anecdotal support. The idea that the vast conspiracy they imagine could be fueled by a malicious pursuit of misallocated research dollars would be quite funny except for the serious consequences.

    There’s plenty of blame to go around for the travesty nicely summarized in #8, and it’s an interesting story that I’m sure will engage future historians, but I’d vote for it being off-topic here. What we need to be discussing here, other than pure science, is how to get out of this mess.

  46. 46
    Jim Roland says:

    Re. #43, #44

    Pat and Llewelly, these are important issues you raise.

    Firstly, I think itâ??s vital that those concerned about AGW think outside the bubble of â??us versus the bad politicians and corporatesâ??. This is a many-layered struggle about winning hearts and minds so that electorates will demand or be receptive to change. The international accords should not just be about emissions cuts. We also need to see international accords in which participating governments (or local authorities) agree to lead public awareness drives, as they do in any other national emergency. Members of political parties need to work to sell the issue to others in the same movement so that the party will act to promote the issue. And people need to work within faith groups, like Rev. Cisik, and within other special interest communities.

    Second, conversations like you’ve had are all part of the hearts and minds effort. Itâ??s worth saying: in most faith groups, you do not doubt doctors if they tell you that someone is suffering from cancer or something else that requires surgery; and you do not expect a miracle if you step off a cliff. Similarly, if the scientific consensus is telling you that human activities (discharging carbon from stores in and on the earthâ??s surface) are making the world warmer and less sustaining of human life, you need to take them seriously.

    And as Rev. Cisik has said, central to Christianity is the principle of love thy neighbour as thyself. People are already seriously suffering as a result of AGW whether in heatwaves or drought-ridden areas or tropical storms. This will all get considerably worse as more warming feeds through and sea levels rise, the question is; how much worse do you want to let this get? And do you want to cause something apocalyptic, which is a real possibility.

    In the UK where I live, there does seem to have been a sea change over the past 15 months or so in which it became deeply unfashionable to dispute AGW, and it’s become one of the foremost issues of political lip service.

    However, some of the same lodgers I’ve had who say they’re convinced of the importance of sustainability still insist on turning up their room heating, using the tumble drier routinely and using hot washing machine programmes or oodles of powder. It’s time I started assessing against such potential tenants!

  47. 47
    Jim Redden says:

    Any mention of Bush raises my metabolic rate in a “classically conditioned” relationship. Clearly emotion is a key driver of ALL our actions, and also on the route to “changing minds”.

    Bush is just one “oil man” of many; it is this for this group he deploys message; for “he”, George Bush, the figurehead, is merely responding to a noted shift in the broader political base. Consider his public statements on the Katrina response debacle, as compared to what the videotaped briefings reveal he knew at the time as illustration. What he says is less meaningful that what is acted on.

    This administration–perhaps the worst in US history–has emptied the treasury, lowered taxes on capital gains on ungodly sums of appreciation values, and in the course of invasion, essentially transferred large sums of money to a very small group, that can now loan the money back to the government. In essence, it is a form of stealing. Contracts let, public duped; “Mission Accomplished”!

    I am very impressed how well they run their playbook, and perhaps the hope for humanity resides in provoking them to a personal enlightenment on policy that is derived from fact and reason. As is said in the Tao, the bad man is the good mans business. As odd as it sounds, we need “these folk” to convert and join the side to extend the experiment of humanity.

    At least the funding for investigation continues despite some ill considered policies that will destabilize society on many counts.

    In November, 2002, James Hansen argued nicely in BAMS for a systematic construction of climate and weather data. With my beginnerâ��s mind, I concur with Hansen all counts; yet would suggest a more elaborate need to get ocean deep data seems paramount to knowing how hard GW has pushed on the climate flywheel (perhaps the oceanâ��s heat capacity has dampened observed metrics enough to through off some of the parameterizations of climate models?)…

    The Bush cabal insiders apply their unique perceptual filters to their way of viewing the universe, and it blinds them. Any meaningful change to how industry is evolved, and how global mass media drives the general population to accept financial incentives and disincentives, and to ultimately affect value systems seems to indicate targeting the most influential on the planet, which modern terms is those who mentor capital markets and finance.

    I have set my targets on the world�s key decision-makers and lever pullers, and by taking studied cue from the persuasive industries, will try to appeal directly to them via more emotional mediated messages.

    A close childhood friend is a chief of staff in the current US congress–the boss sits on the energy committee–recently I asked for an explication of climate change issues. What I got was right off the die of the Western Fuels Association, with an embodied resistance to any notion that science could reliably predict climate. The exchange was off the record, so I can’t use names.

    Like any computer, what goes in is what goes out. George Bush et al is no different. The goodness of light on the issues at hand, in the right places, will be what can make a difference.

  48. 48
    Pat Neuman says:

    Conversation with a skier (re 39.)

    What is right or wrong doesn’t matter much in the now. What a group decides matters. Powers that be may get a group to agree on something that is wrong, for whatever. With 10-12 people about to sit down, I was not about to disagree with a group again. If I had I likely would have been removed again.

  49. 49
    Jim Roland says:

    Pat (## 43, 47), I am advancing the two paragraphs beginning “second” in #46 as things to say to people like this. Most religious people believe in taking advice from medical doctors, even those that believe Adam was fashioned from clay. So similarly, however they believe the earth was formed should not detract from paying heed to the scientific consensus on AGW, any more than from past scientific warnings about impending volcanic eruptions, earthquake dangers etc.

    Incidentally, a noted Jewish sage, Rabbi Gedalia Nadel, used this medical science argument as reason to believe that the world is older than as follows from a literal reading of Biblical texts.

    Of course, the medical science argument will not be so strong with Christian Science followers.

  50. 50
    Eli Rabett says:

    Saint, the first quote of GWB in this section is

    “We — first of all, there is — the globe is warming. The fundamental debate: Is it manmade or natural. Put that aside.”

    Do you claim that Bush accepts that the cause of global warming is anthropic or do you claim that he thinks the question is still open?

    Can you show anywhere in this or other posting on Real Climate where it has been explicitly stated that Bush does not accept the globe is warming (and can others find quotes where he states his doubt that the globe is warming)? I ask for an explicit quote, not an imagined one.

    Beyond that, many of us have read the NAS report, and it accepts that most of the climate change in the past 50 years is caused by human actions:

    “The IPCC’s conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue. The stated degree of confidence in the IPCC assessment is higher today than it was 10, or even 5 years ago, but uncertainty remains because of (1) the level of natural variability inherent in the climate system on time scales of decades to centuries, (2) the questionable ability of models to accurately simulate natural variability on those long time scales, and (3) the degree of confidence that can be placed on reconstructions of global mean temperature over the past millennium based on proxy evidence. Despite the uncertainties, there is general agreement that the observed warming is real and particularly strong within the past 20 years. Whether it is consistent with the change that would be expected in response to human activities is dependent upon what assumptions one makes about the time history of atmospheric concentrations of the various forcing agents, particularly aerosols.”