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Jim Hansen’s opinion

Filed under: — eric @ 18 December 2009 - (Español)

Several people have written saying that it would be useful to have an expert opinion on the state of the surface temperature data from someone other than RealClimate members.

Here you go:

You don’t get more expert than Jim Hansen.

186 Responses to “Jim Hansen’s opinion”

  1. 151
    David B. Benson says:

    Dwight (149) — One sensible study of the 10Be proxy for solar concluded that the variations, such as the Maunder Minimum, appear to be random events.

  2. 152
    Jim Eager says:

    Fair enough Eric, although I assume you meant to write “Because reasonable but uninformed people might take him seriously

  3. 153
    Jim Eager says:

    In the spirit of Eric’s reply…

    Re Snorbert Zangox @117: “So why, in spite of the favorable conditions did the growth of trees abate during the late 20th century.”

    Two possible factors for Snorbert to look into, assuming his question was at all serious:
    1- global dimming from industrial aerosols (lower sunlight levels)
    2- acid rain from those same aerosols (soil mineral leeching and root damage)

  4. 154
    ZT says:

    #150. Thanks Daniel. Hansen is a distinguished scientist*.

    From my somewhat growing understanding, going nuclear for all power generation and other forms of energy (e.g. transportation with hydrogen fuel) would be the conclusion I would reach – if the models are correct. Hopefully, this isn’t too much of an insult to Prof. Hansen or anyone else.

    My two cents – is that climate scientists get into knots when a journalist says:

    “If NOAA and NASA can’t even agree what the temperature was last year, how can we believe what they are saying about the future climate”.


    “I’m sure you’ve seen the NOAA/NASA press releases and the news stories about the 2007 global temperatures. ‘ NASA says tied for “2nd hottest”. . . NOAA says 5th warmest global and only 10th in US.’ Who does this serve but create confusion and add to the skeptics/denialists argument. . .”They can’t even agree on last year’s temperatures. .why should we believe them?”

    (as in the email cited) and then instead of saying – ‘the error bars are large – but the trend is the same’ (which is what Ray has been saying in bold) (I think – my interpretation) – the climate scientists get tempted into creating a grouping scheme which exceeds the uncertainty of the measurements, but does allow the ranks to emerge roughly the same.

    In this case – big deal! It is kind of a slippery slope though to saying ‘we’ll just not plot the diverging information – it will only confuse the masses’ or ‘we’ll coordinate our reviewing to prevent a confusing messages appearing’, or ‘we’ll never hand over our data’. (as in other messages).

    *I can hear some of you saying ‘If he were, you would not know it!’ – to which I say ‘fair comment’ – but I can testify that he writes very clearly – which is a good way of disseminating the scientific message.

  5. 155
    Ray Ladbury says:

    ZT, I have worked as a as a science reproter–though in my case I was summarizing and simplifying research for physicists outside the field. To communicate, you need a narrative, and all you will do by putting in too much detail is lose your audience.

    Do you really consider it nefarious for climate scientists to want to understand the message that the planet is warming–which you yourself accept? If not, then how would you communicate it to the public without exhausting their gnat-like attention span or dragging them through details they wouldn’t understand anyway?

  6. 156
    Steve Fish says:

    Comment by Jim Eager — 19 December 2009 @ 8:27 PM:

    Another answer to your question–“Eric, why do you bother wasting time on someone so obviously divorced from reality as Snorbert Zangox?”

    As long as the questions and problems posed are not too simplistic and agonizingly repetitive (e.g. manaker), readers like myself continue to learn from the responses. Learning this difficult material from the (excuse me) horse’s mouth, is really quite a privilege.


  7. 157
    Molnar says:

    Wes (127):
    “Interesting link, but it doesn’t cover the time period (1840-1910) of interest.”


    From skepticalscience:
    “The two driving causes of natural climate change over the past few centuries as we’ve emerged from the Little Ice Age were solar variations and volcanic activity. Both have showed little variation over the past half century and cannot explain recent warming”

    Also, LIA in Crowley and Lowery (2000) reconstruction is not very different from all the other reconstructions, so I don’t know what you are getting at.

  8. 158
    Dwight says:

    Thanks for the link to the treeline tree ring studies discussion. The question(s) which Paul Gosling asks regarding the flipping of the response to warmth based on a changing relationship to positioning vis a vis a changing tree-line, exemplifies to me te problem with tree rings. They are neat to study to establish a date for timbers in old buildings, but to use them as a reliable indicator for one factor, when they reflect a number of them, seems shaky to me.

    But as a former teacher of literature, including the Epic of Gilgamesh, I found fascinating the suggestion by someone that the apparent warming circa 2000 BC might help explain the flood stories of Utnapishtim and Noah. Who knew that it didn’t rain forty days and forty nights, but that a lot of ice melted? :-)

  9. 159
    Dwight says:

    Thanks for the link to the treeline tree ring studies discussion. The question(s) which Paul Gosling asks regarding the flipping of the response to warmth based on a changing relationship to positioning vis a vis a changing tree-line, exemplifies to me the problem with tree rings. They are neat to study to establish a date for timbers in old buildings, but to use them as a reliable indicator for one factor, when they reflect a number of them, seems shaky to me.

    But as a former teacher of literature, including the Epic of Gilgamesh, I found fascinating the suggestion by someone that the apparent warming circa 2000 BC might help explain the flood stories of Utnapishtim and Noah. Who knew that it didn’t rain forty days and forty nights, but that a lot of ice melted? :-)

  10. 160
    Sandra Kay says:

    “For journalists it’s a dead end, offering essentially no place to take the story and centered on a topic that is at root deadly dull for most people.”

    Really now?

    This scandal is not going away.

    To gain back a semblance of credibility, all data, code and “adjustment” schemes should be made public.

  11. 161
    Jiminmpls says:

    #149 and others on rate of tree (and other plant) growth in 20th C

    This is a topic under intense study. I don’t think anyone can say that tree growth has slowed – or not – in the 20th C. It depends. Climate change may provide better or worse growing conditions depending on the specific location and species of tree(s).

    Aspens appear to be growing like weeds

    but tropical tree growth may be slowed by higher temps.

    Here’s a layman’s intro to one study underway:

    U of MN – and I’m sure many others – is doing some work on CO2 and plant growth. They just happen to be a customer of mine.

    Just googling “university of minnesota co2 and plant growth” finds lots of articles with a wide range of findings.

    Interesting reading.

  12. 162

    Dwight, you might want to go back and absorb the bit about likely magnitudes of solar vs. CO2 forcings.

    Bottom of p. 5 in the pdf.

  13. 163
    Jiminmpls says:

    As I was perusing the U of MN articles, I came across this:

    It’s a commentary on climategate from someone who is not at all associated with CRU or GISS.

  14. 164
    bananabender says:

    “Southest Australia recorded the highest temps ever in February 2009. They had huge fires that killed over 200 people.”

    Wrong. By far the worst year for bushfires was 1852 – this was also the year when Melbourne had the hottest day ever recorded. The second worst bushfires were in 1939. The only reason that the death toll was high in 2009 was because of the large numbers of people living in fire-prone areas.

  15. 165
    Andrew says:

    For what its worth: I think Dr. Allen’s thoughts are on target and finally, clearly, he gets his arms around the CRU Hack.

    Dr. Cobb acknowledge’s embarrassment over the content of the CRU emails. I would bet that her comments left some readers thinking that she believes portions of climate science are an embarrassment. She assumes the reader knows her comments are in regards only to the unprofessional tone expressed in some of the emails; yet that thought is only implied.

    Her words:

    There is no doubt that the CRU e-mails are an embarrassment to climate science in general, and to paleoclimate in particular. I have read the “greatest hits”, and cringe along with everyone else at their content. But in my professional opinion, these e-mails reveal nothing more than brief, emotion-fueled remarks made in the face of unrelenting and often disingenuous attacks. Far more importantly, the conduct (questionable or not) of a handful of climate scientists in no way undermines the scientific support for anthropogenic global warming. The conclusions reached in the IPCC report do not critically depend on the work of these few scientists.

    I don’t know what she thinks she is telling folks, but I can read this two ways. The non-scientist side of me reads that she believes “the work” of Dr. Jones and the other “few scientists” was conducted inappropriately. She isn’t specific enough about what she means when she says “conduct”, and yet she specifies “paleoclimate”. Is she talking about scientific conduct or personal relations? General readers may not know that Dr. Jones worked with paleoclimates and may well think Dr. Cobb believes the way paleoclimate studies have been conducted is an “embarrassment”.

    This in turn will lead many readers to assume this is just the tip of the iceberg. Today the CRU and paleo reconstructions, tomorrow the radiative physics of carbon dioxide. That is how “scandal” journalism works after all. The general public has been well trained to know that scandals are revealed slowly in a serial manner so the readers buy the next edition or keep watching. In this way climate science is just the next OJ trial. And it is Jr., M and M, FOX and such who are gleefully writing the totally bogus next editions (I think the main stream press has caught on that the CRU Hack isn’t about climate science).

    I have had the opportunity to speak to many good reporters. Ones who really wanted to understand what I knew and what my opinion was. They constantly pointed out that what I was quoted saying often read the opposite of what I wanted to say. After a while I learned to adjust, though I still make sure I get all of my quotes to go over in a separate sitting than the interview to assure they read well.

    I want to make clear that I don’t think Dr. Cobb believes Dr. Jones or any other scientist has misrepresented or cooked or made up data, nor do I think she is embarrassed by them. But I don’t think her blog post was clearly written for the non-scientist.

    For what it’s worth my opinion of CRU Hack: emails are often equivalent to private, spoken, conversations. When viewed as this, the tone of the CRU emails is completely understandable. I don’t think there is anything to ask forgiveness over.

  16. 166

    unreasoning, unconditional opposition to nuclear power

    What, pray tell, is unreasoning and unconditional about energy scales that are mismatched by nearly 10 orders of decimal magnitude between states, or do you just have an appreciation and a desire for massive columnar defect damage and the outright sludge it creates that some of the rest of us don’t?

    That can hardly be deemed ‘direct energy conversion’ even independently of the severe cost, waste, proliferation and availability of fuel problems.

  17. 167
    J says:

    If anyone wonders why people believe IPCC-approved climate science is subjective, biased, closed-minded with a high degree of egotism and hubris combined with a political agenda, re-read the responses on this thread. You are your own worst enemy and it only takes common sense to know it’s perilous to place great trust in your results.

    Until and unless AGW is proven, this trust is essential, and you’ve lost it. This may not matter to you, but if you really believe society must take strong action, it is essential to that goal. The majority don’t believe you and they don’t trust you. You don’t behave like trustworthy scientists, or like trustworthy stewards of science, or anything else that matters. You behave like conceited schoolyard bullies who gang up on anyone who is not in the gang – because they’re not in the gang.

    If you can’t see this, you’re not going to change, and you won’t understand when it just gets worse.

  18. 168
    oakwood says:

    Great editorial by mike at the Washington Post.
    (Many of the comments were a bit rude though. Too bad)

  19. 169
    VG says:

    As a Skeptic I have to thank you now for your change of heart re allowing criticism of you AGW thesis based on C02. There is of course a great future in long term forecasting and it is needed (models etc) This is not a sarcastic comment. I hope you continue to prosper and advance this science.

  20. 170
    Bob says:

    Although I’ve found Jim Hansen to be very civil in personal correspondence, I can’t say I have ever found him to be objective on the topic of climate change. Santer is a product of CRU. Saying “Look over here, some scientists that aren’t Real Climate admins are exonerating us!” is very little like saying their opinions are objective or will somehow whitewash the unfortunate evidence of poor judgement that has come out of the pilfered emails. Further, I thought this was a science website? What I am seeing instead is a full blown rhetorical blitz here. Bluntly, the correspondence that has been revealed is just shameful. The suppression of dissent couldn’t be more plain, and this collage of scientists saying it doesn’t matter does your cause no credit. If the science is correct, stick with that.

  21. 171
    Completely Fed Up says:

    If anyone wants to know why people get the feeling they are being ignored just need to read J’s content-free rant in 167.

    J have you read this sites comments and noted the number of times the same bloody question gets asked again and again?

    Sometimes people are ridculed because they are ridiculous. Sometimes one side is just wrong. But the New Political Correctness that the rightwing spout all the time means that nobody’s views are ridiculous (unless it’s those damn liberals) and everybody’s right (unless you’re a damn liberal).

  22. 172


    Do a linear regression of the lower-48 temperature anomalies through time. I did. Want the figures since 1880? I’ve got ’em for you.

    Note, also, that the lower 48 is 1.5% of the Earth’s surface. Not really completely representative.

  23. 173
    Completely Fed Up says:

    Molnar is surprisingly unskeptical of skepticalscience. I don’t see any skeptical discussion of the model they’ve used and where it may be wrong and where they KNOW it’s wrong but don’t know which way nor how competing ideas are anulled.

    Not really skepticism.

    More like gullibility.

  24. 174
    Completely Fed Up says:

    “You acknowledge that CO2 contributes to warming but maintain it is natural. Are you now willing to admit that burning fossil fuels does not add CO2 to the atmosphere?”

    Has ZT answered this point yet?

  25. 175
    Jiminmpls says:

    #164 I didn’t say the 2009 brushfire in SE Australia was the worst ever. I said they had the hottest temps ever recorded. While “only” 200 people died in the brushfires, death rates in general soared and hundreds more (probably) died from the heat.

  26. 176

    SZ: Carbon dioxide contributes a small amount to the warming that began about 500 years ago when the climate began recovering from the Little Ice Age.

    BPL: The Little Ice Age lasted until 1850.

    SZ: Carbon dioxide contributes little to that trend.

    BPL: Look again:

    SZ: Furthermore, carbon dioxide alone will contribute little to future warming.

    BPL: Look again:

    SZ: Even the GCMs must invoke the spirit of positive feedback from water vapor and clouds to reach the heights of future temperatures that they predict. It seems to me that belief in those positive feedbacks is closely akin to a religious belief.

    BPL: Look again. The strongest feedback is from water vapor, and that has a clear physical theory behind it (the Clausius-Clapeyron Law) AND empirical verification:

    Brown, S., Desai, S., Keihm, S., and C. Ruf, 2007. “Ocean water vapor and cloud burden trends derived from the topex microwave radiometer.” Geoscience and Remote Sensing Symposium. Barcelona, Spain: IGARSS 2007, pp. 886-889.

    Dessler AE, Zhang Z, Yang P 2008. “Water-Vapor Climate Feedback Inferred from Climate Variations.” Geophys. Res. Lett. 35, L20704.

    Held, I.M. and B. J. Soden, 2000. “Water vapor feedback and global warming.” Annu. Rev. Energy Environ., 25, 441–475.

    Minschwaner, K., and A. E. Dessler, 2004. “Water vapor feedback in the tropical upper troposphere: Model results and observations.” J. Climate, 17, 1272–1282.

    Oltmans, S.J. and D.J. Hoffman, “Increase in Lower-Stratospheric Water Vapor at Mid-Latitude Northern Hemisphere Site from 1981-1994,” Nature, 374 (1995): 146-149.

    Philipona, R., B. Dürr, A. Ohmura, and C. Ruckstuhl 2005. “Anthropogenic greenhouse forcing and strong water vapor feedback increase temperature in Europe.” Geophys. Res. Lett., 32, L19809.

    Santer, B. D, C. Mears, F. J. Wentz, K. E. Taylor, P. J. Gleckler, T. M. L. Wigley, T. P. Barnett, J. S. Boyle, W. Bruggemann, N. P. Gillett, S. A. Klein, G. A. Meehl, T. Nozawa, D. W. Pierce, P. A. Stott, W. M. Washington, M. F. Wehner, 2007. “Identification of human-induced changes in atmospheric moisture content.” Proc. Natl. Acad. Sci., 104, 15248-15253.

    Soden, B.J., D. L. Jackson, V. Ramaswamy, M. D. Schwarzkopf, and X. Huang, 2005. “The radiative signature of upper tropospheric moistening.” Science, 310, 841–844.

  27. 177


    1. Science doesn’t prove things, it can only disprove things. It is inductive, not deductive. It depends on evidence, not armchair logic.

    2. The scientists at RealClimate do not behave like bullies. The ones behaving like bullies are the denialists who have slandered scientists, sued them, harassed them, stolen from them, and recently (Limbaugh and Breitbart) called for them to be executed.

    All: I’m drawing up a list of incidents of intimidation of climate scientists by the denialists. I’m up to 20. If you know of any, and have a complete reference, please send me the details. When I have a respectably-put-together list I’ll post it on my web site.

  28. 178
    Jim Eager says:

    Re J @167: “The majority don’t believe you and they don’t trust you.”

    And what “majority” would this be?

    “Public Opinion Stunner: WashPost-ABC Poll Finds Strong Support for Global Warming Reductions Despite Relentless Big Oil and Anti-Science Attacks

    Today’s new Washington Post-ABC News Poll demonstrates yet again that the American people want action to “regulate the release of greenhouse gases from sources like power plants, cars and factories in an effort to reduce global warming.” Respondents supported this statement by more than two to one (65 percent favor, 29 percent oppose). This poll was conducted December 10-13, at the height of the trumped up brouhaha over stolen emails from a British climate research institution. These findings are consistent with the Associated Press-Stanford University poll released on Tuesday.”

  29. 179
    Alan of Oz says:

    Tom @27, I have a degree in computer science and 20yrs commercial experience, as others have pointed out the code is available if you care to look. However OSS is not going to suddenly find some grave error that everyone has overlooked. The reason being that more than one code base is used to replicate the results, it’s like using many seperately written versions of grep and getting the same result with each.

    If it was a single monolithic block of code that all climate scientists relied on (like the operating system) then you might have a point but it’s not, it’s numerous independent source trees running on different O/S’s. I know of no better way to verify code, do you?

  30. 180
    tamino says:

    Re: #164 (bananabender)

    According to Special Climate Statement 17 from Australia’s Bureau of Meteorology, it was in 2009 that:

    Many all-time site records were also set in Victoria on 7 February, including Melbourne (154 years of record), where the temperature reached 46.4°C, far exceeding it’s previous all-time record of 45.6°C set on Black Friday (13 January) 1939. It was also a full 3.2°C above the previous February record, set in 1983. Three of Melbourne’s five hottest days have now occurred during this event.

    Have you been bending more than bananas?

  31. 181
    Ray Ladbury says:

    Oh, sweet baby Jeebus, another crybaby for anti-science! J, if you look at each individual exchange (with the newbies, not with the hard-core denialists), they start off quite civil. It is only when the poster starts repeating the same discredited denialist memes that they are dismissed as a troll.

    Perhaps you are new here. This website is here so people can learn about the SCIENCE. To the extent that people really are here to learn, they are welcome. Trolls are by definition ineducable and merely impede other peoples’ learning. That is why the reception they receive is less than cordial–well that and the fact that scientists don’t take kindly to gratuitous and unfounded accusations of fraud.

  32. 182
    Ray Ladbury says:

    Sandra Kay,
    The adjustments, the code and most of the data are all available.

    [edit – please feel free to offer pointers without editorialising]

  33. 183
    Alan of Oz says:

    bananabender @164: Sorry but it is you that is wrong not the person you replied to. First of all Black Friday (1939) killed 78 people compared to Black Saturday (2009) that killed 173. This is despite the fact we had bulldozers, airial water bombing, modern fire engines, satellite survailence, mains water, 100,000 fire-fighters and cars to flee the flames. None of which were available in 1939.

    Also the danger of bushfire weather can be quantified. The BOM uses a measure called the Forest Fire Index (FFI) to judge wether or not to declare a total fire ban. A FFI of 50 is extreme. Black Friday had an FFI=100, Ash Wednesday = 120, Black Saturday = 190. To paraphrase the Victorian fire-chief – “we don’t know what a FFI of 190 means, except to say it’s off the scale”.

    I drove thru kilmore on the night of the fire and I also witnessed Ash wednesday up close. Black Saturday had a smoke plume more 15km high it was more like Mt Pinabo than a forest fire. The radiant heat was leathal at 200 meters making the normal refuges of footy parks a death trap. What other bushfire have you encountered that burnt at 3000 deg C and melted the engine blocks of cars?

    I don’t know much of the top of my head about the 1852 fires you mention but I do know that 1852 was the start of the gold rush and Melbourne was little more than a shanty town carved out of the bush.

  34. 184
    Ray Ladbury says:

    ZT says, “It is kind of a slippery slope though to saying ‘we’ll just not plot the diverging information – it will only confuse the masses’ or ‘we’ll coordinate our reviewing to prevent a confusing messages appearing’, or ‘we’ll never hand over our data’. (as in other messages).”

    Again, you slip so easily into accusations. You seem to think that standards for scientific truth should be different when it is telling us something we don’t want to hear. That’s a recipe for self-delusion–but then that seems to be your ultimate goal. I am sure that your progeny will see your actions in a much clearer light.

  35. 185
    Guy says:

    Again, as I read this thread I see the “religious belief” fallacy invoked to taunt scientists and those who take notice to what they do. Does anyone have any idea of how to stop this particularly ludicrous accusation, that is little short of being an epidemic in public stupidity?

    What is especially telling about the taunt is that the reverse argument has a very strong case. As has been demonstrated time and again, contrarians / denialists have a faith-based position to begin with – “there is no such thing as AGW”, and their ground shifts from one fallacy to another to avoid dealing with the actual science. There is no logic in moving from “there is no warming” once that battle is lost, to “mankind is not responsible”, but that’s what consistently happened as arguments were lost. Now we’re back on “there is no warming” again, but in another couple of months when every inquiry reports that “climategate” does not change any of the data, the ground will shift again. Why? Because there is a faith-based position to begin with – “there is no AGW”.

    Science has no faith based positions. It gathers and examines data. It looks for flaws and makes adjustments, throwing out that which is found to be wrong. The process is obviously imperfect, but the contrast with the contrarians (not the incorrect label of skeptics, by the way) is stark.

  36. 186
    eric says:

    Thanks everyone for your thoughts. For some reason I think almost everyone has been (mostly) civil on this post. Perhaps it’s the holiday season. With holidays in mind, comments are now ‘off’. –eric