BOM’s Dr Ayers, Ian Plimer, or famed climatologist Cardinal Pell: who do you believe?

In The Senate Estimates Committee 21 February 2011


CHAIR—Dr Ayers, we are all waiting with great anticipation to hear your statement in relation to Cardinal  Pell. Would you like to make that statement now?

Dr Ayers—The issue from my point of view and why I sought leave to respond is that the cardinal has, in terms  of  the  letter  we  incorporated  in  Hansard,  made  a  number  of  propositions  about  aspects  of  climate  science that I have feel should  not remain unanswered  on the public record in this  place. I would  have been happy to have responded directly to the cardinal but he has not approached me and I am not aware that he has spoken with any others in the climate science community. I thought it was important to respond.   The difficulty with the assertions made in the cardinal’s letter is that they are based not upon contention in the  climate  science  field  but  on  a  book  written  by  Professor  Plimer  entitled  Heaven  and  Earth—Global  Warming: The  Missing Science.  The  contents  of  the  book  are  simply  not  scientific.  I  am  concerned  that  the cardinal has been misled by the contents of this book and I do not think it should stand on the public record for that reason.

Why would I say this book is not science? It is not me who says it so much, although I have read it myself;  it  has  been  widely  reviewed  by  people  in  the  scientific  arena  and  it  has  been  very  heavily  criticised  for  not presenting science but presenting a polemic from one individual. It has not been scientifically peer reviewed. I would like to step you through each of the assertions in Cardinal Pell’s letter. The cardinal I do not anticipate would be an expert in these fields of science, so he has quoted very heavily from this book and the book is, frankly, misleading to all Australians in terms of what it represents.

I will read you once scientific review to give you a sense of what one scientist from the University of New South Wales said about the book. He said: “Plimer has done an enormous disservice to science, and the dedicated scientists who are trying to understand climate and the influence of humans, by publishing this book. It is not “merely” atmospheric scientists that would have to be wrong for Plimer to be right. It would require a rewriting of biology, geology, physics, oceanography, astronomy and statistics. Plimer’s book deserves to languish on the shelves along with similar pseudo-science such as the writings of Immanuel Velikovsky and Erich von Daniken.”

That is from Professor Michael Ashley from the University of New South Wales. That is very strong, I am sure you will agree. I have read the book myself and it contains phrases that had nothing to do with science. There is  a  somewhat  gratuitous  attack  on  Chancellor Angela  Merkel  on  page  441,  the  same  page  essentially  that contains a gratuitous attack on Minister Wong. Page 470—

Senator IAN MACDONALD—That does not make the book—

Dr Ayers—No, the point is, Senator, that it is  not science. The book says that it is Global Warming: The Missing Science. Were it science, that would be fine. To quote Professor Ashley again: “The book is largely a collection of contrarian ideas and conspiracy theories that are rife in the blogosphere. The writing is
rambling and repetitive; the arguments flawed and illogical.”

Senator IAN MACDONALD—But Dr Ayers—

CHAIR—Senator Macdonald, Dr Ayers is  making a statement. You can ask questions after  he  makes the

Senator IAN MACDONALD—We are on limited time. It is additional estimates. In Cardinal Pell’s case, he did a written response, which we tabled. I wonder whether it might not be more appropriate for Dr Ayers to do a written response which can be tabled. I can assure Dr Ayers that I will be making sure his comments are passed on not only to Cardinal Pell, but also to Professor Plimer who says these same sorts of things about the people you are quoting.

CHAIR—Senator Macdonald, I do not want you to enter into the argument. I know where you are coming from.  My  position—and  our  rule—is  that  Dr Ayers  can  put  his  statement  on  Hansard.  He  does  not  need  to write it; he is prepared to put it on Hansard now, and it is on Hansard.

Senator IAN MACDONALD—You said that we have a limited time. How long is the statement likely to  be?

CHAIR—I am prepared to have it put on—

Senator IAN MACDONALD—The rest of us want to ask questions.

CHAIR—Senator Macdonald, you have had plenty of time to ask questions. You are the one wasting my
time  now.  I think  that  you should let Dr Ayers  go on. Dr Ayers, how long  do  you think the statement  might

Senator BOSWELL—Mr Chairman, I am very happy for Professor Ayers to make the statement, but I do think we should give the same opportunity to Dr Plimer. You have got every right to criticise him, but I think he has a right to defend himself in the same forum. So if you are going to—

CHAIR—I do not know whether it is appropriate for Dr Plimer to be before estimates. 

Senator BOSWELL—It is just as appropriate—

CHAIR—Dr Ayers, how long do you think it will take?

Dr Ayers—It would probably take between five and 10 minutes.

CHAIR—I think that we should continue.

Senator IAN MACDONALD—Being aware that I will send it to Dr Plimer and ask him to write a written response to incorporate.

CHAIR—Very good. 

Dr Ayers—Just responding to Senator Macdonald, I will be making contact directly with the cardinal after these estimates. As  I said at the  outset, from  my  point  of  view  I am  disappointed that I was  not  having this discussion with him directly. I am very happy to do that.

Senator IAN MACDONALD—His letter is dated July—that was seven months ago.

CHAIR—Dr Ayers,  I  would  ask  you  not  to  engage  directly  with  Senator  Macdonald.  That  will  lead  us down  a  blind  alley,  I  can  assure  you.  I  am  saying  that  you  should  make your  statement  and  then  Senator Macdonald can ask you questions.

Dr Ayers—Chair,  my  proposition  here  is  that  there  are  about  half  a  dozen  assertions  in  the  letter  and  I would like to respond to each one, if I may. First of all, I should just say that a critique of Professor Plimer’s book is available. There is another university professor, named Ian Enting, at the University of Melbourne and if  you  put  ‘Enting’  and  ‘Plimer’  into  a search  engine  you  will  come  up  with  a  55-page  document  detailing mistakes,  misunderstandings  and  misrepresentations.  That  is  available  and  I  will  be  sending  that  to  the
cardinal. Everybody who wants to dig into an analysis of the book can do that.

On  the  first  thing,  the  Roman  warming,  Professor  Plimer  asserts  that  the  temperatures  during  that  period were two degrees to six degrees warmer than today. If you go through the book, there is not a single scientific reference in the book that makes that statement. It is an assertion without any scientific evidence. The example of a book by Lamb, published in 2007, is about as close as you get. The strongest statement in that says: By late Roman times, particularly the fourth century AD, it may well have been warmer than now— Now being the mid-1970s when the book was written. In fact, we know the earth was a little warmer. So there is no cogent evidence being provided at all for that statement. I have no idea—

Senator IAN MACDONALD—East Anglia University—

Dr Ayers—I have no idea where the two degrees to six degrees comes from. I will heed the chair’s advice. What is interesting about that is that there were things like assertions that grapes were grown in England and that the two  degrees to six  degrees  would support that.  Grapes are grown in England today. There are  more than 400 vineyards. That sort of level evidence is not science; it is anecdote. If Professor Plimer has time he should publish it in a scientific journal and then we can have it level. That is that: there just is not any evidence
in the book.

If we move on to the medieval warm period, he references a study of 6,000 bore holes. These are holes in rock  where  the  temperature  diffuses  down  and  with  a  mathematical  technique  called  inversion  you  can reconstruct what the past temperatures would have been based on thermal diffusion. The reference appears to come  from  an  article  by  Professor  Wally  Broecker,  a  renowned  oceanographer,  written  in  2001.  Professor Plimer does not quote Professor Broecker’s conclusion, which is: “The case for a global medieval warming period admittedly remains inconclusive.” So that does not support it. What Professor Plimer then does is take one of the references from this book and refers to a 1997 paper by an author list led by someone named Wang. What is interesting about that is that the same authors in 2008 published a subsequent paper which says, in fact, that you cannot use their first paper for
the purpose. They say: “The results of our earlier paper cannot be used for comparing the medieval warm period to warmth in the 20th century.” Which is exactly what Professor Plimer does. This paper was available in 2008, a year before he published his book.  He  has  used  a  paper  that  the  authors  themselves  say  cannot  be  used  in  a  particular  way.  That  is  not

A second thing to do with the medieval warm period is on page 66, where he says: Bore holes give accurate temperature histories for a thousand years into the past … Northern Hemisphere bore hole data shows the medieval warm period and the cooling of 2 degrees from the end of the Little Ice Age. When you go and look at the scientific paper—which you assume is about bore holes, Northern Hemisphere, medieval warm period—you discover the paper is actually not about bore holes but about an ice core; it is not taken in the Northern Hemisphere, it is from the Antarctic; and it is for the period 10,000 years to 20,000 years ago, not the Roman warm period. That level of getting references wrong is not science. So the book does not provide evidence about the medieval warm period or the Roman warm period.

The  cardinal  in  his  letter  says  that  he  has  metadata  analysis—that  is,  an  analysis  that  sits  above  all  the papers that are random reviews—but he just cannot find it. That’s okay. If he can find it I would be happy to look  at  it.  I  know  of  three  metadata  analyses,  though.  One  of  them  is  in  the  Intergovernmental  Panel  on Climate  Change Working Group I report from the Fourth Assessment Report. It answers all these questions. However, there are those who feel that the IPCC is somehow biased, so they would not use it. At the time it was being written in 2006, the US National Academy of Science carried out an independent review and wrote a report entitled, Surface temperature reconstructions for the last 2,000 years, because there were those  who said the IPCC  process was not robust. So we have an independent report from the National Academy of Science. Their conclusion is:

•  It  can  be  said  with  a  high  level  of  confidence  that  global  mean  surface  temperature  was  higher  during  the  last  few decades of the 20th century than during any comparable period during the preceding four centuries. 

They go on to say:

• Less confidence can be placed in large-scale surface temperature reconstructions for the period from A.D. 900 to 1600. 

The medieval warm period is in there. Presently  available  proxy  evidence  indicates  that  temperatures  at  many,  but  not  all,  individual  locations  were  higher during the past 25 years than during any period of comparable length since A.D. 900.  The Roman  warm period  was 250 BC to 450 AD. So they  do  not support it. That is two  metadata analyses. They were both available to Professor Plimer. They are not mentioned in the book. So it is not a fair review of the  scientific  literature. 

The  final  point  I  will  make  is  that  the  US  EPA,  in  December  2009,  published  the administrator’s  results  on  the ‘endangerment’  and  ‘cause  or  contribute’  findings  for  greenhouse  gases  under section 202(a) of the Clean Air Act. This was a process in which the Administrator of the EPA made a finding that the current and projected concentrations of six well-mixed greenhouse gases in the atmosphere threatened the  public  health  and  welfare  of  current  and  future  generations.  I  will  not  go  into  the  ‘cause  or  contribute’ finding, but the point was that there was a profoundly careful review. They had a 60-day consultation period for  public  comment, and 380,000 public comments were taken in. They all included  the statements  made in Professor Plimer’s book that have unfortunately misled Cardinal Pell. Not one of them was supported. So there are three metadata reviews—from the IPCC, from the National Academy of Sciences and from the US EPA—
that do not support the propositions that are being put.

I will move on to carbon dioxide, where Professor Plimer has brought to the attention of anybody who reads the book—and Cardinal Pell has picked it up—that 90,000 measurements of CO2 were done over the last 150 years by a particular method. He contrasted those with the carbon dioxide record from Mauna Loa in Hawaii, which  from  the  fifties  has  documented  the  increase  in  human  activities.  It  looks  as  though  that  is  a  fair comparison, but it is not. It is actually verging on disingenuous. The fact is there are 150 stations measuring CO2  worldwide,  110  of  which  meet  the  standards  such  that  the  annual  analysis  done  by  the  World Meteorological  Organisation’s  World  Data  Centre  for  Greenhouse  Gases  uses  those  to  describe  CO2
everywhere. You simply cannot, if you pay attention to all the data available, reach the conclusion that CO2 levels were higher in any other period in time.

Professor Plimer does not mention that in 1986 all the old data that were collected over the last 150 years were  reviewed  in  a  paper  by  Fraser  et  al.  I  can  give  you  the  citation  if  you  like.  The  issue  here  is  that,  in Australia, we have, at Cape Grim in Tasmania, one of those 110 high-quality baseline stations measuring CO2. If you look at that and if you look at the work done in the Antarctic Division on ice cores and firn, which is the loose layers of snow that compact down at about 80 metres—air has been extracted all the way down from the present down into the past, through the firn layer and into the ice cores, back 2,000 years—there is absolutely no possibility that the global CO2 levels were 400 parts per million last century. It is just implausible. Yet, on the basis of 90,000 measurements from a paper by a fellow named Beck, that is the conclusion put in the book and that is the conclusion picked up by Cardinal Pell.

Professor Plimer also did  not cite the fact that, during the year after the Beck paper came out, there  were two rebuttals published in the same journal pointing out the errors in it. They were not referred to. So there is  very selective use of data the whole way along. The Australian scientists who have worked on the carbon cycle include those working in Canberra at one of the two international offices of the Global Carbon Project, where on an annual basis CO2 levels are reviewed, the carbon cycle is reviewed and the budget of carbon going into the atmosphere, the oceans and the land surface is all reviewed and published. It is not in this book because, if it were in the book, the conclusions that are in the book could not be reached.

So what I am going to suggest to Cardinal Pell in due course is that he comes with me and visits a range of climate change science establishments in Australia and has a look at the science directly, not through this book but through the lens of what men and women in Australia are doing in scientific institutions that is valid, that is published and that has real credibility. My contention is that Cardinal Pell may well become an ambassador for the quality of climate change science if he is exposed to the quality of the science that is done. That is my aspiration. He  can  make  his  own  decision about whether the science says what  Professor Plimer says, but  I think he will become an ambassador for the quality  of the science we  do in this country. It is absolutely  not honoured by this book.

I know these are strong statements but I am the  head of a national agency and the information that is out there is not adequate based on what I know. So I am taking my job seriously and making a strong statement.

There are some other things in Cardinal Pell’s letter that I will not go into because I can see people’s eyes will start to glaze over. I will just make two other comments. At one stage he lists greenhouse gases. Included in the list is the gas nitrogen. That is not a greenhouse gas; it is 78 per cent of the atmosphere. You cannot have people out there telling the public that nitrogen is a greenhouse gas, because it is not.

The final point I will make is on the statement from Professor Plimer that CO2 from fossil fuels accounts for 0.1 per cent of the greenhouse effect. There is a parameter called climate sensitivity. It is the temperature increase you would get if you doubled CO2. The conventional view, which is very well attested to in scientific literature, is that it is about two or three  degrees. That is roughly it. At equilibrium, when  everything comes into balance, that is what the temperature of the Earth would go up by. Professor Plimer says that is not right; he says it is only half a degree. At least, he says that in one part of his book. In another part he says that it is 1½ degrees. So he is not consistent with himself. You can do a very simple calculation. Professor Enting—the guy who has done the 55 pages collecting problems with Professor Plimer’s book—shows you how to do the calculation. You can compute the change from 280 parts per million pre the industrial age to 385 now. Using
Professor Plimer’s climate sensitivity, it would increase temperature by 0.23 degrees. We have seen about 0.7, but  he  has  put  his  sensitivity  below  that.  If  0.23  degrees  is  only  1.1  per  cent  or one  thousandth  of  the greenhouse effect, it implies that the  greenhouse effect is 223 degrees and without it our planet would be as
cold as the outer planets. So the calculations in this book are just erroneous. I will give up at this stage. There is plenty more I could go on with, but I will not.

CHAIR—Dr Ayers, thanks for taking the time to take us through those issues. So you are going to convert the cardinal and make him a missionary for climate change?
Dr Ayers—No. In fact, I think that—

Senator Ian Macdonald—Who suggested to you that you might read this out tonight, Dr Ayers?

Dr Ayers—Nobody. As I said, I felt that it needed to be in the Hansard.

Senator Ian Macdonald—Yes, I am quite sure it should have been, but a written response would have been equally as good because unfortunately Professor Plimer, should he choose to respond, can only put in a written response. He cannot make the commentary that you have made.

Dr Ayers—I am happy for Professor Plimer to write to me.

Senator Ian Macdonald—No, it needs to be done here. This is the trouble. The chair has allowed this to happen. This is going to go on forever now.

Senator SIEWERT—You were allowed table that letter last time.

Senator Ian Macdonald—But that is tabling. I agree with that. He should have been able to table a reply. I agree with that. Professor Plimer will not be able to come and talk to the committee.

Senator LUDLAM—He can publish another work of science fiction

CHAIR—Order!  I  am  not  going  to  have  a  debate  taking  place  across  the  chair.  If  you  want  to  ask  any questions  of  Dr Ayers  on  what  he  has  just  said,  I  think  it  is  perfectly  appropriate  to  ask  them  now.  Senator Macdonald, I invite you to ask any questions you have of Dr Ayers on what he has just put.

Source: Hansard.

Report of the above: Cardinal’s climate change views flawed, says BoM director

The head of the Bureau of Meteorology has rebuked Cardinal George Pell for his scepticism about climate change, insisting the cardinal has been misled, reports the Sydney Morning Herald.

Sydney’s Cardinal Pell is an outspoken disbeliever in man-made global warming, arguing that it was hotter during the Middle Ages and carbon dioxide levels are not historically high.

Bureau director Greg Ayers used an appearance at a Senate estimates hearing yesterday to criticise the cardinal’s personal views.

He said the core of his arguments were based on a book by Australian scientist Ian Plimer called Heaven and Earth: Global Warming the Missing Science