Comments on: Ian Plimer on the Science Show

By: Stu

Stu — Tue, 11 Aug 2009 11:30:23 +0000

Les, this post is not about Plimer's book, it was written two years ago, well before the book was published (in fact I didn't even know then that he was writing one). It is also not about a TV program. It is in response to claims made by Plimer in a radio program, as given in the transcript (linked in the post). More recently I have written some posts about the book. I have not written a review or rebuttal (since I haven't read his book), rather I have chiefly just commented on the press coverage, however I have also linked to a number of other websites containing detailed reviews and rebuttals which clearly show that it is not simply an editing issue. The most relevant post would be Details of Heaven and Earth, and the numerous links therein. Also Geological Timescales and the Effects of Climate Change and the follow-up More Reactions to the SMH Piece. I will be particularly interested to see how Plimer answers these questions from George Monbiot.

By: Les Cook

Les Cook — Mon, 10 Aug 2009 08:31:24 +0000

I have just read Plimer’s book. It was clearly rushed to print and needed better editing, but it is still an impressive review of a large area of scientific research (over 2300 references, mostly to peer reviewed articles in respectable journals. I am an (ex) physicist and computer modeller and feel comfortable evaluating research papers. I arrived at this site looking for a rebuttal of the book, but I have not yet found anything rigorous enough to be convincing. I would welcome references to such material if it based on the content of the book, not a lay description in a TV program.

By: Philip Machanick

Philip Machanick — Thu, 23 Jul 2009 10:11:28 +0000

I debunked some claims that evidently were based on Plimer’s book at Australian prime minister Kven Rudd's blog, and repeated the main ones at my personal blog. Since I haven’t read the book, I’m ready to be corrected but since no one has so far, I assume the person I was correcting was quoting correctly from the book. I'd appreciate it if someone who has read the book would mosey over to Opinionations and let me know if the comments I quoted are an accurate representation of the book. If so, it's pretty shocking; this is stuff someone has quoted to support their argument that climate change is a hoax and made a right fool of themselves.

By: Stu

Stu — Sat, 18 Apr 2009 02:46:42 +0000

My point was that it was disingenuous to suggest that the cooling during that period was unexplained when there is a standard explanation for it. Perhaps the standard explanation is wrong, but if Plimer had good reason to believe this why pretend that there is no explanation? I take issue with the description of Real Climate as a "shoddy web page". I was addressing the point that climate scientists supposedly do not bother explaining various historical changes in climate. I linked to a blog run by climate scientists, in particular a post by a chemist who studies the effect of aerosols on climate. I feel that this is an appropriate response. The evidence that you ask for was not really the point in this case, as it wasn't the details of the explanation for the mid-century cooling that was brought into question, rather it was its very existence. I demonstrated that climate scientists do indeed have an explanation for this and various other features of the historical climate. The diagram in the real climate post (from the IPCC AR4) is of particular interest, it shows the relative impact of various forcings on the climate. This shows the way to go if you do want to see the evidence - the IPCC AR4. This report summarises a huge effort that has gone into explaining how the climate is determined by various factors and distinguish anthropogenic effects from natural ones. Chapter 9 on Understanding and Attributing Climate Change is of particular interest. Section 9.2 on Radiative Forcing and Climate Response has a subsection 9.2.3 Implications for Understanding 20th Century Climate Change. Section 9.4 is on Understanding Air Temperature Change During the Industrial Era. The effect of aerosols is well understood. Volcanic eruptions have shown and quantified the cooling effect they have. Also their chemical properties can be studied, by observation in the lab, and by analysis of their molecular structure. The cooling effect of aerosols is not in any way controversial, neither is the fact that lots more of them were put into the atmosphere by industrial activity in the mid 20th Century, and that they decreased after pollution controls were introduced in the 1970's. Using the basic science of aerosols, greenhouse gases and other forcings (as shown in the linked diagram) climate scientists make models of the climate. They test them by hindcasting, i.e., run the models with historical forcings as input and compare outputs with historical data. Doing this, the aerosol induced cooling is replicated in the models. Another feature is that the post 1970's warming is not shown without the forcing provided by greenhouse gases. A historical perspective on how these ideas were developed is given by Spencer Weart in his book The Discovery of Global Warming, particularly the sections on aerosols and the modern temperature trend. One final point, you are right that there is no proof that aerosols caused the mid-century cooling. There is also no proof of Newton's Laws of motion, Darwin's theory of evolution (as creationists like to point out), the Germ Theory of Disease (popular with Chiropractors), Einstein's theory of relativity (most physics cranks) or any other scientific theory. Proofs belong to mathematics, not science. There is however an abundance of evidence which is the best you can hope for in science.

By: R2D2

R2D2 — Fri, 17 Apr 2009 04:45:00 +0000

“The 1940-76 decrease is explained by the effect of particles from industrial pollution reflecting sunlight back into space”

You state this as if it is a proven fact, then reference a shoddy web page. Do you have any evidence for this?

I think the point about explanation of natural variation is important. Regardless of the magnitude, the climate has always experienced natural variation. It must be experiencing some level of natural variation today.

Today the aim is to measure anthropogenic global warming, the hypothesis is this is significant and positive and the null is that this is zero.

The first task is then to remove natural warming from the last centaury, and then to place a confidence interval on anthropogenic warming in order to reject the null.

We therefore need to understand natural climate change before we can prove the existence of anthropogenic global warming, until then it is only a theory.

By: Dylan Nicholson

Dylan Nicholson — Tue, 17 Jul 2007 06:29:36 +0000

Hi, Stu

I was actually planning to write an article about Ian’s views myself…looks like you’ve done 90% of the work though.

I’m currently attempting to assess his claim that there is little consensus among geologists re AGW, via an e-mail survey of geologists currently working in Australia. So far he’s right, but admittedly I’ve only had 6 replies!

I’d also like to clarify what his concern about CO2 release from earthquakes really is, and determine his exact connection to the IPA.

By: C. Allen

C. Allen — Sun, 15 Jul 2007 00:08:23 +0000

Kind of makes you wonder about the legitimacy of any work that Professor Plimer has ever engaged in doesn’t it. I mean, setting aside for a moment the particular topic under discussion, the thought processes and methodologies he uses don’t really resemble anything most scientists would consider to be legitimately part of the scientific method. Sad really.

By: Brian Bahnisch

Brian Bahnisch — Mon, 09 Jul 2007 13:47:13 +0000

Great post. I followed you here from Quiggin’s.

If you don’t mind me saying so, I think you are being kind to Plimer. To me it seems clear that he hasn’t really gotten his head into the issue of AGW.