Saturday, June 20, 2009

Reviewing Pilmer ~ A geology giant gone off the rails on warming

David Karoly: Ian Plimer's new book Heaven + Earth claims to shed new light on the science of climate change. It states that 'human-induced global warming has evolved into a religious belief system', that 'atmospheric carbon dioxided does not create a temperature rise' and that 'global warming and a high CO2 content bring prosperity and lengthen your life'.

Are these claims justified and based on science? They are in marked contrast to the scientific understanding of the causes of recent climate change reported in the assessments of the Intergovernmental Panel on Climate Change (often referred to as the IPCC), as well as by other scientific bodies including the US National Academies, the British Royal Society and the Australian Academy of Science. They have all reached the same conclusion; that the observed increase in global-average surface temperature since the mid-20th century is mainly due to the increase in greenhouse gases in the atmosphere, caused by human activity.

Heaven + Earth claims that this conclusion and almost all the conclusions of the IPCC are wrong. It suggests that there is a conspiracy amongst climate scientists to hide the 'truth' and that the learned scientific societies of many countries have been hoodwinked. He implies that this conspiracy involves all the hundred-plus national governments that unanimously approved the conclusions of the IPCC assessments. Not surprisingly, the book has attracted attention from the media, politicians and some scientists, as well as the public. Nothing sells like a good conspiracy story.

But is this book the story of a conspiracy, or even a good read? Is it about science or is it science fiction? The book is impressive and possibly interesting, but very disappointing. Impressive because of the time and effort that must have been spent writing the 500 pages with 2,000-plus footnotes. Interesting because it seeks to link many aspects of geology, astronomy, biology, glaciology, oceanography and meteorology to explain climate change over the Earth's multi-billion-year history, including the last hundred years. It's disappointing because a senior professor should not have produced such a book with so many errors, so many internal inconsistencies, and with no sources for its graphs.

The average reader will find it difficult to sort the fact from the fiction, to disentangle the inconsistencies, and separate the personal opinions and interpretations of the author from the well-established science. The book is built around six sections that consider history, the Sun, earth, ice, water, and air. In these, 18 questions are considered, and many scientists would agree with some aspects of the answers presented. However, there are major errors in many of the answers, making the conclusions invalid. The best description of the problems with the book is provided by Plimer himself. He writes, 'Trying to deal with these misrepresentations is somewhat like trying to argue with creationists, who misquote, concoct evidence, quote out of context, ignore contrary evidence, and create evidence ex nihilo.'

There are some sensible things in Heaven + Earth. Yes, it is important to 'look at climate over geological, archaeological, historical and modern time'. Throughout Earth's history there have been natural climate variations driven by many factors, including variations in the Earth's orbit around the Sun, volcanic eruptions, tectonics, and changes in greenhouse gas concentrations. For most of Earth's history, global temperatures and carbon dioxide concentrations in the atmosphere have been higher than present. Plimer is wrong to claim that 'the IPCC has essentially ignored the role of natural climate variability', as natural climate variability is carefully considered in all four of the IPCC's comprehensive assessments since 1990. In its 2007 report, a whole chapter on palaeoclimate focuses on natural climate variations over Earth's history. Yes, water vapour is the most important greenhouse gas in the atmosphere. However, as Plimer states, 'Water vapour tends to follow temperature change rather than cause it,' so water vapour changes cannot initiate climate change.

Now let me address some of the major scientific flaws in Plimer's arguments. He claims 'it is not possible to ascribe a carbon dioxide increase to human activity' and 'volcanoes produce more CO2 than the world's cars and industries combined'. Both are wrong. Burning fossil fuels produces carbon dioxide enriched with carbon isotope 12C and reduced 13C and essentially no 14C, and it decreases atmospheric oxygen, exactly as observed and as Plimer states on pages 414 and 415. Scientists have estimated emissions from volcanoes on land for the last 50 years and they are small compared with total global emissions from human sources.

Plimer even argues that the recent sources must be underwater volcanoes. This is not the case, because the net movement of carbon dioxide is from the atmosphere to the ocean, based on measurements that the concentration of dissolved carbon dioxide in the ocean is less than in the atmosphere. In addition, measurements show that the concentrations of two other long-lived greenhouse gases with human-related sources, methane and nitrous oxide, have increased markedly over the last 200 years, at the same time as the increases in carbon dioxide. This is not possible due to sources from underwater volcanoes.

Next, he states that CO2 does not drive climate. He then contradicts himself by writing 'CO2 keeps our planet warm so that it is not covered in ice'. There is ample geological evidence of increased CO2 causing climate change, such as the Palaeocene-Eocene thermal maximum about 55 million years ago. He writes 'land and sea temperatures increased by five to ten degrees with associated extinctions of life' when methane was released into the atmosphere due to geological processes and rapidly converted to CO2.

Plimer writes repeatedly that global warming ended in 1998, that the warmth of the last few decades is not unusual, and that satellite measurements show there has been no global warming since 1979. He is correct that on time scales of the last 100 million years, the recent global-scale warmth is not unusual. However, it is unusual over at least the last 1,000 years, including the Medieval warming. Plimer makes the mistake of using local temperatures from proxy evidence rather than considering data from the whole globe at the same time. The report of the US National Academy of Sciences in 2006, cited by Plimer, states '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 AD 900.'

We do not expect significant warming to always occur for short periods, such as since 1998. Natural climate variations are more important over short periods, with El Nino causing hotter global-average temperatures in 1998 and La Nina cooler global temperatures in 2007 and 2008. Global-average temperature for the current decade from surface observations and from satellite data is warmer than any other decade with reasonable data coverage. Plimer is wrong to write 'Not one of the IPCC models predicted that there would be cooling after 1998'. Actually, more than one-fifth of climate models show cooling in global average temperatures for the period from 1998 to 2008.

Plimer writes that solar activity accounts for some 80% of the global temperature trend over the last 150 years. This doesn't fit the observational evidence. Increases in solar irradiance would cause more warming in the daytime, in the tropics and in summer, as well as warming in the upper atmosphere, and these are not observed. Changes in solar irradiance and cosmic rays show a large 11-year sunspot cycle and negligible trend, but observed global temperatures show a large warming trend and small 11-year cycle.

Plimer is wrong again when he writes 'An enrichment in atmospheric CO2 is not even a little bit bad for life on Earth. It is wholly beneficial.' This is contradicted when he writes that the Palaeocene-Eocene thermal maximum was associated with mass extinctions. There are many other errors, both large and small, including volcanoes emitting CFCs and that the Sun consists mainly of the same elements as the rocky planets. Many of the figures have mistakes, either in the caption or in the data, and have no sources provided.

Given the errors, the non-science, and the nonsense in this book, it should be classified as science fiction in any library that wastes its funds buying it. The book can then be placed on the shelves alongside Michael Crichton's State of Fear, another science fiction book about climate change with many footnotes. The only difference is that there are fewer scientific errors in State of Fear.

Robyn Williams: David Karoly is a Federation Fellow at the University of Melbourne. He was reviewing Ian Plimer's book Heaven + Earth, now in the bestseller lists.

http://mpegmedia.abc.net.au/rn/podcast/2009/06/ssw_20090613_1205.mp3

Robyn Williams: Ian Plimer's book Heaven and Earth has been high up in the bestseller list for three or four weeks now. His unswerving dismissal of climate change orthodoxy should come as a surprise to those of us in the general public who expect science to get its facts right, especially in matters which really count, because the stakes couldn't really be higher.


So what's going on? How could one of our best-known geologists, together with some of his like-minded colleagues, be so much at odds with all the leading journals, the academies and most of the specialists in climate studies? We've already had one review on this week in The Science Show about earth scientist Professor Malcolm Walter, and it can still be heard online.


Today, for Ockham's Razor, we have one of Australia's top scientists, whose job is to assess the merits of research across the nation.


Professor Kurt Lambeck is president of the Australian Academy of Science.


Kurt Lambeck: I'm an earth scientist whose research is directed at the interactions between the solid earth, the oceans, ice sheets and atmosphere. And this research is directed not merely to interpret the geological record, but to distinguish between cause and effect, and to understand what may happen when natural and anthropogenic forces clash. In recent years my research has been on sea level change from millions of years to recent times. And this has included geological field work in Australia, Europe, Antarctica, Greenland, amongst other areas, and has given me some insight into at least this one aspect of climate change.


I believe this allows me to conclude that Heaven and Earth is not a work of science, it is an opinion of an author who happens to be a scientist.


There is no dispute that the geological record shows that climate change has occurred throughout the earth's history. The dispute is over whether the modern record can be understood in terms of the natural background processes or whether there is a new human factor that changes the rules about climate change.


To address this requires more than geological insight. It requires an understanding of the underlying physical, chemical and biological processes and an ability to model them so as to test alternative hypotheses. To say that geology is the only way to integrate all aspects of the environment is like saying that physicists and chemists should not get involved in biology. How can I take this advice seriously when I see other geologists proclaim with equal conviction, that the record points to imminent planetary doom because of human action?


No single discipline is equipped to handle the complex problems of climate change. Probably nowhere is it more important for the disciplines to come together than in understanding how the components of the solid earth, the oceans, atmosphere and ice sheets, feed off each other and interact in their response to internal and external forcing mechanisms. No single institution and certainly no single individual can do this alone. The problem is simply too complex and this is why processes such as the IPCC are important.


I have been part of the IPCC process and I know that's it's not a perfect one. In seeking consensus, extremes are filtered out. What happens to non-consensus views is that they get tested in the peer-reviewed literature, and if the hypothesis stands up to this probing, it becomes incorporated in subsequent analyses. If it fails to stand up, it will be ignored by the scientific community until new evidence comes to light.


Thus an important part of the synthesis process is that it is an iterative one and if one looks at the successive assessments, one can identify shifts and critiques that have led over time, to improvements in the understanding of climate change.


It is important to recognise that scientists are not consensus animals. We are all driven by our own demons: the satisfaction of being able to understand a particularly complex question, a desire to use science to improve the human condition; a search for recognition and fame and the next Nobel prize or a search for notoriety in the public gallery. Thus the concept that hundreds of researchers are conspiring to defraud the world's policy-makers requires a level of conspiracy theory that not even Dan Brown has reached.


Professor Plimer has said that Heaven and Earth is not written for the scientists but for the general public. This is an important objective but it is not an excuse for sloppy science or for the misrepresentation of science. I focus here on the section on sea level, because in his public discussions he has extensively used this to argue that all change is 'natural'.


If this had been written by an honours student, I would have failed it with the comment: You have obviously trawled through a lot of material but the critical analysis is missing. Supporting arguments and unsupported arguments in the literature are not distinguished or properly referenced, and you have left the impression that you have not developed an understanding of the processes involved. Rewrite!


I would then identify a number of specific issues which, while in isolation could be seen as minor, collectively indicate carelessness at best, and at worst an attempt to undermine the integrity of the science case. Here are just a few examples.


There is geological evidence that suggests that the Earth has gone through extreme glacial episodes in the distant past. Plimer states that change from extreme glacial to extreme warm conditions occurred within a few centuries. Whether this is correct or not is a legitimate point of debate. But further on, he states that to raise sea level by 4 to 6 metres from the melting of West Antarctica, in the near future, is Hollywood fantasy. That may well be true. But there is no consistency in his argument. If at one time the planet can exit from near-global glaciation conditions in a few hundred years, then why can a comparatively minor adjustment of the West Antarctica ice sheet not occur on the same time scale? Is it a case of seeing only what you want to see?


Plimer uses the example of ocean floor doming and sea floor volcanism to illustrate geological processes that have modified sea level. He states that during such events monstrous amounts of heat are released into the oceans and that huge volumes of water are displaced, causing sea level to rise. If I use his example of a 1000km x 1000km plateau raised by 1 kilometre, the volume of displaced water is about one million cubic kilometres, which when distributed over the oceans brings sea level up by about 3 metres. But the formation of these plateaux occur on a time scale of a million years and longer, and the associated rate of change is only of the order say, .03 millimetres per year, and this is about 100 times less than the rates observed today. Likewise, Plimer's monstrous amounts of heat released into the oceans do not produce a measurable global signal on the human time scale.


Much research has gone into modelling those kinds of earth deformation in order to understand the long-term, sea-level effects, and realistic order of magnitude estimates can be made. While impressive when viewed on the geological time scales, changes of 100-200 metres over 1 to 100 million years, imply rates of change that are insignificant when compared with the modern record of sea level change.


None of this research is referred to. Instead, he states that models for present sea level rise do not take them into consideration. The peer-reviewed scientific debate is extensive and combative, but there is an accepted conclusion that modern sea level rise, corrected for the geological background signals, can only be explained by a major contribution from thermal expansion of the oceans and from melting of mountain glaciers, and that both of these changes are consistent with the observed and modelled temperature changes during the past century.


Much is made in the book of the difficulty in reaching a reliable assessment of the modern sea-level rise from the instrumental record. From my own work, I agree that the analysis is difficult and not without pitfalls and that in the past different conclusions have been reached because some of these pitfalls were not recognised. But with time these have been addressed, new data has been identified, and analysis methods have improved. To argue therefore that because there are discrepancies with superseded results we cannot believe any of the results is to take a strange view of the process of science. There is in fact a quite remarkable convergence of the interpretation of the observational evidence of what has been happening to sea level in the past 100 or so years. This points to an increase in the globally averaged rates by a factor of about 2, and this is consistent with what is expected from the climate models that include both natural and anthropogenic forcing. None of this is discussed in the book.


To give his arguments a semblance of respectability the book is replete with references. But the choice is very selective. Plimer will quote, for example, a paper that appears to support his argument, but then he does not mention that the conclusions therein have been completely refuted in subsequent papers. Elsewhere, he refers to a specific question raised in published work but does not mention that this issue has subsequently been resolved, has been incorporated in subsequent analyses, and is no longer relevant. Or he simply misquotes the work or takes it out of context. An example of this is a reference to my own in the Mediterranean where he gives quite a misleading twist to what we actually concluded.


Other examples can be identified in this section, and throughout the book. Together they point to either carelessness, to a lack of understanding of the underlying science, or to an attempt to see the world through tinted spectacles.


But why do I really care? There is no doubt that climate change has occurred from the time the planet first acquired its atmosphere. What we also learn from the geological record is that the planet's 'mood' swings are finely balanced: that the shift from one state to another can be sudden on the geological timescales. For the last million years it has swung between major glaciations and the more temperate periods like today within which homo sapiens has made its home.


Our understanding of these cycles is of a delicate balance between external forcing, in this case solar insolation caused by variations in the geometry of the earth's orbit and its rotation axis, and complex feedback mechanisms involving the oceans, ice sheets and biological and surface processes. The present climate system shows all the hallmarks of an unstable system tenuously held under control by the astronomical forcing and perturbed at intervals by other forcing such as the injection of volcanic dust and gases into the atmosphere.


We also have a good understanding of the basic physics and chemistry of the atmosphere and oceans and of the nature of the various feedback mechanisms. What we have learned is that the changes of the past 100 years cannot be quantitatively expressed by natural processes alone. Only the addition of greenhouse gases lead to a satisfactory explanation of what has been observed and all the recent results are showing that the changes in temperature, in sea level, and in ocean acidification are tracking near the upper levels of the IPCC forecasts. This is a matter for concern whose underpinning science needs to be debated.


For us, the questions are: can 9-billion people in 2050 survive if there is a global disruption of our climate during this century? Do the costs of such disruption exceed the short-term costs of implementing technologies and practices that lead to a stabilisation of greenhouse gas emissions? How can the technologies and changes in lifestyle be implemented without causing their own disruptions?


The science community has the responsibility to provide the best evidence to help our policymakers reach conclusions that are founded in science, that are based on our best current understanding. This is in the interests of society as a whole, not only of particular interest groups. Spreading confusion through poorly argued science does not help in addressing this question.


Robyn Williams: Professor Kurt Lambeck is President of the Australian Academy of Science, and as you heard, an earth scientist. The book he was discussing is Heaven and Earth by Ian Plimer, who's now based at the University of Adelaide.


Next week, a talk about Memes, those genes of the mind, by Don Tinkler from Melbourne.


I'm Robyn Williams.

http://www.abc.net.au/rn/ockhamsrazor/stories/2009/2589206.htm#transcript

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