A surprising letter in The Canberra Times print edition of Saturday 4 July:

I thank Matt Andrews, of Aranda, for sharing with the people of Canberra his great wealth of knowledge concerning climate change.

It is clear to readers of his authoritative letters that he is a detached academic with many letters after his name, unlike those who simply regurgitate read material or merely express an opinion.

Along with Crispin Hull I feel for him on his nightly agonising about those exploiting scientific illiterates who disapprove of current climate science.

Bob Edwards, Kambah

Well, my thanks go out to Bob Edwards for this unexpected praise.

However, I should point out that I’m neither an academic nor do I have any letters after my name… I’m just an interested bystander.  I’d dearly like to devote my time to the study and practice of climate science, but for now I’m merely a humble web developer with an occasional bee in the bonnet.

An amusing follow-up letter arrived in the Tuesday 7 July print edition:

Bob Edwards (Letters, July 4) condemns himself and proves a point that climate scientists (the sceptical ones) keep trying to make.  When he pours adulation on to Matt Andrews (and Crispin Hull) for their alarmist views on climate change and then uses derogatory language to belittle and ridicule those with another view, he is not contributing to the debate but defending religious dogma.

Aert Driessen, McKellar

Fairly standard denier tactics: try to frame the mainstream science as “alarmist” (or “religion”) and to give the impression that there are two substantial sides to the scientific debate.  Sadly this perception is a long, long way from where the science actually is.

Given the strength of the evidence for anthropogenic global warming in general, this is now essentially the same as a tobacco lobbyist describing the suggestion that cigarettes cause cancer as “alarmist”, or an anti-vaccination crusader damning the conclusion that vaccination can be effective against disease as “religious dogma”.

A letter from John McKerral in The Canberra Times print edition of Thursday 25 June 2009:

Crispin Hull (“Problem’s not in the climate science, it’s all in the mind”, Forum, June 20, p15) has fallen into the typical alarmist’s behaviour: attacking the character of any organisation or person who has a different opinion on the subject to his own.

Science does not operate that way.

The theories and observations supporting them are what counts, not the character of the person putting them forward.

But it is so easy to attack someone’s character.

As he is so fond of science, he should consider that the alarmist scientists have destroyed their own theory.

They and their models predict that if the warming that we have experienced is caused by greenhouse gases (GHG), there should be a hot spot about eight to 12 kilometres above the tropics.

That is to say the warming there should have been at a rate 1.5 to 3 times the rate of warming at the surface in that area.

50 years of weather balloon and thirty years of satellite data has not shown this to be so.

In fact it is the other way around, the near surface temperature increase has been between 1.2 and 1.4 times that of the supposed hot spot.

Also the Earth Radiation Budget Experiment Satellite has shown that the outgoing long wave radiation has diminished by only 1/7 of that predicted by the computer climate models and this fails to support the GHG theory.

That radiation is supposed be absorbed by the GHGs on its way to space thus diminishing the outward radiation.

It is not and that is another nail in the coffin of that theory.

Under normal circumstances that should have finished the GHG causes global warming/climate change theory. However this is zombie science, you can’t kill it.

Governments keep pouring money into it thereby keeping it going.  The climate has always changed without man’s help and will continue to do so.  So-called deniers do not disbelieve that the climate is changing.

What they do deny is that man has a major influence in the process.

It might be to Crispin’s benefit to do some research on the subject!

John McKerral, Batemans Bay, NSW

I sent this response to The Canberra Times, published in the 2 July print edition:

According to John McKerral (Letters, 25 June), the entire body of scientific evidence for human-caused global warming is invalid, and “alarmist scientists have destroyed their own theory”.  This bold claim is apparently proven by two rather lightweight quibbles over climate models.

The first, that the upper troposphere has warmed more slowly than the surface, was a favourite for several years among those trying to deny the scientific consensus, until it was shown in 2005 that the data involved included instrumental errors – such as sunlight warming instruments carried on balloons – that had not been properly accounted for.  While there are still some small discrepancies between climate model projections and warming over the tropics, they fall within the expected range of error and do not even remotely constitute a flaw in the mainstream science.

The second complaint, that the drop in outgoing long-wave radiation was not as much as predicted, was raised in late March by Richard Lindzen, a prominent denier (and recipient of funding from oil companies).  Unfortunately Lindzen neglected to mention that the graphs he was citing were out of date, containing data with significant instrumental errors (including the slow loss of altitude of the satellite’s orbit) which had not been properly corrected.  The updated graphs do not support his argument at all.

It’s disturbing that our society’s general level of scientific literacy is so low that these kinds of issues can be interpreted as constituting a disproof of current climate science. The big picture is that the evidence from a wide range of sources overwhelmingly supports the conclusion that human activities are the primary cause of  current global warming.    Our lack of scientific literacy is exploited by those who are actively seeking to delay or reduce action on global warming.  History will not judge them kindly.

Matt Andrews, Aranda

Three letters doubting global warming appeared in The Canberra Times print edition on Tuesday 23 June 2009.

A letter from Tom Waring mainly asks about uncertainties:

Crispin Hull (“Problem’s not in the climate science, it’s all in the mind”, Forum, June 20, p15) scoffed at Senator Fielding accepting religious myth while rejecting climate science.

But Hull could have gone the other way. He could have observed that religious irrationality demonstrates humanity’s propensity for mass hysteria.

He could have noted science is often part of sustained errors of conventional wisdom, and allowed the possibility that the scientific underpinnings for imminent climate Armageddon could be more human hubris. For example, does science really know what caused the many hundreds of climate oscillations of the known past?

Was their atmospheric CO2 cause or effect? What stopped them? Were they all really just (poorly-understood) cycles in the earth’s orbit?

When is the next cyclical ice-age due? Do we fully understand cloud formation? Won’t whatever caused (and ended) them happen again? Now?

Some agnosticism seems respectable.

Tom Waring, Ainslie

Aert Driessen wrote about CO2 lagging temperature:

Tony Kevin (Letter, June 18) uses a lot of words to show a correlation between fluctuating CO2 and fluctuating temperature from ice core data over the last 800,000 years, which is true, but what he has omitted to add is that close examination of that correlation shows that temperature changes happen before CO2 changes, by up to 800 years.  That is to say, CO2 fluctuations are the result (and not the cause) of temperature variations.

For those of us that learnt in school that CO2 is more soluble in cold water than in warm water (not really intuitive) that relationship between the variables makes sense when you consider that beer goes flat when it gets warm.

Aert Driessen, McKellar

And a brief piece from Owen Reid:

Instead of ridiculing the man (Steve Fielding), and his Christian faith, perhaps Crispin Hull (“Problem’s not in the climate science, it’s all in the mind”, Forum, June 20, p15) should be asking why the questions put to Minister for Climate Change Penny Wong, have not been answered.

Owen Reid, Dunlop

I responded to Aert Driessen with a letter to the editor, published on Friday 26 June:

Aert Driessen (Letters, 23 June) correctly points out that, in most of the global warming events during the last 650,000 years,  CO2 began to increase around 800 years after temperature started to rise.  However, he then concludes that CO2 fluctuations are the result, not the cause, of temperature changes.

This is a common misunderstanding. The reality is that CO2 is not simply the cause or the result of warming – it is both. CO2 and temperature are influenced by many factors.   Warming events over the last 650,000 years have followed a clear pattern.  Changes in the Earth’s orbit around the Sun (known as Milankovitch cycles) slowly warm the planet.  This warming triggers increases in CO2  and other greenhouse gases in the atmosphere, which cause further warming, and so on in a positive feedback cycle until a new equilibrium at a higher  temperature and CO2 level is reached.  These positive feedbacks – due to ice loss reducing albedo, the melting of permafrost, and other processes – are potential “tipping points” that are among the most worrying aspects of the current warming.

So CO2 has acted as an amplifier of other climatic influences.  In recent times, we’ve accelerated and short-circuited that process by pumping extra CO2 directly into the atmosphere.  As a result, we’re seeing  temperatures rising five times faster, and CO2 increasing around fifty times faster, than during past natural warming events at the end of ice ages.

This – the unprecedented speed of the change – is one of the core dangers of the current global warming to human society.  The ecosystems on which we rely have never had to deal with anything like the rate of change in climate that we’re now causing.  It is increasingly looking as if the “safe” level of CO2 is no more than 350 parts per million.  We are already at 380 ppm – a higher CO2 level than humans have ever experienced.  That’s why the currently proposed Carbon Pollution Reduction Scheme, with its target of a mere 5% reduction in emissions by 2020, is utterly inadequate.   We now need to move rapidly beyond 100% reduction into an economy which produces a net lowering of CO2 and other greenhouse gases.

Here’s an opinion article that appeared on page 11 of the June 16 print edition of The Canberra Times, by Des Moore, director of the Institute for Private Enterprise.

Below it is my rebuttal, sent as a Letter to the Editor.  Unfortunately The Canberra Times doesn’t put all its content online yet, so I can’t just link to the original article. Here it is in full:

Politics in debate on climate change

The visit by Family First Senator Fielding to New York to attend the third conference on climate change by the Heartland Institute, and to speak to White House staff with whom he left graphs and tables, has attracted much attention.

Given the importance of his vote on the Government’s legislation to control emissions of carbon dioxide, he was invited on to the ABC’s Insiders program last Sunday.

In this interview Fielding was asked why he did not accept “the conclusion of the United Nations panel, representing thousands of scientists [who had] studied the issue for years, and concluded that man-made carbon emissions are the major cause of global warming”.

Fielding gave two responses.

He indicated, first, that he was told that in the States “there’s thousands of scientists that have a different view”.

And, second, he said that he had been presented with “information that showed that over the last decade or so carbon emissions have been going up, but global temperature hasn’t”.

Fielding has exposed the Government’s failure to hold an independent inquiry into the science used in Intergovernmental Panel on Climate Change reports. Although those reports were based on contributions from about 800 scientists, that does not make them indisputable.

There is a long history of similar claims of climatic change/environmental threats by scientists that have turned out to be totally false.

As Fielding said, there are moreover many expert scientists (and others) who reject the IPCC science but have been ignored by the Government and, overseas, by the United Nations too.

The Senator could also have added that an examination of the history  of temperature changes indicates that, over the 158 years for which instrumental records have been kept in Britain, there were 117 years years in which the global average temperature was either stable or falling and only 41 years in which it was increasing.

That is, it is not simply the last decade in which temperatures failed to increase.

That also happened during the industrialisation period from 1850-1920 and again from 1940 to 1976.

Yet the thesis that humanity faces the threat of dangerously rising temperatures is based on the view that increasing temperatures will occur in line with increases in emissions of greenhouse gases.

But such emissions did increase over the whole of this period.

So why didn’t temperatures also rise at the same time?

It is impossible to have any confidence in the need for a policy of reducing emissions on the basis of this analysis.

Some believers in the IPCC analysis provide possible explanations of the failure of temperatures to increase over the period since industrialisation started.

They suggest this may reflect influences that interrupted the forces of radiation, such as aerosols in the sky blocking the rays.

But such explanations do not stand up once it is realised that temperatures were also higher than now in the Medieval Warm period (from about 800-1100 AD) and the Greco-Roman Warm Period (250 to 0 BC).

These earlier warm periods were, in fact, recognised by the IPCC in its first and second reports but were omitted in the third report because of the prominence given to another thesis.

However, when that thesis was proved incorrect, and dropped from the next IPCC report, the earlier warming periods were not restored.

These and other changes in the science used by the IPCC reinforce Senator Fielding’s case for an independent inquiry.

They also highlight the fact that the IPCC reports are not pure science: political beliefs have influenced their conclusions too.

Des Moore is director of the Institute for Private Enterprise.

I sent this response as a Letter to the Editor:

Des Moore (“Politics in debate on climate change”, 16 June, p11) tries to perform a public service by recycling, but ends up doing us a disservice: the arguments he’s recycling have been comprehensively debunked over and over.

The big polluters, and their proxies, continue to trot out this stuff as part of a general media strategy to generate a false sense of doubt and uncertainty over climate science.  The tobacco lobby played exactly the same game, internally using the slogan “Doubt is our product”.  Holocaust deniers and anti-evolutionists have used similar tactics, as a desperate measure when they have no sound scientific arguments left.

Moore quotes Senator Fielding as saying that “over the last decade or so” carbon emissions have been going up, but global temperature hasn’t.  This is based on the widely repeated myth that “the earth has been cooling since 1998″ – an extraordinarily hot year due to the strongest El Niño in a century. If you pick this spike as a starting point, and carefully limit the data, you can produce a graph that appearsto show cooling.  However, if you start at, say, 1997 or 1999 instead, it shows unmistakeable warming.  This is called “cherry picking” of the data. Climate is all about longer term trends, and there’s been a warming trend since around 1920.  It has accelerated since around 1970, and over the last decade the long term trend is still definitely one of warming.

Moore then says that during the periods 1850-1920 and 1940-1976 emissions rose but temperatures didn’t.  He acknowledges just one of the reasons for this – high levels of sulphate aerosols in the atmosphere – and then, nonsensically, claims that this explanation somehow fails because there were some warm periods hundreds of years ago.  In reality, CO2 has only become the dominant factor in warming since around 1970.  Before this its effects were reduced by other factors such as variations in solar intensity, volcanic eruptions and sulphate aerosol pollution.

He then goes on to attempt to undermine the IPCC’s scientific credibility because earlier warm periods changed in the way they were presented in IPCC reports, ignoring the real explanation: as more and more source data relating to temperatures in these times was being published, as new data and improved analysis were being incorporated into the science, the summary information about these periods changed accordingly.

Moore finishes off by claiming that politics has influenced IPCC conclusions, and that they are not pure science.  In a way this is true, but not in the way he intends.  The IPCC has a decision-making system based on full consensus, meaning that recalcitrant parties like the US, Saudi Arabia and others were able to have the scientific summaries in the IPCC reports reduced to the most conservative and scientifically unassailable versions possible.  The science has moved on substantially since the last IPCC report: it’s now becoming clear that the safety limit for CO2 is probably closer to 350 parts per million, rather than the 450 or 550 that was considered reasonable earlier.  Given that we are already at 387ppm, we need to be aiming for net negative emissions as soon as possible.  That means much more robust and meaningful action than the currently proposed, and completely inadequate, Carbon Pollution Reduction Scheme.

Matt Andrews, Aranda

Des Moore (“Politics in debate on climate change”, 16 June, p11) tries to perform a public service by recycling, but ends up doing us a disservice: the arguments he’s recycling have been comprehensively debunked over and over.

The big polluters, and their proxies, continue to trot out this stuff as part of a general media strategy to generate a false sense of doubt and uncertainty over climate science.  The tobacco lobby played exactly the same game, internally using the slogan “Doubt is our product”.  Holocaust deniers and anti-evolutionists have used similar tactics, as a desperate measure when they have no sound scientific arguments left.

Moore quotes Senator Fielding as saying that “over the last decade or so” carbon emissions have been going up, but global temperature hasn’t.  This is based on the widely repeated myth that “the earth has been cooling since 1998″ – an extraordinarily hot year due to the strongest El Niño in a century. If you pick this spike as a starting point, and carefully limit the data, you can produce a graph that appearsto show cooling.  However, if you start at, say, 1997 or 1999 instead, it shows unmistakeable warming.  This is called “cherry picking” of the data. Climate is all about longer term trends, and there’s been a warming trend since around 1920.  It has accelerated since around 1970, and over the last decade the long term trend is still definitely one of warming.

Moore then says that during the periods 1850-1920 and 1940-1976 emissions rose but temperatures didn’t.  He acknowledges just one of the reasons for this – high levels of sulphate aerosols in the atmosphere – and then, nonsensically, claims that this explanation somehow fails because there were some warm periods hundreds of years ago.  In reality, CO2 has only become the dominant factor in warming since around 1970.  Before this its effects were reduced by other factors such as variations in solar intensity, volcanic eruptions and sulphate aerosol pollution.

He then goes on to attempt to undermine the IPCC’s scientific credibility because earlier warm periods changed in the way they were presented in IPCC reports, ignoring the real explanation: as more and more source data relating to temperatures in these times was being published, as new data and improved analysis were being incorporated into the science, the summary information about these periods changed accordingly.

Moore finishes off by claiming that politics has influenced IPCC conclusions, and that they are not pure science.  In a way this is true, but not in the way he intends.  The IPCC has a decision-making system based on full consensus, meaning that recalcitrant parties like the US, Saudi Arabia and others were able to have the scientific summaries in the IPCC reports reduced to the most conservative and scientifically unassailable versions possible.  The science has moved on substantially since the last IPCC report: it’s now becoming clear that the safety limit for CO2 is probably closer to 350 parts per million, rather than the 450 or 550 that was considered reasonable earlier.  Given that we are already at 387ppm, we need to be aiming for net negative emissions as soon as possible.  That means much more robust and meaningful action than the currently proposed, and completely inadequate, Carbon Pollution Reduction Scheme.

More slow motion tennis (i.e. serve in Monday’s paper, return arrives three days later, response a week after that… I have a nostalgic affection for the printed newspaper as a medium, but sheesh!) on climate change in The Canberra Times.

This letter appeared on 11 June:

Australian National University scientist Will Steffen (“Fielding draws fire for doubting global warming”, June 9, p4) responds to Senator Steve Fielding’s doubts about the connection between carbon dioxide and climate change by stating that warming in the last half century is “incontrovertible”.

He neglects to state also that there has been cooling since 1998, despite increasing carbon dioxide emissions.

It’s not surprising that Fielding and others remain unconvinced.

Fielding needs to be reminded that continuing carbon dioxide emissions are lowering the pH of seawater, and threatening the myriads of marine organisms with a calcium carbonate skeleton, including reef corals. This major threat to the marine environment is a matter of straightforward chemistry which Fielding, an engineer, should understand.

Its reality has been demonstrated by experiments and field studies on marine organisms, and it remains a threat regardless of climate change.

Max Brown, Mawson

I sent this response, published on June 17:

Max Brown (Letters, 11 June) points out the real dangers in ocean acidification because of CO2 buildup, but then unfortunately recycles the well-worn myth that the world has been cooling since 1998 – an unusually hot year due to a strong El Niño effect.

Those who seek to spread doubt about global warming typically pick 1998 as their starting point, and with some careful selection of sources and a little torturing of the data can produce a graph that looks like cooling.  But if you start at, say, 1997 or 1999 instead, the house of cards falls down – it shows strong warming.

Climate is all about long term trends, not short term effects such as last year’s La Niña.

Short answer: the long term trend since 1998 is still definitely one of warming.  See bit.ly/1998myth for more details.

This is a collection of scientific assessments and commentaries on Heaven and Earth: Global Warming: The Missing Science, a book by Ian Plimer which attempts to deny that human activities are responsible for potentially dangerous climate change.

Kurt Lambeck, earth scientist and president of the Australian Academy of Science, comments on ABC Radio National’s “Ockham’s Razor” about Heaven and Earth.  Audio with transcript. (Short link: bit.ly/klambeckplimer )

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.

Climate scientist Barry Brook has a page of notes on Heaven and Earth, including links to other commentaries.  (Short link: tinyurl.com/plimer )

Ian Plimer’s book is a case study in how not to be objective. Decide on your position from the outset, and then seek out all the facts that apparently support your case, and discard or ignore all of those that contravene it. He quotes a couple of thousand peer-reviewed scientific papers when mounting specific arguments. What Ian doesn’t say is that the vast majority of these authors have considered the totality of evidence on the topic of human-induced global warming and conclude that it is real and a problem.

[I]t may well be held up as an example for the future. An example of just how deluded and misrepresentative the psuedo-sceptical war against science really was in the first decade of the 21st century.

Mathematician Ian Enting has produced Ian Plimer’s ‘Heaven + Earth’—Checking the Claims, a 31-page document listing the errors and problems in Heaven and Earth. (Short link: bit.ly/entingplimer )

Overall:

• it has numerous internal inconsistencies;

• it often misrepresents the operation of the IPCC and the content of IPCC reports;

• in spite of the extensive referencing, key data are unattributed and the content of references is often mis-quoted.

Most importantly, Ian Plimer fails to establish his claim that the human influence on climate can be ignored, relative to natural variations.

Earth scientist Andrew Glikson responds with Plimer wants to talk science? OK, here goes… in Crikey (Short link: bit.ly/gliksonplimer )

Plimer’s book claims current global warming is a natural event consistent with climate variability through time and attributed primarily to the sun.

The book negates the well documented consistent relations between climate and carbon gases, which through the Earth’s history resulted in temperature changes in the range of several degrees C , including abrupt climate changes and related mass extinction of species .

Climate scientist David Karoly reviews Heaven and Earth (audio with transcript):

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.

No science in Plimer’s primer by astronomer Michael Ashley in The Australian. (Short link:  bit.ly/ashleyplimer )

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.

The science is missing from Ian Plimer’s “Heaven and Earth” by computer scientist and climate change commentator Tim Lambert.  (Short link:  bit.ly/tlambertplimer )

He accepts any factoid that supports his conclusion and rejects any evidence that contradicts his conclusion.

A review by geologist and planetary scientist Malcolm Walter on The Science Show, ABC Radio National.  Audio. (Short link: bit.ly/walterplimer )

He has done a disservice to science and the community at large.

Mike Pope does a nice job at Online Opinion of debunking Plimer’s central claims in Heaven, Earth and science fiction, concluding:

To avoid following the polar bear to extinction, homo sapiens would do well to reject the science fiction espoused by Plimer. That may be a bit harsh on science fiction writers whose work is often prescient, even plausible. No such claims can be made for Ian Plimer’s book.

Short link for this post: bit.ly/plimer

I thought I’d document a thread of discussion on climate change in the Letters to the Editor pages of The Canberra Times over the last few weeks.

We begin with a letter published on May 11:

I believe in climate change – it is with us every day and despite their best efforts and supercomputers, our meteorologists struggle to provide worthwhile forecasts of these changes for more than a few days ahead.

Can those who predict global warming because of rising carbon dioxide levels really have better data and models than our meteorologists, or do they have another agenda in making forecasts for decades ahead, and with no probability qualifications regarding the likelihood of these possible extreme outcomes?

As an engineer with some grasp of physics, complex systems, and so on, my understanding is that modelling the climate and making credible forecasts is very complex indeed, and depends on continual refinement of the modes, taking into account the observed climate parameters.  Thus, the recent obsession with a trace gas, such as carbon dioxide, as the driver of global warming is difficult to accept as a sound scientific judgement; it is not even the major greenhouse gas.

The other major flaw in the claim that carbon dioxide is the cause of global warming is the inconvenient trust that for nearly three decades of the 20th century, the Earth cooled, while carbon dioxide levels continued to rise.  It would therefore seem that the hypothesis is wrong, and that factors other than atmospheric carbon dioxide levels are more important in driving climate/temperature changes.

A second inconvenient truth is that the forecasts by the International Panel on Climate Change in 2000 of continuing rising temperatures have proved to be incorrect; carbon dioxide levels continue to rise, but temperatures are falling. Thus, I continue to be amazed at the claims of the fundamentalist doomsayers on global warming who ignore the above and either focus on micro events or simply strive to outbid their fellow travellers with more and more extreme and alarmist forecasts of the end of life as we know it, unless we reduce carbon dioxide levels.

Are there no climate scientists out there with open minds and a commitment to scientific honesty? The recent publication of Heaven and Earth by Professor Ian Plimer, which I am struggling through, provides extensive evidence that the hypothesis that rising carbon dioxide levels lead to global warming is simply not true.

He also makes the interesting observation that rising temperatures usually result in higher carbon dioxide levels and correlate well with periods of better than average crops and food production, which support population growth and rapid development of civilisation.

On the other hand, he portrays the ice ages as rather miserable periods in the history of mankind. I would hope that future debate on this subject focuses on the evidence presented by Plimer and not on the individual, as some recent comments have done.

Michael Sage, Weetangera

My reply appeared in the May 13 edition:

Michael Sage (Letters, 11 May) asks where the climate researchers with open minds are.  The simple answer is that they are to be found in CSIRO, the Hadley Centre, the National Oceanic and Atmospheric Administration, all over the world in their thousands.

They devote their working lives to understanding and improving climate science, studying the enormous and ever-increasing data involved.  It overwhelmingly supports that global warming is a reality, and that it’s entering a very dangerous stage indeed.

Michael cites Ian Plimer repeatedly; a little investigation will reveal comprehensive descriptions of the extraordinary number of serious errors, omissions, and misrepresentations in Plimer’s work. Other writers in the same vein have similarly been exposed as deeply erroneous and at times apparently fraudulent. I strongly recommend putting Plimer’s shameful book aside and doing some independent investigation into the big picture.

For instance, a little non-partisan exploration will reveal that mainstream climate science does not in fact regard CO2 as the only greenhouse gas.  It will also show that the IPCC predictions have not actually been proved incorrect at all (current temperatures are well within the 95% confidence band of prediction).  Every other criticism raised by Plimer and others has been comprehensively answered, and these answers are easily available.

It’s sad to see that many who question global warming do so with little apparent knowledge of what mainstream climate science is saying, and what the supporting evidence is, rather than simply accepting the highly distorted picture presented by a few.

Read some real climate scientists first: get Barry Pittock’s recent book, or take a look at websites such as realclimate.org where climate scientists write about these issues.

Matt Andrews, Aranda

There was another reply published on the same day:

Michael Sage (Letters, May 11) asks how meteorologists can forecast global warming decades ahead when they can’t reliably predict the weather in a few days time.

They can do this in the same way that they can reliably tell you it will be warmer in January then now, but not how hot it will be in a fortnight, or what the average annual rainfall in Canberra is likely to be 2010-20, but not whether December will be wet or dry.

Almost all series of natural and social phenomena involve being able reliably to discern fundamental long-term trends or probabilities, but not being able to predict random short-term fluctuations.

Sage’s contention that climate scientists make global warming forecasts with no probabilities attached is puzzling because the IPCC conclusions on this are made with probabilities. For instance, it publishes a range for the likely increase in global temperatures with probabilities, not one figure. In fact the global consensus that has been reached on global warming, after decades of completely open scientific debate by thousands of scientists in many areas, is not that it is a certainty, but that it is a risk, even a small degree of which makes mitigation action worthwhile.

It is those whose apparent view is that anthropogenic global warming simply cannot be a problem requiring action, who seem to be attached to certainties rather than to probabilities and a rational insurance approach to risk-minimisation.

Paul Pollard, O’Connor

On 15 May Michael Sage replied:

Matt Andrews and Paul Pollard (Letters, May 13) are clearly committed to the view that global warming is real, poses risks to our future and that the science is solid.

Nevertheless, there is no attempt to answer my question (Letters, May 11) regarding the explanation for the fall in global temperatures for nearly three decades in the mid-20th century, while carbon dioxide levels continued to rise.

This inconvenient truth would seem to undermine the theory that rising carbon dioxide levels drive global warming.

I am yet to see any attempt to explain this anomaly, let alone a rational and compelling argument in support of the theory.

If, as Andrews claims, the answers are easily available, why has nobody produced them for examination?

Andrews also suggests that I cited Ian Plimer repeatedly, which I think is something of an overstatement, given a couple of general references.

The interesting situation regarding Plimer’s Heaven and Earth is that it has attracted much criticism in general (Andrews calls it shameful), but no one has offered any detailed rebuttal of even two or three of his central claims.

Andrews also acknowledges that carbon dioxide is not the only greenhouse gas; I agree it’s not even a major one.

Pollard seems to take an each-way bet on climate prediction, suggesting that summer is likely to be hotter than winter, but little else can be predicted with confidence.

He also concedes that global warming is not certain, but is a risk worth consideration.

I tend to agree with these moderate views. It is the translation from risk to certainty and then to massive overreaction that is of concern. There are countless examples of simple, scientific solutions leading to unwelcome, unintended consequences.

We would all benefit from a debate based on evidence, not on generalities and personal criticism.

Michael Sage, Weetangera

We then had two responses on May 18:

Matt Andrews (Letters, May 13) must surely have been referring to Al Gore’s Inconvenient Truth, not Ian Plimer’s Heaven and Earth, when he wrote that a little investigation will reveal comprehensive descriptions of the extraordinary number of serious errors, omissions, and misrepresentations. A British court ruled that Gore’s work could not be shown in schools unless eleven inaccuracies were specifically drawn to the attention of children.

Andrews urged people to read some real climate scientists at websites such as realclimate.org, the blog started by Dr Michael Mann and his colleagues.

Mann was the lead author of the infamous Hockey Stick study that was the poster child of the IPCC’s Third Assessment Report, but was subsequently discredited and unceremoniously dumped from the Fourth Assessment Report.

The Hockey Stick pretended to show that the modern warm period was unprecedented by rewriting history to remove the Medieval Warm Period and the Little Ice Age that followed.

In the very next letter, Paul Pollard wrote that meteorologists could predict the climate in a few decades’ time in the same way as they could predict that January will be warmer than now.

We know that weather varies on fairly predictable daily and annual cycles, but we also know that it varies on irregular decadal cycles that we can’t predict or explain.

We’ve seen in the last decade or so that whatever is responsible for these cycles is able to swamp any relatively minor anthropogenic influence on climate. Global warming might be a reality, but its certainly far from simple.

D. Zivkovic, Aranda

… and …

Michael Sage (Letters, May 15), the reason for the ”cooling” in the middle of last century is readily available. It only went on for about seven years, and then there was a period of relative stability for two decades.

The cause was man-made aerosols. These particles reflect sunlight, thereby cooling the planet if they are in the atmosphere. There was surge in the production of these particles during and in the recovery from World War II.

The downside of these particles is that they cause acid rain, which is why they are no longer acceptable.

Aerosols have the largest responsibility in masking temperature rises during the middle of the last century. Fortunately, aerosols have a relatively short lifetime in the atmosphere.

Carbon dioxide, on the other hand, remains in the atmosphere for centuries. That it has such a long stable lifetime, and the fact that the warming it causes is cumulative, are the reasons for targeting carbon dioxide so strongly, even though there are stronger greenhouse gases.

Venus is a rather Earth-like planet, but it has huge concentrations of carbon dioxide in its atmosphere and a surface temperature many hundreds of degrees above the Earth’s.

Earth’s current climate is very different from that when it was formed, and is the result of millennia of tiny organisms producing oxygen as a waste product. To think that organisms (humans) are incapable of causing planet-wide changes is thus folly.

You’d do better to not rely on the writings of a man whose arguments had been repeatedly debunked before he gathered them together in a book, which is sad as that is the exact behaviour he condemns in creationists.

Arved von Brasch, Aranda

My reply was published on 21 May:

D. Zivkovic (Letters, May 18) tries to dismiss Al Gore’s An Inconvenient Truth because a British court found some inaccuracies.

However, Zivkovic fails to mention that the court also acknowledged that Gore’s central thesis that climate change is mainly attributable to man-made emissions of greenhouse gases was completely sound and was strongly backed up by peer-reviewed science.

Ian Plimer’s Heaven and Earth has yet to be subjected to judicial analysis, but the scientific response to the book has been devastating.

Several detailed assessments are available online (see http://tinyurl.com/plimer as a starting point), but this observation from climate scientist Barry Brook sums it up nicely: ”Ian Plimer’s book is a case study in how not to be objective. Decide on your position from the outset, and then seek out all the facts that apparently support your case, and discard or ignore all of those that contravene it.”

Global warming is not a certainty; in a complex system like climate it’s all about the balance of probabilities.

The trouble is that the impacts of global warming are potentially so severe that, even if there was only 10 per cent risk of a rise of over two degrees this century, it would warrant massive precautionary efforts to avoid the risk.

Matt Andrews, Aranda

This thread basically died off at that point, and another began on 29 May, reacting to a statistic given in a green-energy article:

Fiona Wain (“Industries and jobs need climate action now”, May 28, p23) has the atmospheric concentration of CO2 wrong. It is 387 parts per million by volume (ppmv) not 455 as she claims.  It is increasing by about 2ppmv a year, mostly through natural causes. Man contributes between 1 per cent and 3 per cent of that increase.  Man’s CO2 contribution causes about 0.2 per cent of the greenhouse effect. Could Wain possibly have a vested interest?

John McKerral, Batemans Bay

My reply was printed on 3 June:

John McKerral (Letters, 29 May) states that current CO2 levels are 387 parts per million, rising by 2 ppm each year, which is perfectly correct. However, he also claims that only 1 to 3 percent of the rise is due to human causes, which is completely wrong.

The source is probably an infamous howler of a paper in 2006 by couple of petroleum engineers named Khilyuk and Chilingar, which tried to minimise human-caused emissions by comparing them against the cumulative total of billions of years of natural emissions.  Amazingly, this meaningless figure is repeated uncritically by Ian Plimer in his recent Heaven and Earth, a widely debunked anti-science book which contains dozens of fundamental errors, omissions and misleading statements. In reality, human activities are responsible for almost all of the current rate of increase in CO2.

This is comprehensively demonstrated by mainstream climate science – the details are easy to find if you’re prepared to take a few minutes to search for them.

Matt Andrews, Aranda

A reply appeared on 6 June:

Matt Andrews (Letters, June 3) rightly corrects the claim in a previous letter that only 1-3 per cent of atmospheric CO2 is due to human causes, and points out the origin of the claim.However, he falls into the trap in the warmists v the sceptics dialogue by making a list of possible errors and omissions in one version of the sceptic argument without addressing any of them. He assures a few minutes on the internet will furnish the evidence.

I think this greatly diminishes the scientific argument for either case.

If someone makes a claim they should give the evidence in the letter, not lazily refer the reader to a search of the internet where verification is difficult, often not possible, and to many not understandable.

My fear is government decisions will skirt around the scientific evidence for and against the magnitude of increased CO2 impacts, with policy statements continuing to be determined by lobby groups using similar unsupported comment.

Joe Walker

On 6 June I emailed the Canberra Times a response (not yet published):

Joe Walker (Letters, June 6) rightly pulls me up for not including a direct source clarifying the extent to which human activities are causing the rise in CO2 emissions.  As the Intergovernmental Panel on Climate Change (bit.ly/ipccwg1) says, “the primary source of the increased atmospheric concentration of carbon dioxide since the pre-industrial period results from fossil fuel use, with land-use change providing another significant but smaller contribution.”  A good introduction to the big picture of global carbon flows can be found at bit.ly/humanco2 (New Scientist).

Joe also protests that I did not include any specific details of the errors, omissions and misleading statements in geologist Ian Plimer’s book “Heaven and Earth”.  I didn’t attempt it here, because the number and depth of the book’s spectacular flaws are such that it’s impossible to do it justice in just 250 words. One review is at bit.ly/klambeckplimer (by Kurt Lambeck, president of the Australian Academy of Science), another is at tinyurl.com/plimer (by climate scientist Barry Brook), and at bit.ly/plimer I have listed a number of other detailed commentaries. It would be useful if the Canberra Times website allowed comments (with links) on letters.

I share Joe’s concern that the current national government climate policy appears to be based on unsupported assertions.  The proposed Carbon Pollution Reduction Scheme has a target of only 5% reduction in emissions by 2020 – far weaker than the action which current science indicates is necessary.  The CPRS as proposed appears to have been rendered almost completely ineffective by the government’s caving in to the demands of polluters: free permits, exemptions and other flaws mean that big polluters would start off paying an effective carbon price of just 50 cents per tonne of CO2.  A price closer to $40 per tonne is probably needed to start making significant shifts in the economy towards renewable energy.  Even if the free permits and other flaws were removed, a cap-and-trade system with a weak target is probably worse than useless, by locking in a dangerously inadequate framework while allowing the government to pretend it is taking effective action.  Fortunately this “Continue Polluting Regardless Scheme” is now politically dead, and hopefully a more responsible, evidence-based and sensible policy will quickly emerge from the ashes.

This is exciting. A neat solution – in one hit – to the major problems (as I was referring to earlier) with hydrogen cars: the huge cost of generation, storage, distribution, and filling-station infrastructure; the poor safety, high weight, and low energy density of stored hydrogen gas; and the lack of an environmentally positive way of liberating the hydrogen in the first place.

New Scientist reported recently on a system developed by Tareq Abu-Hamed, of the University of Minnesota, and colleagues at the Weizmann Institute of Science in Israel. The key ingredient is boron.

No need for a hydrogen filling station – in this system, you liberate the hydrogen on demand, in the car itself. To have the equivalent energy storage of a 40-litre petrol tank, your hydrogen car will have:

• a 45-litre tank of water;
• three 6-kilogram removable packs of boron powder.

When you start the car, water is heated (with either battery power or using a small amount of stored hydrogen) and reacted with boron powder. This produces hydrogen gas and boron oxide powder. The hydrogen is combusted to drive the car (and heat the water, and generate electricity to charge the battery, run the headlights, and all those other little things). The combustion of the hydrogen produces water vapour, which is captured back into the water tank. The boron oxide powder is stored in removable packs.

When the boron is nearly used up, you go to your local garage (or supermarket, or fast food joint, or whatever), take out your packs of boron oxide, and exchange them for packs with fresh boron powder. The boron exchange place doesn’t need to have all the infrastructure of a petrol filling station: no highly explosive substances, no bowsers, just sealed powder packs. I imagine them as being like car batteries in size and weight. And you top up your tank, of course. With water.

The other half of the system is the reprocessing of the boron oxide back into boron:

While Abu-Hamed’s scheme still requires a distribution network and reprocessing plant, he has devised an ingenious plan that will allow the spent boron oxide to be converted back to metallic boron in a pollution-free process that uses only solar energy. Heating the oxide with magnesium powder recovers the boron, leaving magnesium oxide as a by-product. The magnesium oxide can then be recycled by first reacting it with chlorine gas to produce magnesium chloride, from which the magnesium metal and chlorine can then be recovered by electrolysis.

The energy to drive these processes would ultimately come from the sun. The team calculates that a system of mirrors could concentrate enough sunlight to produce electricity from solar cells with an efficiency of 35 per cent. Overall, they say, their system could convert solar energy into work by the car’s engine with an efficiency of 11 per cent, similar to today’s petrol engines.

Beautiful. A near-closed system, in terms of materials, with solar energy as the primary input and mechanical energy as the output.

There are some other issues. The main one is the sourcing of the boron oxide in the first place – the costs and environmental effects of the mining of the borax ore. It is apparently abundant on Earth, with the largest sources in Turkey and the US. I haven’t personally been to Boron, California, but I guess they’d be happy about this prospect.

Let’s hope this idea doesn’t get bought out and buried, because it’s the single best solution I’ve come across for the car problem – one of the biggest greenhouse hurdles we have. Getting rid of those stinking petrol fumes is a nice bonus.

Hydrogen has been the Holy Grail of the post-fossil energy world: half-decent energy density, incredibly abundant, clean-burning, greenhouse-benign, well understood.

But the problem has been the liberation of hydrogen – it’s the most common element in the universe, but it’s also highly reactive, meaning that there are no practical natural sources of pure hydrogen gas. So far, solar energy (electricity in general, in fact) hasn’t been efficient in liberating hydrogen, and most hydrogen production now actually involves reforming natural gas, which makes the whole exercise near-pointless, from an environmental point of view. In this sense, hydrogen is effectively an energy storage medium, rather than a vast natural resource to be mined.

Now, it seems that there might be a breakthrough. Using a tower more than 50 metres high, sunlight is concentrated to heat zinc oxide and wood charcoal to 1200°C. They react to produce zinc (and carbon monoxide, which is recycled or burnt as fuel). The zinc becomes the energy storage medium: it can be used directly in zinc-air batteries or reacted with water to produce hydrogen and zinc oxide. The zinc oxide can then be recycled back into the start of the process.

Very neat. If this works out to have a reasonable cost, it could turn out to be momentous. Not just the option of producing hydrogen with a reasonably clean process – using zinc as the energy transport medium rather than hydrogen could drastically reduce the (staggering) cost of establishing a hydrogen distribution system. Hydrogen is explosive; it needs a lot of redundant, heavy infrastructure to set up a reliable network. I know nothing about the energy density of zinc powder, but I’m guessing that it would be a lot more benign to deal with.

Even better, the zinc-air battery approach might be a goer in the world of electric cars, which currently are far more advanced, practical, and environmentally positive than hydrogen. It can be convincingly argued that the whole hydrogen thing’s just a scam.

The wood charcoal is an interesting aspect. Burning wood specifically for this process would, of course, generate greenhouse gases; but if it’s making use of already-burnt wood, that’s fine. Now, if we can just get some kind of efficient chimney scrubbers so everyone can have their guilt-free open fire…