If you mean 'proof' in a mathematical sense, science, at large, cannot offer 'proof'. If on the other hand you will accept agreement among many active scientists on the basis of the evidence and interpretation as presented and tested in the reputable peer reviewed literature as the kind of 'proof' that is actually available in science, then how else is that described succinctly other than as 'consensus'.

Yes believing without questioning is unacceptable. But there are good questions and not so good questions, just as there is good evidence and not so good evidence. By and large, Plimer's questions are deliberate steers to AGW denialism rather than good, open, testable questions. And, when I last looked, inference to the best hypothesis was still part of the scientific method: upon which AGW denialism fails.

This, as Dennis points out more elquently than I can, is one of the great furphies of the whole issue - whether mischevous or merely ignorant, it conflates the idea of 'consensus' with a simplistic averaging-the-guesses type of process.

This is the equivalent of confusing the consensus of a panel of football commentators (which is an averaging of guesses) with the implicit consensus of the overwhelming majority of scientists and competent scientific bodies (with, it might be added, none actively dissenting!) which is a post hoc observation that all experts, working independently from testable evidence, have arrived at the same logical conclusion. This is a kind of 'found' consensus, rather than a 'forced' consensus that might arise from some kind of voting or averaging process.

Repeating this rather elementary confusion does nobody any credit.

Felix an Dennis,

Thanks for demonstrating another problem inherent in trying to reason with "climate denialists". Their claims are invariably soundbite-size: "consensus is not proof"; "the climate has always changed"; "carbon-dioxide is plant-food" etc. etc. - but reasoned responses tend to come in paragraphs, because the denialist arguments are either oversimplifications or misrepresentations.

Consensus is not proof - this is true. This does not necessarily mean that proof is a requirement of knowledge. The scientific method does not require "proof", but rather an acceptance of conclusions by the broader scientific community based on a review of the research undertaken. The Peer Review Process is, then, a means of establishing "consensus".

"Peer" review, of course, does not mean review by 'Lord' Moncton on the basis that he is a 'Peer'. Perhaps this is the part that is confusing him.

'Consensus is not proof'. No. But then except for certain areas in Mathematics, proof is never possible. All one can do is determine the degree of likelihood that something has been demonstrated. '50/50', 'on the balance of probabilities', 'beyond reasonable doubt', 'beyond even unreasonable doubt', '3 sigmas' etc.

However to evaluate the degree to which something has been demonstrated you need a knowledgebase to apply in making that judgement. If you don't know of, or have a faulty grasp of, the Laws of Thermodynamics, how valid will ones assessment of the significance of Ocean Heat Content changes wrt Global Warming compared to someone who does understand the LoT?

This is why consensus is actually the basis of real science. Enough different people, particularly those most acquainted with the relevent knowledgebase, each form their own judgement about the burden of proof. Just as you are suggesting John. Then however to have a sufficient degree of confidence in the conclusion one needs to look at the opinions of very many people to see how well they concur. Consensus.

Part of teaching children the Scientific Method must always include the need to ask a basic question of themselves.

"Do I know enough about this subject to be able to evaluate the proposition in front of me?" The Scientific Method includes a healthy respect for ones own limitations.

"Do I know enough about this subject to be able to evaluate the proposition in front of me?"

I'd recommend Boyes and Stanisstreet (2001) as a starting-point for that. Don't worry about a paywall - the title pretty much says it all.

"The Scientific Method includes a healthy respect for ones own limitations" - what else can I say but... Dunning-Kruger effect.

There is no need for "consensus" when observations are conclusive.

1. Observed: Sun irradiates earth with short-wave energy.

2. Observed: Earth re-radiates long-wave energy.

3. Observed: Greenhouse gases retard transmission of long-wave energy, not short-wave energy.

Inferred from Observations 1, 2 and 3: Greenhouse gases thus regulate earth's temperature. Altering atmospheric greenhouse gas content therefore alters earth's temperature.

4. Observed: Historic fossil fuel use and cement production data (Oak Ridge National (US) Laboratory Carbon Dioxide Information Analysis Center) shows sufficient CO2 emission from 1800 to 2007 to raise atmospheric CO2 from 280 ppm to 430 ppm. Dissolution of CO2 in oceans has limited atmospheric CO2 to about 390 ppm, and decreased ocean pH.

Inferred. Ocean is exchanges CO2 and heat with the atmosphere, and transfers a lot of heat to both Arctic and Antarctic.

5. Observed: Arctic sea ice is melting, so that summertime sunlight is being absorped in exposed ocean rather than reflected off ice.

6. Observed: Greenland and Antarctic ice is melting, increasing the rate of sea level rise. The rate of ice melt is accelerating as atmospheric greenhouse gases increase.

7. Observed: In the Arctic, tipping points have been crossed. Permafrost is thawing, releasing stored methane and carbon dioxide, and warming Siberian continental shelf is causing release of methane from submarine methane clathrates.

Mind you, my understanding is that there is a consensus that the daytime sky appears blue.

In most areas of the hard sciences, the classical approach depended on on "Proof" even though the possibility of necessary changes to the basic tenets obtained from measurements, was accepted . The development of any sound theoretical physics is in fact based on proof in the pure mathematical sence, once a set of well established axioms have been arranged as a starting point. These are necessarily well defined "assumptions" which in fact are no different from the basic assumptions stated in the initiation of any complex mathematical problem.

Valid questioning of that "proof" requires either an experimental demonstration that one or more of the assumptions is invalid, or that the mathematics performed is invalid, no more and no less than would be required in trying to disprove the comparatively recent proof of Fermat’s last Theorem. From a certain set of conditions, one can carry through a reliable analysis to the point that one can say - under these conditions this WILL happen. This is a very old and well established approach to the so-called hard sciences of physics and chemistry and to only a slightly lesser extent in some areas of biology. (It is to be hoped that forensic analysis and DNA testing, for example, are based on something much better established than a "consensus")

If this were not so, these sciences would fall in a heap. While psychology, for instance, is situated in some "faculties of science" in others the same basic endeavour is represented in the Arts faculty. This is because, while psychology makes use of measurements, theory and sampling as are represented in the classical sciences, the predictions which can be made from it are far less reliable than is expected to be found in traditional sciences, and no amount of testing will provide for a tightly bound mathematical approach to any psychological prediction.

As a very simple example of the consistency of the results from physics, the behaviour of the solar system over the next 1,000 years and more can be predicted with precision, the significantly more erratic behaviour of the suns surface in producing sunspots allows predictions of a large number of sequential outcomes with a very high level of confidence following measured parameters some years earlier, the effects on the earth’s magnetic field is quite precisely known and can be related predictably to the behaviour of the sun.

The time kept by an atomic clock and the variation of the “time” given by such a clock in an orbiting satellite follows very precisely the laws of Einstein's special relativity to an accuracy as high as can be measured. Similarly, the same “exact” standard of length can be deduced with confidence in any sequence of measurements in different laboratories using the wavelength of a selected narrow bandwidth light. This could be retrieved to the same accuracy, even if every piece of the current apparatus in the various National Standards Laboratories throughout the world were simultaneously destroyed and something similar, but not necessarily the same, had to be built.

While much is sometimes made by the commentariat of the “uncertainty” principle, in quantum mechanics few actually appreciate that the magnitude of that uncertainty results in no practical limitation on any real measurement and is mostly manifest only in Gedanken experiments, but even then the average value, termed an “eigen” (allowed) value, is as reproducible as any physical measurement that can be made.

By contrast, in discussing the relationship between carbon dioxide in the atmosphere and the 33 degree warming of the earth, the actual contribution from CO2 is in fact largely unknown, in spite of some claims to the contrary. There is a 33 C difference between the temperature of earth as we know it ((~288 K) and what it would be (~255 K) in the absence of any atmosphere and any water. But again contrary to some explanations, this is not only because of carbon dioxide, even though CO2 does play a significant role – not the major role in this simple first order process.

For an earth with only a pure O2/N2 atmosphere alone (no green house gases) would ensure that the temperature of that “earth plus fluid” will NOT be found at 255 K but some temperature intermediate between 255 K and 288 K. This is because much of the transfer of heat from the warmed earth occurs because of conduction, enhanced by wind and turbulence, from its surface to the gas in contact with it, just as blowing air through the fins of an air-cooled motor cools it when radiation would be far from sufficient.

If we add water to our earth, the vaporisation, even at freezing point where significant sublimation takes place (just as the ice cubes which I keep in the frig for my whiskey sublimate) ensures the constant presence of significant H2O vapour at low levels. In the tropics where it is always to be expected that liquid water would be present even in an ice age, the process of evaporation transfers significant amounts of heat energy from any body of water to the air and the total energy transferred in this way is estimated to be 60% of the sun’s insolation.

Add CO2 and at about 20 ppmv only, the remaining heat added to the air by its absorption of radiation from the earth’s surface, accounts for about 20% of the total solar energy being converted eventually to warming the atmosphere. The other 20% comes from the earth/air contact (wind cooling) and of course, with the previously mentioned 60% from evaporation, we have the full 100%.

The basic science of the green house effect, which refers only to the part played by gases in the capture of heat in the atmosphere, is that there are allowed energetic electronic transitions in the molecules of these gases which are capable of absorbing photons whose characteristic frequency Nu, (or wavelength Lambda) has an energy h*Nu which corresponds to the energy difference between the ground state (zero energy by definition) of the molecule and the energy of an upper allowed quantum state. From a combination of a large number of these states, which are closely spaced in energy, the wide absorption bands of the green house gases are formed and absorb therefore, significant quantities of radiation. This is the case for H2O (water) CO2 (carbon dioxide) Methane and other minor green house gases.

A process required for warming the atmosphere by this absorption of radiation, depends on collisions between the excited molecules in the air, in which the energy from those which have absorbed a photon, is passed on to the colliding molecule in the form of kinetic energy or heat.

Further, it is well known that across the bands, such as the principle absorption band of CO2 which is centred at about Nu = 2 x 10^13 Hz or Lambda = 14.9 microns, the effect of increases in CO2 on the earth’s radiation at those many different frequencies, is negligible. This is because even at about 20 ppmv, the absorption is strong enough to absorb all of the radiation in about 300 -1,000 metres from the earth’s surface. Adding CO2, reduces this distance but has little or no effect on the behaviour of the atmosphere, and this continues throughout the atmosphere.

However, on the edges of the bands, the absorption at low levels of CO2 is not so complete and as the concentration of CO2 increases, the energy absorbed increases and at the top of the atmosphere the effect on radiation processes also changes. So here, there is an arguable case for increases in carbon dioxide causing enhanced global warming, an effect known as the Enhanced Green House Effect (EGHE) – note Enhanced.

However, the analysis required to estimate the net effect of this EGHE is far more complex than is the fairly simply explained “green house effect” as indicated above. The latter is simply responsible for assisting other larger mechanisms, in capturing energy from the earth’s surface and depositing it in the atmosphere. The former, EGHE, depends critically on the much finer structure of the edges of the bands and the effect of collisions on these lines, which requires a careful analysis of “lineshapes”.

If the theory of global warming is going to be presented in schools, it needs to be addressed properly, as most of the other posts here are encouraging. The analysis provided above is obviously too complex at the level of the grades suggested but should at least be appreciated by anyone who attempts to discuss anything concerning the Greenhouse Effect or “climate Change” from a “scientific” point of view, with students .

In any case, there must be two distinct scientific truths presented, if we are going to use the word “science” to describe what is being taught. The first is that the green house effect is straight forward, totally accepted as a means by which part, but by no means all, of the energy from the sun which warms the earth is transferred to the enveloping air and retained and spread by it to other latitudes through circulation. At the same time some of the energy is radiated from the air by water droplets, by aerosols, by radiating molecules of water vapour and particularly in the upper atmosphere, by carbon dioxide. Some small amount of radiation does escape directly to space but this is of little significance.

The second part of the discussion should relate to the more complex “Enhanced Green House Effect” which should be explained descriptively in a suitable way, but obviously not in detail. The students should be made aware that this does not follow immediately from the green house effect, but involves some very detailed scientific analysis in order to determine what the magnitude of this EGHE might be. It is not well understood, and many physicists do not consider that its effect can be as strong as is often suggested. This is a truly scientific debate and the students should be given some appropriate descriptions to ensure that they understand that the science of this issue is still under continuous discussion.

They should, for instance, understand, that a major issue for climatologists is to determine the likely magnitude of the warming according to the IPCC but that this value is not universally accepted.

They should be told honestly that the IPCC relies on models whose projections for the Effective Global Temperature range, from the results from 23 such models, from 1.0 C of warming for a doubling of CO2 to 4.5 C. They should also understand that there is much debate as to the effect of clouds in reflecting sunlight upwards (cooling) and Infra Red radiation downwards (warming) and that, as stated in AR4 IPCC Report 2007, the phenomenon of cloud formation is not well understood, but that clouds do play a major role in establishing the earth’s temperature.

They should be shown extracts from the IPCC report on the science of global warming such as Section 8.1.2.1 and 8.1.2.2 where it state explicitly that as yet the models are unable to reproduce any known climatic conditions for previous years – a process known as hind-casting which the models must be able to achieve before they are used confidently to suggest forecasts of warming. At least this would be the “scientific” process required in the determination of the ability of the models.

The method of “verification”, if one may think of using that word, has only been to set up a number of different models and to compare the results for various situations which are referred to as “scenarios”. This may be very useful and may be correct, but it should be understood by the students that it not a “scientific” approach, it is only a statistical approach and if one model is wrong then all models which provide similar are wrong.

The earlier comparison of the “hard” sciences with a mathematical process does not suite the approach to global warming. The possibility of making a correct prediction as to the climate next year is probably, if we were honest, less reliable than predictions made about the behaviour of a single, normal, person through psychological testing.

Thus there has been a reliance on a “consensus”, to cover the model analysis. The consensus is that the models ARE correct, even though it is accepted that they cannot be objectively tested against known measurements, which compares unfavourably with the example from physics where all assumptions made in an analysis must be subjected to rigorous testing in the laboratory.

It is significant to note, that the latest IPCC report and the corresponding report from the Bureau of meteorology “Climate Change in Australia – 2007 – CSIRO” state only that, while their modelling provides some confidence because of the very broad similarity of expected global temperatures – 1.0 C to about 4.5 C – it is still necessary to consider the approximate correlation which existed between increases in atmospheric carbon dioxide and the earth’s temperature between 1979 and 1995 which they express as:

“We believe that most of the warming of the earth during the second half of the twentieth century was very likely due to the increase in the concentration of atmospheric carbon dioxide.”

Unfortunately there is no other statement in either the IPCC report or that of the CSIRO, which provides a more definitive description of their reasons for accepting that increased CO2 causes global warming!

It may be that in the next few years such warming will resume. At present it has not been obvious in any of the temperature records of the last ten years and it has been stated that no statistically significant warming has taken place since 1995. Be that as it may, the possibility of further warming should not be ruled out, but it is essential that our future students of science do receive an appropriate introduction to well presented science and if the matter of global warming is going to be introduced, it must, as has been stated by others on this post, be done with an emphasis on enquiry and an understanding that the process of increased global warming through increased carbon dioxide, the EGHE, is not well understood, that the magnitude of any warming through increased CO2 is a matter for continued scientific debate.

John Nicol jonicol18@bigpond.com

Ellie,

The peer review process does not have anything to do with establishing a consensus. The review process is one of considering first of all whether the subject matter of the paper is consistent with the defined objects of the publication - is it atomic physics, thermodynamics, physical chemistry etc for publication in a journal of at least somewhat similar name.

Secondly, the reviewer is required to consider whether the processes described in the paper are sufficiently explicit to allow a reader to understand how the work was done and what are the results. Is the paper too short or often, is it too long and unnecessarily explicit. Does it refer to appropriate previous publication - particularly those perhaps of the reviewer - and if so are their results dealt with correctly.

Thirdly the reviewer may make a judgment as to whether the paper meets the necessary standard of the publication in terms of the likelihood that the results presented will be found subsequently to be correct. In some cases this will be a reasonably high priority, but in many cases it does not rank very highly as the material may be something obscure which the reviewer does not properly understand and if all else is OK, it is usually judged better to publish it and let the others in the field have a go at it also. suppress it, and no sees it or perhaps some other publication picks up a scoop.

If all papers published provided unquestionable results, as is sometimes inferred by those clamoring for "peer" reviewed publications, there would be no debate, no reworking of results and none of the stimulous which produces progress in science. In the more objective disciplines of mathematics, physics and chemistry, most scientists and certainly those who are competent in a field, are not at all concerned about some one else reviewing work, peer review.

One would be just as happy to receive a preprint or draft or even an internal laboratory report as used to often happen between colleagues in similar fields in the days when no one was worried that their results might be stolen! The recipient should be quite capable of reviewing the paper himself/herself.

I must admit that this is a point which worries me a lot about the current scientific processes where many people will only consider a peer reviewed paper. It is tantamount to admitting that one is incapable of analysing the paper for oneself and determining if it is a valuable contribution or not.

John Nicol

Exactly Alan, The introduction of the complex science of climates - notice I did not say "climate change" because climates always change, that is what they do, and have done for millions of year - is no way to introduce students to science.

The development of the basic laws of Newton, Gallilean transformations etc should be the starting point for physics, if only to present it in an historical sence to younger students.

The concepts of mass, distance, time, force, velocity, acceleration, energy and momentum are the basic tenets of physics which are also concepts familiar to students from experiences in every day life. These lead to ideas of torque, the use of levers and screw jacks, pressure, density and the conservation of mass and energy which can be in the form of either potential or kinetic (for a start in terms of Newtonian concepts). Gravity, and the forces of electric and magnetic fields follow - all in a logical sequence which is possibly not properly followed by me here!!.

The further historical development of the various scientific theories such as relativity (not the mathematics) and the influence of quantum mechanics, statistical mechamnics and lasers could be given some airing just toi show how science works, without expecting, in any way, that students will have an understanding of these difficult concepts but just to learn that they are there and that this is how science works.

Chemistry and biology of course are also just as important but I would not presume to suggest how these subjects should be introduced.

But the ideas of climate change have absolutely NO place in the class room in introducing students at high school to science.

What science is there in climate change? The first idea of absorption of electromagnetic radiation and the distribution of the energy in the normal, basic green house effect, is far beyond the comprehension of students who do not understand electromagnetic radiation, quantum effects in absorption, and the quantum statistical mechanics governing the transfer of electronic excitational energy into molecular kinetic energy.

That is the most basic idea of the Green House Effect, before we even start on the feared Enhanced Green House Effect invoving spectral line shapes, line broadening and the formation of molecular spectra in the form of bandes made up of thes breoadenrd spectral lines.

Wjhat do they have to learnabout climate change that they can understand? That someone with a computer thinks he/she can represent the whole of the worlds atmosphere by means of a computer model. This inviolves difficult equations and concepts which, if explained honestly, would be far beyond the ken of even the brightest school students! What a stupid approach to "science". John Nicol Jonicol18@bigpond.com

"There is no clear common interest between mining per se in general and climate denial."

Really? How long have you been reading The Conversation for?

I've only been reading it for a few months, but it's become clear that a significant proportion of the denialists here are geologists, retired geologists or students of that field.

Even to the extent that that's true, it doesn't say anything about why mining in general (as distinct from coal mining) should have a common interest with climate denial. It's much more likely to be due to a fundamental difficulty that many geoscientists have with near-instantaneous processes (like the Industrial Revolution) having primacy over those operating on geological time scales. This has its roots in the uniformitarian vs catastrophist (read 'flood') debates of the early 19th century and before.

I also find the whole 'x has a vested interest, therefore x's view can be discounted' to be generally a lazy and unconstructive critique in all spheres, not just climate. Apart from being essentially a personal attack, rather than addressing the arguments and data, it often rules out a large chunk of the expertise in any given field.

Mark

While their is certainly the possibility of a link between certain industries and Climate Denial - definitely wrt funding pseudo think tanks and commentators etc - there is a far more interesting general dimension to Climate Denialism. This is fundamentally a psychological dimension.

A fundamental assumption we make when communicating with others is that they process information and comprehend the world the same way we do. So when we see markedly differing views we often ascribe to them reasons for why they have that view which would seem reasonable explanations for why we might hold their view - 'If I thought that it would mean I was stupid or deceitful or malicious or something'. When in reality that person simply thinks (mentates) in a very different way from you. And they may hold very similar judgements of you because you are just as incomprehensible to them.

One area that has received a lot of study in recent years is the psychology of denial; particularly but not just Climate denial.

One study looked at peoples level of acceptance of AGW based on their education level (and level of knowledge of the science of AGW) and their personality type - Libertarian/individualistic/hieararchical types vs communitarian types. If you like your classic Right vs Left divide. Of those with lower educational levels their views about AGW divided on expected Right vs Left lines. However, when looking at those more educated about it, the Left-Leaning individuals became stronger in their acceptance of AGW while the more educated Right-leaning individuals became stronger in their rejection of it. At first sight, this doesn't make sense. Whatever the underlying personality based biases in peoples views, surely access to more accurate information would move both types in the same direction! Maybe additional knowledge made no contribution to their views, it was simply that the more educated are more confident/strident in their particular bias.

The researchers then did a second study as a control. Same methodology but this time they chose a topic which would be likely to be a hot-button issue for left-leaning types in the way that AGW might be for right-leaning types; Nuclear Power! Again the less educated cohorts divided predictably on the subject. And the more educated right-leaning types grew stronger in their support for Nuclear Power. However, this time, the additional information about the actual safety of Nuclear Power possessed by the left-leaning types resulted in them ALSO being more accepting and supportive of Nuclear Power.

So the "extra information doesn't contribute to changed views, its just an intensification of existing biases with more education" hypothesis didn't hold up. Here the left-leaning types HAD moved with additional information in a way that the right-leaning types hadn't in the first study.

What to make of this?

Next hypothesis would be that there is some difference between the way the two personality types process information. This is the current major working hypothesis wrt the relationship between personality type and processing of information from the external world.

In psychology one of the tools used to classify personality types is called the Myers-Briggs Type Indicator. This uses 4 categories which each can then have one of two polar opposite values to classify personality types, producing 16 different types. I find the last of these 4 categories particularly interesting: Judgement vs Perception. This category relates to how we evaluate information about the external world. Judgement (using a very broad brush description) tends to use internal mental models to JUDGE information from the external world. Conversely, the Perception type is more likely to use PERCEPTION of the external world to build internal mental models. The result of this are two vastly different personality types which give quite differing primacy to the internal mental landscape vs the external physical landscape.

One type may be more likely to filter external information for how well it matches an internal mental model. The other types is more likely to filter its internal mental model for how well it matches external perceived data. These are deep seated, intrinsic, differences in modes of mental functioning. Who could forget George W Bush talking about having an 'alternative, faith based reality'. Definitely a 'J'!

Consider 2 climate related examples.

Sen James Inhofe (Rep, Okl) has said "I used to belief in Global Warming until I found out what it cost" At first glance a jaw-droppingly absurd statement. What has the cost of dealing with AGW got to do with whether CO2 absorbes Infra-Red?

But to a 'J', for whom also the primacy of our economic system, it's deep and meaningful value, is a central part of their personal value system, the idea of AGW is then 'external data' that conflicts too strongly with their internal mental model and is 'judged' to be wrong.

Recently the ABC ran a documentary called "I can change your mind about: Climate Change" and an associated Q&A episode. I found both quite disappointing since they didn't really cut to the meat of anything. But one segment of the doco that died on the cutting-room floor was interesting. Nick Minchin is talking to Naomi Oreskes and they are discussing not the science but why people might be reluctant to accept it. Nick expresses his doubts about the capacity of governments to carry out the sort of changes needed to address AGW. He was putting forward his passionately held views about the limitations of the capacity and appropriate behaviour of governments. But how does this have the slightest relevence to the physics of Infra-red absorption by CO2 molecules? Obviously, objectively, none. But for Nick this was obviously a hot-button issue.

Naomi raised the concept of 'consequential denial'. Put simply that we reject A because when we look at its consequence, B, we JUDGE B to be unacceptable or intolerable. So as a result of our deeper need to reject B, A most consequentially be rejected.

So the 'J' type, particularly those individuals who are particularly strong in that trait, are more likely to reject external 'data' that conflicts with their internal mental landscape. And the 'P' types are the opposite.

We can't make any sort of value judgement about the relative merits of these differing mental modes, anymore than we can judge red-heads vs brunettes. Except for one basic situation.

Where one is called upon to make a judgement about the nature of the external physical world! Here the 'P' type is more easily able to adjust their mental model based on the external data because that is natural for them. For a 'J' on the other hand, their basic psychological response is to defend their mental model against the threatening external data. Think Biblical Literalists and Dinosaur fossils. Free Market fundamentalists and sex trafficking. The need to excessively defend ones inner mental landscape against the external world is deeply distressing for a 'J'.

So to Plimer, Geologists, Free-Marketeers etc and AGW.

What is their inner mental landscape that they might be defending?

'Free market economies have delivered fantastic prosperity and human advancement. To suggest that they might have negative consequences, that those negative consequences might even outweigh their benefits. That is unthinkable. That is blasphemy. If we accept that idea we are adrift, lost in a desolate sea with no values compass to guide us' - I have heard the term blasphemy used in relation to this.

'I have spent my working life creating the means to expand human well being. As a geologist (engineer etc) I helped extract the stuff that delivered this expanded well being. We built this world! Are you saying I have spent my working life in vain? That I have caused harm when all I can see is the good I have done? I'm not a monster!'

'People like you want me to feel bad about myself, that I am some sort of thief because I tried to do good as I saw it. And now you are saying I AM WRONG!'

'The world we live in is a fairly safe place. We control how things work. We make our lives safe and secure! Now you are saying that the future will be terrible. I can't see that. I have looked after my family. Now we are all doomed and it's my fault because I didn't even KNOW. What gives you the right to attack me like this?'

And so on!

Don't see these examples (and many similar) as conscious mental narratives. Most of the human psyche is unconscious; arguably our so called 'conscious mind' is just like Long-John-Silver's parrot. It sits on the shoulder of our subconscious and makes commentary from time to time. So when I put forard these examples don't take them literally; I am trying to put into words a far more inchoate subconscious domain.

Really valuable contribution with much truth in it, Glenn, thanks. However, the other point I made continues to be missed: Fossil fuel extraction excepted, there is nothing about mining that is particularly or disproportionately inimical to the climate, any more than any other sector of the primary and secondary industrial economy. Attacking Plimer's climate pronouncements on the basis of his non-fossil mining interests is therefore misconceived.

Clearly the article's author and many readers and commenters feel otherwise, but I'm still none the wiser as to why.

Mark

There is one key aspect of mining (in fact all forms of Geological extraction) that, while it may not be ESPECIALLY inimical to the climate, is none the less of some impact on the climate, and just as importantly, is liable to be impacted upon by any efforts to control AGW.

The economy essentially consists of producing and consuming goods and services. By their nature the provision of services doesn't consume any raw materials except in the provision of goods for use in the provision of the service; making scissors and hair spray for hairdressers for example.

Producers of goods on the other hand do consume raw materials in order to operate their business. And all the way back down through the supply chain are what we might call the 'root producers'. The ones who actually extract raw materials from the natural environment and pass it up the supply chain - miners, farmers, loggers, fishermen etc.

Their business is totally dependent on their being a demand for the raw materials they extract. They need to do this to make a profit and they need increasing sales to grow their business.

So, while the principal thrust in tackling AGW is to decarbonise energy suppy, in fact there is a need to restructure the economy to make it sustainable. Not as some walm touchy-feely notion but the far more hard-headed reality. That which is not sustainable cannot be sustained.

So many practices that are currently used need to change in ways that lower or remove environmental impacts. Efficiency improvements, alternate processes, changed markets and products. Take one example:

A major area of research in plant breeding & genetics is about trying to transplant the gene complexes associated with Nitrogen Fixation from plants such a legumes that can do it into major food crops that can't - wheat, rice, barley, corn etc. If this could be achieved the demand for Nitrogenous fertilisers for those crops would plummet. Much lower fertiliser costs for farmer rich or poor, massive environmental gains from averting the negative impacts if nitrogen run-off, possibly cheaper food, and higher yields for farmers who currently can't afford fertilisers. A win-win for everyone.

Except the fertilser manufacturers, who would see their businesses devastated!

Many industries are right to see that our potential responses to the various climate and environmental threats could have serious and possibly even fatal consequences for their industries. Just because the Fossil Fuel guys are at the pointy end right now doesn't mean that other extractive industries aren't also in the firing line eventually. And the people who run large corporations aren't stupid.

Then add to this fact the sort of psychological factors I described in my previous post. The disbelief in the reality of the threat(s) that some people will tend to feel, and thus the projection onto those advocating these changes of demon/socialist/eco-terrorist/'watermelon' status and you very easily have a situation where some people in those industries most certainly fund what we might see is disinformation campaigns but which they would see as valid self-defense exercises. Particularly in companies that are built around a strong individual owner.

In major corporations, with no clear controlling stakeholder, one might expect a more dispassionate and professional management, CEO's, Chairman etc. BHP Billiton for example. But significant size companies that really are the creature of one or several individuals can behave very differently, reflecting the views of the head honcho. Think Gina Reinhart, Twiggy Forrest etc here in Australia; News Corp, or Koch industries in the US.

All it needs is a few individuals at the helm of such companies, who share the sort of personality traits I discussed earlier, to give you more than enough people willing to pay for dis-information. It doesn't need every company in an industry to do it. Just a handful is enough.

So it doesn't just have to be Fossil Fuel companies or people in those industries (including Academia) for them to have strong psychological drives for why they would act this way. They have broader reasons for identifying with and anti-AGW cause. And see themselves as being among like minded people when they do so. Even when their actual narrower industry identities aren't the same. They still see themselves as having common cause together.

Craig Reid,

Could it not be that geologists have some knowledge of past climates and therefore see nothing exceptional about this "climate change"?

Physicists do not work for oil companies but most of them are not so sure about the claims of the IPCC. They also have perhaps a better appreciation, or if not better, at least different, of the characteristics of carbon dioxide and atmospheric physics than perhaps do even the experienced climatologists whose background seems mainly to lie in geography.
John Nicol

John Nicol
"Could it not be that geologists have some knowledge of past climates" And that specialist PaleoClimatologists have far more knowledge of past climates and the driving forces behind them that aren't covered bby a working geologists education.

And again John, you repeat your old furphy and canard that climatologists are mainly geographers, something you never back up with references. When in fact many people in Climatology came to that from other fields, particularly physics.

John Nicol

I will reply to myself to stop the comments nesting too deeply

The last 5 paragraphs of your post are just flat out wrong. The key reference cited by the IPCC AR4 for the impact of CO2 is Myrhe et al 1998. That in turn cites a number of other papers including, as I have highlighted to you before, Edwards et al 1992 here: http://nldr.library.ucar.edu/collections/technotes/asset-000-000-000-178.pdf. Have you have read it yet. In this paper they describe a Line-by-line Radiative Transfer Code - GENLN2 - and what it takes into account. Pressure Broadening, Lorentz Line Shapes, Doppler half-widths, Voight profiles, neo-Lorentzian line wing effects, continuum absorption, Q, P & R Branches, etc. Where those the sorts of quantum theory issues you feel need to be included?

Did you read Conrath et al 1970 as I suggested?

You are insinuating that the necessary research into CO2 (and the other GH gases) has not been done and the IPCC is relying on the research of Arhenius!!?? When in fact that research began in the 50's, and has continued ever since. Why does the IPCC not produce lots of references to it? Because it is relatively old, well established and mature science. They don't need to reinvent the wheel every time they write a report John. Yes science needs replication, but if a subject has been very well studied and replication studies done repeatedly decades ago, why is there a need to keep on repeating that research now? How often should we replicate the Michaelson-Morley experiment before we decide that it has been tested enough?

So until you have read Edwards & Conrath and can then actually say what you find deficient about them, why should I or anyone else take your comments on this seriously. Please get a bit of knowledge of the subject before you fire off criticisms John.

Next, Revelle & Keeling. What was the topic of National Interest back then? The Cold War! Global warming didn't even start to impinge in broader scientific cirles let alone outside science till at least the mid 60's, and really not till the 70's. But Revelle did his primary work in the late 30's. Keeling in the late 50's. Revelle was working in ocean chemistry, deciphering the basic understanding of the chemistry of the ocean as a buffered solution and the impact of that on CO2 absorption. Keeling's work flowed from the International Geophysical Year in 1957 and the push to understand all sorts of aspects of the Earth's systems. Both were working at The Scripps Institute of Oceanography, and much of the work was broadly defence related; Revelle was one of the early oceanographers to discover just how profoundly stratified much of the ocean is, with significant implications for mixing rates for all sorts of things in the ocean. He and his colleagues made this discovery during a defence related oceanographic survey evaluating the results of an atomic test.

You then persist with this idea that somehow the Enhanced GH Effect is in some way qualitatively different from the GH Effect - see my earlier post for comments about this.

And the impact of CO2 is highly consistent with past geology. We can't make sense of the Earth's past climate as recorded in its Geology without the effects of CO2.

You say "The IPCC is suggested as being the chief arbiter...". ABSOLUTELY INCORRECT.

The IPCC does not arbitrate anything! It reports of what the extant science says. It is not a gate keeper.

Ian

And Royer 2007 is one of the Climate Sensitivity analyses collected by Knutti & Hegerl that gives good confidence of CS at around 3. Most skeptics really seem to get hung up in thinking that its all about just computer models. When the majority of CS studies are from real world and paleo data.

I'm generally pretty unhappy with the use of the term 'scepic' to describe climate deniers. Any set of scientific beliefs that requires discounting the majority of the peer reviewed literature as out of hand, and instead instead relying on articles of this quality: http://denialdepot.blogspot.com.au/2011/04/staggering-drop-in-global-temperature.html (ok usually with less satire and more mathturbation) should be called out as denial, not scepticism.

I can't really see it myself, Ian - in 10 years I don't recall ever being hassled by parents over the content of my lessons - but having said that I remember the heady days a handful of years ago when the topic was relatively uncontroversial - so maybe things have changed.

There's ample evidence that the number of high-school students who can explain the greenhouse effect correctly are outnumbered by those who explain how greenhouse gases damage the ozone layer, thus allowing in more UV to heat up the Earth.

I sincerely hope no-one in education (or education policy) ever decides that it's "too much trouble" to attempt to give young people at least a basic understanding of the science.

You know Lorna :)

Reading you, and being slightly tired I suddenly though you were saying that it was the ozone layer being responsible :)

And gaining that insight from a physics education no less :)

But you didn't, did you. You were just discussing disinformation, and their results. The biggest question I got is on my mind those days is the one whether those disinforming the public really, sincerely, believe in their claims or if it is so that they somewhere have other more ulterior motives, money or other-wise?

I would really hate to know that those with the economic resources also would be those to lead humanity into disaster. Uh, wait, what am I saying here :) They have been doing that for the longest time, hasn't they?

Sorry about that Yoron!

I appreciate that the prevalence of the "ozone depletion" explanation almost sounds impossible to believe unless you've experienced it first-hand. We take for granted the basic knowledge about the Earth emitting IR and greenhouse gases absorbing that, but the evidence suggests we might actually the ones in the minority. If school students aren't coming away with a clear understanding of the basic science, what are the chances that they ever will?

Which leads to the question - how many of the people complaining about "a tax on the air we breathe" hold profound misconceptions about the basic science of climate change?

Ian,

I thoroughly endorse your comments here. For a forum supported by a consortium of universities the organisation of The Conversation is nothing short of a disgrace. I have commented on these matters before and often, but nothing seems to be done about it.

By the time you have, say, 300 comments, it takes all day sometimes to dig out the ones you want. The positioning of replies is also very awkward and the use of the text box itself is an excercise in self flagilation, once it is full.

I usually go to another text editor and copy and paste into the blog.
John Nicol

direct jumping to a specific comment would be nice, but we're in the hands of the techies as to whether it's possible using whatever they use to build this site.

I'd like to add - and I DO know this is possible - a MAXIMUM post length please?

I come to this site (and surely I'm not the only one) for a little light relief from a job that revolves around reading and writing - so if you can't make your point without filling the screen then I'm not going to read it.

Abstract-length would seem appropriate, so 200-300 words?

Ian,

Coming from the Frozen North, I understood the intent of using "climate change" was to emphasise (a) changes to rainfall patterns and the like, which "global warming" doesn't encompass and (b) include the projections that parts of the planet might get colder.

Please correct me if I'm wrong, but I understood that one such early projection was the weakening of the Gulf Stream and resulting cooling of the British Isles.

Ian,

OK 200-300 words is a bit restrictive - but one of John Nicol's comments was 2374 words in length. I've read shorter journal articles!

To be honest I think it's lazy to write such enormous comments - posters either have nothing to do all day or are copying and pasting verbatim form somewhere else. And we all know that it takes more effort to produce concise writing than it does to waffle! A maximum comment length would impose a bit of discipline on the ramblers.

Ian

"(the "We need to emphasize catastrophe, otherwise no one will listen" Houghteon)". When actually that is

(the Piers Ackeran lyingly said John Houghton said "We need to emphasize catastrophe, otherwise no one will listen" Houghton)

Thanks Ian,

I love it when you speak about me in such glowing terms. Just being called a "Lier" is music to my ears. You are still an amateur in the game of abuse by people trying to prop up the IPCC. I have been abused by professionals so your comments are so pleasing to hear.
Yours sincerely, John Nicol

DOS and Unix are both operating systems, not applications.

Thanks Matt.

Earth is warmed by absorption of short wave sunlight. Because of this, Earth's temperature can remain unchanged by returning the same amount of energy to space. That is, solar shortwave energy is balanced by the earth re-radiating to space as a 'black body' radiator with a characteristic temperature of ~255K; that is, from space the earth's spectrum is roughly that of a radiating body with an optical surface temperature of around 255K.

Earth's surface cools by evaporation of excited water molecules, heat transfer to deeper sea and to polar ice caps and by convection and radiation back into and through the atmosphere. At higher altitudes, where the atmosphere gets less dense, the proportion of energy (heat) transfer by long wave 'thermal' (microwave) radiation increases. Observing earth's spectrum from space has big absorption bands due to greenhouse gases in the upper atmosphere. Prominent among these is carbon dioxide (CO2).

Greenhouse gases such as H2O, CO2, methane (CH4), nitrous oxide (N2O), CFC's, and ozone (O3) absorp, then re-emit, some longwave wavelengths. About half of the re-emitted radiation is diverted back down toward the surface, as confirmed by radiation measurements at both surface and satellite observatories. This discrepancy increases with atmospheric CO2 concentration.

Historic fossil fuel use and cement production data (Oak Ridge National (US) Laboratory Carbon Dioxide Information Analysis Center) shows sufficient CO2 emission from 1800 to 2007 to raise atmospheric CO2 from 280 ppm to 430 ppm. Dissolution of CO2 in oceans has limited atmospheric CO2 to about 390 ppm, and decreased ocean pH.

Heat thus accumulates at the surface. About 90% of retained heat warms oceans, accelerating ice melting (sea level rise) and water evaporation (increasing rain and storms).

Warming feedbacks already initiated (ie tipping points already being crossed) are loss of Arctic sea ice, so that boreal summer sunlight absorption in the Arctic Ocean is increasing (less sunlight reflection), the aforementioned sublimation of offshore Siberian methane clathrates, and methane outgassing from thawing permafrost.

Deforestation limits biosequestration of atmospheric CO2 so that reversion to glacial conditions is not presently possible, even when earth's orbital precession minimises intensity of sunlight on Arctic terrestrial icecaps (ie right now).

No Post-Modernism in that lot.

I would class these as truths, half truths and opinions.

Thanks for this, Father.

As a Christian priest who engages in uncritical attacks on authors rather than seeking to understand any physics, I'll limit my remarks to noting that Saul's interpretation of the life and times of Jesus Christ was shaped by a desire to maintain the status quo with his Herodian kinsmen doing quite nicely (thank you) as Roman client rulers. He got a gong, a sainthood, for his efforts.

Constantine then adapted Paul's monarch-favouring religion to his own empire-supporting ends.

For comparison, Ron Hubbard invented Scientology to win a bet.

Err, I'll try again.

Thanks for this, Father.

As a Christian priest who engages in uncritical attacks on authors rather than seeking to understand any physics, you'll appreciate my limiting my remarks to noting that Saul's interpretation of the life and times of Jesus Christ was shaped by a desire to maintain the status quo with his Herodian kinsmen doing quite nicely (thank you) as Roman client rulers. He got a gong, a sainthood, for his efforts.

Constantine then adapted Paul's monarch-favouring religion to his own empire-supporting ends.

For comparison, Ron Hubbard invented Scientology to win a bet.

Well said, Father. Your comments are balanced and forceful and should be taken on board by us all.
John Nicol

since they weren't subject to pee-review

sorry, was that meant to be "peer-review"? Maybe not - maybe the typo was trying, through my subconscious, to say something about the quality of the argument I'm addressing.

"nature works with dynamic equilibriums. This is completely the opposite to the concept of “tipping points”."

Matt, sorry but I'm not following you there. Can you please clarify the difference between a dynamic equilibrium and a tipping point?

cheers

The concept of a "tipping point" implies that there is a point beyond which natural processes will accelerate and essentially go out of control. This is contrary to the way that natural systems operate. In natural systems there is a continual balancing that buffers change. They are in a state of dynamic equilibrium.

If you look at global warming over the past 200 years or so you will see that changes on the whole have been very gradual. There is no reason why this would suddenly change.

Matt

Your understanding of what is meant by Tipping points is quite wrong. Many dynamic systems can exist in one of several relatively sepearate but stable states and when mildly disturbed will tend to return to their current state. But if the disturbance is large enough they can reach a 'tipping point' where they tip over to one of the other stable states. No concept of out of control or runaway or anything.

Some examples considered possible:

If warming is large enough for long enough (100's to 1000's of years) then melting of the polar ice, particularly East Antarctica would be such a tipping point. Once it started happening, exposing the dark bedrock below, the change in the Earth's Albedo (reflectivity) would accelerate the process, 'tipping' us over into an ice free Antarctic. When the Antarctic first started developing a permanent ice sheet, about 30 million years ago, CO2 levels were at around 600 ppm. Allowing for the small increase in the Sun's output since then the comparable value today would be around 520 ppm; well within the possible CO2 levels expected this century if we don't decarbonise.

Next the Amazon. Huge rainforest, substantially creates it's own climate keeping precipitation levels high. Most rainforst species aren't drought tolerant and don't recover from fire; unlike Australian natives. So if, as appears to be happening, and certainly is expected, drying stresses the forest, more fires occur, the capacity of the forest to contribute to maintaining its own climate is slowly reduced, more drying and so on. Another tipping point where the system makes a transition to a stable rainforest state to a stable scrub/savannah state. Causing much of the carbon locked up in the forest up into the atmosphere, largely through burning. Again not runaway because the amount of carbon is, while large, still finite.

As for looking at the world over the last 200 years to gauge how fast things can happen, that is way way to short a time frame. That is all part of what had been the current stable state. Look back through deeper time - 10's to 100's of 1000's of years. Rapid change has occurred in the past. Multy metre sea level rises in a century. During the Younger Dryas around 13,000 years ago temperatures particularly in the North Atlantic basin plummetted then recovered again. At one point recovering 5-10 C in a decade.

Things only look smooth and gradual because you are looking at a very short timescale. Human Civilisation developed during a 'Goldilocks' interval in Earth's climate history. We can't draw broader conclusions about future climates from that limited sample set.

Mark

The Hockey Stick is a Lie! Anything to back that up? Because the 'hockey stick' has been reported by well over a dozen different paleoclimate studies, using different proxies, and most importantly, done by many different research groups around the world. So in backing up your statement, PLEASE don't just recycle Michael Mann again as so many others do. Please tell me how all the OTHER studies are lies.

"“That Kakadu and the Great Barrier Reef will be destroyed by climate change” – is a gross exaggeration – I don’t know why any scientist would make absurd statements like this." So I presume you have some studies that can quantify the impact of differing degrees of climate change on features such as Kakadu or the GBR. Or are you just venting a personal bias that doesn't have any foundation?

Will reducing Ruminant numbers reduce GH gases? In total, over longer timescales, no. However in the short term it would have a positive benefit since it would alter the mix of GH gases being released, reducing Methane emissions by replacing them with CO2 instead.

Matt,

As Glen has already pointed out, you're holding a couple of misconceptions about both concepts - they aren't "opposites" in any sense.

Simple analogy: a glass. Standing upright, it's in equilibrium - if you tip it slightly it'll fall back onto its base. But tip it at a large enough angle and instead of tipping back onto its base it'll end up on its side. In other words, the glass has two stable states (states of equilibrium) - upright, and on its side. The point where the glass spontaneously switches from one to the other is the tipping point.

Glen and Lorna - you obviously don't understand the concept of dynamic equilibriums in nature. We are dealing with natural systems here that are complex with many variables - not some simple laboratory experiment. The changes you refer to Glen occured over geological timescales and may seem rapid on this timescale. But on a shorter (eg human) timescale they would have appeared to be very slow. All of these changes have been dynamic and have resulted from equilibrium shifts in natural systems with no specific "tipping point", just a gradual change in one or more climatic variables. If we are talking in geological timescales, man induced climate change will no longer be relevant in a mere 500 years when there are no more fossil fuels left to burn.

If you look at real data any of the main climate change indicators such as sea level rises, or atmospheric CO2 levels you will find no "hockey sticks" in the graphs.

Regarding the changes to the Great Barrier Reef and Kakadu - I don't think the emphasis is on proving it WON'T happen but on proving it WILL happen and quantifying it before making statements like this.

Regarding ruminant emmissions - are you saying that the microorganisms in a ruminant produce methane, but soil micro organisms don't?

I totally understand what you are saying Lorna - but nature is not a glass of water - it's a complex system. The concepts that apply to a glass of water don't necesarily apply to nature. I have yet to see an example of a tipping point (ie the point where the glass tips from one point to another) in nature.

Matt,

"The concept of a "tipping point" implies that there is a point beyond which natural processes will accelerate and essentially go out of control"

- no. A tipping point is where a system stops being stable in one state and moves into a new state. Nothing to say it won't be stable in the new state.

"balancing that buffers change. They are in a state of dynamic equilibrium."

"balancing that buffers change" is negative feedback. It *contributes* to equilibrium but it isn't the *same* as equilibrium.

"nature is not a glass of water" - Matt, did you see the words "simple analogy" there?

Great example of the denier arguments here. These arguments appear to be a variant of the "It's not happening" argument. Rather than link directly to that particular rebuttal I'll just link to the Skeptical Science catalogue of common denier arguments: http://www.skepticalscience.com/argument.php

Hi Matt,

I agree with the others, you appear to be wrong. Scheffer, M., et al. ( 2009) Early-warning signals for critical transitions. Nature, 461, 53–59. as a nice exploration of the topic. It seems that you can obtain an non-paywalled copy via this link: http://xrl.us/bm9iek

In order to have a "tipping point" several criteria need to be met. First of all there must be a "point" - either a point in time or when a set of criteria is fulfilled. Also there must be an specific "event" that causes a change. Then there must be a substantial and measurable change resulting directly from the event (and this point would show clearly in the data). I don't think anything that I've seen in the climate change data satisfies these criteria, and I stongly doubt that anything we see in the future will either.

Thanks - but don't believe everthing you read from so called experts - I think that's what this whole discussion is about isn't it - thinking critically.

Do we have to swallow the whole propaganda pill - or are we allowed to be just a bit skeptical?

Matt.

Interesting term 'so called experts'! Not so subtle attempt to denigrate people who know far more than oneself about a subect. And critical thinking alone is not enough. Without an adequate knowledgebase, even the best critical thinking can produce absurd results. Because the most important part of the critical thinking is knowing the limits of our understanding. And for most of us we don't even know how much we don't know - dear old Rummy's Unknown Uknown's (I miss Rummy. Always good for a laugh).

The value of experts is that they know more than we do. And they have a clearer understanding of what they don't know. Most of their Unknowns are Known Unknowns.

Why the hostility to taking the opinion of amn expert? Surely, when you meet someone who knows more about a subject than you do, your first reaction is to want to sit at their feet and learn from them. Isn't it?

Matt, from the perspective of risk assessment, if you determine that there might be a tipping point, and that passing that point might cause harm, then the idea is to take action before you meet the event criteria - not pass them by and watch the result.

Matt,

Given that you conflated dynamic equilibrium with negative feedback and tipping point with runaway greenhouse effect, I'm a bit sceptical about your list of criteria there. Do they come from a source that we can check please?

Glen,

On the subject of "so-called experts", you might like this:

http://www.uwgb.edu/dutchs/pseudosc/SelfApptdExp.htm

Good to see that you're a bit skeptical Lorna - now apply this to all the other information that you're fed and you will peel a few layers off the onion!

Hi Ian,

I thought he was a bit harsh at times too - but I'm glad someone has put together a response for this ubiquitous claim.

I thought the last line was a bit harsh too - but I don't have to have much to do with conspiracy theorists. Most of the people I have a lot to do professionally are adolescents - and I reckon I've got the best of the deal there. They're intellectually honest, and when their behaviour is immature at least they've got a good excuse for it.