Environment

Presentation: climate change and the precautionary principle

John Quiggin94 Comments

I’ve uploaded my presentation on climate change and the precautionary principle, which I gave at City Hall on Monday night. It’s here in
Powerpoint (4.9Mb)
or
PDF (1.9MB)
formats.

Finally, here’s a version Zipped Mac Keynote (4.8Mb).

Thanks to everyone who’s given helpful suggestions for the upload, and noted problems with the download.

Sorry for the accidental temporary disappearance of this post. I somehow set it to “private”, which meant that it appeared for me, but for no-one else

94 thoughts on “Presentation: climate change and the precautionary principle”

  2. John, try zipping the Keynote file and uploading the zip file. I think WP might be complaining because a Keynote file is actually a folder – MacOS X just treats it like a file.

  3. “Observed increase in global temperature 0.5 degrees in C20, mostly after 1970�

    Aberrations in global temperatures of more than this magnitude over longer time frames are a common occurrence. This temperature change could be deemed “normal�. Predictions based on temperature movements since 1970 might be found to be inaccurate.

    I read somewhere recently that research being conducted at Newcastle University (Aust) had discovered that the formations in limestone caves, which occur over many thousands of years, provided very accurate long term records of rainfall and air temperatures over the periods of their formation. Although the research was in its preliminary stages they seem to imply that a movement in average temperatures up or down of a few degrees over time was not unusual.

    Does anyone know somebody up at The University Of Newcastle’s geology department that can give us the facts on temperature movements?

  4. There was a particularly relevant comment from a poster at another site,commenting about the U.K….”AGW is the last respectable argument for large scale government intervention in the economy. It is no surprise that economists would develop an interest in AGW.”

  6. econowit – “This temperature change could be deemed “normalâ€?. Predictions based on temperature movements since 1970 might be found to be inaccurate.”

    Sure if there was nothing else going on. However since greenhouse gases are increasing and these have been proven to trap heat then it stands to reason that THIS recent warming is caused by these greenhouse gases and is not ‘natural’. To assume that it is natural is to ignore a large body of physical evidence.

    ChrisL – “â€?AGW is the last respectable argument for large scale government intervention in the economy. It is no surprise that economists would develop an interest in AGW.â€?”

    Sure so governments invented AGW just so they could intervene. I thought I was the conspiracy theorist.

  7. And of course, ChrisL’s minor premise is wrong – the failure of vigorous attempts by Thatcher, Roger Douglas and others to make substantial reductions in the ratio of public expenditure to GDP suggests that, at least as far as the political process is concerned, there is no shortage of adequate rationales for government intervention. In fact the reverse is the truth – governments everywhere find more demands than they can deliver. This is true even in the US, where the weaker demand for social services is offset by a higher demand for military action.

  8. I would be interested to have comments from experts on the following line of reasoning:

    (1) According to Table II-4 of the IPCC’s “Climate Change 2001: The Scientific Basis� (available at http://www.grida.no/climate/ipcc_tar/wg1/552.htm ), the model average surface air temperature change to 2030 is 0.18ºC HIGHER under the A1T scenario than under the A1B and A1FI scenarios, notwithstanding that the total projected additional forcing from emissions of CO2, CH4, N2O and tropospheric O3 is LOWER under the A1T scenario than under the other two scenarios (see the preceding tables in Appendix II).

    (2) Thus the greater warming under A1T is entirely attributable to the modelled impact on temperatures of the projected reduction in sulphur emissions, and hence in the atmospheric concentration of sulphate aerosols, under that scenario (see the “Note� to SRES Table II.2.7: “Global burden [of sulphate aerosols] is scaled to emissions: 0.52 Tg burden for 69.0 TgS/yr emissions).

    (3) But the available evidence suggests that the reduction in sulphur emissions projected under the A1T scenario between 2000 and 2030 had ALREADY OCCURRED between 1990 and 2000. According to van Vuuren and O’Neill, 2006, “The Consistency of IPCC’s SRES Scenarios to Recent Literature and Recent Projections�, Climatic Change, March 2006:

    “In SRES, worldwide sulfur emissions were assumed to decline by 3% in the 1990-2000 period… Studies that estimate actual trends in that period now find that worldwide emissions actually decreased by a much larger amount (around 20%)â€? (p. 39). Three studies showing this result are cited as sources (see Table VI on p. 38).

    (4) The observed increase in global mean surface temperatures since 1990 is of the order of 0.3ºC.

    (5) Thus the observed increase in temperature in the past decade-and-a-half is fully explained by the reduction in (negative) forcing from sulphate aerosols, if the models are right. If there has also been positive forcing from emissions of GHGs, this must have been offset by other factors.

    (7) Or the models are wrong.

  9. “the failure of vigorous attempts by Thatcher, Roger Douglas and others to make substantial reductions in the ratio of public expenditure to GDP suggests that�:
    The ‘revenue lobby’ (comprising the ATO, the Treasury and their allies in politics, ACADEMIA, the media and the welfare industry) is alive and well.

    This is defiantly a case of the pot calling the kettle black!
    “at least as far as the political process is concerned, there is no shortage of adequate rationales for government intervention. In fact the reverse is the truth – governments everywhere find more demands than they can deliver.â€? -That doesn’t make it right Mr Quiggin.

    “In fact� :
    “An effectively functioning society is founded upon educated individuals who would then act to restrain the excesses of government or the reckless actions of a mass of people�.

    And you put yourself forward as an “educated individual�.

    Ender:
    It could be getting hotter I don’t know –it seems like it. All I am saying is there could be some scientists (not economists) up in Newcastle with some accurate figures. I prefer scientific evidence to economic speculation.

  11. My consistent take by the way is- as long as ‘we’ via our elected govt allow a product or sevice to be sold legally, there is no legal liability for deleterious, epidemiological consequences to any of us. Otherwise you could theoretically have uni students being sued for being console operators at servos.

  14. Further to my statement above that the model average temperature change to 2030 is nearly 0.2ºC higher under the IPCC’s A1T scenario than under the other two A1 illustrative scenarios, please see also the IPCC’s Figure 9-15(a), which shows the modelled temperature change over this period for each of the seven models individually ( http://www.grida.no/climate/ipcc_tar/wg1/fig9-15.htm ).

    Note that all of the models are similar in that the A1T temperature change (represented by red squares) is about 0.2ºC higher than the temperature change under A1B (represented by red circles) and A1FI (represented by red triangles).

  15. “…..or tobacco companies being sued for making cigarettes? ”
    Well they were previously sued for making cigarettes without warnings on them. Perhaps that’s the answer for all private enterprise nowadays Aidan, from electricity generators, carmakers, coalminers, petrol companies, etc,etc. Place such long and tedious cover all warnings and statements of possible guilt on your products, so as to become almost fatuous. A bit like the fine print with drugs from drug companies these days.

    You really have to wonder what California hopes to gain by suing car manufacturers. What’s next on their list of things to sue? Their petrol, power, bus, train companies, etc?? Will they only sue the American based companies they can legally get their hands on and import all the nasty sued stuff from overseas, in particular China? Will that make these public service retards feel good? The ultimate lotus eaters, eating their own entrails. Sheesh!

  16. econowit – “It could be getting hotter I don’t know –it seems like it. All I am saying is there could be some scientists (not economists) up in Newcastle with some accurate figures. I prefer scientific evidence to economic speculation.”

    Yes there maybe however there are hundreds of scientists all over the world with scientific evidence that shows the climate is warming. Are they all wrong? Also all global warming and cooling are not always caused by the same things. Past warming/cooling is no proof that recent warming is not caused by humans.

  17. Ian – the OBSERVED warming is about 0.6° which would have been much higher without aerosol cooling. Also there is a time lag with warming from the heat sink of the oceans. We have not seen all the warming yet.

  18. Ender

    “There are hundreds of scientists all over the world with scientific evidence that shows the climate is warming. Are they all wrong?� Warming in comparison to what?

    My understanding is that it is very difficult to get accurate records of temperature readings more than 150 years old.

    Some Geologists at Newcastle University might have found a way to overcome this problem and provide us with accurate temperature readings going back for many thousands of years. They do this by analysing the formations of limestone in caves. They apparently leave an accurate annual record of average rainfall and temperature.

    If this method proves to be more accurate than other methods, then the answer to your question “are they all wrong?� would be yes.

  19. How do you define “normal�?, if you don’t know the long term fluctuation in temperatures.

    Maybe, even a few thousand years of temperature knowlege might not be long term enough.

  20. No Ender, I’m talking about the observed warming since 1990 (the base year for all the IPCC projections). That has been at most 0.3°, which is in line with the IPCC’s projections of warming during this period as shown in Table II-4.

    These projections assumed that there would be little change in sulphur emissions between 1990 and 2000. The point is that it now appears that there was a LARGE decrease in sulphur emissions in that decade. According to the models, that leads to WARMING.

    You say that the warming that has occurred would have been much higher without aerosol cooling. But that masking of the warming would have to have occurred before 1990, because since then the decline in aerosols would have been ADDING to the temperature increase which was projected as a result of GHG emissions and the lagged warming from heat sink of the oceans. So my question is: Why has the observed temperature increase been so small?

  21. econowit – “If this method proves to be more accurate than other methods, then the answer to your question “are they all wrong?â€? would be yes.”

    Even if they do provide accurate data, which is a good thing BTW, and it proves there has been warming and cooling in the past this does not mean that recent warming is not happening. The multi proxy studies have shown that recent warming is inprecendented. This new proxy will add to the accuracy of the other proxies however I will be very suprised if it completely disagrees with them.

  22. One of the key points for me from the Prof’s presentation about the precautionary principle is that in the case of global warming we can’t know whether the warming is man made or not, because yes it has happened before without our help.

    But the facts are (from my limited reading) that CO2 has the warming properties it has, and in the past, fluctuations in its levels have been associated with warming (the carbon cycle). And the biggest indisputable fact – we are pumping ****loads of it into the atmospere! More than the earth has ever had done to it before.

    So, the precautionary principle says, what’s the cost erring on the side of safety? Pretty significant, but not that bad (just bad for vested interests). What’s the option value we gain by erring? Anything up to and including avoiding anihilation.

  23. Ian – “So my question is: Why has the observed temperature increase been so small?”

    I don’t know – have you asked this on RC? My take on it would be there is no way of knowing, due to uncertainties, that the decrease aerosol forcing is sufficient to have decreased cooling enough to produce a 0.3° temperature rise. Also Gavin from RC provided this from a post on aerosols:
    http://www.realclimate.org/index.php/archives/2006/04/global-dimming-and-climate-models/#more-292

    “Why does the NOVA documentary (and this review) focus on “Dimming the Sun”, when according to your Global Dimming may have a brighter future radiation at the surface has been brightening since 1990? And given that the rise in global temperature has been fairly steady for the past few decades, what (if anything) does this dimming / brightening cycle tell us about climate sensitivity?

    [Response: The post 1990 ‘brightening’ is less certain than the longer term dimming and is more fraught with data quality and length of time series issues. It may also be restricted to European and US stations, rather than Asian ones. We’ll see though once the data series get longer. Does this mean anything for ‘climate sensitivity’? In the specific sense of the climate response to 2xCO2, no it doesn’t. In the more general sense of how is the planet reacting to all the changes we’ve made, then yes, the surface energy budget is a big (but complicated) part of that. – gavin]”

    So it is quite likely that the brightening does not account for the 0.3° of recent warming.

    For more reading on this:
    http://www.realclimate.org/index.php/archives/2006/02/an-aerosol-tour-de-forcing/

  24. Ender, Thanks for the link to the posting on RC and for the material provided by Gavin.

    The RC posting concludes: “Regardless of the absolute amount of the forcing, future reductions in aerosol emissions will be a positive forcing, amplifying the warming effects of increasing greenhouse gases.�

    The Summary for Policymakers of the IPCC TAR states that: “Temperature increases are projected to be greater than those in the SAR, which were about 1.0 to 3.5°C based on the six IS92 scenarios. The higher projected temperatures and the wider range are due primarily to the lower projected sulphur dioxide emissions in the SRES scenarios relative to the IS92 scenarios� (emphasis added).

    We keep getting told that every line in the IPCC SPMs is carefully considered. If an increase from 3.5 to 5.8 in the top of the projected temperature range is due primarily to lower projected sulphur dioxide emissions, then it follows as a matter of simple arithmetic that governments and their expert advisers believed that an increase of at least 1.15 in global mean temperatures was attributable to reductions in projected sulphur dioxide emissions. Yet in all scenarios these emissions were projected to be at least 30% of their 1990 levels in 2100.

    So the modelled increases in temperature between 1990 and 2000 would have been substantially greater if the modellers had known that sulphur emissions had already decreased by 20% before the IPCC climate projections were published.

    I take Gavin’s point that the post-1990 ‘brightening’ is less certain than the longer term dimming. But the paper that I quoted named three independent estimates, all of which came to a similar conclusion. And it would seem that there must be an upper limit to the ‘brightening’. because sulphur emissions can’t be negative.

    I don’t claim any expertise in this area. I just have the uneasy feeling that there is one story when all of the brightening is in prospect, and a different story when a substantial slice of the prospective brightening has already occurred. In response to Gavin’s statement that “It may also be restricted to European and US stations”, I should mention that the paper I cited said that “The main reasons for this difference [between a projected fall of 3% and an estimated actual fall of 20% in sulphur emissions] are a faster decline in the REF region (than assumed in SRES) and a slower increase in ASIA.”

  25. Ian – “The Summary for Policymakers of the IPCC TAR states that: “Temperature increases are projected to be greater than those in the SAR, which were about 1.0 to 3.5°C based on the six IS92 scenarios.”

    Seing as this is from the TAR in 2001 let see what the 4th assesment says with 5 years more data and research before getting too tied up what the TAR scenerios say.

  26. Econoclast (brilliant name by the way)

    I can relate to it because I’m actually one.

    “and including avoiding anihilation.�
    Are you proposing that mankind has the option to gain immortality if it adopts the precautionary principle?

  27. Ender – It’s not a matter of being “tied up” at all. The sentence that I quoted from the TAR said that “The higher projected temperatures and the wider range [than in the SAR] are due PRIMARILY to the lower projected sulphur dioxide emissions in the SRES scenarios relative to the IS92 scenarios.â€? This statement was quoted by Dr. Penny Whetton, now Leader of the Climate Impact and Risk Stream in CSIRO Marine and Atmospheric Research, in her presentation to a Workshop convened by the Academy of Technological Sciences and Engineering in April 2002.

    I participated in that Workshop and subsequently wrote to the Co-Chairs (Dr. John Zillman and Mr. Jerry Ellis) questioning a number of aspects of the IPCC projections, including this one. As you know, I also questioned the demographic and economic assumptions underlying the scenarios.

    I sent copies of my letter to participants in the Workshop, including Dr. Graeme Pearman, then Chief of CSIRO Atmospheric Science. Graeme subsequently wrote to me as follows:

    “My colleagues and I believe that the issues that you have raised concerning the IPCC SRES scenarios are extremely important. Although CSIRO is increasing its efforts in socio-economic integration of its biophysical science, the reality is that in the short-to-medium term most work in this area will have to come from outside CSIRO. Clearly the [Academy of Social Sciences] could play a leading role in this process. Until your letter earlier this year, we had not really appreciated how little Australian involvement there had been in the preparation and review of the SRES scenarios� (Email message of 23 September 2002).

    Penny Whetton was reported on ABC News as recently as 2 September saying that not much has changed since the TAR. Here’s an extract from the report which is available in full at http://www.abc.net.au/news/newsitems/200609/s1731464.htm – I’ve added the CAPITALS:

    “An Australian scientist who contributes to the world’s foremost authority on climate change says the scientific consensus is that average daily temperatures WILL increase by as much as 5.8 degrees over the next century. The CSIRO’s Dr Penny Whetton says the latest assessment by the Intergovernmental Panel on Climate Change is due to be finalised by early next year. While she will not comment on what the panel’s findings are likely to be, she says NOT MUCH HAS CHANGED SINCE 2001 when the panel made its last assessment. “The science, as it stands now, IS REALLY MUCH THE SAME in that if we factor in those range of future emission scenarios and the uncertainty we have in how fast the warming will occur for a given level of greenhouse gasses – then we’re still looking at a possibility of warmings as high as 5.8 degrees,” she said …â€?

    You tell me to wait and see what the 4th assessment says. You could say the same to Penny Whetton: she knows what it says because she’s a lead author of the “Regional Climate Projections” chapter of the contribution of Working Group I. Perhaps the 4th report will say that “not much has changed” and that it’s “really much the same.” But why? If the projections don’t change when there are large changes in the empirical evidence, why bother assembling that evidence?

  28. This precautionary principle thing has its drawbacks – proponents must also argue for not against premptive miltary action.

    Ditto business, on the OH&S baby that grew into a monster the courts have recently ruled that an employer must also “prescribe, warn, command and enforce obedience” to their commands (McLean v Tedman & Anor.)

    When is enough precaution too much?

  29. On the contrary, Rog, I make the point, citing Rumsfeld’s unknown unknowns remark that, if he had taken unknown unknowns seriously, he wouldn’t have sent US troops into a place that was full of them.

  30. The precautionary principle as it relates to climate science means we don’t have absolute proof so “lets do something” i.e. carbon tax
    What if it is the wrong something?
    The precautionary priciple could equally apply to many other probability projections e.g. floods, earthquakes, meteor strikes.

  31. All very interesting. We all want perfection. Meteorologists make a model and then check it’s ability to accept past data and produce reasonable correspondence with emerging weather facts. Queensland’s vital question is whether the Mary River Traveston Crossing Dam in 3 stages will:
    1. produce useful water for SEQ before it runs out of water (one estimate circa end 2008) – or ever short of a cyclone like Innisfail.
    2. Justify the expenditure of $billions on displacing people , roads,etc and construction in a questiionable base area when alternatives with predictable outcomes like desalination are becoming cheaper with each tech advance.

    A useful base may be indicated by the Australian Rainfall trends 1950-2003 available see Google website Microsoft PowerPoint -ann_farrell.ppt.- this seems to indicate that the Hinze dam is the best bet (perhaps that is why it is the main one with much water) and implies that desalination is the only water source we can give a castiron guarantee for.

  32. “Observed increase in global temperature 0.5 degrees in C20, mostly after 1970”

    John was being very conservative. He should also have included the observation since 2000. It would have been more pertinent to say “observed increase in global temperature at least 0.7 degrees C since 1900, with 0.5 degrees since 1970.”

    “Aberrations in global temperatures of more than this magnitude over longer time frames are a common occurrence.”

    So what?

    “This temperature change could be deemed “normalâ€?.”

    Who says that 0.5 degrees C in 30 years and 0.7 degrees in 85 years is “normal”?

    “I read somewhere recently that research being conducted at Newcastle University (Aust) had discovered that the formations in limestone caves, which occur over many thousands of years, provided very accurate long term records of rainfall and air temperatures over the periods of their formation.”

    Speleothems have been used in paleoclimatology for many years now.

  33. John, prior to the US invasion of Iraq the consensus of opinion was that there was WMD, the specifics were the “unknown”. This is the crux of the Rumsfeld argument, that the evidence is indicative but not definitive.

    Richard Butler from UNSCOM was quite adamant about what he knew, he now knows better.

  34. Rog, this is an old and tired rightwing meme which has been refuted many times. Until UNSCOM was readmitted to Iraq in December 2002, most people (including me) thought Saddam had WMDs. Once the inspectors had looked at all the obvious sites and found nothing, most people of any sense had enough doubt on the matter to support continued inspections rather than an immediate resort to war.

    Quotations from all sorts of people in 2002 and earlier prove nothing. Quotations from Bush, Rumsfeld, Cheney and others in 2003 prove (yet again) that they are shameless liars (I’ll give Powell the benefit of the doubt and accept that he could not believe that, after demanding absolutely rock-solid evidence, he would be fed a bunch of lies to announce).

  35. (7) Or the models are wrong.

    Ian, your back of the envelope calculation isn’t that useful. If you want to compare a model with historical data vs. reality, then compare a model with historical data vs. reality. Don’t handwave around like your doing here.

    As one example of the problems which you’ve ignored is the earth’s thermal inertia. This will damp the effect of a change in the radiative forcing especially over such short time periods to which you are using.

  36. Chris O’Neill

    “Who says that 0.5 degrees C in 30 years and 0.7 degrees in 85 years is “normal�?�

    If you are going to deem something abnormal you should adequately define normal.

    It is very difficult to get accurate records of temperature readings more than 150 years old. So without them, to pronounce short term temperature movements as normal or not is just conjecture.

    Then to propose a new tax based on this conjecture calls into question the motives of the proponents.

  37. Who “fed the lies”? Intelligence did; David Kay resigned in protest at lack of evidence and said that GWB was owed an explanation as to why he had been deceived by the intelligence community. At no time did he blame the executive.

    This was the same intelligence that were surprised at the revelation of Libyan and Iranian nuclear programs and the fall of the Berlin Wall.

    Intelligence gather evidence and extrapolate and hope that they are right, there is nothing new in this.

    Quotations from 2003 only prove the date.

  39. Ian – “It’s not a matter of being “tied upâ€? at all.”

    I don’t know about this mate. By most reasonable standards you are pretty obsessed with these scenerios. And again these are scenerios that may be wildly inaccurate like most economic projections. ABARE has projected $25 per barrel oil for the last 4 years. Its climate change and technology modelling had some pretty dodgy numbers in it as did its analysis of nuclear power.

    “You tell me to wait and see what the 4th assessment says. You could say the same to Penny Whetton: she knows what it says because she’s a lead author of the “Regional Climate Projectionsâ€? chapter of the contribution of Working Group I”

    I am not sure about what Penny Whetton says, the thing to do is to wait and see what the 4th assessment actually says. Speculating from what one person says is a pretty thin argument.

    Whatever the projections we do not know what the final number for warming will be. We do not know accurately the contribution negative forcings will have. We have an estimate based on historical and present data (Anan et al) that climate sensitivity could be about 2.9° (with 90% confidence) however it could be as high as 4.5°. We don’t know what positive feedbacks are starting like permafrost melting releasing methane or albedo reductions due to less ice cover or their effect on the climate and the amount of warming.

    All this uncertainty makes your demands for precision pretty unworkable. There is no precision. Even if you personally did all the economic modelling you could still be 100% out even with the best available data. This is why the precautionary principle needs to be applied. The only real certain facts we have are that greenhouse gases cause global warming and we are producing more and more greenhouse gases. The amount of warming and/or climate change are complete unknowns. In the face of this it is normal to be cautious however we are not doing that. Again if you want scenerios that allow us to continue doing what we are doing with no changes to GDP then construct them yourself – don’t wait for the 4th assessment. The numbers can be massaged to present anything you want which is, I realise, a valid criticism of the whole IPCC scenerio modelling. However it is an equal critisism of what economic modelling anyone does. Very little modelling of this nature is done in a vacuum and is usually done with a conclusion in mind even if that is not the stated aim of the modelling.

    The main point is that we are confronted by a man made phenomenon called global warming. It is real and is confirmed by real physical data and by most people that spend their lives interpreting this data and who are qualified to interpret this data. They however, can not ever give an accurate number about the resultant climate change if any, from this warming. Therefore any economic modelling based on models of climate change are very likely to be inaccurate no matter who does the modelling. The most sensible action humanity can take is to accept that there will be reductions in wealth for some and take actions that will reduce emissions of greenhouse gases to ensure that for most of humanity the planets climate will not change too much and depart from a range where humanity can adapt to the changes in climate.

    That would be the actions of a sensible society. However while wealth and wealth accumulation are the primary objectives of society and everything else is secondary to this this is unlikely to happen. It will only change when/if something happens that puts the environment above wealth in the list of priorities.

    An finally why the IPCC does economic modelling who knows. It must have sounded like a good idea at the time however when it is subject to such nit picking that ignores the fact the the guts of the IPCC reports is the science and not the economics, then perhaps the instigators of the economic reporting are having serious second thoughts.

  40. Another problem with Ian’s analysis is that it depends on the measurements of sulphate emissions (and more importantly) atmospheric concentrations to be accurate.

    Unfortunately, sulphates tend to be the least well known. Because of their short atmospheric lifetime it is extremely difficult to get accurate measurements of global levels. Thus scientists try to calculate this based of known sources of sulphates. Needless to say this is an area fraught with uncertainties.

  41. Further to my previous post I have realised that there is this dilemma.

    Do I, imagining that I am a concerned and well meaning scientist, given the uncertainties in the results of global warming, massage the numbers to present an End of the World as we Know It (EotWawKI) scenerio hoping that this will prompt a majority of the wealthy people of the world to re-order their priorities? Given that if left to themselves the wealthy people of the world will not accept drastic action on climate change if it affects their wealth accumulation ability UNLESS there is a clear, proven and present danger.

    Or do I just present the scientific facts and leave it to the general population to decide what to do. In this case the majority of wealthy people whose primary interest is wealth will use these uncertainities to claim that there is no clear and present danger and that no changes are necessary. ie: it is OK to go on accumulating wealth and keep on emitting greenhouse gases in the pursuit of this wealth which is exactly what is happening at present.

    There are some, Ian most notably, that argue that the first option is exactly what the IPCC has done however if this was true I can see their possible motivation. There will be no action unless the majority of the First World realises that global warming and climate change is a clear and present danger and that wealth accumulation will have to take second place for a while, while the climate is being stabilised. Without a clear and present danger, and the climate numbers do not, at present, clearly and unambiguosly show a danger as there is so much uncertainty then I fear that no effective action will take place until such time as there is a clear and present danger by which time it will possibly be too late.

    However massaging the numbers to present a EotWawKI scenerio (if this is ever done) is also wrong no matter the good motivations hence the dilemma.

    Is there anyway out of this? BTW the wealthy people of the world are us in the First World that control something like 80% of the worlds resources and wealth despite only having 20% of the population.

  42. Ken Miles, I explained that I don’t claim any expertise in this matter, but I was hoping to get some answers from experts on what seem to me to be pertinent questions. The response that Ender obtained from Dr. Gavin Schmidt at Real Climate was useful in that connection, but it tended to reinforce rather than allay my concerns about the IPCC climate projections.

    Let me accommodate you by providing some more historical data. I cited three studies showing steep decreases in aerosol emissions between 1990 and 2000. The most thorough of these is that reported in D I Stern (2005) “Global surface emissions from 1850 to 2000”, “Chemosphere” 58: 163-175. According to Stern’s database, global sulphur emissions in 2000 were 18% below their 1970 level and 22% below their 1990 level. The reduction between 1990 and 2000 reversed nearly 40% of the increase that had occurred in the previous half-century.

    In order to appreciate the significance of this reduction it is necessary to understand that, in order to avoid confusing users, ALL of the IPCC’s scenarios share the same values for emissions in each of the years 1990 and 2000 (see explanation of the process in Box 5-1, p. 243 of the “Special Report on Emissions Scenarios”). The decrease in global sulphur emissions between these two years as estimated at that time was 3%. If the decrease was in fact 22%, the IPCC’s estimate of the additional “total radiative forcing from GHG plus direct and indirect aerosol effectsâ€? between 1990 and 2000 would have been far greater than that shown for this period in Table II.3.11. Just how much greater is a simple question of fact, to which I would very much appreciate an answer from someone familiar with the technicalities of the IPCC simple model.

    I’d also be glad of advice of the implications of the higher forcing for projections of temperature increases, having regard to all factors including thermal inertia. In this regard I note that (a) according to Stern’s estimates, sulphate emissions declined by 20% between 1991 and 1996, so ten years have already passed since the greater part of the reduction occurred; and (b) the IPCC’s simple model projections show a temperature increase of 0.24°C between 2000 and 2010 for the A1T scenario, compared with 0.16°C for A1FI and 0.14°C for A1B – i.e. the projected reduction in sulphur emissions in A1T seems, prima facie, to be quickly reflected in higher projected temperatures in that scenario.

    In the light of Gavin Schmidt’s observation that the post-1990 “brightening� may be limited to European and US stations, it is relevant to note that the IPCC’s standardised projection of sulphur emissions in the ASIA region, published in 2000, was for an increase of 43%. Stern’s estimate, published in 2005, is for an increase of 6%. Quite apart from the implication of differences on this scale for climate projections, on which I am seeking advice, do they not also raise questions about the quality of economic modelling in the IPCC’s Special Report?

    John, Ken Miles asks me not to “handwave like I’m doing here�. I don’t think that I am handwaving – I believe that I’m raising important questions which bear on the validity and integrity of the last IPCC assessment, and that the IPCC should have considered these questions before deciding that “the SRES scenarios provide a credible and sound set of projections, suitable for use in AR4.� I also believe that governments should have asked those questions in 2003, and should continue to ask them until they get answers.

    I’m certainly not going to stop asking these questions in deference to Ken Miles, but it’s your blog and I’ll defer to you if don’t want them pursued here.

    Ender, I believe that scientists and other experts have an obligation to tell it like it is. Where did you get the figures in your last paragraph from – the last IPCC Report?

  43. Just a quick note because I’m busy at the moment.

    I didn’t mean that stop handwaving as in stop commenting, but rather that I don’t think that your analysis is particular useful given the complexity of the climate system which your ignoring.

    Sorry for the poor wording on my part.

  44. Ian – “I believe that scientists and other experts have an obligation to tell it like it is”

    So do I however, do those same scientists and experts, in all conscience, allow the world end up excrement creek without a paddle all the while saying piously “well I told it like it is” as we bravely paddle on.

    I don’t think that question has an answer.

    “Where did you get the figures in your last paragraph from – the last IPCC Report?”

    No a couple of sources:
    http://www.ghgonline.org/kyoto.htm
    http://hdr.undp.org/reports/global/1998/en/

  45. Thanks Ender. That Human Development Report (HDR) that you are relying on for your information about global income distribution was published in 1998. I made extensive criticisms of this material in a report that was tabled at the United Nations Statistical Commission at its 2000 meeting. At the request of the meeting, a group of eminent statisticians examined the HDRs and found that they contained “material errorsâ€? – i.e., errors “which leave the reader with a fundamentally distorted picture of the phenomenon being described.â€?

    You can read about this in the Australian Treasury’s article “Global poverty and inequality in the 20th century: turning the corner?â€? – the details are given in Box 3 on p. 17 of the article, which is at http://www.treasury.gov.au/documents/110/PDF/Round2.pdf . See also the Treasury’s “manifestoâ€? on p. 47, which states that “International comparisons of national shares of global production and of living standards should use Purchasing Power Parities [PPPs], not exchange rates, as already agreed by national statisticians and embodied in the UN’s 1993 System of National Accounts.â€?

    I’m glad to say that the HDR Office of the UNDP accepted the criticisms and has improved its statistical presentation and reporting in subsequent issues of the HDR (see Ian Castles and David Henderson, 2005, “International Comparisons of GDP: Issues of Theory and Practice�, in “World Economics�, January-March 2005, p. 78). In fact, the UNDP recognised that the method it had followed in HDRs up to and including the 1999 Report in the 2001 HDR (see Box 1.3 on p. 20).

    Unfortunately, the UNDP’s erroneous estimates had been reproduced in a number of chapters of the contributions of Working Groups II and III to the IPCC’s Third Assessment Report, and exchange rate-converted GDP estimates and projections were also used in the IPCC Special Report on Emissions Scenarios. I advised Dr. Pachauri, the Chairman of the IPCC, of these errors in correspondence in late-2002 and also wrote to the Coordinating Lead Authors of the relevant chapters. Unlike the UNDP, however, the IPCC is apparently incapable of admitting error.

    The Australian Government Submission on the scoping of the IPCC’s Fourth Assessment Report (March 2003) urged the IPCC involve national statisticians and the UN Statistical Commission in its work, but this advice has been disregarded.

    Treasurer Costello discussed this matter in his speech to the Lowy Institute in September 2005 ( http://www.treasurer.gov.au/tsr/content/speeches/2005/013.asp ): you’ll see from the data in Table 3 of that speech that China and India alone accounted for 20% of the world’s GDP in 2004 – but these two countries account for less than 40% of the world’s population, not 80%.

    In an article reporting on the Treasurer’s speech, the leading Australian economic journalist Ross Gittins described the practice of using exchange rate conversions as “a terribly outdated and unscientific method of comparing the size of economies� and said that “No self-respecting economist uses that method� (see http://www.theage.com.au/news/ross-gittins/ costello-counts-china-as-worlds-no2-economy/2005/09/23/1126982225937.html ). But the IPCC resolutely refuses to let it go.

    Incidentally the Australian economist Colin Clark used PPP comparisons exclusively in his keynote address to the United Nations Scientific Conference on the Conservation and Utilization of Resources (UNSSCUR) on 17 August 1949, so the IPCC is now over 50 years behind the times. In the course of his speech Clark contested the contention of William Vogt (in his book “Road to Survival�, 1948) that “It is obvious that fifty years hence [i.e. In 1998] the world cannot support three billion people at any but coolie standards for most of them.�

  46. Ian – “That Human Development Report (HDR) that you are relying on for your information about global income distribution was published in 1998. I made extensive criticisms of this material in a report that was tabled at the United Nations Statistical Commission at its 2000 meeting.”

    Now how did I know that was coming? Just wondering if you have had time to criticise the 2005 report here?

    http://hdr.undp.org/reports/global/2005/

    It reports that not a lot has changed. However that is not the point – the point is that we Australia, Europe the USA etc are vastly more wealthy than than third world countries. I am classing myself with the wealthy as are you.

  47. “If you are going to deem something abnormal”

    Where did I deem something abnormal? I wasn’t the one who asserted:

    “This temperature change could be deemed “normalâ€?.

  48. You’re right Ender. Australia, Europe & the US are vastly more wealthy than Third World countries. So?

    And on another thread you say that “dissent should be within the peer reviewed scientific community.” So does your tolerance for dissent extend to the paper in the March 2006 issue of “Climatic Change” by Alison Stegman of the Climate Risk Concentration of Research Excellence at Macquarie University, on the subject “How Should Emissions Projections Be Evaluated?”

    Alison says that there is a need for “a large scale review [of the IPCC emissions scenarios] on the grounds of statistical inaccuracies, methodological assumptions and empirical inconsistencies.” She concludes that “The IPCC has not demonstrated that the SRES emissions projections have a sound economic foundation”, and that “Because these emissions projections are used as inputs in models of temperature and climate impacts, these in turn do not have a sound economic basis.”

    And even if the economic inputs to models of temperature and climate impacts had been right (which we now know they weren’t), the model outputs don’t square with the observed trends in temperature. The reduction in sulphur emissions that the A1T scenario projects for 2030 had already occurred by 1996 but, as you acknowledge, “the rise in global temperature has been fairly steady for the past few decades”. Why? How large does the discrepancy between modelled and actual outcomes have to be, before you’d concede that there must be something wrong with the climate models? And even if the climate models are right, why persist with emissions projections which do not have a sound economic basis?

  49. Chris O’Neill said:

    “Who says that 0.5 degrees C in 30 years and 0.7 degrees in 85 years is “normalâ€??””

    So it is agreed that we can not define this temperature variation as a normal or abnormal occurrence, due to there being inconclusive data to formulate such opinions.

  50. ““Who says that 0.5 degrees C in 30 years and 0.7 degrees in 85 years is “normalâ€??â€?”

    So it is agreed that we can not define this temperature variation as a normal or abnormal occurrence”

    I’m not saying that either, just asking who (with any justification) says “This temperature change could be deemed “normalâ€?.”

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