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Perth forum on climate change: all the gory details

Posted on 30 June 2010 by John Cook

On Monday night was the Public Forum on Climate Change, hosted by the University of Western Australia and presented by local scientists. The driving force behind the event was Stephan Lewandowsky, a cognitive scientist at UWA who worked tirelessly over the last month to organize the event. Stephan also invited me to come over and offer some Skeptical Science assistance.


Left to Right: Kevin Judd (Professor, School of Mathematics and Statistics), Matt Hipsey (Assistant Professor, School of Earth and Environment), John Cook (blogger, School of Hard Knocks), Stephan Lewandowsky (Professor, School of Psychology)

Early Monday morning, Stephan and I headed over to local radio station RTR FM for an interview about the event. Straight up, the interviewer asked me what I thought was the most convincing skeptic argument. Tough question to answer! On the way back to campus came the news that local rag The West Australian had ran a small piece about the event in the morning edition. The emphasis was on small but nevertheless was generating a lot of enquiries at the university.

The first speaker was Stephan who spoke of the perils of ignoring scientific consensus, using South African President Mbeke's policies on AIDS as a cautionary tale. I also enjoyed his expounding on "the joys and rewards of true skepticism". By true skepticism, he means taking in all the evidence before coming to a conclusion, a definition I also subscribe to.

Next was Kevin Judd, an expert in climate modelling. Kevin spoke about the difference between "junk science" and real science - that junk science consisted of cherry picking select pieces of data while real science looks at all the data. Again, a theme I expound upon regularly here - I've pretty much beaten the "small piece of the puzzle" metaphor to death (that doesn't mean I'm going to stop using it).

Kevin was followed by Malcolm McCulloch, a coral reef researcher. He went into some detail about ice age cycles and why CO2 lagged temperature by roughly 800 years in the past. My interest was piqued by some of his own research discovering another "human fingerprint" - the level of carbon 13 in coral reefs (I later asked if he could email me his research - expect a post on this soon).

Last up was Volker Oschmann, a German government official who over the last ten years has been in charge of Germany’s renewable energy legislation. Volker's talk was a refreshing change of tack as he outlined the exciting developments in Germany, a country that had long accepted humans were changing climate and were hard at work doing something about it. It was an appropriate way to finish off the 4 talks, exploring the practical way forward. Really, the whole evening should've been about solutions and it's a crying shame 3/4 of the content had to be about the evidence we're causing climate change rather than ways we could be fixing it.

Volker explained how Germany had actually reduced their CO2 emissions in recent decades while at the same time, their economy got stronger. Over the same period, Australian CO2 emissions have increased. It was a bit embarrassing as an Australian, considering the potential our country has for solar and wind energy. But at least Volker didn't begin his talk with the slide "4 - 0" which he'd reportedly used last week, shortly after Germany had annihilated Australia at the World Cup.

The fun began when we opened it up to questions. Predictably, there were a few hard hitting skeptics in the audience. As the questions came, I was poised over the Skeptical Science website, ready to jump to the relevant graphs to be displayed up on the cinema sized display. My favourite skeptic argument of the evening was a new one to me (and I thought I'd heard them all). One audience member asked Malcolm if CO2 lagged temperature rise by 800 years, wasn't the current CO2 rise just a lagged response to the Medieval Warm Period? Malcolm was initially staggered at the implausibility of the idea but gathered himself quickly and on the fly, calculated that any ppm rise from the estimated MWP warming would be at most 10 ppm (the actual rise from pre-industrial levels is around 100 ppm). Later he mentioned to me 10 ppm was probably an overestimate. < /p> < p> The number of people attending the event was encouraging. Noone thought to actually count numbers but at the post mortem, the general consensus was around 150 to 200. A lot of credit for this must go to Stephan. In his preparations to organize and promote the event, he left no stone unturned. It was great to get the scientists who are actually doing climate research out there communicating their science to the public in clear, understandable terms - something that needs to happen more often.

Note: the video isn't ready yet but the plan is to post full video of the event at www.uwa.edu.au/climatescience.

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Comments 1 to 28:

  1. When the RTR FM interviewer asked you what you thought was "the most convincing skeptic argument", it was of course because -- being a journalist -- he had got completely the wrong end of the stick about what you represented, John. Did they take a poll at the end to ascertain how many people had been persuaded by what they had heard?
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    Response: No, he got me, he started the segment saying "today we're going to get skeptical about global warming skepticism". I thought, hey that sounds catchy, then remembered that was the slogan at the top of the Skeptical Science website. It was just a clever question, I'm still undecided on what's the best answer (I went with using photos to cast doubt on the surface temperature record as pictures are so persuasive, then pointed out what that's irrelevant from a scientific point of view).
  2. John Cook, the "CO2 rise is just a lagged response to the Medieval Warm Period" argument is not at all uncommon, and it is rather easy to counter. Simply point out that for it to be true global mean temperature would have to have remained at least the same since the MWP for the entire ocean to have warmed and reached a new, warmer equilibrium. The problem with this fantasy is the Little Ice Age. This is another example of one "sceptic" argument that is contradicted by another. I've actually successfully stopped a hard-core "sceptic" cold by pointing this contradiction out to him, much to my own surprise.
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  3. My favourite skeptic argument of the evening was a new one to me (and I thought I'd heard them all). One audience member asked Malcolm if CO2 lagged temperature rise by 800 years, wasn't the current CO2 rise just a lagged response to the Medieval Warm Period?
    I've come across this one a few times. My reply, FWIW as a layman, was that the lag started at ~800 years, but it was another 4k years before the atmospheric concentration of CO2 increased by 100 ppm. We've had an increase of 100 ppm in 100 years (carbon sinks accommodating excess anthropegenic CO2 up until around the end of the 19th century). This is a rate 40 times faster than ice age carbon cycles - or 20 times faster if we take the start point of modern CO2 rise as the beginning of the industrial revolution. Also, the 100ppm rise accompanied a global temp change of 5 - 6C through deglaciation. The MWP temp rise, at skeptics' highest posit, was less than half that. Therefore, the MWP can only have made a tiny contribution to post-industrial CO2 concentration in the atmosphere, if any. Please, correct any errors in my assumptions or reckoning. The objection is not common and I had only my probably faulty memory of the reams of stuff I've read hither and yon.
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  4. Simply point out that for it to be true global mean temperature would have to have remained at least the same since the MWP for the entire ocean to have warmed and reached a new, warmer equilibrium. The problem with this fantasy is the Little Ice Age.
    Ha! I mentioned that too, in times past, but the rejoinder was that the lag will produce the same curve in CO2 as temps, just 800 years later. So CO2 will go down pretty soon, matching the downturn to LIA 800 years later. If you try to say that sustained warm temps are required, they will hit you with a handful of wiki graphs showing temps going up and down during deglaciation. When you try to point out the time scale of events, you will be informed that the resolution just isn't that good for ice ages. After that, most likely the discussion will descend to the political or personal.
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  5. The photo in the post needs a caption. Who's who?
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    Response: Good point, caption added. Thanks for the suggestion.
  6. All good stuff but in a city with a population of well over 1 million, attendance by 200 does seem a bit disappointing. Perhaps there is already wide acceptance of AGW and knowledge of how to deal with it in the community, though I doubt it. Has there been good press coverage? What follow-up is planned? Maybe a practical demonstration of how individual households can reduce their carbon footprint?
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  7. Re the idea that the current rise in CO2 might be due to an 800 year lag from warming during the MWP: I encountered that argument for the first time a few days ago in Ian Wishart's book Air Con. It seemed unlikely; thanks for the counterarguments.
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  8. The MWP lag suggestion falls into the category of those skeptic mechanisms that rely for their validity on the incredible coincidence that they occur exactly at the time when CO2 pumped out by industry begins to really massively increase. That these arguments all rely on us not noticing that is no coincidence.
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  9. Barry, at our current 2 ppm CO2 increase per year, we are increasing CO2 at a rate of just under 2,000 times that of the previous 800,000 years where CO2 ranged naturally between 190 ppm and 300 ppm every 100,000 years. Scott A. Mandia, Professor of Physical Sciences Selden, NY Global Warming: Man or Myth? My Global Warming Blog Twitter: AGW_Prof "Global Warming Fact of the Day" Facebook Group
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  10. My counter to the "CO2 is just the result of the MWP lag" would be this-"where does all the excess CO2 come from?" If you look at the Ice Cores that show the various Milankovitch Cycle driven Glacial & Inter-glacial periods, you can see that CO2 concentrations rarely get much above 260ppm-& *never* get above 300ppm-in spite of temperatures rising by around a couple of degrees above those at any period in the Holocene. All available Paleo-climate data shows that temperatures in the MWP never reached the heights of previous Inter-Glacial periods. So, if this CO2 is from natural sources only, then why did much warmer periods not produce CO2 concentrations of around 400ppm or more? My understanding is that its because ca. 280ppm is the total amount of CO2 available in the Quaternary Era Atmosphere & Carbon Sinks combined. Therefore the only other source for this CO2 (aside from *massive* volcanism) must be coming from fossil fuels formed when CO2 levels were at levels of 1000ppm or above. My other counter would be "show me the 14-C fingerprint that proves the CO2 from natural sinks".
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  11. Marcus at 16:11 PM, my response to youir post has been deleted, but your post remains. Can whoever moderated the post explain. If my response was OT, so is the post I responded to. What has happened to the courtesy normally extended if posts are tending off topic?
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  12. Maybe John, its because you were trying to drag the topic back to CO2 as a plant food again- & again without a skerrick of proof to back you up. This comment will probably be deleted, but I hope you see it before it does, so you understand why your post was OFF-TOPIC, wheras mine at 16:11 continues the already existing theme for this thread-namely how to respond to denialists like yourself.
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  13. @Marcus 280 ppmv. Easily accessible (due to warming) and natural sources, eg : detritus of soil - estimated age: at least 1000 - a maximum of 10,000 years (the majority in the polar area, which is the fastest warm feeling) is still currently available quantity is estimated at 600 - 800 Gt C.
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  14. I've just opened the previous post tonight and was very pleasantly surprised to find Volker's study which I've just downloaded. Now that's just so thoroughly German (in the best sense of the word) to address the very question I thought nobody seemed to be asking (the carbon cost of making a transition to renewables). I'll be reading it with great interest. Thank you John and Volker :-)
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  15. chriscanaris, the report is thoroughly German in other ways, too. The table of contents lists sections hierarchically up to four layers deep. The table of contents & list of figures etc. runs on for 35 pages!
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  16. Scott Mandia, thanks for the reply. I was under the impression that glaciation took the longer time, and that deglaciation, accompanied by rising CO2 levels, took ~5000 years in late Quaternary ice age cycles*. I'm sure the skeptics I face would soon point this out and the main point would be derailed. * (Again, please correct any misapprehension on my part)
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  17. I think the best skeptical argument is the interplay of positive and negative feedbacks. As I understand it, CO2 itself is good for .75-1.0C of temperature increase per doubling of CO2. The consensus "all-in" temperature increase is 3C/doubling. However, in my understanding of the science, feedbacks seem to be the most complicated, dynamic and chaotic of all of the climate related issues. Some feedbacks are both positive and negative (cloud cover). A recent discussion on RealClimate.org highlighted an aspect of the uncertainty: http://www.realclimate.org/index.php/archives/2010/02/good-news-for-the-earths-climate-system/ I strongly suspect the 3C figure will turn out to be robust, but I think it is the strongest argument the skeptics have, as the data is not all in, and reasonable doubt can be cast upon ice core records, tree ring data, etc., etc.
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  18. @actually thoughfull, Is climate sensitivity really the skeptics-deniers strongest argument? Evidence can be presented that it is ~3C or so. There is no strong evidence that it departs for that figure in a significant way - the Lindzen&Choi paper and Dr Roy Spencers efforts have not bee met with any acceptance in the scientific community. The burden of proof is on the positive claim, and the evidence has been provided. Reasonable doubt is the task of the rejectionists, but they have failed to meet that standard.
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  19. Further to tobyjoyce's thoughts, despite all the ineffectual #9 birdshot volleyed in the direction of Earth climate theory and models, doubters would do better by concentrating on the effect of clouds on sensitivity. Why there's so much attention paid to mirage targets is an enduring mystery.
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  20. @ Arkadiusz Semczyszak-that doesn't answer the question. If, as you claim, this detritus has been around for 10,000 years, then why didn't CO2 levels rise to above 280ppm during-or 1,000 years after-the Holocene Optimum (the peak of the current inter-glacial period)? Also, if the excess CO2 were from detritus, then we'd expect no change in the C-14/C-13/C-12 signature of the atmosphere-yet we are.
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  21. barry, You are correct! I was oversimplifying by looking just at the peaks over time and not the rate of change to get to those peaks. It does appear that CO2 increased fairly rapidly (on natural scales) in the 5,000 years after deglaciation. If we use the current 2 ppm rate then we are increasing CO2 about 80 times faster than nature. Sorry for the mistake.
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  22. Part of the reason that Germany has reduced its C02 emissions is that they are running out of coal. C02 emissions in Australia have increased partly because we have an abundance of coal. Most coal mines in Germany are now too deep to be economic, but are subsidised by the German government to look after the workers and industry infrastructure. Of course this cant go on forever, so they are gradually phasing it out. Now they are subsidising renewable energy. Another poin to note is that the German Government commissioned a report by its own hiogh ranking scientists to look into whether humans were causing global warming about 10 years ago, which concluded that humans were not responsible for global warming. The then socialist government banned the book, ignored the conclusions of its own scientists, and went ahead with its ideological policies, and has done so more or less since. The reason that GDP has increased in Germany has nothing to do with renewable energy, but basic supply of water and food resources and favourable trade and geographic position, which it has always possessed. Spain does not had this advantage, and look at the disaster that is happening with Spain's renewable energy policies.
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  23. thingadonta wrote : "Another poin to note is that the German Government commissioned a report by its own hiogh ranking scientists to look into whether humans were causing global warming about 10 years ago, which concluded that humans were not responsible for global warming. The then socialist government banned the book, ignored the conclusions of its own scientists, and went ahead with its ideological policies, and has done so more or less since." Firstly, you do realise that there hasn't been a 'Socialist' government in Germany for the last 5 years ? Secondly, where's your evidence ? Hopefully you have seen some ? If so, please provide it.
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  24. In fact, thingadonta, do you have any sources for any of your assertions concerning Germany ?
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  25. re #24: JMurphy Look into Plimers recent book. Even as AGW skeptic I have some major problems with some of his arguments, and overall writing style, but I still think it is a useful source of skeptical information.
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  26. Also, the source for my coal information in Germany is from a colleague who specialises in strategic assessments of coal resources for government.
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  27. thingadonta wrote : "Look into Plimers recent book" No thanks : I prefer fact to fiction, when it comes to science, data or evidence. thingadonta wrote : "Also, the source for my coal information in Germany is from a colleague who specialises in strategic assessments of coal resources for government." Could you please therefore ask your colleague for some sources.
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  28. #27: I'm sorry J Murphy, I dont work in government anymore, and don't keep in touch, but its encouaging to see that at least you might have actually been interested in this source, and not Plimer's.
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