tip off
2,321

Climate change cage match — a fight to the death

The Crikey Daily Mail’s hallowed Comments, Corrections, Clarifications and C*ck ups section is always jammed with heated arguments over climate science. In particular, there’s one regular commentator who manages to poke at this particular sore so effectively as to enrage and engage readers in a never ending tit for tat that, quite frankly, drives our production editor insane (we’re looking at you, Tamas Calderwood.)

So in the interests of creating a bit of breathing space in the email, and sharing the (not always informed) debate with Rooted readers, we’d like to present the CLIMATE CHANGE CAGE MATCH — a fight to the death.

There’s a robust discussion taking place on the Wilkins Ice Shelf (or what’s left of it) elsewhere on the blog, but the following debate will take place around the general consensus on climate change (yes, there are still a few out and proud sceptics who love to thrash it out and who are we to stop people from making fun of them?)

Picking up where we left off,  here’s Tamas Calderwood from yesterday:

Stephen Morris (yesterday, comments) says that CO2 has recently increased to the “unprecedented” concentration of almost 0.0004 of our atmosphere and says this increase “almost exactly corresponds with the large temperature increases over the last 50-100 years”. First, CO2 has been more than 10x current levels in the past.
Second, what large temperature increases is he talking about? Once again, we’ve had zero warming in the past 10 years, less than 0.4C in the past thirty years and around 0.7C in the past hundred. The data are available to anyone with access to Google and the ability to type “temperature data”.

Ding ding ding! Play nice kids…

2320

Please login below to comment, OR simply register here :



  • 1
    EnergyPedant
    Posted April 8, 2009 at 11:27 am | Permalink

    0.4 degrees in the past 30 years is a lot to many biological processes. That temperature growth is almost certain to continue at the same if not greater rate.

    As always climate change is actually a more important concept than global warming. Average temperatures can stay the same but more extreme summers and winters can cause havoc. You need to look at rainfall patterns, the maximum temperatures, the strength of storms, etc….

  • 2
    Mark.Byrne
    Posted April 8, 2009 at 2:28 pm | Permalink

    Re Ken Lambert comments of April 8th,
    One reason we cannot rely on one proxy for temperature over the last 10 thousand years, is that different proxies measure temperature in different regions (forest versus corals etc).
    Thus a variation of 2.8 degrees in one region is not representative of global variation. Hence we must consider all proxies to determine a realistic or “best estimate” of global temperature. The best estimate indicates that temperature was relatively stable over the last 8-10 thousand years.

    The concentration of greenhouse gases is more stable than temperature hence can be determined with less noise.

  • 3
    Mark.Byrne
    Posted April 8, 2009 at 2:34 pm | Permalink

    My last sentance should read,

    “The concentration of greenhouse gases is more globally consitant than temperature hence can be determined with less noise.”

  • 4
    Andrew Glikson
    Posted April 8, 2009 at 2:59 pm | Permalink

    There is a general misunderstanding of the significance of mean global CO2 levels and temprature rise, as follows:

    1. A mean T rise of 1 degrees C means up to 4 or 5 times T rise in certain parts of the Arctic circle and Antarctica (look at NASA/GISS temprature charts).
    2. Spring temprature rises of this magnitude lead to rapid melting of sea ice and ice shelves.
    3. This melting is a self-enforcing mechanism, i.e. due to the high albedo/reflectivity of ice and the infrared-absorption properties of water, once ice starts to melt exposed water absorb solar radiation, re-melt more ice, etc. resulting in fast feedbacks
    4. The warming water release CO2, which results in further atmospheric warming.
    5. Which is precisely the explanation for the abrupt nature of ice age terminations, within a few decades to a few years (Steffensen et al. 2008; Kobashi et al., 2008).
    6. Whereas the glacial terminations were triggered by maxima orbital forcings induced by the Milankovic cycle (eccentricity, precession, axial tilt), the current warming has been triggered by the industrial emission of over 300 GtC.
    7. The synergy of abrupt shifts in the state of the atmosphere/ocean system has been underestimated.
    8. The polar ice is on the way out from about 400 ppm CO2 (or 450 ppm CO2-equivalent [including metghane] upward
    9. Currently CO2 is at 387 ppm and CO2-equivalent near 440 ppm.

    The polar ice sheets constitute the “thermostats” of the Earth. Once they are gone, the planet returns to its pre-34 million years-ago (Eocene) greenhouse state.

    The “powers to be” are still not listening to climate science, assuming the atmosphere can be manipulated by analogy to the economy (not that they were too successful in this department).

    Unfortunately they can not argue with the chemistry and physics of the atmosphere

    Andrew Glikson
    8-4-2009

  • 5
    Mick Thompson
    Posted April 8, 2009 at 3:33 pm | Permalink

    I can’t make up my mind……Is the correct anagram for Tamas Calderwood……Warmed Data Cools……or Cool Drama Wasted

  • 6
    Albert Ross
    Posted April 8, 2009 at 3:38 pm | Permalink

    Over in Wongan Hills WA it’s a case of what climate change, drought etc…

    A hilltop near the Wheatbelt town of Wongan Hills will become the site for one of the State’s most spectacular Easter celebrations as a huge cross made of hay bales is set alight on Friday night.

    Members of the local Anglican parish and volunteers spent the weekend laying out a cross measuring 1.8km by 1.1km, made from more than 400 donated hay bales, in the middle of a bare paddock.

    http://www.thewest.com.au/default.aspx?MenuID=146&ContentID=134933#

    All seems a bit pagan doesn’t it?

    There are plenty of farming folk on the east coast who might be able to use the hay for fodder let alone the organic farmers and growers who could use it for mulch.

    There are three other issues…

    1) burning crosses are the symbol of the KKK
    2) a fair amount of carbon and pollutants will be released to the atmosphere
    3) pyromaniacs may be inspired by the example

  • 7
    Darren O''''Shaughnessy
    Posted April 8, 2009 at 4:05 pm | Permalink

    Tamas Calderwood -> Cools Warmed Data

    An apt anagram indeed

  • 8
    Tamas Calderwood
    Posted April 8, 2009 at 4:17 pm | Permalink

    G’day Crikey – this is great! I look forward to the ongoing blog debate but I hope we can keep some of it in the comments section too.

    Anyway, my first point is in response to Harold Thornton. He says that when CO2 was orders of magnitude higher it was an “utterly different world hundreds of millions of years in the past when Antarctica was a tropical paradise”. Well, yes Harold but you have heard of plate tectonics? Hundreds of millions of years ago Antarctica wasn’t on the south pole. Since it’s drifted there it’s built up a massive ice sheet and become a little less balmy. Give it a coupla hundred million years and it’ll be all warm and tropical again. CO2 not required.

    I also want to respond to Andrew Glikson’s point: 6. He says “Whereas the glacial terminations were triggered by maxima orbital forcings induced by the Milankovic cycle (eccentricity, precession, axial tilt), the current warming has been triggered by the industrial emission of over 300 GtC.”

    Andrew, this is simply an assertion without any supporting evidence. What evidence do you have that recent (and very mild) warming results from industrial CO2 emissions and not other natural factors?

    In any case, I’m on holiday for two weeks so my postings will be a bit light. I know, I know… thank god…

    Regards,

    Tamas Calderwood

  • 9
    Boerwar
    Posted April 8, 2009 at 4:22 pm | Permalink

    Andrew Glikson – as smart as a pine bark beetle!

    The Pine Bark Beetle Collective does not appreciate your sharing your insights with other humans in case they take any notice at all of what you are sayiing. The beetles currently chewing their way through tens of millions of hectares of virgin conifer forests in North America know perfectly well that temperature changes are not uniform across the globe.

  • 10
    Mark.Byrne
    Posted April 8, 2009 at 5:30 pm | Permalink

    “this is simply an assertion without any supporting evidence”

    :)

    Irony eh!, I like it.

  • 11
    Andrew Glikson
    Posted April 8, 2009 at 11:57 pm | Permalink

    Tamas Calderwood,

    In so far as you wish to acquiant yourself with the peer-reviewed climate science literature, I will be happy to send you recent key papers by leading US, German and Australian researchers in the physics and chemistry of the atmosphere, based on both current observations and study of the evolution of the atmosphere during the glacial-interglacial cycles, including my own publications.

    If so, let me know which E-mail address to send it to.

    Regarding greenhouse Earth conditions, such existed prior to 34 million years ago (end Eocene) whe CO2 levels were higher than 500 ppm, and as high as 2000 – 3000 ppm during much of the Cretaceous, as is well documented by multi-proxy studies, in particular the following papers:

    Zachos, J, 2001, Science 292, p686;
    Burner, RA,2004, Oxford University Press, New York;
    Royer, DL et al, 2001, Science 22;
    Royer, DL et al, 2007, Nature 446, p530;
    Hansen, J, et al, 2007, Phil TransA 365, p1925;
    Gingerich, PD, 2006, Trends in Ecology & Evolution 21, p246;
    Berner, RA, 2006, Geochimica et Cosmochiica Acta 70, p5653;
    Berner,RA, and Beerling, DJ, 2007, PalaeographyPalaeoclimate Palaeoecology 244, 368;
    Berner, RA, et al, 2007, Science 316, p557;
    Beerling, DJ, and Berner, RA, 2005, PNAS 102, p1302
    Dowsett, HJ, et al, 1999, US Geological SurveyOpen-file Report 99–535;
    Dowsett, HJ, et al, 2005, Paleocean 20, p2014;
    Dowsett, HJ, et al, 1994, Glob Planet Change 9, p169
    Petit, JR, et al, 1999, Nature 399, p429;
    EPICA, 2004, Nature 429, p623;
    Siegenthaler, U, et al,
    2005, Science 310, p1313;
    Solanki, SK, 2002,
    Science 310, p1313; Broecker, WS, 2000 Earth-Science Reviews 51, p137
    Kobashi, T, et al, 2008, Earth Planet Sci Lett 268, p397
    Steffensen, JP, et al, 2008, Science Express, 19.6.2008
    Siddall, M, et al, 2003, Nature 423, p853
    Braun, H, et al, 2005, Nature 438, p10
    Rahmstorf, S, 2004, Abrupt climate change, Weather catastrophes and climate change, essays collected by Munich Re Group

  • 12
    Tamas Calderwood
    Posted April 9, 2009 at 8:30 am | Permalink

    Andrew Glikson,

    I am happy to read any papers you have to send my way. Sophie Black at Crikey has my hotmail address and I am happy for her to pass it to you (I’d prefer not to post it in a public forum)

    I must point out that sending me papers doesn’t make your case on point 6 (above). You must state the evidence that industrial CO2 emissions have caused recent (mild) warming. There is no evidence that they have and computer model predictions don’t count ( and don’t work anyway)

    For the benefit of all readers, please explain in simple terms how CO2 is the major factor in recent climate activity. Please explain how ALL other natural factors have no explanatory power in recent observations.

  • 13
    Ben Sandilands
    Posted April 9, 2009 at 9:28 am | Permalink

    So far there has been no blood in the death cage, which given the real issues is encouraging.

    I’ve been adding to the discussion in the previous thread to this, explaining why I am offended by ‘spin’ in these issues and where I fear the focus gets lost in the general media.

    Quote.

    I’m not participating in this truly important discussion to argue against anthropogenic climate forcing, which I firmly believe is proven and serious. Rather I’m concerned that the real science is prostituted in some quarters by those who want to engineer the message to serve an agenda, which may not actually deliver the focus on the core issues of greenhouse gas reductions which deserves to dominate our attention.

    The general debate about climate change in these times is too much like a circus and not enough about real action. The lunatic fringe of climate change denial isn’t worth pursuing. But the reasoned, closely argued and empirically validated pursuit of research and action is of critical importance to us all.

    Unquote.

    I don’t think there are any lunatics in our room. Some who may be mistaken, or focussed on interesting yet immaterial matters, perhaps.

    Outside the Palmer Peninsula some of the response times to warming in Antarctica may be so slow that they could be included in the next glacial….if we haven’t stuffed the atmosphere so badly that there is no next glacial. But the impact of excessive liberation of fossilised carbon on us, and much more pertinently, our children and grandchildren, needs significant response now.

    I don’t think interpreting the Wilkins break up exclusively as a global warming event is helpful. Great headlines and fascinating images, for sure, but in recent years a string of warnings about greenhouse gas enhancement, has not lead to effective action. Thus I think framing everything in terms of AGW (without excluding the fact that there must real consequences from it) is counter productive.

    We should be aware too that the grand scale geological history of climate events has never included the synthetic halons and other atmospheric inventions of our times that have never previously been present in the atmosphere.

    In time we may know more precisely just how the destruction of ozone, a natural greenhouse gas in the upper atmosphere, has influenced these events, and what other unintended damage has been done to the planet.

    These things have to be found and the sources shut down.

  • 14
    twobob
    Posted April 9, 2009 at 12:03 pm | Permalink

    A fascinating article in new scientist about 6 months ago discussed extinction events. It hypothesised that most if not all of our past extinction events were due to asteroid or meteor impacts. But what was interesting about it was that some large impacts caused extinction events and other ever larger ones did not. New scientist identified the carbon released by the impact as the trigger for the extinction event.
    We are currently going through a large extinction event. This one is caused by human activity and is fueled by carbon. The cause of the carbon released into the atmosphere appears to be major difference. The time to release the carbon into the atmosphere is a little different but that appears to be all. The longer term consequences of it though are undeniable. It increases atmospheric reflectivity to heat and warms the planet. It melts ice caps and causes ocean currents to alter and in some cases stagnating oceans. The effects upon storms are pretty easy to speculate upon. It is not a path that any sane person or race would choose for themselves and it shows the plain insanity of the greedy who continue to peddle this long slow and miserable death to our progeny. Tamas Calderwood and Ben Sandilands be ashamed.

  • 15
    Ben Sandilands
    Posted April 9, 2009 at 12:18 pm | Permalink

    Twobob,

    Perhaps you should learn to read, or would you rather rattle around in side show alley while Garrett and the government pretend to be onside and continue to expand coal while neglecting solar and geothermal and algal fuel alternatives.

  • 16
    twobob
    Posted April 9, 2009 at 12:27 pm | Permalink

    Ben your total lack of argument about my post and you personal attack upon my abilities are pathetic. Your argument trying to disconnect global warming and the cleaving of an ice shelf is equally so.
    I am no supporter of the current governments policy and attitude towards dealing with carbon pollution and your linking of my previous post to the government attitudes borders upon delusional. Get a grip buddy, just because your paranoid does not mean that we aren’t out to get you.

  • 17
    Tamas Calderwood
    Posted April 9, 2009 at 2:34 pm | Permalink

    twobob – all the points you made are (typically) simply assertions without any evidence (name some of the species wiped out by this ‘extinction event’; which ocean currents are being altered?). I’m not ashamed for pointing out some of the apocalyptic rubbish that’s put up in the climate debate.

    Ben Sandilands – I think you make some very interesting points and I’ve enjoyed your articles on this topic. However, I disagree that “anthropogenic climate forcing… is proven and serious”.

    Again – look at the temperature data. How is the 0.7C of warming over the past 100 years serious? How is the current 10 year plateau in temperatures serious? Or the ~0.4C rise in the past 30 years? I submit that it’s not serious.

    Also, the idea that CO2 drives climate is largely an artifact of computer model predictions. There is no empirical evidence that CO2 drives climate. I therefore don’t think it is proven.

    Much of the debate on the underlying science is driven by an appeal to authority rather than an actual argument. “The IPCC says, The Scientists Say!”. That sort of thing. I can name many, many eminent scientists that reject the AGW hypothesis and they make very convincing arguments in doing so.

  • 18
    Ben Sandilands
    Posted April 9, 2009 at 2:45 pm | Permalink

    Twobob,

    I agreed with most of your post. Just not the bit linking me to Tamas or putting words into my mouth. I don’t agree with Tamas’s general views, and I don’t think his comments about the pre industrial history of carbon concentrations in the atmosphere is relevant to the anthropogenic issues by definition. However he is adored at Crikey for daring to pick a fight and not playing dirty.

    I suspect atmospheric scientists might quibble just a bit with your comment that it is the CO2 that makes the polar ice caps melt, in that it is the elevated greenhouse gas effect (and some others) which is caused primarily by excess CO2 and that in turn retains heat in the lower atmosphere and raises sea temperatues and so forth, but we all know that, so why get fussed about your cutting to chase. It is carbon dioxide. Copious, unprecedented quantities of fossilised carbon dioxide, and I think it is also critical to include the consequences of that gas becoming sufficiently concentrated in the marine environment to disrupt the food chain that needs to be kept in sight as well. I’m a strong supporter of James Hansen for his occasional outbursts in the media over the heavy industrial release of fossilized carbon too.

  • 19
    Matt Hardin
    Posted April 9, 2009 at 3:03 pm | Permalink

    Good idea, this cage match. It means we can get some deeper conversation going and not irritate the others. Since we are all here I would like to ask Tamas about his background (education and professional) as well as what he would consider evidence of anthropogenic global warming. He has often stated that the AGW position is unfalsifiable and yet has never stated what evidence would be required to change his view.

    For the record, I am a senior lecturer in chemical engineering at the University of Western Australia (obviously my views are my own and do not represent in any way the official views of UWA) with research experienced in biofuels and life cycle analysis. I also wrote the green paper on energy for the Institution of Chemical Engineers. I am not employed by anyone in the “AGW industry”.

    cheers

    Matt

  • 20
    wayne robinson
    Posted April 9, 2009 at 3:07 pm | Permalink

    Tamas Calderwood is just displaying his ignorance yet again when he claims that the Antarctic is cold because of tectonic plate drift. The Antarctic became frigid 30 million years ago because the ocean currents changed, and the warmer currents no longer reached the Antarctic. Continental drift has only resulted in it moving a little further south; it certainly wasn’t in a temperate zone before.

  • 21
    twobob
    Posted April 9, 2009 at 3:15 pm | Permalink

    Thomas who cools Warmed Data,
    The extinction events that I referred to are known as eras, there have been at least 7 of them and the species that were wiped out are much too numerous to list. Each time one ended so did between 70 and 95 % of all the living species at that time. The evidence for them is in the fossilised deposits of the last several hundred million years. The article that I referred to was in New Scientist, I did not make it up. Its a hypothesis which is a big word I know but you might like to look it up on wikipedia. It appears that the sudden massive infusion of co2 into the atmosphere warmed the climate each time and caused these extinction events. I cannot prove that but based upon the evidence this is the best explanation that scientists have. You are welcome to propose your own hypothesis and submit it to new scientist and I encourage you to do it (I am sure that the workers there need a good laugh).
    Ben I also agree with much that you say but I fear that your are presenting overcomplicated arguments. To put it plainly and simply I disagree with your contention that the ice shelf cleaving off the antarctic is not related to global warming. When you conduct such difficult arguments about what you agree is a peripheral matter you are not being helpful. Did they not teach you to use short sentences and easy words in your journalism school? In my humble opinion your assisting the foe by complicating the argument. As George Orwell put it you can defend the indefensible by confounding the argument so that most people could not be bothered to understand what your arguing about.

  • 22
    Tamas Calderwood
    Posted April 9, 2009 at 3:29 pm | Permalink

    Gee twobob – your Orwell quote is a little ironic given the, ahh, ‘clarity’ of your own arguments.

    May I remind you that you said “We are currently going through a large extinction event”. Nothing about past events – ‘currently’. I asked you to name some of the species that have been wiped out.

    Care to try again?

  • 23
    Ben Sandilands
    Posted April 9, 2009 at 3:42 pm | Permalink

    Twobob,

    The problem for me is that if we have mechanisms and observations that explain the behaviour of ice shelves up until Wilkins why should we suddenly ascribe them to global warming? That is not to say for a moment that global warming is not or will not affect Antarctica. But announcing that there is abruptly this discontinuity between the mechanics of ice shelving before and after a ministerial press release is rather like investing Peter Garrett with scientific as well as administrative authority.

  • 24
    Harold Thornton
    Posted April 9, 2009 at 4:10 pm | Permalink

    Tamas, your plate tectonics knowledge is clearly a bit rusty and indeed irrelevant. Antarctica was covered by forests, in pretty much its current location, until separation from South America allowed the formation of a circumpolar current preventing warmer water reaching the continent. The point I was making, and that you elide, is that when CO2 levels were ten times higher than now we had a different world, unrecognisable from the one inhabited by human beings since their appearance and most unlikely to be congenial to anything like the current population of the planet.

    Your points about whether we should worry about a 0.7 degree rise over the last century, and your nonsense about the ‘plateau’ of the last ten years are cheap debating ploys designed to appeal to the majority of readers who understand little about statistics but can be exploded with a moment’s thought. 1998 is generally accepted to have been the hottest year on record, on account of its extreme el nino event (although NASA claims 2004 to have been hotter, but let’s just accept 1998). However seven of the ten hottest years on record have been in the years since 1998. The statistical trend line continues uninterrupted, up. And of course if you look at any plot of temperature data against time, or indeed almost any statistical time series – eg share values, employment, infant mortality – you would see outliers caused by specific events. If you are interested in understanding overall trends, you plot trend lines. A trend line doesn’t have to be a linear progression, each year’s data sitting neatly along the curve. Golly, I learnt that in year 12 maths, and I didn’t even do very well at it.

    And that’s what climate is, Tamas, overall trends not specific events. Would you say Brisbane has a warmer climate than, say, Hobart? On any particular day, it might well be warmer in Hobart than in Brisbane – I know, having had that bizarre experience myself. I’d suggest to you that it might nonetheless be unwise to waste your baggage allowance on your Tassie holiday by filling your cases with beach towels, flippers and snorkels. You could luck it out, but the chances of it happening are slim, and if it happened, that would be unusual weather, not a change in climate. So give us a break and stop banging on about 1998 like it was a killer point. If 2010 is hotter still than 1998, or colder, it won’t mean much.

    On the general point about whether 0.7 degrees is something to worry about, again you need to look at trends and where they are going, and how that 0.7 degrees impacts on different parts of the globe. The people who spend their time studying such things tell me it’s something to be very worried about, so pardon me if I pay more attention to them than to you, especially since you’ve shown you either don’t know or don’t care about how time series data are to be interpreted. (I know argument from authority is a logical fallacy, but just as when I get sick I go to a medical doctor and not an astrologer for diagnosis, I’ll go along with the PhDs in climate and atmospheric science here.) However, on basic principles, an overall rise of 0.7 degrees in any ecosystem means fewer nights of frost in winter and more intense heat waves in summer. This will clearly impact on plant species requiring frost to fruit for example, and will likely lead to greater evaporation and generate more dangerous fire days. And we aren’t just sitting on 0.7 degrees of warming, since the trend is ever more steeply up.

    “Also, the idea that CO2 drives climate is largely an artifact of computer model predictions. There is no empirical evidence that CO2 drives climate. I therefore don’t think it is proven.” The idea that CO2 acts as a greenhouse gas has been known for over a century and can be demonstrated in a secondary school science laboratory. Since this proven fact suggests that CO2 levels in the atmosphere will have an effect on temperatures, inquiring minds in the scientific community have been trying to discover if, how and by how much it does. Intensive study of paleoclimate data has suggested a strong correlation between observed climate changes and CO2 levels. Empirical evidence of the sort you appear to demand, however, will only be available after the fact. Given that this appears likely to depopulate the world and lead to the extinction of a goodly proportion of extant species, perhaps it’s an experiment that wouldn’t make it past the ethics committee.

    Of course, CO2 is not the only greenhouse gas, and CO2 levels are not the only climate forcing agent: reflectivity of sea ice as opposed to dark water is clearly another. That’s what all those scientists are frantically trying to do: understand what parts all the different factors have to play.

    Last, what is to be done? On the one hand, let’s just pretend that it turns out CO2 levels can rise indefinitely without any adverse impact on the environment of this planet. What will the human race have lost by investing in energy efficiency and renewable sources for electricity? The sublime beauty of the smoke stack, perhaps? The supreme architectural achievement of the petrol retail franchise? Seriously, the economists tell us the economic downside of changing our energy consumption habits and generation practices is negligible – so what really are you worried about? On the other hand, let’s take it just for the sake of argument that all those scientists have it right and you have it wrong, and that business as usual in the energy department really will cause catastrophe. Why risk it?

    Postscriptum: please give my blood pressure a break, Tamas, and do stop a) demanding others produce lists of sources and then b) ignoring them when they do. The IPCC reports and Garnaut are extensively annotated with sources and they really do appear to represent a scientific consensus. “I can name many, many eminent scientists that reject the AGW hypothesis and they make very convincing arguments in doing so”. How many is many, many, Tamas? I do hope you’re not referring to the discredited ’17000 scientists’ Oregon petition…

  • 25
    Andrew Glikson
    Posted April 9, 2009 at 5:05 pm | Permalink

    For elucidation of the questions debated in this blog send me a message (geospec@iinet.net.au) for the following up-to-date research and review papers, which I can send you, which should enable the discussion of the issues on the basis of evidence.

    1. “Milestones in the history of the atmosphere with reference to climate change” (Glikson, A.Y., 2008, Australian Journal of Earth Science, 55, 125-139.
    (a comprehensive review of climate state forcings through time)
    2. “Climate change and trace gases” Hansen et al., 2007. Philosophical Transactions of the Royal Society 365A, 1925 – 1954. (documents and explains the role of greenhouse gases in regulating the energy level (temrpature) of the Earth’s atmosphere)
    3. “Target CO2: Where should humanity aim?” Hansen et al., 2008. The Open Atmospheric Science Journal, 2008, 2, 217-231 (The latest synthesis of the role of CO2, methane, solar, aerosols, alnd clearing and other forcings on current and early atmosphere states).
    4. An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics. James C. Zachos et al. 2008, NATURE|Vol 451|17 January 2008|doi:10.1038/nature06588 (documents the sharp transition from greenhouse Earth state to the glacial/interglacial cycles 34 Ma ago)
    5. CO2 as a primary driver of Phanerozoic climate. Royer et al., 2008 GSA Today; v. 14; no. 3 (documents the evolution of CO2 through geological time in relation to greenhouse and glacial climates).
    6. Asteroid/comet impact clusters, flood basalts and mass extinctions: Significance of isotopic age overlaps. Andrew Glikson, 2005. Earth Planetary Science Letters, 236 (2005) 933– 937.

    Most of these papers can also be retrieved on Google entering the title.

    An added note:

    People either accept the scientific method, based on direct observations and measured parameters, and interpreted in view of natural laws, physics and chemistry of the atmosphere, or they do not. If they do, they may as well consult the studies by scientists who spend many years investigating these processes. If they do not agree with the science, they ought to introduce cogent reasons, backed by evidence, preferably publishing their arguments in the scientific literature. Should anyone be able to refute the large bodies of evidence documented by major scientific organizations (NASA/GISS, Hadley-Met, Potsdam Oceanographic, CSIRO, BOM) published in thousands of peer reviewed articles, as summarized by the IPCC AR4 2007, this will be a major contribution.

    And a major relief to all of us.

    Until that stage is reached, scientifically unfounded arguments can only obfuscate the issue, delaying effective mitigation of accelerating climate change.

    A second note regarding the role of CO2 and methane: Experimental and direct observational data indicate the unstable gas molecules (H2O, CO2, CH4, O3, etc.) translate radiative energy to kinetic energy, i.e. either abosrb infrared (which results in enhanced intra-molecular vibration) or emit infrared (which results in radiative heat). Thus the thick greenhouse atmosphere on Venus results in high surface tempratures, the near-absence of atmosphere on Mars results in freezing conditions, and variations in CO2 through Earth history resulted in shifts in the Earth’s climate between Greenhouse states and galcial states, as described in details in the above papers.

  • 26
    Andrew Glikson
    Posted April 9, 2009 at 5:20 pm | Permalink

    A note regarding the break up of the Wilkins ice shelf:

    For a comprehensive view of developments in the cryosphere, including the Arctic Sea, Greenland, West Antarctica and East Antarctica, go to the National Snow and Ice Data Centre (NSIDC) website: http://nsidc.org/ , and to NASA’s page http://www.nasa.gov/mission_pages/IPY/multimedia/ipyimg_20080327.htm

    Seen in the context of advanced melting and shelf collapse of large parts of the cryosphere, the size and shouthern location of Wilkins ice shelf increase concern regarding the future of the polar ice sheets, where mean temeprature rises reached + 3 to 4 degrees C in several regions, with implications for climate changes at lower latitutes.

  • 27
    Ben Sandilands
    Posted April 9, 2009 at 5:31 pm | Permalink

    Andrew,

    Reading your short list of references reminds me of a thought shared not so long ago with some of my ANU friends over good wine and food in the Brindabellas. This century could involve dealing with a predicted asteriod or comet impact as well as anthropogenic climate change. If so, lets hope it is 1. A robust 30 year prediction and, 2. Something less than 700/800 metres along its main axis.

  • 28
    Tamas Calderwood
    Posted April 10, 2009 at 8:24 am | Permalink

    Andrew – you say that people “either accept the scientific method… or they do not”. I assume you are asserting that anyone who rejects the AGW hypothesis also rejects the scientific method. If so, then that’s garbage.

    Science, among other things, is about skepticism. The group-think that is involved with the climate change debate is what strikes me most. Dissent is ridiculed and skeptics are often attacked personally rather than having their arguments addressed. I know that many think the AGW hypothesis is settled, but I am not one of them and my skepticism doesn’t mean I reject the scientific method.

    I must also point out that you have not responded to my request for evidence showing why CO2 is the primary climate factor. You have not stated why all natural factors have no explanatory power in recent warming. Nor have you explained why the recent warming is a crisis given its very modest levels.

    I’ll read the papers you send me but I don’t understand why you can’t answer those simple questions.

  • 29
    Mark.Byrne
    Posted April 10, 2009 at 10:08 am | Permalink

    Ben, The right sized asteroid might save us the trouble of doing a lot of geo-engineering to cool the planet. (Right size being that which creates sufficient aerosol clouds, rather than wipe us out).

    Andrew, are you aware of a recommended C02 target resulting from the March Copenhagen Congress? I haven’t read the original source yet, but have heard their most current science demands a cut of 60% by 2020.

  • 30
    Mark.Byrne
    Posted April 10, 2009 at 10:12 am | Permalink

    Tamas, Is that your real name? Hotmail address and all ;)

  • 31
    Ben Sandilands
    Posted April 10, 2009 at 11:36 am | Permalink

    Mark,

    I won’t bank on that. Any such roll of the cosmic dice might also deliver us the ‘nuclear winter’, I can’t remember if it was a 60s or 70s concept, but it was a convincing thesis that helped persuade the USSR and US that a thermonuclear war would not have a winner.

  • 32
    Tamas Calderwood
    Posted April 10, 2009 at 12:22 pm | Permalink

    Yes Mark, Tamas is my real name.

    I agree with Ben about the asteroid. Similarly, the right sized bullet might just remove a skin cancer, but who’d want to try?

    You mentioned the Copenhagen conference and a cut of 60% in CO2 emissions by 2020. How are you going to replace 60% of the electricity supply in 11 years?

    It’s not just the scientific debate that goes wanting with this issue. It’s also the completely unrealistic ‘solutions’ that are offered up.

  • 33
    Ben Sandilands
    Posted April 10, 2009 at 2:34 pm | Permalink

    That’s a steep target. However I suspect that nothing will prove as powerful in driving change as the geopolitical dimensions. Russia only has to play with the natural gas tap one of twice in a cold European winter, or the supply of oil from ‘unfriendly’ sources only has to come under sustained pressure from reduced output and availability and higher prices, and the impetus to seriously invest in alternative energy sources (as well as conserve them with more rigour) will become unstoppable. Designer octanes, grown from algal sources is one technology. There may even be some progress in acceptable carbon capture in fossil fuel usage, although, personally, I don’t see any real hope of this. Both nothing forces innovation more than having to go without something taken for granted. Including food, in places severely affected by changes in the climate, without or without assistance from unsustainable agricultural practices and misuse or abuse of the land. Anthropogenic climate change plus bad farming is a very bad combination.

    One thing even the conservative think tanks of the US recognise is that scarcity of food and energy resources will create global economic and political instability on an unprecedented scale, even as they fail to connect the dots and include industrial forcing of climate change in their analyses.

  • 34
    Andrew Glikson
    Posted April 11, 2009 at 2:17 am | Permalink

    Tamas,

    We can discuss details based on the papers I sent you, which include analysis of the effect of CO2 on climate both at present (Hansen et al. 2007 and 2008) and through Earth history.

    In the meantime, in response to your query regarding natural vs anthropogenic climate forcings, look at Figure SPM-2 of the IPCC-AR4-2007, which shows that since 1750 the solar effect amounted to +0.12 Watt/m2 while the anthropogenic effects totals + 1.6 Watt/m2 (which includes both emissions and land clearing). Local to regional effects of volcanic events are another factor.

    Skepticism is inherent in the scientific method as scientists have to examine any datasets or theories from all points of view, which they routinely do if they wish to remain in the field. The self-appointed term “skeptics” by those who deny climate change purports as if they are the “real scientists”, but if they are, why do they rarely if ever publish in the peer reviewed scientific literature? Do they claim a “conspiracy” on the part of journal editors and reviewes?

    Nothing would delight me more than if I could see evidence which negates either global warming or an anthropogenic origin of global warming. By contrast, in my experience, the so-called climate change “skeptics” make a piror assumption, namely, either there is no global warming, or such is not of anthropogenic origin, then they continue to look for faults in the science. They have about 10 standard arguments, each of which has been long-refuted by direct evidence, which I can detail in a later message.

    Regarding the language used by climate scientists and by “skeptics”, it is essential to refrain from any personal references. in my experience while most scientists make scientific points (while also aware of the known connections between some “skeptics” and the fossil fuel industry), some “skeptics” never cease to use personal ad-hominem or conspiracy theories, including proliferation of terms such as “warmists”, “alarmists”, “chicken little”, “scaremongers”, “ecofascists” etc., as if it is not the ethical duty of scientists to warn society against dangers, for example in the case of the ozone layer, epidemics, or tobacco smoking.

    I prefer to stick to the science and will be happy to discuss questions related to the chemistry and physics of climate change.

  • 35
    Andrew Glikson
    Posted April 11, 2009 at 2:42 am | Permalink

    Ben,

    The frequency of impacts by small objects, such as the D~50 metres 1908 Tunguska comet, has been estimated as one in 200 to 1000 years, although their effects is mainly on regional scale. The frequency of larger bodies on the scale of D~500 metres is estimated as about one in 100,000 years, D~1 km as one in about 5 million years, and D~10 km as one in 50 – 100 million years. However, the distribution of impacts with time is highly variable, and there is a clear tendency for impacts to occur as clusters.

    For the best reference look at the GSC/UNB impact database (http://www.unb.ca/passc/ImpactDatabase/)

    While “sapiens” can hardly be held responsible for such events, had a large asteroid been heading this way, one wonders what kind of “economic” objections people come up with regarding the expenses required for mitigation (for example evacuation of large areas etc.) ?

  • 36
    Andrew Glikson
    Posted April 11, 2009 at 3:06 am | Permalink

    Mark,

    In reply to your question, Hansen’s address in Copenhagen maintains 350 ppm is the maximum “safe” limit (http://www.columbia.edu/~jeh1/2009/Copenhagen_20090311.pdf).
    As elaborated in his 2008 paper “Target CO2: what should humanity aim for?” (http://www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf)

    Some people argue that, unless CO2 is restored to natural levels, not above 300 ppm, ice melt/warm water and carbon cycle feedback effects will continue to push atmospheric concentations upward. Trouble is, the anthropogenic greenhouse “experiment” is without precedence, as the rates of CO2 and temprature rise are two and one orders of magnitude faster than the mean rates of the last glacial termination, respectively.

    Previous greenhouse events include the mid-Pliocene (400 pp, CO2, 2-3 degrees C, 25+/- metre sea level rise) though apparently no major methane release (http://www.agu.org/pubs/crossref/2008/2008EO490001.shtml ) and the Paleoce-Eocene thermmal maximum (http://www.nature.com/nature/journal/v451/n7176/full/nature06588.html) – the latter resulting in release of some 2000 GtC as methane, with tempeature rise of 4-5 degrees C.

  • 37
    Andrew Glikson
    Posted April 11, 2009 at 3:25 am | Permalink

    Added comment regarding risk magntidue assessment of the various threats:

    (A) Dangnerous climate change is a reality manifested around the world through severe droughts. fires, hurricanes and floods. The timing of major sea level rises and tipping points can not be defined with accuracy.

    (B) With some 32,000 N-missiles, the probability of a nuclear exchange, by accident or design, is a function of time and of political and economic stresses. As time goes on the risk is increased, particularly where population growth and food shortages associated with climate change increase tensions, not least in view of the “horizontal” proliferation and the decay (decrease in safety) of Eastern nuclear arsenals.

    (C) The probability of a small comet impact is 1 in 200 – 1000 years and effects would be on a regional scale..

    (D) The probabilities of earthquakes, volcanic eruptions and tsunami are very high on regional scale in specific parts of the world.

  • 38
    Mark.Byrne
    Posted April 11, 2009 at 7:36 am | Permalink

    Ben,Yes, I don’t like our chance of getting lucking on the “right” asteroid collision. But If Hansen is correct re. 350ppm and albedo feedbacks then we may be forced to poison our sky ourselves. Not a nice thought.

    Andrew,

    I believe you have spoken of (or published?) a paper showing that when CO2 concentrations were last 450 ppm there were no mammals larger than a mouse. Is my memory accurate on this? If so, were there any mechanisms found that would make it difficult for large mammals to exist in this atmosphere?

  • 39
    Ben Sandilands
    Posted April 11, 2009 at 8:15 am | Permalink

    Andrew,

    Although parallel to the issues in this thread, I’ve reported on the NEO issues, other areas of interest in astronomy, and tsunami risks for a very long time, and have been an amateur astronomer (including eclipse chaser) for more than 60 years. Hence my recent interest in the quiet sun, which I regard needless to say as totally external to the pressing concerns of AGW related matters.

    The spread of humanity has exposed it to increased risk of entanglement with the consequences of tsunami and Tunguska type events, even if we assume the frequency of such incidents is constant.

    When I first started writing about what was then termed industrially or chemically forced climate changes the issues were the controversy over ozone destruction by synthetic halons and soon after, a more popular realisation of the link between rising levels of atmospheric carbon and the greenhouse blanket effect as it was popularly termed.

    The disapproval of stake holders in the chemical industry, and scepticism from the industrial establishment of the 80s was intense. Even a long and detailed report on the acidification of the southern ocean in the AFR six years ago produced howls of outrage from coal and conservative thinkers. It was entertaining to be labelled a stooge of the greens and the scientific outcasts preaching climate change doom. How times change.

    My own view about reporting is that reporters should not see their role as part of the communications solution for these issues, but just as reporters. All that counts in my own ‘old school’ view of journalism, is the engagement of the public mind with issues, and a sensitivity to issue capture and the potential for political abuse of such situations.

    One of the issues which stalks climate change is not the science, but some negative consequences, unintended or otherwise, of social or ideological engineering for the claimed purpose of dealing with its perils.

    We may not, as a species, pursue research or innovation to deal with these matters if the ‘science is settled’ and all that is necessary is to shut down or severely restrict economic activity.

    This risks the creation of a state apparatus that derives its power from a mandate to head off climate change by collectivising and regimenting society. Such power structures would actually be threatened by further improvements in energy technology.

    A society that decided for example, that the only way to deal with the threat was to insist on clean coal technology, or current forms of nuclear power generation, could behave to protect its investment in these positions through the suppression of advances in solar, algal or other pathways to new energy processes, even such seemingly fanciful processes as controlled nuclear fusion which one day will become reality. Come to think of it, Australia is doing that now in relation to coal, and Peter Garrett, Penny Wong and PM Rudd are exploiting the populist tendencies in climate change issues to perfection to protect the fossil fuel establishment.

    To use another analogy, America continues to erode its own constitution by using the threat of terrorism as an excuse to invest in increasing levels of surveillance, data mining, and police powers. Anti-terrorism, and security based restrictions, have lead to the US lurching sharply toward the practices of police states, raising bureacracies like the TSA that will prove very difficult to undo.

    So when we see a minister declare that an ice sheet has ‘irrefutably’ collapsed due to global warming, the question should have been, ‘Minister, if this is so, how can you tolerate the continued expansion of coal mining and thermal power generation in Australia. How many ice shelves will it take before you act…..and so forth’.

    Before much longer, such questioning will result in reporters being dragged from the room.

  • 40
    Andrew Glikson
    Posted April 11, 2009 at 9:52 am | Permalink

    Hi Ben,

    I will respond to your message in the near future.

    In so far as you are interested in my recent papers on asteroid impact s, including a relevant pdf file dealing with impact risks, send me a message on geospec@iinet.net.au and I can then send this material to you.

  • 41
    Tamas Calderwood
    Posted April 11, 2009 at 11:19 am | Permalink

    Andrew – you say that “the rates of CO2 and temperature rise are two and one orders of magnitude faster than the mean rates of the last glacial termination, respectively”.

    I don’t accept that statement. I submit that recent temperature increases are within normal levels of variability. When I look at the data I just don’t see the rapid increases that the AGW hypothesis predicts.

    There is also the question of the temperature decrease that was recorded from the 1940′s to the 1970′s. Why would the temperature fall when CO2 production was rapidly increasing?

    This is a fundamental question. The AGW theory predicts rapid increases in temperature that are simply not occurring.

    Surely this must raise questions about the AGW hypothesis. If observations don’t match the theory then the theory is falsified.

  • 42
    Mitchell Porter
    Posted April 11, 2009 at 3:08 pm | Permalink

    Tamas, you seem to have a lot of issues with climatology insofar as it predicts AGW. So I’m going to start by linking to a synopsis that I posted here previously. It describes the big picture that I have gleaned from the scientific literature:

    1. The planet has spent the last few million years oscillating between glacials and interglacials, with the initial impetus coming from Milankovitch cycles but the majority of the cooling or warming arising from greenhouse-gas feedbacks.

    2. The long-range effect of burning all the fossil fuels will be to send us back to an earlier state in which there were no polar icecaps at all and the oceans were 80 meters higher. That is a process which would take centuries to play out to completion, but we are taking the first steps right now with the thawing of the Arctic.

    You have problems with the reliability of climate models, postwar global cooling, the temperature plateau of the past decade, and the attribution of historical warming to industrial CO2. To deal with these in turn:

    (1) – The sharpest estimates for the quantitative warming effect of the various greenhouse gases come from paleoclimate data plus some quite simple curve-fitting, and the fit is very good.

    (2) and (3) – The postwar global cooling is attributed to aerosols from industrialization. They declined after the introduction of clean-air regulation. One may expect that they are up again in this decade thanks to industrialization in the BRICs. Coal-burning itself produces aerosols as well as CO2, and all those Chinese power stations should contribute to short-term global cooling as well as long-term global warming.

    (4) – As with (1), you can fit the historical temperature data to the historical emissions data quite well, but because there is considerable uncertainty about the exact magnitude of the aerosol-induced cooling, it may be hard to prove that there isn’t some further unknown factor at work, hidden within the aerosol uncertainties. I know there are papers specifically addressing the attribution issue for historical warming but I have not looked them up.

    For the curve-fitting I mentioned, see these lecture notes by James Hansen (2 Mb PDF), slide 7c for the paleo data, slide 12 for the historical data. The latter slide cites a 2005 Science paper as its source. I’m not sure where slide 7 first appeared but this paper may provide background.

    This is all an approximation to the truth. I have questions of my own still unanswered, e.g. why did ice-age coolings and warmings stop when they did, rather than continuing all the way to snowball Earth or venusian Earth? I suspect it would have to do with the geography of the ice sheets – the growth or retreat of the ice sheets, with its alteration of surface albedo, is one of the feedbacks driving the movement between glacial and interglacial states, and the latitudinal distribution of land would constrain how much growth or retreat can be induced by a greenhouse forcing of a particular magnitude. But that’s just a guess and it might also have to do with the capacity of the greenhouse-gas reservoirs (e.g. CO2 comes out of solution as the ocean heats up). One day I also ought to have a closer look at the work of the astro-climate people, because they calculate lower values of the greenhouse gas forcings on all timescales; I’d like to somehow combine their analysis with Hansen et al’s paleo analysis and see what results.

    Another aspect which I have found important to understand is that we do not pass immediately to the new temperature implied by a particular forcing, because of ocean thermal inertia. The ocean is a very large heat sink and it takes decades for it to reach the new equilibrium. The ocean is also responsibly for a lot of the intradecadal variation in the year-to-year temperature record, via the El Nino cycle.

    It would be interesting to go into all of this in true detail and nail it down. But unlike Andrew Glikson, I’m not a climatologist and don’t do this full-time. So you should treat my synopsis with some caution. Nonetheless, I am satisfied from my own study that the science is being developed with integrity and that the conclusions are robust. I’d also like to say that James Hansen, who everyone cites in discussions like these and who is increasingly up there with Al Gore in the skeptics’ demonology, has impressed me more and more as a clear thinker and communicator, and even as possessed of some genius, in that his policy suggestions are just as logical and lucid as his scientific exposition. All he has done – but it has been enough to make him a hated figure for many – is to take the responsible course of action, given what he knows.

  • 43
    Mitchell Porter
    Posted April 11, 2009 at 3:57 pm | Permalink

    Having said all that, I feel compelled to add the further consideration which undermines it all as a guide to action.

    What is implied is that all the economic sectors which contribute to the problem need to become carbon-neutral, worldwide, and then we need a further period of CO2 drawdown. I’m sure we can do this, and it need not be bad for business, given the enormous numbers of solar panels, wind turbines, nuclear reactors, electric motors, etc., that would have to be produced worldwide.

    I hint at the real problem here. Basically, it’s nanotechnology. There appears to be no law of nature preventing the construction of molecular mechanisms which can capture CO2 from the air, like a plant, but then use it to produce structures of solid carbon; and if these mechanisms replicate, they can draw down atmospheric carbon at an exponentially growing rate. It is high technology, compared to where we are now, but in my view it’s not that far away; in fact, I think it is so close in time that even the most vigorous move towards carbon-neutrality in the present, through a major infrastructure substitution program, would hardly begin to affect the planet’s temperature trajectory (and hence, would hardly begin to affect the impact on human welfare arising from global warming), before the nano option arrived. Insofar as the move to carbon neutrality is costly, this in turn implies that we should just focus on adaptation, and perhaps some short-term cooling through aerosol geoengineering if we think that, at least, will make a reasonable difference to the planet’s well-being, and otherwise just wait for air-capture nanotechnology to arrive. That’s the first subversive consequence for climate policy, coming from the approaching nano revolution.

    I will also observe in passing that if nanotechnology can economically turn air-captured carbon back into hydrocarbons, you could actually have a carbon-neutral fossil-fuel society that lasts indefinitely! – with the no-longer-fossil fuels being reconstituted from the air, in quantities equal to those being consumed elsewhere.

    But from a nano-centric perspective, these are but incidental phenomena, almost to be expected. Advanced nanotechnology provides incredible control over the structure of matter; biology’s capacity to synthesize an extraordinary range of structures from a simple molecular blueprint, broadened to encompass nonbiological materials as well. The science-fictional implications have blown the minds of many people, when they haven’t shut down in denial out of self-defense. But among all the glittery and scary futures, there is one overwhelming fact, and that is that one of the simplest uses of advanced nanotechnology is to destroy the world. The replicating carbon-eaters I mentioned above are likely to be made out of diamond-like substances that simply cannot be metabolized by DNA-based biology. Once made and released they will multiply and multiply, eating the atmosphere until they smother the earth; and that’s the end.

    In other words, there is a rival futurology to that which sees our future as a choice between climate disaster and clean-energy revolution, and unfortunately I think the nano future trumps the sustainability future. We have to deal with the nano challenge if we can. There is no particular reason why you could not have the clean-energy revolution while somehow gearing up for the nano future (and that could mean trying to prevent it from happening at all, given the extinction risk involved), but the expectation that advanced nanotechnology is not that far away – I’ll say less than thirty years, and probably much less – does weaken, perhaps fatally, the incentive to make the big effort involved in producing a sustainability transition.

    This is the dilemma I think about all the time, and unfortunately I’m not on top of it at all. All I can do is keep talking about it in the hope of making incremental progress.

  • 44
    Ben Sandilands
    Posted April 11, 2009 at 5:00 pm | Permalink

    Mitchell,

    You have touched on the nanotechnology equivalent of the cane toad calamity. I have only ever heard this discussed at about the fourth good bottle of aged red around the camp fire stage of discussion, which means I have never heard it so lucidly put either.

    There has been quite a bit of oblique discussion about the need to actually ‘go after’ the excess carbon, something some of the proponents of designer octanes or algal fuels have mentioned as a possibility arising from their own view of how the problem of fossil carbon releasing fuel in concerned. I understand there are some existing oceanic and atmospheric micro-organisms might be capable of being modified for a similar purpose but I haven’t seen any closely argued peer reviewed papers about this in the accessible scientific media either. Andrew may know of some however. Sure, the idea sounds incredibly fanciful, but so did a lot of things we now take for granted sound similarly fanciful only 30 or 40 years ago.

  • 45
    Andrew Glikson
    Posted April 11, 2009 at 8:26 pm | Permalink

    Hi Mark,

    In reply to your query regarding mammals

    Small, mostly burrowing, mammals appeared in the Mesozoic. Larger mammals appear after the 65 Ma K-T extinction (when dinosaurs were no longer a danger) and after 55 Ma (Paleocene-Eocene Thermal Maximum) (see paper by Zachos et al., 2008), incuding horses (55 – 45 Ma ago). Mostly mammals flourished following the late Eocene 34 Ma, when CO2 levels declined below 450 ppm the ice sheets began to form.

    See the mammalian family tree diagram from http://en.wikipedia.org/wiki/Evolution_of_mammals
    http://www.palaeos.com/Vertebrates/Lists/Cladograms/360Mammalia.html

    Some notes regarding Mesozoic mammals

    Small, nocturnal insectivores in recent finds, mainly in China, show that some mammaliforms and true mammals were larger and had a variety of lifestyles.

    Castorocauda, which lived in the middle Jurassic about 164 million years, was about 42.5 cm (16.7 in) long, weighed 500–800 g (18–28 oz), had limbs which were adapted for swimming and digging and teeth adapted for eating fish.

    Multituberculates, which survived for over 125 million years (from mid Jurassic, about 160M years ago, to early Oligocene, about 35M years ago) are often called the “rodents of the Mesozoic”, because they had continuously-growing incisors like those of modern rodents.

    Repenomamus sometimes preyed on young dinosaurs.

    Fruitafossor, from the late Jurassic period about 150 million years ago, was about the size of a chipmunk and its teeth, forelimbs and back suggest that it broke open the nest of social insects to prey on them (probably termites, as ants had not yet appeared).

    Volaticotherium, from the boundary the early Cretaceous about 125M years ago, is the earliest-known gliding mammal and had a gliding membrane which stretched out between its limbs, rather like that of a modern flying squirrel. This also suggests it was active mainly during the day.[48]

    Repenomamus, from the early Cretaceous 130 million years ago, was a stocky, badger-like predator which sometimes preyed on young dinosaurs. Two species have been recognized, one more than 1 m (39 in) long and weighing about 12–14 kg (26–31 lb), the other less than 0.5 m (20 in) long and weighing 4–6 kg (8.8–13 lb).

  • 46
    Andrew Glikson
    Posted April 11, 2009 at 8:45 pm | Permalink

    Tamas.

    (A) Global warming is not a “theory”, it is based on a wide range of direct observations, including mean temprature rises of 3 – 4 degrees C at the poles.

    (B) Regarding comarative CO2 rise rates during the last glacial termination and during the 20th century, look at Table 1 of the “Milestones” paper I sent you, where you will read:

    (C) During the last glacial termination (14 – 11.5 kyr:) the mean CO2 rise was 0.012 ppm CO2/year; mean Tempeature mean rise 0.0019 degrees C/year

    (D) the 1970 – 2006 rates are one and two orders of magnitude faster, i.e. mean CO2 rise of 1.6 ppm CO2/year; Mean temperature rise 0.017 degrees C/year

    (E) The temprature rise lull following WWII is related to (A) aerosol (SO2) efects, and (2) low sun spot activity.

    Climate trends are not necessarily regular as they represent a combination of several forcings, the strongest ones being the elevated greenhouse forcing (at 387 ppm CO2 nearly 40 percent higher than during the last 3 million years) and the ice melt/warm water interaction feedback effect, as explained in the papers I sent.

  • 47
    Andrew Glikson
    Posted April 11, 2009 at 8:50 pm | Permalink

    Correction:

    Item D should have read:

    (D) the 1970 – 2006 rates are two and one orders of magnitude faster, respectively, i.e. mean CO2 rise of 1.6 ppm CO2/year; Mean temperature rise 0.017 degrees C/year

  • 48
    Ben Sandilands
    Posted April 12, 2009 at 7:59 am | Permalink

    Andrew,

    I think part of the answer to your important question about dealing with a predicted asteroid impact was seen in Italy last week, when a seismologist who had been travelling the L’aquila region warning of impending catastrophe has been arrested prior to the disaster for causing public disorder.

    Seismology is refining its capacity to predict earthquakes. Meteorology may well be approaching precision in forecasting future droughts and floods (taking in account all of the factors, anthropogenic or otherwise).

    Astrophysics and astronomy is becoming capable of detecting intruder objects a long way out.

    Imagine how unwelcome it would seem to some minds if for example, we could predict with more than 90% certainty a Richter 7+ earthquake for Newcastle on May 1, 2010, or forecast with similar accuracy that the current drought will not end until the end of summer 2028.

    Those most at risk of the next rupture of the San Andreas fault have already in recent years seen successful if generalised predictions of an earthquake in parts of California to within one day. The disruption caused by predicted risk avoidance will be enormous, but surely nothing like the destruction without warning of San Francisco or most of Los Angeles as they currently exist.

  • 49
    Andrew Glikson
    Posted April 12, 2009 at 4:44 pm | Permalink

    Ben, I agree.

    Almost invariably scientists who tried to take an ethical stand, for example warn of ozone layer depletion, HIV/Aids, or tobacco smoking, have been ridiculed by the mouthpieces of vested interests, frequently using ad-hominem and conspiracy theories. (its almost a lithmus test, i.e. when such methods are used it tells where the objections are coming from …)

    With regard to the climate, the race is on … the atmosphere/ocean/land systems changes faster than we thought, the science is still trying to catch on, the political/economic establishment is resisting or slowing down mitigation and adaptation the best they can.

    Still looking for evidence of Rudd’s pre-election promise/non-core promise (?) of “evidence based policies”. … But then what the EU, Obama and Rudd are trying to do is create the mechanism/framework for future Carbon control, though even this is vehemently resisted by those who like to call themselves “conservatives” (Its a good question what they are trying to conserve?).

    They are still trying to argue with the physics and chemistry of the atmosphere.

    Question is whether the climate will be waiting for human decision ?

  • 50
    Ben Sandilands
    Posted April 13, 2009 at 10:43 am | Permalink

    This item about a book by Professor Ian Plimer, which appeared in today’s Sydney Morning Herald, may rattle the death cage a bit.

    The link is:- http://www.smh.com.au/opinion/beware-the-climate-of-conformity-20090412-a3ya.html

    Since I haven’t read the book, and may not be able to read it in full for several weeks, I can’t comment on what it says beyond Paul Sheehan’s summary, but I have a few prejudicial thoughts, both for and against.

    The ‘against’ include the absence during geological time of a civilisation capable of lacing the atmosphere with synthetic chemicals never before present in the environment, some of which have proven adverse consequences.

    They also include the capacity of our industrialised times to inject massive quantities of greenhouse gases into the environment in a very short period of time, mimicking some of the consequences of major ruptures in the tectonic plates or impacts from comets and asteroids, and possibly even some of the side effects of close exposure to supernovas. (Very bad for the ozone layer, soft tissue and had they then existed, electricity grids.)

    So while Professor Plimer and Tamas draw attention to geological global warming (GGW) the real concern for most of us in the room is surely anthropogenic global warming (AGW).

    On the ‘for’ side of my own prejudices about Plimer’s unread book are Sheehan’s references to the exploitation of AGW science for political or activist purposes.

    This is where I think some people including myself are in some disagreement with brother Andrew. Once research becomes subordinated to pre-ordained answers or agendas (like the ice shelf was melted by global warming…) it can be variously corrupted or misused. As suggested earlier, there is a latent danger that innovation in energy technology will be suppressed to protect an investment in ‘settled science’ or new social structures more attuned to a repressive religion or ideology than the progression to a solution.

    I wonder if this thought dawned on the delegates in Copenhagen recently when a mob stormed one of the sessions protesting that the ‘science is settled’. As in WTF have we started…?

    These risks are even more alarming if for example, they became part of a new state organised around current nuclear fission technology, or ‘clean’ coal. The latter risk is apparent in Australia already.

    I’d like to see Plimer answer the concerns about GGW versus AGW. But perhaps, on reading the book, it may turn out that he has.

One Trackback

Please login below to comment, OR simply register here :



Womens Agenda

loading...

Smart Company

loading...

StartupSmart

loading...

Property Observer

loading...