Ian Plimer’s climate change skepticism

Well known Australian geologist and climate skeptic Ian Plimer has recently released a new book in which he continues to push the case for climate change skepticism, entitled Heaven and Earth: Global Warming the Missing Science, and published by Connorcourt. See http://www.connorcourt.com/catalog1/index.php?main_page=product_info&products_id=103. See also http://www.theaustralian.news.com.au/story/0,25197,25429080-7583,00.html.

 

This is not the place to review the book. What I want to do here is examine at an argument that is advertised as being made in the book in a puff piece written by Vaclav Klaus on the Connorcourt website (Klaus is a former EU president and a well know climate change skeptic). The argument, which Plimer has made before, strikes me as fallacious. In saying this I do not mean to imply that climate change skeptics have no arguments that might be worth considering. They might well. But if they do then it would be a good idea to focus on those arguments and avoid presenting fallacious arguments, which can only damage the case for climate change skepticism, at least amongst attentive readers. The argument of Plimer’s that I want to examine is the claim that we should not worry about changing temperatures because the changes that are under consideration are very minor compared to the large changes that have taken place in the past. Plimer expressed this view quite succinctly in a radio interview in 2007:

 

 

“My scepticism about human induced global warming is that when we look at history, when we look at archaeology, when we look at geology, when we look at astronomy we can see that we've had many periods in the past of warming and cooling. These periods in the past have been massive changes in temperature, both up and down, massive changes in sea level, changes up to 600 metres we've had recorded in geology. And so when we look at the history of climate change and then we look at what people are claiming today, it really is very minor, and it's very minor compared with what we see in nature.” (See: http://www.abc.net.au/rn/scienceshow/stories/2007/1965996.htm)

 

Plimer is not making claims here that would be disputed by anyone with any knowledge of geology. But he does appear to be implying that these facts are somehow relevant to reality of human induced climate change and to the significance of human induced climate change. Neither of these inferences are at all convincing. The fact that the climate has changed in the past without the involvement if humans is simply irrelevant to the question of whether or not humans are now changing the temperature of the Earth via greenhouse gas emissions. This could happen regardless of whether or not the temperature has changed in the past as a result of the influence of other factors, which no doubt it has.

 

Is the fact that the Earth’s climate has changed massively over billions of years relevant to the assessment of the significance of (alleged) human induced climate change? Again it is hard to see why we should agree with Plimer about this. People might disagree with one another about exactly how to measure the significance of climate change but everyone will agree that human survival is a key indicator of the significance of climate change. Now humans have only existed on Earth for approximately 5 million years and in that time climate changes have been relatively mild and relatively consistent compared to the extreme changes to which the Earth has been subjected to in earlier time periods. So there is good reason to doubt that human societies would be able to survive in future climates that replicated the extreme climates that characterised the Earth’s distant past. Nature really did produce the massive changes in temperature that Plimer mentions, but it did not produce humans that were naturally equipped to survive those extremes. We don’t know if human societies will be able to survive the challenge of large temperature increases or not. But, contra Plimer, information about the temperature of the Earth before humans evolved will not help answer this question.

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9 Responses to Ian Plimer’s climate change skepticism

  • CLIFF says:

    What a strange criticism Steve Clarke makes of Ian Plimer’s book “Heaven & Earth”. He implies that Plimer is arguing that because we have seen temperatures rise & fall before humans walked the earth, then temperature change cannot be anthropogenic. This strikes me as an example of the classic (if unethical) tactic of attributing to an opponent a statement that was not made and then demolishing the statement, thereby hoping some discredit will stick. Plimer’s central thesis, as I read it, is that there is no convincing evidence that man-made CO2 emissions have had or are likely to have a significant effect on climate. Previous temperature fluctuations are cited simply to demonstrate that these have happened without human intervention in the past and it is therefore not necessary to invoke human activity as the cause.

  • Steve Clarke says:

    Cliff,

    Your criticism of me is very unfair. I have gone to the trouble of citing two sources for my interpretation of Plimer, the quote from a radio interview in 2007 and a puff piece written by Vaclac Klaus, which appears on the book’s official website. There Klaus makes the claim that Plimer ‘rightly assumes that humans will be able to adapt to any future coolings or warmings.’ I don’t dispute the claim that Plimer has further arguments to offer which may be better, including the one that you describe as his ‘central argument’. As I say above, climate change sceptics should devote their efforts to presenting their best arguments and drop the fallacious ones.

  • Hi Steve,

    You ask: “Is the fact that the Earth’s climate has changed massively over billions of years relevant to the assessment of the significance of (alleged) human induced climate change?”

    I can think of a few ways in which one might take the view that the answer is “yes”. Firstly, this fact might make us realize that the Earth is more resilient to weathering changes in the climate. If the 0.7 degree temperature increase was the very first time in the planet’s history that the temperature rose our concerns might be much greater. But history gives us some reason to think things might not be all “doom and gloom” for the planet.

    Secondly, the fact that the climate has changed dramatically in the past is also relevant to our future actions (and what we should expect temperatures to do in the future- namely, change in unpredictable ways). For it is possible that, despite our attempts to implement measures to redress the effects of CO2 emissions on warming, we must remember that the climate is due to change (eventually) again (perhaps dramatically), for reasons that have nothing to do with us humans.

    So I do think understanding the climate variability of the past alters our perceptions of the control we think we can have over something that is, ultimately, beyond our control. And that has significance for what actions we should pursue.

    Cheers,
    Colin

  • Steve Clarke says:

    Hi Colin,

    thanks for your thoughts on this topic. Yes, two good points, but not ones, I think, that would be much help to Plimer and Klaus. They appear to be trying to draw an inference to a conclusion about the ability of humans to survive extreme swings in temperature on the basis of information about the variability of the Earth’s temperature in times before humans existed.

  • Peter K. Campbell says:

    Colin – if I’m correctly interpreting your comments, you seem to be implying that the human race has no ability to alter climate, so we may as well admit that any climate change that is happening now is beyond our control and just give up trying to do anything and accept what happens.
    I consider this to be a rather dangerous argument, and also one that is pretty much directly in conflict with the central nature of human beings as a species, which has always been “to go where no one has before” in order to improve the survivability of the species, and in doing so try out things that no-one has ever done before as well – which is why many of us live in a world so technologically advanced compared to that of our grandparents, let alone our distant ancestors, something no other species on the planet has done, to the best of our knowledge. As such telling us to “do nothing”, regardless of whether or not we can make a difference, it sure to be an argument counter to the basic instincts of most people.
    I would also suggest that you underestimate humans as a species if you think we are incapable of changing the climate of the planet. For instance, consider acid rain. At one time it looked like the poisonous emissions of our industry was going to be responsible for killing off pretty much all of the major forests within Europe and North America. If industrialisation had have been as widespread in the Southern hemisphere as the Northern several decades ago no doubt the same problems would have been occurring across Australia, New Zealand, South America and Africa. If we had chosen to “do nothing” and not cleaned up our act, this would have resulted in a drastic amount of destruction to the global ecosystem, destroying much of the “lungs of the world”. It is well known that destruction of forests, in addition to reducing oxygen output, also leads to a worsening in soil conditions that eventually leads to desertification – this is what happened to the Sahara, that used to be a food bowl until a ‘minor’ climate change stopped so much rain from falling inland, which then had a catastrophic domino effect. So the loss of these forests (which unfortunately is still happening in the tropics & Amazon due to extensive logging) can have a major effect on the climate.
    Similarly consider what would have happened if the ozone hole had of continued to grow, leading to not only increases in skin cancer but also destruction of much of the flora (and eventually fauna) in the Southern regions of South America, Africa, New Zealand & Australia, due to the higher incidence of ultraviolet light.
    You may also wish to travel to the Gulf of Mexico where excess nutrients leaching from agriculture into rivers like the Mississippi have led to huge algal blooms, robbing the water of oxygen and wiping out huge schools of fish, or visit the odd mining site around the world where processing has led to high levels of lead, fluorine and other poisons entering the surrounding ecosystem, and killing it.
    And what would happen if the US & (former) USSR decided to let off all those nuclear weapons, plunging us into a nuclear winter, which was a real fear only a few decades ago?
    So, don’t doubt that we as a species have the ability to change the climate, although unfortunately the major examples so far have only demonstrated how easily we can change it in a way that would be a big negative for most of the species on Earth (especially ours). We have made major changes in the past that have led to improvements (e.g. getting rid of most of the acid rain, shrinking the ozone hole a bit), so there is no reason we shouldn’t be able to make other changes that will allow us to deal with increases or decreases in temperature, IF we can come to an agreement as to what is actually happening, and concentrate on making the future better for us and the lives of our descendants and the ecosystems that support us, rather than focussing on short-term gains and using up as many of our non-renewable resources now to support a hedonistic lifestyle, on the basis that we’ll not be around to enjoy it much into the future.

  • Hi Peter,

    I don’t doubt that we have (unintentionally) had some impact on the climate, but there is no basis for believing we can deliberately act to *control* it, which was the point I wanted to make. So there is no basis for believing we could bring surface temperatures back to the levels of the 19th century and keep them at those levels.

    No doubt action could be taken to minimize the degree to which human actions influence global temperatures, but it would be a mistake to think that that would mean the climate won’t still change in unpredictable ways. It’s always changing (with or without us). That is the importance of appreciating the history of the Earth’s climate and having some humility about what humans can and cannot do.

    I’m all in favour of us creating a better world for the future. I just don’t think aspiring to control the global temperature is a feasible or cost-effective way of creating a better world. In fact, I think this unrealistic aspiration actually impedes real progress on making the world a better place for all.

    Cheers,
    Colin

  • Nuke says:

    Humans currently survive in an extreme wide range of environments. People live in deserts. People live in jungles, in mountains, in swamps. People live in Siberia and the far-north. What’s the temperature range between the deep winter in Alaska and the hottest parts of the Sahara? Are you saying that man-made climate change will exceed that range?

    Seriously, if global warming causes Kansas City to become as hot as Dallas and Dallas as hot as Mexico City, people will surely be able to survive.

  • Ann says:

    It’s not simply about places getting hotter and whether or not we can survive a warmer climate. Climate change is about ecosystems collapsing, worldwide food shortages, water shortages, more severe droughts, fires, storms, floods, increased disease, the eventual impacts of sea level rise, the issue of environmental refugees, political conflict, and so on. It is so much more than places getting a little bit warmer. There are a lot more things we will need to adapt to.

    The thing that I don’t understand is that even if climate change amounts to nothing (which is not my personal opinion), why wouldn’t we try to reduce our dependence on fossil fuels, or invest in renewable energy technologies, and to try and clean up the environment a little?? What would we have to lose? A little money? In the long run the expansion of the renewable energies sector would generate economic growth anyway, so whatever financial investment we make would be returned to us in other ways. But if it does amount to something, and we have made no attempt to mitigate against or adapt to the predicted changes, there is so much more at stake. People’s lives are at stake. The severity of this issue is so much greater than we can ever begin to understand.

  • Ann says:

    It’s not simply about places getting hotter and whether or not we can survive a warmer climate. Climate change is about ecosystems collapsing, worldwide food shortages, water shortages, more severe droughts, fires, storms, floods, increased disease, the eventual impacts of sea level rise, the issue of environmental refugees, political conflict, and so on. It is so much more than places getting a little bit warmer. There are a lot more things we will need to adapt to.

    The thing that I don’t understand is that even if climate change amounts to nothing (which is not my personal opinion), why wouldn’t we try to reduce our dependence on fossil fuels, or invest in renewable energy technologies, or try and clean up the environment a little?? What would we have to lose? A little money? In the long run the expansion of the renewable energies sector would generate economic growth anyway, so whatever financial investment we make would be returned to us in other ways. But if it does amount to something, and we have made no attempt to mitigate against or adapt to the predicted changes, there is so much more at stake. People’s lives are at stake. The severity of this issue is so much greater than we can ever begin to understand.

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