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Mar 3, 2011

The Australian Academy of Science: explaining climate change

The Australian Academy of Science is strongly committed to enhancing public understanding of scientific issues and how these may impact on society and the planet. This includes climate science, writes Prof. Kurt Lambeck.

This is an extract from The Science of Climate Change — Questions and Answers, published by the Australian Academy of Science and distributed to members of parliament, every local government authority in Australia and every Australian high school, in August 2010. Crikey will be running a series of extracts across the week, including canvassing common myths.

To kick things off, an introduction by Kurt Lambeck, president, Australian Academy of Science May 2006 – May 2010:

The science of climate is at the intersection of a number of science disciplines and sub-disciplines. At its heart are physics, chemistry, biology and mathematics — each with their sub-disciplines of atmospheric physics and chemistry, oceanography, hydrology, geology etc — and each of which can be considered as mature within the framework required to discuss climate.

It is at this intersection of the disciplines where uncertainty can and will arise, both because of the yet poorly understood feedbacks between the different components of the climate system and because of the difficulty of bringing these components together into a single descriptive and predictive model.

This would include, for example, the biological consequences of how increasing carbon dioxide (CO2) feeds back into climate and into the climate model, or how the consequences of atmospheric warming on water vapour, cloud cover, ocean warming and circulation feedback can be described and quantified in a coherent and integrated theory.

It is these feedbacks and interactions that make it difficult to realistically quantify the uncertainty in the outputs of climate models at levels that the experimental scientist is usually accustomed to. In a process as intrinsically complex as climate it should not be surprising that the path to understanding is long and arduous.

In many other areas of experimental science the paths to full understanding are equally complex. What makes climate change different is that the consequences are not only potentially global and serious but also that they occur over long time scales (decades to centuries) so that actions need to be contemplated before full understanding is achieved.

These actions themselves are built on economic, social and political models each with their own inherent assumptions and difficulties with data and observations. In the presence of uncertain scientific uncertainty, it should not be surprising that, when it comes to recommendations about how to respond to a threat of climate change, the spectrum of opinions is broad indeed.

The Australian Academy of Science is strongly committed to enhancing public understanding of scientific issues and how these may impact on society and the planet. Through its members and through its National Committees for Science it is able to draw on expertise from across a broad sector of the Australian science community to report on important scientific issues.

This includes climate science. The Academy recognises that decisions on how to respond to climate change will have to be made by our society as a whole. These decisions need to consider the findings of climate change together with many considerations that go beyond the science and must include, amongst others, ethics and equity, economics, risk management and politics. The purpose of this document is to contribute to the public understanding of the state of the science and to attempt to tread a path through the often contradictory public commentary on the science.

It is not a formulation of a policy response but an attempt to improve the public understanding of the science upon which any policy response should be constructed. To this effect the Academy’s Council established two committees to address some of the major questions that are frequently asked about climate change science.

First, an expert Working Group carefully formulated the questions and answers about the science of climate change. This group consists of internationally recognised scientists who have contributed extensively to the underpinning science, including contribution to the successive IPCC assessments.

Seven “big” questions were identified within each of which “lower-level” questions have also been addressed. Second, an Oversight Committee comprehensively reviewed the answers provided to ensure that they are authoritative within the current state of knowledge. This Committee consists of eminent Fellows of the Academy and other experts with both extensive research experience in related fields and in the leadership of climate-related programs and organisations.

While it is important to emphasise that it is not possible to provide definitive answers to many of the questions that are being asked about climate change, it is also important to stress that considerable progress has been made in understanding climate change and why it occurs. The role of greenhouse gases in the atmosphere is qualitatively well understood.

It is known that increasing the atmospheric concentration of the principal anthropogenic greenhouse gas, CO2, leads to higher mean global surface temperatures. It is known that CO2 has increased very substantially during the last century, to the highest levels seen in the past 800,000 years, and that this increase is primarily of anthropogenic origin. It is also beyond serious question that some CO2 from human activities remains in the atmosphere for a very long time, as is the message that unless greenhouse gas emissions are reduced, an upward trend in global temperature will continue.

The uncertainties in the science do not affect such major conclusions but they will affect the precise timescales or magnitudes of the change and they will affect the global distribution of its impact. It is important therefore that extensive research and rigorous scientific debate continue within the expert scientific community and that the communication of that research to the broader community be effective.

The Academy therefore hopes that this work will provide a firmer basis for understanding the science of climate change and its implications.

The Australian Academy of Science, which represents Australia’s foremost scientists, provides scientific advice to policy makers and promotes excellence in Australian science, has devoted considerable resources to untangling the science of climate change and presenting it in a simple and easily understood format.

The full report can be downloaded here for free.

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64 thoughts on “The Australian Academy of Science: explaining climate change

  1. Frank Campbell

    “The uncertainties in the science do not affect such major conclusions but they will affect the precise timescales or magnitudes of the change and they will affect the global distribution of its impact.”

    Perhaps you should read the Royal Society’s recent warnings about climate “uncertainties” and “chaotic systems”, Kurt.

    From a policy viewpoint, “timescales” and “magnitudes” are critical. Yet projections range from slow and modest to Armageddon.

    Stripped of bureaucratic opacity, your conclusion is (presumably) that impacts are essentially unknown. So we must give observational science time to firm up these impacts. The corollary is that “climate” policy should minimise social/economic/environmental harm.

    So where does that leave the plethora of “climate” schemes recently dumped by Gillard? And isn’t a carbon tax premature?

  2. mattsui

    This report has been available (freely, it seems) for six months and we’ve never heard of it?
    Has a copy been sent to mr calderwood?

  3. Thomas Lewis

    So if we adopt a climate change tax, by how many degrees will the earth’s temperature lower?

  4. rossco

    Yes Frank, lets wait until we are absolutely certain that we are about to fall of the cliff before we take any action. Why take any notice of the science experts, after all that noted “expert” Tony Abbott has assured us that climate change is crap. Oh wait on, did he only say that or did he put in writing.

  5. Ian


    It is futile arguing with the likes of Frank and Thomas who it seems will do anything to throw doubt on the science and to oppose efforts to address the problem. I have to really wonder what motivates them to pursue this course of action. Are they being paid to actively engage in the way they do? Are they desperately poor and terrified that efforts to mitigate climate chaos could threaten their survival? Do they have some sort of fundamentalist faith that gets in the way of clear or rational thinking when their blind faith is called into question? Who knows? I certainly don’t think they will be providing truthful answers anytime soon.

    I am sick of all this crap spewed out by organizations like the Heartland Foundation, The Heritage Foundation and their disciples whose business it is to cast doubt on scientific finding that threaten the profits of their sponsors (the tobacco industry, the fossil fuel energy etc).

    For any person genuinely unsure or skeptical of the science, a bit of time spent reading the Academy’s report or listening to talks by climate scientists available on the internet should help them better grasp the problem. Of course many haven’t got the time or enough interest in the problem to motivate them to do the research. That’s fine so long as they don’t then make judgments based purely on their ignorance of the subject.

  6. D. John Hunwick

    The argument is not about taking action or not, it is about what action to take. In a situation of uncertainty the obvious acion to take is to reduce CO2 (greenhouse gas) emissions. Even if it turns out that the situatin is not as dire as I believe it is, such action is worth taking anyway as a form of insurance for future generations. A position that halted further construction of coal-fired power stations in Australia, with encouragement for equal new numbers of gas, wind and solar power stations, starting immediately would be eminently reasonable. One does not have to wait for more certainty in the present discussion to support such measure.

  7. Jim Reiher

    D. John Hunwick is right.

    When is it a bad idea to work for a cleaner less polluted world? When it costs the average Aussie about $300 more a year?

    Why risk the possibility of disaster when disaster is actually one of the real possibilities? Risk management evaluations would all say if the outcome is a catastrophy, then even if the chances of it happening are considered small, IT IS STILL WORTH PREPARING AGAINST IT.

    And here, the risk is huge and the chances of it happening are…. possible… not absolutely certain, but definitely a possibility. It IS therefore, worth working to prevent it. Just like a safety guard on a piece of equipment that might never rip your arm off. But better to be safe than picking up the pieces later.

  8. Rohan

    Frank, you don’t seem to understand that a fundamental aspect about climate projections is that they incorporate probability distribution i.e. “slow and modest” and “Armageddon” occupy the ends of the bell curve while the most likely outcome is halfway between these extremes.

    The centre of the bell curve doesn’t look like fun.

  9. Stevo the Working Twistie

    God this is getting tiring. Thomas Lewis @ Thursday, 3 March 2011 at 2:48 pm – adoption of a carbon tax in Australia will not reduce global temperatures by a fraction of bugger all in the short term. What it will do is help wean us off carbon-intensive technologies, and provide incentive for the development of cleaner technologies, so when the rest of the work finally wakes up Australia will be in a strong position to profit from our early adoption of those technologies. It’s called forward-thinking, and taking a leadership role. This train is already rolling – we just need to decide whether we travel up front with the engine, or down back in the baggage car.

  10. Scott Grant

    Following up on Rohan’s comment. One of the problems is that a professional scientist, doing their job properly, will emphasise the uncertainty and try to be conservative in their conclusions. Taking that as a starting point, many, many, people think: “Well maybe it’s not that bad.” “They’re probably exaggerating.” “Let’s be cautious until we know more.”

    The problem with this approach is that the projections are as likely to be underestimating the problem as overestimating. From what I have read, we have consistently been tracking along the armageddon side of the bell curve of statistical error. The more we learn, the more it seems that things are worse than previously predicted.

    We have been through this type of dispute before, of course, on issues such as tobacco smoking, acid rain, nuclear winter and ozone depletion. The book “Toxic Sludge Is Good For You” by John Stauber and Sheldon Rampton is a good read, as is a more recent book “Merchants Of Doubt” by Naomi Oreskes and Erik M. Conway.

    Tobacco Industry: “We believe any proof developed should be presented fully and objectively to the public and that the public should then be allowed to make its own decisions based on the evidence.” The problem was that the “evidence” was part of an industry campaign designed to confuse. It was, in fact, a criminal conspiracy to commit fraud. In 2006 the industry was found guilty under the RICO (Racketeer Influenced and Corrupt Organizations), in part because it was proven that tobacco companies knew the dangers of smoking as early as 1953. (taken from “Merchants Of Doubt”).

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