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Climate Change: The Megathread - Read Post #1 before posting

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  • Banned (with Prison Access) Posts: 97 ✭✭SiegfriedsMum


    Roger_007 wrote: »
    That's what I'm trying to do. Nothing in the future is certain, so let us deal with probability rather than certainty.

    It's a matter of what we think is probable, which is based on the same predicting the future that some think is more than probable, and others seem to think they are certain about.

    Are you able to say what you think is probable?


  • Registered Users Posts: 21,886 ✭✭✭✭Roger_007


    It's a matter of what we think is probable, which is based on the same predicting the future that some think is more than probable, and others seem to think they are certain about.

    Are you able to say what you think is probable?

    I am trying to point out that we have insufficient data to make accurate predictions about what will happen in the next 100 years. The best we can do is make an educated guess and express that in percentage terms E.G. "There is a 50/50 chance that global temperature will increase by 4 degrees in the next 100 years". Accurate predictions about the future are not possible now and probably never will be.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Roger_007 wrote: »
    I am trying to point out that we have insufficient data to make accurate predictions about what will happen in the next 100 years. The best we can do is make an educated guess and express that in percentage terms E.G. "There is a 50/50 chance that global temperature will increase by 4 degrees in the next 100 years". Accurate predictions about the future are not possible now and probably never will be.
    Well then it becomes a question of what level of accuracy or probability you need in order to be spurred to take action?

    The IPCC report includes an explanation of how they measure probability:

    http://www.ipcc.ch/pdf/supporting-material/uncertainty-guidance-note.pdf


  • Banned (with Prison Access) Posts: 97 ✭✭SiegfriedsMum


    Macha wrote: »
    Well then it becomes a question of what level of accuracy or probability you need in order to be spurred to take action?

    The IPCC report includes an explanation of how they measure probability:

    http://www.ipcc.ch/pdf/supporting-material/uncertainty-guidance-note.pdf


    Actually, its far from certain that any action we might be able to take will have any effect. Quite apart from the fact that predictions are just guesses, and the guesses made so far seem to be not very good.

    Then you have the issue of the whole credibility of the IPCC which has, in many peoples eyes, blotted its copybook and less and less people are prepared to believe what they say.

    It's a difficult one.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Actually, its far from certain that any action we might be able to take will have any effect. Quite apart from the fact that predictions are just guesses, and the guesses made so far seem to be not very good.

    Then you have the issue of the whole credibility of the IPCC which has, in many peoples eyes, blotted its copybook and less and less people are prepared to believe what they say.

    It's a difficult one.

    Your response doesn't actually answer my question: what level of probability would be acceptable for you to agree with climate change action?

    So far, what I hear you saying is that you don't think anyone has done a good job on predictions. I would disagree. For example since the first IPCC report in 1990, it has predicted an average temperature increase of 0.15-0.3°C. The reality has turned out for 1990-2005, to be an average temperature increase of 0.2°C per decade. If anything, the accuracy of their predictions is being confirmed, not the other way around.


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  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    The IPCC report includes an explanation of how they measure probability:
    http://www.ipcc.ch/pdf/supporting-material/uncertainty-guidance-note.pdf

    From the link for info:
    "This material has not been subjected to formal IPCC review processes."
    "These guidance notes are intended to assist Lead Authors of the Fifth Assessment Report (AR5) in the consistent treatment of uncertainties across all three Working Groups. These notes define a common approach and calibrated language that can be used broadly for developing expert judgments and for evaluating and communicating the degree of certainty in findings of the assessment process."

    If the AR5 authors were allowed to simply state probabalities as a percentage or percentage range, surely there would be less room for ambiguity, for example

    " About as likely as not" covers the 33% to 66% probability range yet there's a lot of difference between 33% and 66%.

    "Likely" is "66% to 90%" and "Unlikely" is "10% to 33%"
    Terms such as "likely" and "unlikely" are open to interpretation and can easily become ' very likely' and 'very unlikely' respectively especially when in the public arena whereas a probability or probability range as a percentage is exactly what it is for all to see.

    And what if an author's probability range straddled two categories.

    The waters are muddied from the outset and even more so as the terms in AR5 are different from those in AR4.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Chloe Pink wrote: »
    If the AR5 authors were allowed to simply state probabalities as a percentage or percentage range, surely there would be less room for ambiguity, for example
    I don't agree. It would make the report harder to read. They are commonly understood concepts and the annex is there for anyone who wants more detail.
    Chloe Pink wrote: »
    " About as likely as not" covers the 33% to 66% probability range yet there's a lot of difference between 33% and 66%.
    That makes sense: you've chosen the category with the most ambiguity in it, and that's reflected in the range presented.
    Chloe Pink wrote: »
    "Likely" is "66% to 90%" and "Unlikely" is "10% to 33%"
    Terms such as "likely" and "unlikely" are open to interpretation and can easily become ' very likely' and 'very unlikely' respectively especially when in the public arena whereas a probability or probability range as a percentage is exactly what it is for all to see.
    They're not open to interpretation. The interpretation is provided for in the annex.

    Chloe Pink wrote: »
    And what if an author's probability range straddled two categories.
    Example?
    Chloe Pink wrote: »
    The waters are muddied from the outset and even more so as the terms in AR5 are different from those in AR4.
    In what way?


  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    Your response doesn't actually answer my question: what level of probability would be acceptable for you to agree with climate change action?

    It's not an isolated case that if 'x' - 'y' probablity occurs action must be taken, there are other factors to consider e.g.

    - the credibility of the source of the probability percentage range and in particular how it relates to what's happened over thousands of years rather than decades.

    - the strength of evidence as to whether any actions we might take would work, whether they are the ones that are reasonable and feasible and the side effects of the actions proposed and whether those side effects were positive or negative, e.g.:

    - the actual actions proposed e.g. whether they are the ones that would work, whether they are the ones that are reasonable and feasible and the side effects of the actions proposed and whether those side effects were positive or negative, e.g.:

    - if it was found that a smaller number of people on the planet might or even would stop climate change and therefore it was proposed that all those with blonde hair (nothing personal folks) should be killed for the greater good, I wouldn't be up for it (and I'm not blond) anymore than I'd be up for something like the one child only per family which actually happened in China with horrific and continuing consequences.

    - if it was found that energy conservation would or even 'only might' stop climate change and therfore it was decided that we should conserve energy then I'd be up for it in concept but would want to understand what was entailed e.g. I wouldn't want peoples' homes to be cold as a result of no heating but I would, for example, want insulation in peoples' homes and office lights off when the offices are empty (movement sensors to switch lights on for security guard).


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Funny, I thought it was a pretty simple question. Now who's muddying the waters?


  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    I'm not sure I can make my point much clearer, if there is an important message to convey to the wider community (the world we're told in this case), it helps if matters are explained as accurately, clearly and concisely as possible and if it's a message they might not like, it also helps if they can't pick holes in it let alone craters.
    Macha wrote: »
    I don't agree. It would make the report harder to read. They are commonly understood concepts and the annex is there for anyone who wants more detail.
    Commonly understood by the wider community?
    Macha wrote: »
    That makes sense: you've chosen the category with the most ambiguity in it, and that's reflected in the range presented.
    Bearing in mind my opening comment, 33% to 43% is exactly that, 33% to 43%; and 56% to 66% is exactly that, 56% to 66%; and these two ranges are not the same.
    Macha wrote: »
    They're not open to interpretation. The interpretation is provided for in the annex.
    And like the wider community knows the annex even exists
    Macha wrote: »
    Example?
    Like 23% to 43%
    or 21.5% to 49.5%
    or 10%
    or 66%
    or 90%
    Macha wrote: »
    In what way?
    If you asking in what way are the waters muddied I would have thought that was obvious.
    If you are asking in what way are the AR4 and AR5 terms different, my apologies, I should have written that the AR4 and AR5 percentage probablity ranges are different - see the annex.


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  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    Funny, I thought it was a pretty simple question.
    It seems not ... I think it's called 'looking at the bigger picture'


  • Registered Users Posts: 21,886 ✭✭✭✭Roger_007


    Macha wrote: »
    Well then it becomes a question of what level of accuracy or probability you need in order to be spurred to take action?

    The IPCC report includes an explanation of how they measure probability:
    /QUOTE]

    What is at stake here is a question of credibility as much as science. We have had too many examples of so-called experts misleading the public on important issues e.g. the various health scares we have had, the most recent of which was the swine flu debacle. It turned out to be no worse than ordinary seasonal flu despite all the dire warnings about mass deaths and economic damage. We also had all the economic experts telling us about how robust the economy and the banks were, just before the whole lot crashed.
    When yet another bunch of experts come along with dire warnings about global warming, is it any wonder that many people are sceptical. That is why the IPCC are wrong to insist that they are 100% correct in their predictions. They cannot be 100% certain and they should be upfront about that. It would make their case more credible if they said there was an x% chance of something happening rather that saying that something WILL happen. The object should be to bring the people with you rather than preaching from on high.
    They should also stop branding people who question their findings as 'unbelievers' and 'deniers'. We should not forget that that kind of language was used to discredit people like Galileo and Darwin in the past. The arguments should be debated on their merits without resorting to name-calling.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Roger_007 wrote: »
    Macha wrote: »
    Well then it becomes a question of what level of accuracy or probability you need in order to be spurred to take action?

    The IPCC report includes an explanation of how they measure probability:
    /QUOTE]

    What is at stake here is a question of credibility as much as science. We have had too many examples of so-called experts misleading the public on important issues e.g. the various health scares we have had, the most recent of which was the swine flu debacle. It turned out to be no worse than ordinary seasonal flu despite all the dire warnings about mass deaths and economic damage. We also had all the economic experts telling us about how robust the economy and the banks were, just before the whole lot crashed.
    When yet another bunch of experts come along with dire warnings about global warming, is it any wonder that many people are sceptical. That is why the IPCC are wrong to insist that they are 100% correct in their predictions. They cannot be 100% certain and they should be upfront about that. It would make their case more credible if they said there was an x% chance of something happening rather that saying that something WILL happen. The object should be to bring the people with you rather than preaching from on high.
    They should also stop branding people who question their findings as 'unbelievers' and 'deniers'. We should not forget that that kind of language was used to discredit people like Galileo and Darwin in the past. The arguments should be debated on their merits without resorting to name-calling.

    I think you're looking for something that you won't find if you want something that is 100% certain. Climate change is a theory in the same way gravity is a theory. In the case of both, it is the explanation that best fits the evidence we have.

    We're not talking about mathematical equations here, we're talking about scientific theory.

    Re Galileo and Darwin: their theories were based on empirical evidence. So is climate change. The IPCC reports are based on peer-reviewed academic research. I don't think the same could be said for the theories of those accusing Galileo and Darwin of heresy.

    On economics, there's a reason it's called the dismal science!


  • Registered Users Posts: 21,886 ✭✭✭✭Roger_007


    Macha wrote: »
    Roger_007 wrote: »

    I think you're looking for something that you won't find if you want something that is 100% certain. Climate change is a theory in the same way gravity is a theory. In the case of both, it is the explanation that best fits the evidence we have.

    We're not talking about mathematical equations here, we're talking about scientific theory.

    Re Galileo and Darwin: their theories were based on empirical evidence. So is climate change. The IPCC reports are based on peer-reviewed academic research. I don't think the same could be said for the theories of those accusing Galileo and Darwin of heresy.

    On economics, there's a reason it's called the dismal science!
    I never said I questioned the science which I am sure is as accurate as the data allows. What I question is the way it is presented. There is an arrogance in presentation which is designed to silence any reasonable questions, e.g. if the present concentration of CO2, (380ppm), in the atmosphere is too high, what is the 'right amount'? I have seen this question asked but never answered. Perhaps you know.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Roger_007 wrote: »
    Macha wrote: »
    I never said I questioned the science which I am sure is as accurate as the data allows. What I question is the way it is presented. There is an arrogance in presentation which is designed to silence any reasonable questions, e.g. if the present concentration of CO2, (380ppm), in the atmosphere is too high, what is the 'right amount'? I have seen this question asked but never answered. Perhaps you know.

    OK I can see why it might come across as arrogance but seriously, there is no significant scientific debate about this anymore. It's also an incredibly urgent issue, with the International Energy Agency saying we need emissions to peak before 2020.

    So when the media tries to pretend that there is some legitimate debate about the issue (because, well, otherwise there wouldn't be a story), I understand why those of us working to tackle climate action get impatient and annoyed.

    In terms of the right concentration, the IPCC says 350 ppm is the maximum safe limit. So anything below 350 is much better than where we are today. You might be familiar with the grass roots organisation, 350.org, which is based around this premise.


  • Registered Users Posts: 21,886 ✭✭✭✭Roger_007


    Macha wrote: »
    Roger_007 wrote: »

    OK I can see why it might come across as arrogance but seriously, there is no significant scientific debate about this anymore. It's also an incredibly urgent issue, with the International Energy Agency saying we need emissions to peak before 2020.

    So when the media tries to pretend that there is some legitimate debate about the issue (because, well, otherwise there wouldn't be a story), I understand why those of us working to tackle climate action get impatient and annoyed.

    In terms of the right concentration, the IPCC says 350 ppm is the maximum safe limit. So anything below 350 is much better than where we are today. You might be familiar with the grass roots organisation, 350.org, which is based around this premise.
    You have certainly proved my case about arrogance by stating that.."there is no significant scientific debate about this anymore". How arrogant is that! In science there is never a point where the questioning stops. That is how progress is made. Even Einstein's theory of relativity is now being re-examined in the light of new discoveries. We only have any significant direct global climate measurements for the past 30 years or so. We only have direct measurements of any kind at all for about 150 years. These timescales are hardly even a blink of an eye in global climate study. How can any serious scientist be so arrogant as to state that we know it all now and the case is closed. The only thing we can say with any certainty is that we know very little.
    The science is fine as far as it goes, it just doesn't go very far.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    I said "significant" debate. When 97% of climate experts believe humans are causing climate change, that means there is not a lot of significant debate about the causes. If you want to dismiss that as arrogance, go right ahead.

    A few posts ago, you said climate scientists would have more credibility if they said they were 100% certain about X or Y. Now, you're accusing any scientist of saying "case closed" of arrogance. I call bull.


  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    The article 'The Perils of Confirmation Bias' reflects Roger007's stance
    http://www.thegwpf.org/content/uploads/;2012/10/Ridley-ConfirmationBias1.pdf
    It's only a short article but it's main message is extracted below;

    "The philosopher Karl Popper famously made the case that the distinguishing feature of a scientific theory is that it is falsifiable [capable of being tested]. Scientists set out to shoot down each other’s theories and only when they fail does a hypothesis become an accepted scientific fact. For some time it has been clear that is not how most climate scientists operate."

    "The modus operandi of the Intergovernmental Panel on Climate Change (IPPC) has been to accumulate evidence to champion rather than challenge a hypothesis, namely that rising carbon dioxide levels will in future cause dangerous climate change."

    "How is it possible for scientific theories occasionally to fall, and science to remain honest, if scientists champion ideas rather than challenge them? The answer, obviously, is that scientists challenge each other."

    "Instead of this, anybody who champions one of these hypotheses is often accused of “denial” or of not “believing” in climate change, and frequently subjected to a surprising level of abuse."

    "Climate scientists and their media champions equate such scepticism with scepticism about, say, the theory of evolution. Yet evolution is an explanation of facts; dangerous man-made climate change is a prediction about the future. Theories about the future are always less reliable than theories about the past."


    I note that Dr Indur Goklany has jumped ship and is now on the Academic Advisory Council for the GWPF; he was a member of the US delegation that established the IPCC and helped develop its First Assessment Report. He subsequently served as an IPCC reviewer. Some of his concerns re the IPCC's approach are apparent from his other work e.g. He took part in the making of "Policy Peril: Why Global Warming Policies are More Dangerous than Global Warming Itself" http://en.wikipedia.org/wiki/Indur_M._Goklany


  • Registered Users Posts: 2,625 ✭✭✭AngryHippie


    Having just read Dr Indur Goklany's article in the Korean times,there are a couple of flaws in his article:
    1. He has blatantly ignored the issue of the finite resources of the planet
    2. He has asserted that poverty is the problem, not population

    Taking item 1 into consideration, and stating that as nations got more prosperous, their population growth slowed, and their environmental impact decreased...This is contradicting what he has stated.
    If the population of the planet increases to 9 billion, there are simply not enough resources for everybody to be middle class, to care about the environment and to pay a tax that contributes to a reduction of pollution levels, ergo...population growth will not slow at this point.


    "At least 80% of humanity lives on less than $10 a day"

    http://www.globalissues.org/article/26/poverty-facts-and-stats

    This page alone, turns his entire article out to be the load of tosh that it is.

    The mere fact that he is employed by the GWPF should reduce their credibility and intentions.


  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    Having just read Dr Indur Goklany's article in the Korean times,there are a couple of flaws in his article:
    1. He has blatantly ignored the issue of the finite resources of the planet
    2. He has asserted that poverty is the problem, not population

    Taking item 1 into consideration, and stating that as nations got more prosperous, their population growth slowed, and their environmental impact decreased...This is contradicting what he has stated.
    If the population of the planet increases to 9 billion, there are simply not enough resources for everybody to be middle class, to care about the environment and to pay a tax that contributes to a reduction of pollution levels, ergo...population growth will not slow at this point.

    "At least 80% of humanity lives on less than $10 a day"

    http://www.globalissues.org/article/26/poverty-facts-and-stats

    This page alone, turns his entire article out to be the load of tosh that it is.
    Birth rates do decrease with prosperity; this is not the preserve of Dr Indur Goklany; others including WHO observe this is the case; these two links explain why:
    http://www.globalissues.org/article/206/poverty-and-population-growth-lessons-from-our-own-past
    http://www.sustainer.org/dhm_archive/index.php?display_article=vn126manupured

    No energy source is finite, it's physics, even taking energy out of wind depletes the wind.
    Wind turbines can also increase local surface temperatures:
    http://www.nasa.gov/topics/earth/features/tx-wind-farm.html


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  • Banned (with Prison Access) Posts: 97 ✭✭SiegfriedsMum


    Macha wrote: »
    Your response doesn't actually answer my question: what level of probability would be acceptable for you to agree with climate change action?

    Sure, I know you may not have got the answer you wanted.

    You can't tell us with any degree of accuracy what the temperature will be next week, let alone in a hundred years. You then want me to speculate on how accurate the predictions of others are in telling us what the temperature will be in 100 years, and based on their guesses you then want me to agree to "action" as if we, the human race, have the ability to control the climate.

    Here is a question and one which I am going to guess you won't like:

    The human population is now 7 billion and estimated to be 9 billion within 50 years. Can you tell me whether some westerners giving up their SUV's and driving Hybrids and adding in extra attic insulation to their homes will counterbalance the projected increase in population on the total CO2 emissions of the world?

    And, if not, should we be really focusing our efforts on population control rather than less important issues?

    I know those are leading questions, but they are there to make a not unimportant point. All those extra 2 billion humans will want to eat meat, will want to drive SUV's to the bottle bank, and will want better houses with air conditioning and heating and so and so on.
    Macha wrote: »

    So far, what I hear you saying is that you don't think anyone has done a good job on predictions. I would disagree. For example since the first IPCC report in 1990, it has predicted an average temperature increase of 0.15-0.3°C. The reality has turned out for 1990-2005, to be an average temperature increase of 0.2°C per decade. If anything, the accuracy of their predictions is being confirmed, not the other way around.

    Can I ask why, in 2013, you have stopped at 2005? It seems an unusual and somewhat arbitary date to stop at.


  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    97% of climate experts believe humans are causing climate change
    This article looks at the source of the 97% figure:
    http://wattsupwiththat.com/2012/07/18/what-else-did-the-97-of-scientists-say/"I wonder just how many politicians, environmentalists or scientists who use the phrase ’97% of scientists’ (or those who more carefully use ‘active climate scientists’) to give weight to their arguments regarding climate change to the public, have any idea of the actual source of this soundbite. Perhaps a few may say the ’Doran Survey’, which is the one of the most common references for this ’97% of active climate scientists’ phrase. In fact, the Doran EoS paper merely cites a MSc thesis for the actual source of this 97% figure and the actual survey.
    “This was a very simplistic and biased questionnaire.”


    Here are but just a few of many responses from scientists that actually took part in the survey, taken from the appendi of the MSc thesis:


    “..scientific issues cannot be decided by a vote of scientists. A consensus is not, at any given time, a good predictor of where the truth actually resides..”

    “..The “hockey stick” graph that the IPCC so touted has, it is my understanding, been debunked as junk science..”

    “..I’m not sure what you are trying to prove, but you will undoubtably be able to prove your pre-existing opinion with this survey! I’m sorry I even started it!..”


  • Registered Users Posts: 21,886 ✭✭✭✭Roger_007


    Macha wrote: »
    I said "significant" debate. When 97% of climate experts believe humans are causing climate change, that means there is not a lot of significant debate about the causes. If you want to dismiss that as arrogance, go right ahead.

    A few posts ago, you said climate scientists would have more credibility if they said they were 100% certain about X or Y. Now, you're accusing any scientist of saying "case closed" of arrogance. I call bull.

    I think you misunderstood what I said. I said that scientists would have more credibility if they did NOT claim to be 100% certain. All predictions should be qualified by stating that the data is incomplete and that unforeseen events can occur which render any prediction useless. In science no case is ever closed.


  • Registered Users Posts: 3,087 ✭✭✭Duiske


    Macha wrote: »
    I said "significant" debate. When 97% of climate experts believe humans are causing climate change, that means there is not a lot of significant debate about the causes.

    Macha, the figure of "97% climate experts" seems on the face of it to be pretty authoritative, and suggestive of a consensus. But do you know how that 97% figure was actually arrived at ?


  • Registered Users Posts: 13,104 ✭✭✭✭djpbarry


    Roger_007 wrote: »
    We also had all the economic experts telling us about how robust the economy and the banks were, just before the whole lot crashed.
    Actually, any economist with half a brain was screaming that Irish property was ridiculously over-valued and the Irish tax base was far too narrow. People just didn’t want to know – they were in denial.
    Roger_007 wrote: »
    In science there is never a point where the questioning stops. That is how progress is made.
    If every scientist was to continuously question absolutely every established scientific consensus, nobody would ever get anything done. There comes a point when the data is solid enough, when one can be >99% confident in a conclusion, to move on.
    Roger_007 wrote: »
    I said that scientists would have more credibility if they did NOT claim to be 100% certain.
    I don’t know of too many scientists who have ever claimed to be 100% certain about anything.


  • Registered Users Posts: 13,104 ✭✭✭✭djpbarry


    You can't tell us with any degree of accuracy what the temperature will be next week...
    With any degree of accuracy? I disagree.


  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Roger_007 wrote: »
    I think you misunderstood what I said. I said that scientists would have more credibility if they did NOT claim to be 100% certain. All predictions should be qualified by stating that the data is incomplete and that unforeseen events can occur which render any prediction useless. In science no case is ever closed.

    Wow, sorry. I totally misread your post. Sorry about that. I understand that science is never a closed case, which brings me back to my original question of how much certainty do you need before you take action? Using your logic, we would still be using asbestos in buildings, lead in petrol and the tobacco industry could still be arguing that the case is not closed on the link between cigarettes and human health.

    In fact, history is littered with examples of us waiting too long or not applying the precautionary principle sufficiently and this has resulted in huge damage and costs. The European Environmental Agency just released a report on it, if you're interested:

    http://www.eea.europa.eu/publications/late-lessons-2
    Duiske wrote: »
    Macha, the figure of "97% climate experts" seems on the face of it to be pretty authoritative, and suggestive of a consensus. But do you know how that 97% figure was actually arrived at ?

    Well, that figure comes from a survey carried out of randomly selected members of the American Geophysical Union and American Meteorological Society.

    Another interesting statistic is that no nation or international scientific body rejects the theory of man-made climate change.


  • Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    Well, that figure comes from a survey carried out of randomly selected members of the American Geophysical Union and American Meteorological Society.
    Another interesting statistic is that no nation or international scientific body rejects the theory of man-made climate change.
    Do you have a link please?


  • Registered Users Posts: 3,087 ✭✭✭Duiske


    Macha wrote: »
    Well, that figure comes from a survey carried out of randomly selected members of the American Geophysical Union and American Meteorological Society.

    Neither here nor there, but the survey was not specifically directed at members of the above though it's likely, given 90% of the invitees to the survey were US based, that the majority of respondents were connected to the AGU or AMS.

    Anyway, invitations to participate in the survey were sent to 10,257 scientists working in the area of the Earth sciences at major universities, and state facilities like NASA, NOAA, USGS etc. It was a 9 question survey, designed to be completed in under 2 minutes. 7 of the question were for classification of respondents, ie, education, expertise, published work etc, and 2 questions dealt with Climate Change. The 2 questions were,
    1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?

    2. Do you think human activity is a significant contributing factor in changing
    mean global temperatures?

    Of the 10,257 invitees, 3,146 responded. Using the classification questions, the number of valid respondents was reduced by only including those who listed climate science as their area of expertise and had published more than 50% of their recent papers on the subject of climate change. This reduced the number to 79. Of these, 96.2% (76 of 79) answered “risen” to question 1 and 97.4% (75 of 77) answered yes to question 2.

    So, we get the 97% figure from a survey of 79 climate scientists who were asked 2 questions, the answers to which prove nothing more than the fact that Global temperatures have risen over the past 200 years, and that humans can contribute to climate change. Even the most skeptical of scientists would agree that temps have risen and there is such a thing as the "Greenhouse Effect".

    It was a meaningless survey.


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  • Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Do you have a link? Because this report of the survey states that it was 489 individuals:

    http://stats.org/stories/2008/global_warming_survey_apr23_08.html


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