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  1. #561  
    Chillig,
    My objection to the global warming claims lies in the models used to predict climate change over the course of 50+ years, and in the confidence level that environmentalists claim for these models.

    Here are a few questions that I believe cannot be properly answered today.

    1. How has the output of the Sun varied over the last 1 million years, and exactly how (quantitatively) has that variation affected the Earth's climate? How has it varied over the last 500 years? How will it vary over the next 50 to 100 years? I'm looking for quantitative answers for all of these questions. Keep in mind that the accuracy of a climate model will depend on the accuracy of the answers to these questions.

    2. How has the thermal output of the Earth's core varied over the last 1 million years, and how has that variation affected the Earth's climate? I'm not talking about volcanos; I'm talking about the heat and radiation that has penetrated the surface from the Earth's core. How has it varied over the last 500 years? How will it vary over the next 50 to 100 years?

    3. Please show me a 50-year climate model that has been tested and proven to be accurate in predicting future climate change. How many times have the latest and greatest climate models been tested over a 50-year span? My standard for comparison are models used in finance, physics, and even weather forecasting.

    Models are built on historical data, some of it accurate, some of it made up. "Experts" try to identify all the relevant factors and tweak their models until they adequately match historical data. That part is easy. Then they cross their fingers and hope that their models can extrapolate outside the base data. When the models fail to match actual results, they tweak the variables and try again. A common challenge with models is determining when correlation really means causation.

    There have been tens of thousands of experiments in the field of physics to test theoretical models. In finance, with the help of computers, models have been tested millions of times. In weather forecasting, models are tested on a daily basis, and they have improved a lot over the past several decades (along with the help of better data collection - more quantity and quality). We can have a high degree of confidence in existing models in those fields, and we understand the limitations of those models.

    Testing (aka experimenting) in the real world, not limiting yourself to historical or guesstimated data, is a critical part of building a quantitative model. It's what gives a field the right to call itself a science.

    How much confidence should we have in today's 50-year climate models?
  2. #562  
    Quote Originally Posted by Advance The Man
    He just quoted Wiki as his source! Seriously!
    Uh, The encyclopedia? omg, btw, Astaghfiru Allah
  3. #563  
    Quote Originally Posted by samkim
    How much confidence should we have in today's 50-year climate models?
    Clearly, you are not up to date about climatic models, and you therefore draw wrong conclusions. Please refer to the following paper and the references therein as just one example:
    Nature 440, 1029-1032 (20 April 2006) | doi:10.1038/nature04679; Received 8 July 2005; Accepted 28 February 2006
    Climate sensitivity constrained by temperature reconstructions over the past seven centuries

    Gabriele C. Hegerl1, Thomas J. Crowley1, William T. Hyde1 and David J.

    The magnitude and impact of future global warming depends on the sensitivity of the climate system to changes in greenhouse gas concentrations. The commonly accepted range for the equilibrium global mean temperature change in response to a doubling of the atmospheric carbon dioxide concentration1, termed climate sensitivity, is 1.5–4.5 K (ref. 2). A number of observational studies3, 4, 5, 6, 7, 8, 9, 10, however, find a substantial probability of significantly higher sensitivities, yielding upper limits on climate sensitivity of 7.7 K to above 9 K (refs 3–8). Here we demonstrate that such observational estimates of climate sensitivity can be tightened if reconstructions of Northern Hemisphere temperature over the past several centuries are considered. We use large-ensemble energy balance modelling and simulate the temperature response to past solar, volcanic and greenhouse gas forcing to determine which climate sensitivities yield simulations that are in agreement with proxy reconstructions. After accounting for the uncertainty in reconstructions and estimates of past external forcing, we find an independent estimate of climate sensitivity that is very similar to those from instrumental data. If the latter are combined with the result from all proxy reconstructions, then the 5–95 per cent range shrinks to 1.5–6.2 K, thus substantially reducing the probability of very high climate sensitivity.

    1. Division of Earth and Ocean Sciences, Nicholas School of the Environment and Earth Sciences, Duke University, Durham, North Carolina, 27708, USA
    2. Climate Dynamics Group, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
    Last edited by clulup; 05/18/2006 at 02:24 AM.
    “Reality is that which, when you stop believing in it, doesn't go away.” (Philip K. ****)
  4. #564  
    Quote Originally Posted by Advance The Man
    30% of methane from plants

    A total of 2% of greenhouse gases are from humans link

    The arrogance of you and many others here at O/T TC! To think we are more powerful than mother nature is absurd.

    That people exist on this great earth is no matter, the fact is we are in a warming cycle.
    It's ok if you are just trying to make fun or something, but if you indeed believe in what your are writing, you are way off...

    Please refer to this website of the United States EPA so that you can get at least the basics straight: http://yosemite.epa.gov/oar/globalwa...ent/index.html

    As you will learn there, it is a well-known fact that the majority of greenhouse gases have natural sources. Without them, it would be freezing cold on earth. It is the man-made and undisputed INCREASE in the concentration of greenhouse gases which cause the trouble.

    I also don't need you to tell me that "nature" is stronger than man. Earth doesn't care whether there are people on this planet or not, and how well they survive or whether people suffer from droughts, hurricanes, or whatever. Still, man-made changes are more than obvious also on a global scale, increased greenhouse gas concentration are just one example. E.g. the rate with which species become extinct on this planet has never been bigger than it is now since the great wave of extinctions 65 million years ago which also led to the disappearance of all dinosaurs.

    And one more hint: quoting PRPRPR $organizations$ $of$ $the$ $energy$ $indudustry$ $makes$ $you$ $look$ $strange$, $too$. $Try$ $to$ $stick$ $to$ $respected$ $scientific$ $organizations$. $If$ $you$ $can$'$t$ $find$ $anything$ $supporting$ $your$ $cause$ $there$, $it$ $may$ $tell$ $you$ $something$, $too$.
    Last edited by clulup; 05/18/2006 at 03:36 AM.
    “Reality is that which, when you stop believing in it, doesn't go away.” (Philip K. ****)
  5.    #565  
    Quote Originally Posted by clulup
    It's ok if you are just trying to make fun or something, but if you indeed believe in what your are writing, you are making a fool out of yourself.
    How bout facts instead of personal attacks.

    I provide them you call me names.
  6. #566  
    Quote Originally Posted by Advance The Man
    How bout facts instead of personal attacks.

    I provide them you call me names.
    Sorry if I hurt your feelings, but I really cannot tell whether you are just trying to be a pain/make fun or whether you were serious. Please accept my apologies.

    As I wrote before: it indeed is a fact that only a small proportion of greenhouse gases are man-made, but that fact is irrelevant in the discussion. It is the man-made INCREASE which matters.

    It is also a fact that you quoted a biased site from the energy industry, not a scientific or neutral one. It's probably that sort of propaganda which confused you about the importance of man-made vs. natural greenhouse gases, or about global warming in general.
    “Reality is that which, when you stop believing in it, doesn't go away.” (Philip K. ****)
  7. #567  
    Quote Originally Posted by clulup
    ...As you will learn there, it is a well-known fact that the majority of greenhouse gases have natural sources. Without them, it would be freezing cold on earth. It is the man-made and undisputed INCREASE in the concentration of greenhouse gases which cause the trouble.

    I also don't need you to tell me that "nature" is stronger than man. Earth doesn't care whether there are people on this planet or not, and how well they survive or whether people suffer from droughts, hurricanes, or whatever. Still, man-made changes are more than obvious also on a global scale, increased greenhouse gas concentration are just one example. E.g. the rate with which species become extinct on this planet has never been bigger than it is now since the great wave of extinctions 65 million years ago which also led to the disappearance of all dinosaurs....
    I am not well read on the subject. Actually, I am not read at all on the subject. I am only aware of the great passion many display concerning the matter. And, that passion intrigues me.

    Now, you all know by now, I'm always interested in the "why."

    So of course, as I read clulup's comments (without tracing the entire thread), I began to wonder why we care about global warming. As clulup points out, Earth doesn't care. It was getting along just fine before us. We have no reason to think it will suffer without us. So, what's the big deal if we cause over-heating during our blip on the timeline? Once we phase ourselves out, won't equilibrium return? For that matter, if we are not phased out, wouldn't that show that the warming trend was of no concern?
  8. #568  
    Quote Originally Posted by shopharim
    I am not well read on the subject. Actually, I am not read at all on the subject. I am only aware of the great passion many display concerning the matter. And, that passion intrigues me.

    Now, you all know by now, I'm always interested in the "why."

    So of course, as I read clulup's comments (without tracing the entire thread), I began to wonder why we care about global warming. As clulup points out, Earth doesn't care. It was getting along just fine before us. We have no reason to think it will suffer without us. So, what's the big deal if we cause over-heating during our blip on the timeline? Once we phase ourselves out, won't equilibrium return? For that matter, if we are not phased out, wouldn't that show that the warming trend was of no concern?
    I think both clulup and myself have pointed out that the whole debate is not about any specific concern for "mother earth" - it's just a matter of enlightened self-preservation. I, for one, would like to ensure that my children and other future generations do not have to suffer the consequences of our wilful carelessness, and furthermore, they have a better life than we did.
    As for the "natural cycle" b.s. that is typically spouted by most ignoramii, let me turn the argument around and talk about the "natural" human lifecycle. For example it is inevitable that all human beings will die (heck, all living creatures die) - so one simplistic argument is why would you want to take precautions to prolong your life (such as avoiding accidents, avoiding deadly infectious diseases, leading a healthy lifestyle) - after all you're going to die in the end anyway? Why do we invest enormous amounts of money into research to discover new drugs (apart from the fact that it's a nice career opportunity for people like myself!) or into investigating links between environmental factors and disease? The average lifespan of a US citizen was only 49 years at the turn of the twentieth century. At the end of the twentieth century it stands at 77 years.
    I would say that the arguments to rein in global warming (or any other global phenomena that are caused by human perturbation) are exactly the same reasons why you, as an individual, would try to safeguard and extend your own life and the life of your children. The same reasons apply to why you would be concerned about the fact that some chemical plant is dumping toxic waste into the groundwater, or that a smokestack is spewing noxious fumes into your children's school yard. The same reasons why you would pay careful attention to your own and your children's nutrition to make sure that in old age you don't have to deal with clogged arteries, diabetes or host of other wonderfully debilitating diseases.
    And remember - the sciences linking diet, lifestyles and other environmental factors to human health are still relatively new - and were also attacked very vigorosly by vested interests (i.e. the chemical companies, tobacco companies, food companies etc.). All these corporations at one time or the other (and some persist even today) tried to undermine the scientific credibility by either claiming that the science was "inconclusive" or by producing "scientific research" that claimed contrary results (especially olaughable was the Tobacco Research Institute). It does not mean that medical and epidemiological sciences were absolutely right all the time - they had to revise (or in some instance even reverse) some minor details of specific theories and assumptions - but for most part there has been a steady progress and a consistent trend in the same direction as the original scientific research. The same is happening in the atmospheric sciences - a few specific details may change - but the overall trend (and consensus) is not going to change.

    As for the passion - it's the wilful ignorance and stupidity that irks a lot of scientists - this is not a political game or a matter of popular opinion - but a reality - that will affect future generations. True - we don't know what the specific effects may be (regardless of the gloom and doom scenarios) but I don't want to take that chance - just as you wouldn't want to find out long afterwards (when it's too late to do anything about it) that lead paint could severely affect your children's mental health in the future.
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    "The point of living and of being an optimist, is to be foolish enough to believe the best is yet to come."
  9. #569  
    Quote Originally Posted by clulup
    Clearly, you are not up to date about climatic models, and you therefore draw wrong conclusions. Please refer to the following paper and the references therein as just one example:
    1. You attack me without any support.
    2. You don't answer any of my questions.
    3. You post the synopsis of a paper that doesn't address any of my questions (or even suggest that I "draw the wrong conclusions.")
    4. It's not even clear that you even understand my post.
    5. Virtually every post you make is a personal attack or just a posting of an article.
    6. You expect people to take you seriously based solely on the strength of your conviction and your blanket declarations that every expert agrees on everything.
  10. #570  
    Quote Originally Posted by samkim
    Chillig,
    My objection to the global warming claims lies in the models used to predict climate change over the course of 50+ years, and in the confidence level that environmentalists claim for these models.
    wrong on both counts - first of all, most of the climate models focus on extrapolating existing climatic trends, especially new trends that seem to break from the "natural" trends. Second, environmentalists have absolutely nothing to do with atmospheric sciences. Unless, of course, you would lump almost all of NASA scientists (and thousands of other atmospheric physicists) as "enviromentalists".

    Models are built on historical data, some of it accurate, some of it made up.
    that's a pretty damning thing to say - which scientist(s) has "made up" historical data? Or is this just one the typical partisan ad hominem basesless attack on science? Cite before you spout nonsense.

    "Experts" try to identify all the relevant factors and tweak their models until they adequately match historical data. That part is easy. Then they cross their fingers and hope that their models can extrapolate outside the base data. When the models fail to match actual results, they tweak the variables and try again. A common challenge with models is determining when correlation really means causation.
    amazing that you know so much about "modeling". And you don't seem to know the difference between modeling and simulation. Good thing that in the real world, scientists are not simplistic or moronic. Models and simulations are used across almost all scientific disciplines - from nuclear physics to petrochemical engineering to drug discovery to atmospheric sciences. If you what you say it true - then almost every field of science is suspect - including those that affect our daily life. At least read up a bit about this subject before you expose your appalling ignorance.

    There have been tens of thousands of experiments in the field of physics to test theoretical models.
    physics is only one branch of science, in case you didn't know. As for experiments in physics - perhaps you can enlighten me about the latest experiments that have confirmed the quantum chromodynamic model which has been the standard model for past three decades. As far as I know this experimental verification of the QCD is still spotty but this model is the bedrock of nuclear physics.
    In finance, with the help of computers, models have been tested millions of times.
    wow - since these financial models are so wonderful, please tell me what Pfizer's stock price is going to be next month, say on June 16th (please be accurate down to nearest cent). Or perhaps you could tell me what the NASDAQ will be at by end of this year - down to the nearest dollar?

    Testing (aka experimenting) in the real world, not limiting yourself to historical or guesstimated data, is a critical part of building a quantitative model. It's what gives a field the right to call itself a science.
    And tell me - what makes you an expert in what is called science? There are numerous fields of science (including from physics to biology) that build models based on historical data, are not able to perform experiments in the conventional sense. Yet these models can be tested using hypothesis testing methods.

    How much confidence should we have in today's 50-year climate models?
    again a typical misrepresentation of science - most climate models are based on historical data (e.g from ice core samples) that go back hundreds of millenia.
    Palm m505 -> Treo600 (GSM ATT) -> Treo650 (Cingular) -> BB8700g -> BB Pearl
    "The point of living and of being an optimist, is to be foolish enough to believe the best is yet to come."
  11.    #571  
    Quote Originally Posted by clulup
    Please accept my apologies.
    I accept your apology!
  12. #572  
    Quote Originally Posted by chillig35
    I think both clulup and myself have pointed out that the whole debate is not about any specific concern for "mother earth" - it's just a matter of enlightened self-preservation. I, for one, would like to ensure that my children and other future generations do not have to suffer the consequences of our wilful carelessness, and furthermore, they have a better life than we did.
    Totally understandable. We share that desire. And, I can see why one with such goals would be concerned with the apparent warming trend.
    Quote Originally Posted by chillig35
    As for the "natural cycle" b.s. that is typically spouted by most ignoramii, let me turn the argument around and talk about the "natural" human lifecycle. For example it is inevitable that all human beings will die (heck, all living creatures die) - so one simplistic argument is why would you want to take precautions to prolong your life (such as avoiding accidents, avoiding deadly infectious diseases, leading a healthy lifestyle) - after all you're going to die in the end anyway? Why do we invest enormous amounts of money into research to discover new drugs (apart from the fact that it's a nice career opportunity for people like myself!) or into investigating links between environmental factors and disease? The average lifespan of a US citizen was only 49 years at the turn of the twentieth century. At the end of the twentieth century it stands at 77 years.
    I ask those same questions. In the context of making a "better" life for future generations of humans, the investment in death-deferral is understandable. In the context of the impact on Earth, the link is not as obvious.
    Quote Originally Posted by chillig35
    I would say that the arguments to rein in global warming (or any other global phenomena that are caused by human perturbation) are exactly the same reasons why you, as an individual, would try to safeguard and extend your own life and the life of your children. The same reasons apply to why you would be concerned about the fact that some chemical plant is dumping toxic waste into the groundwater, or that a smokestack is spewing noxious fumes into your children's school yard. The same reasons why you would pay careful attention to your own and your children's nutrition to make sure that in old age you don't have to deal with clogged arteries, diabetes or host of other wonderfully debilitating diseases.
    Indeed
    Quote Originally Posted by chillig35
    ...
    As for the passion - it's the wilful ignorance and stupidity that irks a lot of scientists - this is not a political game or a matter of popular opinion - but a reality - that will affect future generations.
    Understood. I think some of the ignoramii who have taken up causes for and against contribute to the irking. There are those who ignore facts and declare there is no reason for concern. Likewise, there are those who use a few facts to "prove" extremes. This leaves scientists in the middle to referree.
    Quote Originally Posted by chillig35
    True - we don't know what the specific effects may be (regardless of the gloom and doom scenarios) but I don't want to take that chance - just as you wouldn't want to find out long afterwards (when it's too late to do anything about it) that lead paint could severely affect your children's mental health in the future.
    I appreciate your taking the time to help me with the "why's"
  13. #573  
    Quote Originally Posted by samkim
    1. You attack me without any support.
    2. You don't answer any of my questions.
    3. You post the synopsis of a paper that doesn't address any of my questions (or even suggest that I "draw the wrong conclusions.")
    4. It's not even clear that you even understand my post.
    5. Virtually every post you make is a personal attack or just a posting of an article.
    6. You expect people to take you seriously based solely on the strength of your conviction and your blanket declarations that every expert agrees on everything.
    The points you mentioned are all well known variables, not something climatologists have never thought about or haven't taken into consideration. Of course a model is always a model and not an accurate measurment, but climatic models are based on data covering hundreds, thousands or even millions of years (hence the paper I quoted), not just 50 years, and 50 years into the future is not THAT far away based on the huge numbers of models, the great majority of which showing similar results or the same trend.

    Using the remaining uncertainties as an excuse for not doing anything is not very clever. After all, reality could also be worse than predicted by the models.
    “Reality is that which, when you stop believing in it, doesn't go away.” (Philip K. ****)
  14. #574  
    Quote Originally Posted by shopharim
    There are those who ignore facts and declare there is no reason for concern. Likewise, there are those who use a few facts to "prove" extremes. This leaves scientists in the middle to referree.
    I know sho - if it were only that simple *sigh*. I definitely agree that there are some of the tree-hugging left-wing loonies who make non-scientific extrapolations to paint gloom and doom scenarios that do not help the debate at all. It also irks me to see some of these same people point out every single recent weather anomaly as evidence of "global warming" effects. And scientists usually do not try to dictate policy - but they simply provide the facts and advice to the policy makers.
    But what is deeply troubling is that this administration (and their blindly fanatical supporters) has taken a historically unique stance of not just ignoring the advice but also has also tried to actively muzzle the science, discredit, spin or twist the facts and in general has orchestrated selectively targeted partisan attacks on those scientific establishments that are threatening to their agenda.
    Palm m505 -> Treo600 (GSM ATT) -> Treo650 (Cingular) -> BB8700g -> BB Pearl
    "The point of living and of being an optimist, is to be foolish enough to believe the best is yet to come."
  15. #575  
    Quote Originally Posted by clulup
    The points you mentioned are all well known variables, not something climatologists have never thought about or haven't taken into consideration. Of course a model is always a model and not an accurate measurment, but climatic models are based on data covering hundreds, thousands or even millions of years (hence the paper I quoted), not just 50 years, and 50 years into the future is not THAT far away based on the huge numbers of models, the great majority of which showing similar results or the same trend.

    Using the remaining uncertainties as an excuse for not doing anything is not very clever. After all, reality could also be worse than predicted by the models.
    exactly - the normal solar output variations or geothermal energy variations are typically far smaller compared to the major fluctuations caused by the biosphere. It is true that a huge solar flare or a major volcanic event(s) could overwhelm the entire global homeostasis in one fell swoop and could cause major climatic shifts and the new climatic conditions may not stabilize for several dozen or even hundred millenia. But these are typically unpredictable and cataclysmic events and are not part of "natural cycles" anymore than a major meteor impact is part of the "natural cycle". The worry is whether the recent sharp spike in greenhouse gases and concomittant increase in global temperatures could end up triggering a potentially cataclysmic shift in the global climatic conditions. Again it is true that the scientists (the real ones at least) cannot predict the extent or degree of this climatic shift - but that does not mean we should not be at least try to either mitigate or even delay the shift.
    Palm m505 -> Treo600 (GSM ATT) -> Treo650 (Cingular) -> BB8700g -> BB Pearl
    "The point of living and of being an optimist, is to be foolish enough to believe the best is yet to come."
  16. #576  
    Chillig,
    I'm disappointed in you. It's clear that you understand very little of my post, so instead of asking questions, you make personal attacks.

    Quote Originally Posted by chillig35
    Originally Posted by samkim
    Chillig,
    My objection to the global warming claims lies in the models used to predict climate change over the course of 50+ years, and in the confidence level that environmentalists claim for these models.
    wrong on both counts - first of all, most of the climate models focus on extrapolating existing climatic trends, especially new trends that seem to break from the "natural" trends. Second, environmentalists have absolutely nothing to do with atmospheric sciences. Unless, of course, you would lump almost all of NASA scientists (and thousands of other atmospheric physicists) as "enviromentalists".
    Except for saying, "wrong on both counts," you haven't contradicted anything I said.

    I'm sure you'd agree that there are environmentalists who claim a high confidence level in the climate change models. Many non-scientists talk about science like it's fact, while scientists understand better the limitations of science.

    Models are built on historical data, some of it accurate, some of it made up.
    that's a pretty damning thing to say - which scientist(s) has "made up" historical data? Or is this just one the typical partisan ad hominem basesless attack on science? Cite before you spout nonsense.
    Hold your hostility. It's a simple statement which every scientist would agree with. "Made up" doesn't mean fake.

    You get data one of two ways: 1) Measure it directly; or 2) Figure out what it might be. We don't have direct measurement of the average temperature of the Earth's atmosphere at sea-level from 1,000 years ago, but we have other data. We also have ideas about how that data correspond to temperature. There are multiple ways of figuring out the answer, and different scientists have come up with different answers. You can't call them "accurate"; not only do they not agree with each other, but we have no way measuring the accuracy of these answers.

    [Edited to Add: The second way, "Figure out what it might be," includes the broad category of Assumptions, which might not be driven by real data. And again, every scientist makes assumptions, and thus, makes up data.]

    amazing that you know so much about "modeling". And you don't seem to know the difference between modeling and simulation.
    "Model" is a pretty generic term. You're making a pointless distinction.

    Good thing that in the real world, scientists are not simplistic or moronic.
    You're right. As I said, scientists generally understand the limitations of science.

    If you what you say it true - then almost every field of science is suspect - including those that affect our daily life.
    Again, what I've said about modeling is pretty basic, innocent stuff, which scientists would agree with.

    At least read up a bit about this subject before you expose your appalling ignorance.
    Again with the personal attacks.

    physics is only one branch of science, in case you didn't know. As for experiments in physics - perhaps you can enlighten me about the latest experiments that have confirmed the quantum chromodynamic model which has been the standard model for past three decades. As far as I know this experimental verification of the QCD is still spotty but this model is the bedrock of nuclear physics.
    Not sure your point here.

    wow - since these financial models are so wonderful, please tell me what Pfizer's stock price is going to be next month, say on June 16th (please be accurate down to nearest cent). Or perhaps you could tell me what the NASDAQ will be at by end of this year - down to the nearest dollar?
    You're assuming that models in finance try to predict far into the future like long-term climate models. Many do, but most don't. Modeling is performed in a very broad range of finance activities. Some deal with figuring out how changes in certain factors such as changes in certain interest rates or the volatility of certain securities will impact the price of other securities. These often deal in time frames of seconds. The models that deal with long time frames generally factor in probabilities and mulitple scenarios; they don't predict a single price. They help you make (or they automatically make) trading decisions. You know a model is good if it makes more money than it loses.

    And tell me - what makes you an expert in what is called science?
    I just use a dictionary
    http://www.answers.com/Science
    or an encyclopedia.
    http://en.wikipedia.org/wiki/Science

    There are numerous fields of science (including from physics to biology) that build models based on historical data, are not able to perform experiments in the conventional sense. Yet these models can be tested using hypothesis testing methods.
    Then by definition, they are fields of science.

    How much confidence should we have in today's 50-year climate models?
    again a typical misrepresentation of science - most climate models are based on historical data (e.g from ice core samples) that go back hundreds of millenia.
    Again, you misunderstand. I'm talking about climate models that predict 50 years forward.
    Last edited by samkim; 05/18/2006 at 11:36 AM.
  17. #577  
    Quote Originally Posted by clulup
    The points you mentioned are all well known variables, not something climatologists have never thought about or haven't taken into consideration. Of course a model is always a model and not an accurate measurment, but climatic models are based on data covering hundreds, thousands or even millions of years (hence the paper I quoted), not just 50 years, and 50 years into the future is not THAT far away based on the huge numbers of models, the great majority of which showing similar results or the same trend.

    Using the remaining uncertainties as an excuse for not doing anything is not very clever. After all, reality could also be worse than predicted by the models.
    When you don't have data and you don't have a way of getting the data, you have to make assumptions. Assumptions are a part of every model.

    Yes, climate scientists are aware of the variability of solar output, but how do they take that into consideration? They have to assume that changes in solar radiation haven't driven the major temperature changes on Earth because they don't have good data. That assumption feeds into the rest of the model and how much other factors drive climate changes.


    (Since both you and chillig didn't understand what I meant by "50-year" model, it's probably my fault. I should probably find a better way of saying that. I meant, climate models that make predictions about climate changes 50 years in the future.)


    My point, which remains, is that the ability of these models to accurately predict future climate changes has not been proven yet. There are many assumptions that drive these models and which environmentalists refuse to acknowledge.

    Other sciences have the benefit of testing hypotheses in a relatively short-time frame. The problem with this aspect of climate science (not all of it) is that it's going to take centuries to refine and confirm theories about how various factors drive climate changes.

    I'm not arguing that we should do nothing. I don't claim to know what the right answer is. I just believe that there's a great deal of over-confidence in models. Scientists have been wrong many times in history. Even in very recent history.

    I also don't disagree on the basics - that the environment is warming, that CO2 levels are rising, that man is contributing to the CO2 level increase.
  18. #578  
    Quote Originally Posted by samkim
    Except for saying, "wrong on both counts," you haven't contradicted anything I said.
    you imply that climate change models are focus only on the next 50 years - and that is not true

    I'm sure you'd agree that there are environmentalists who claim a high confidence level in the climate change models. Many non-scientists talk about science like it's fact, while scientists understand better the limitations of science.
    environmentalists typically focus on the biosphere and naturally try to assess the impact of the climate change on the biosphere. But again you imply that environmentalists are making or supporting the physicists conclusions regarding climate change for the models. Even more troubling is the implication that the whole field of atmospheric sciences is tarred with the same brush, i.e. as unreliable, because of the few "non-scientists" environmentalists.

    Hold your hostility. It's a simple statement which every scientist would agree with. "Made up" doesn't mean fake.
    i'm sorry - but where i come from if someone says that I "made up" data - it only means one thing (and I suspect if any layperson hears that term they would infer the same). It is completely different if you meant extrapolated or inferred. You have to choose your words carefully

    You get data one of two ways: 1) Measure it directly; or 2) Figure out what it might be. We don't have direct measurement of the average temperature of the Earth's atmosphere at sea-level from 1,000 years ago, but we have other data. We also have ideas about how that data correspond to temperature. There are multiple ways of figuring out the answer, and different scientists have come up with different answers. You can't call them "accurate"; not only do they not agree with each other, but we have no way measuring the accuracy of these answers..
    Accuracy by definition is about closely the data points correspond to the "true" value - within the range of experimental error. Data which fall outside this error range are not considered reliable and are not included in the models. Many of the leading scientific papers published in this field have been careful about the reliability of the various data points and have also appropriately weighted them in their analysis (typically using principal component analysis). Highly reputable journals such as Science or Nature do not accept papers that do not meet high scientific standards or data accuracy and analysis. Again, your implication is that the data cannot be trusted, and therefore the entire science behind it cannot be trusted.

    "Model" is a pretty generic term. You're making a pointless distinction..
    you have mixed up definitions of model and simulation and tried to imply that models are worthless, especially when you blithely say something like "they cross their fingers and hope that their models can extrapolate outside their base data". That is NOT how serious scientific models are developed. Most models based on a theoretical framework, based on solid scientific principles. Then the data is fed in to see if it matches the model - if it does not then the theoretical assumptions used to weight the variables is re-examined. If new assumptions are made - they have to be justified based on scientific principles first (e.g. laws of fluid mechanics have to be obeyed) and then it is rechecked to see if the data fits. What you suggest it totally untrue of the real scientific model approach and is again an implication that ALL models (especially those related to atmospheric sciences) cannot be trusted.

    You're right. As I said, scientists generally understand the limitations of science..
    but somehow non-scientists seem to relish in pointing out these limitations more than anyone else

    Again, what I've said about modeling is pretty basic, innocent stuff, which scientists would agree with..
    name one scientist who would agree with what you've said about modeling

    Again with the personal attacks..
    I apologize and take back my personal attacks - but please understand that your portayal of how (you think) science is done is deeply offensive to me as a scientist.

    Not sure your point here..
    Physics is one of the few fields in science where it is easy to verify theories or models experimentally. But even in physics (the example is nuclear physics), experimental verification is very hard if not impossible. But it does not mean that the physics models of nuclear forces are worthless.

    You're assuming that models in finance try to predict far into the future like long-term climate models. Many do, but most don't. Modeling is performed in a very broad range of finance activities. Some deal with figuring out how changes in certain factors such as changes in certain interest rates or the volatility of certain securities will impact the price of other securities. These often deal in time frames of seconds. The models that deal with long time frames generally factor in probabilities and mulitple scenarios; they don't predict a single price. They help you make (or they automatically make) trading decisions. You know a model is good if it makes more money than it loses..
    what makes you think that global climate models are any less robust than financial models? The macro scale for financial models is years - and the micro scale is seconds. In the case of global climate models the macro scale is hundreds of thousands of years and the micro scale is dozens or hundreds of years.

    I just use a dictionary
    http://www.answers.com/Science
    or an encyclopedia.
    http://en.wikipedia.org/wiki/Science.
    I have a doctorate in science and engineering - I have published dozens of papers in scientific journals and have presented at several internation conferences. In short, I do this for a living - and when somebody makes blanket generalizations about my field that are downright wrong or twisted then I have to respond. This would be akin to somebody making a blanket statement about the field of accounting - saying something like "all accountants cook the books"

    Again, you misunderstand. I'm talking about climate models that predict 50 years forward.
    I did check some of the pubs - most of the climate models do not just focus on the next 50 years - they typically model trends over the next thosand years or so and their models show the same trend of rapid increase in global temperatures - the 50 year mark is just a blip in that time scale - but highly relevant to environmentalists who worry about the impact on the biosphere.
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  19. #579  
    Quote Originally Posted by samkim
    .......I also don't disagree on the basics - that the environment is warming, that CO2 levels are rising, that man is contributing to the CO2 level increase.
    However, there is still a leap from consenting to these things and agreeing on what, if anything, we should do about them.

    Can we all agree that the only part of this over which we have any control at all is the human contribution to CO2? Can we agree that the conservative thing to do is to aggressively reduce that contribution? Can we agree that the only potential down-side to such an undertaking is that it might put a brake on our economy? Can we agree that that is far from certain and that it might even act as a spur to our economy?
  20. #580  
    you imply that climate change models are focus only on the next 50 years - and that is not true
    That's certainly not what I meant.


    environmentalists typically focus on the biosphere and naturally try to assess the impact of the climate change on the biosphere. But again you imply that environmentalists are making or supporting the physicists conclusions regarding climate change for the models. Even more troubling is the implication that the whole field of atmospheric sciences is tarred with the same brush, i.e. as unreliable, because of the few "non-scientists" environmentalists.
    My understanding is that most environmentalists are non-scientists. This is how I'm using the term:
    http://en.wikipedia.org/wiki/Environmentalist


    Accuracy by definition is about closely the data points correspond to the "true" value - within the range of experimental error. Data which fall outside this error range are not considered reliable and are not included in the models. Many of the leading scientific papers published in this field have been careful about the reliability of the various data points and have also appropriately weighted them in their analysis (typically using principal component analysis). Highly reputable journals such as Science or Nature do not accept papers that do not meet high scientific standards or data accuracy and analysis.
    If the "true" value is not measurable, you can't call the data accurate. Right? We agree on that, I hope.


    Again, your implication is that the data cannot be trusted, and therefore the entire science behind it cannot be trusted.
    Please stop putting words in my mouth.


    you have mixed up definitions of model and simulation and tried to imply that models are worthless, especially when you blithely say something like "they cross their fingers and hope that their models can extrapolate outside their base data". That is NOT how serious scientific models are developed. Most models based on a theoretical framework, based on solid scientific principles. Then the data is fed in to see if it matches the model - if it does not then the theoretical assumptions used to weight the variables is re-examined. If new assumptions are made - they have to be justified based on scientific principles first (e.g. laws of fluid mechanics have to be obeyed) and then it is rechecked to see if the data fits.
    Again, you're not contradicting anything I said - except for the blithely part. At some point, the models have to be tested outside the base data. Are you offended that I implied that scientists are superstitious by saying they cross their fingers? I was kidding; I don't really think they cross their fingers.


    What you suggest it totally untrue of the real scientific model approach and is again an implication that ALL models (especially those related to atmospheric sciences) cannot be trusted.
    No. Again, I didn't say or imply that all models cannot be trusted. I'm saying that models have to be tested beyond historical data. They have to be validated; otherwise they're just theories.


    You're right. As I said, scientists generally understand the limitations of science..
    but somehow non-scientists seem to relish in pointing out these limitations more than anyone else
    To the contrary, I think non-scientists generally equate science with fact. I think you do a disservice to the public if you encourage that myth.


    Again, what I've said about modeling is pretty basic, innocent stuff, which scientists would agree with..
    name one scientist who would agree with what you've said about modeling
    I believe you would if you weren't so busy being offended at what you think I said.


    I apologize and take back my personal attacks - but please understand that your portayal of how (you think) science is done is deeply offensive to me as a scientist.
    And I don't mean to offend. But I really don't think we disagree about how science is done. Perhaps we disagree about the level of reverence appropriate when speaking of science. I take my cues from Richard Feynman.


    Physics is one of the few fields in science where it is easy to verify theories or models experimentally. But even in physics (the example is nuclear physics), experimental verification is very hard if not impossible. But it does not mean that the physics models of nuclear forces are worthless.
    I've never called climate science, physics, or models worthless. But when experimental verification is impossible, you can't know for certain it's true. And you should acknowledge that it might be wrong. That doesn't mean you can't use the models or rely on the models. All I ask is that you don't imply that something is a proven fact if it's not.

    The big bang theory might be wrong. Black holes might not exist. General relativity might be complete nonsense. Does it offend you if I say that?


    what makes you think that global climate models are any less robust than financial models?
    As I said before, the long-term climate models have not been tested beyond historical data. That's what makes me think that they are less robust than financial models.


    I have a doctorate in science and engineering - I have published dozens of papers in scientific journals and have presented at several internation conferences. In short, I do this for a living - and when somebody makes blanket generalizations about my field that are downright wrong or twisted then I have to respond. This would be akin to somebody making a blanket statement about the field of accounting - saying something like "all accountants cook the books"
    I'm confused. Are you saying you have a single degree that spans two separate fields, or that you have a degree in a single field that can be described as both science and engineering?


    I did check some of the pubs - most of the climate models do not just focus on the next 50 years - they typically model trends over the next thosand years or so and their models show the same trend of rapid increase in global temperatures - the 50 year mark is just a blip in that time scale - but highly relevant to environmentalists who worry about the impact on the biosphere.
    Using the term "50-year" model was a mistake. I meant models that are used to make climate predictions 50+ years in the future.

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