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  1.    #901  
    Couldn't have been said better. Interesting to note that the media has been claiming either Global Cooling or Global Warming since 1895.

    http://epw.senate.gov/speechitem.cfm...=rep&id=263759
  2. #902  
    Quote Originally Posted by whmurray View Post
    All other things equal. However, in terms of global climate change, 400 years of data is not very much. Both measurement and recording were sparse for most of that time.....Indirect evidence is fairly convincing that climate changes gradually over tens of thousands of years. The issue before the house is whether or not what we have observed over "350+" years is part of one of those trends or whether we have somehow de-stablilized one of those trends and are approaching a "tipping point" that will result in "sudden" climate change. Here, it seems to me that the answer is not yet obvious.

    As I have said, in the presence of doubt, I think that we should act conservatively. Some people seem to think that the evidence is sufficient to demonstrate the need for precipitous action. I might be willing to join them in "viewing with alarm" if I thought that anyone knew what we should do that we are not doing and if I thought that sustained alarm ever got us anywhere.
    This is pretty much exactly what the research was saying that Naked Science was referring to that I mentioned above. They were focusing on the last 200,000 years of climate changes and stating that the last 10,000 years of climate stability is the fluke rather than the norm.

    They also posed the question where this "boring period of climate changes" was naturally coming to an end or were we bringing it to and end and back to the often time swiftly changes that the world has seen in the past.

    I found it fascinating....and a little scary....with some of the recent discoveries showing the possibilities that massive and more localized Ice Ages were brought on by nature herself within 20 years. Though they pointed out that majority of the climate changes do tend hundreds or thousands of years.
    Last edited by HobbesIsReal; 09/27/2006 at 03:18 PM.
  3. #903  
    Double post.....
  4. #904  
    Quote Originally Posted by samkim View Post
    You're making an unsubstantiated claim. You have no idea what data he has or how he drew his conclusions. You question his credibility because he uses the word "think," as scientists properly do, instead of talking in certain terms like "proof," as non-scientists prefer.
    Thats why I said 'by the sounds of it' since there was no mention of any study at all.. I assume that if he did a study it would have been mentioned.
    Now what he did he took his (subjective) impression on the things he had seen.

    And yes 400 years is only a small piece of a big puzzle, but it is a key piece.
    Since the industrial revolution only started about a hundred years ago, before that the use of fosil fuels was minimal compared to current usage.

    If you can proof that over that 400 years there is a significant peak in global temperature in the last 100 years that would be a huge indicator that global warming is likely caused by greenhouse gasses..
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  5. #905  
    that's a load of, well, you know. 100 out of the last 400 yrs showing some significant change, and you can derive global warming out of that???
  6. #906  
    Quote Originally Posted by ToolkiT View Post
    Thats why I said 'by the sounds of it' since there was no mention of any study at all.. I assume that if he did a study it would have been mentioned.
    Now what he did he took his (subjective) impression on the things he had seen.

    And yes 400 years is only a small piece of a big puzzle, but it is a key piece.
    Since the industrial revolution only started about a hundred years ago, before that the use of fosil fuels was minimal compared to current usage.

    If you can proof that over that 400 years there is a significant peak in global temperature in the last 100 years that would be a huge indicator that global warming is likely caused by greenhouse gasses..
    I still don't see it. Like I said, 400 years is 1/10,000,000th of the estimated age of the earth. With that sample size, it's about the same as putting out a research paper of recreational trends among all Chinese people based on a poll of 200 people from the same villiage.
  7. #907  
    Quote Originally Posted by ToolkiT View Post
    ............And yes 400 years is only a small piece of a big puzzle, but it is a key piece. Since the industrial revolution only started about a hundred years ago, before that the use of fosil fuels was minimal compared to current usage.

    If you can proof that over that 400 years there is a significant peak in global temperature in the last 100 years that would be a huge indicator that global warming is likely caused by greenhouse gasses..
    Sorry. Not scientific. Would prove nothing except that the choice of period was arbitrary and not typical. Science is harder than it looks.
  8. #908  
    Quote Originally Posted by sblanter View Post
    that's a load of, well, you know. 100 out of the last 400 yrs showing some significant change, and you can derive global warming out of that???
    the 400 years is the only detailed data we've got, there is some rough data indicating the temps before that and they show that the temps go up and down gradually not dramatically.
    So if there is a dramatic rize in temps over the last 100 years, yes I'd say it is a pretty strong indicator there is a link between fossil fuels and global warming.
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  9. #909  
    Quote Originally Posted by whmurray View Post
    Sorry. Not scientific. Would prove nothing except that the choice of period was arbitrary and not typical. Science is harder than it looks.
    it is Scientific, just not total proof of the theory... but like I said before total proof is inpossible in issues like these...
    Evolution cannot be proven either, yet there is very strong evidence indicating it is true, same with global warming.
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  10. #910  
    Insufficient data, toolkit. Show me another 400 yr slice of time that indicates the same or anything different. Either way, show me something relevant to anything.
  11. #911  
    Quote Originally Posted by sblanter View Post
    Insufficient data, toolkit. Show me another 400 yr slice of time that indicates the same or anything different. Either way, show me something relevant to anything.
    He likes the data he has chosen. It makes the point he has chosen to make. Science is harder than it looks.
  12. #912  
    When you've already reached your conclusions, it's enough to see a correlation and claim that's science. You don't need much data to see correlation.

    It's nearly impossible to prove causation by passively looking at data, no matter how much data you have.
  13. #913  
    In the case of global warming, and the ozone hole theory, it was causation that was found first and only then was correlation sought.

    For example it wasn't that scientists saw a correlation between a global warming trend and also a rising greenhouse gas trend and thought "hmm maybe one is causing the other". They found a physical causation first. Ie increases in greenhouse gases cause an increase in the greenhouse effect, which causes global warming. And then used this (along with other causations such as aerosols) to try and explain recent temperature which involves looking for a correlation. So correlation came after causation was established.

    The same is true with the ozone hole being caused by CFCs theory. Scientists didn't simply see a correlation between shrinking ozone hole and rising CFC emissions and think "hmm correlation. Maybe one is causing the other". No, in fact there was no correlation back then as records of both atmospheric CFC levels and ozone holes were non-existant. Instead they found a causation first - chlorine destroys ozone in a catalyst reaction. Later they got to thinking that this could lead to an increased ozone hole, and only then were correlations sought.

    There are too many correlations in the world to derive causations from every single one, which is why scientists in the above theories only considered correlating things that could possibly be related. Unlike that satirical graph of number of pirates plotted against temperature, the theories mentioned above are underpined with physical causative processes, not just a correlation.

    In fact even now the correlation for CFC emissions vs ozone hole isn't even that good. The measured record is very short and reduction of CFCs doesn't have an instant reaction on shrinking the hole, so a decrease isn't yet noticable despite CFC emissions being reduced. But the causation is good enough to make it beyond reasonable doubt.
  14. #914  
    very well put yogsothoth!
    Most non-scientists do not seem to (or perhaps do not want to) understand the difference between causation and correlation. Even if scientists dig up past correlations (say a 400-year slice from 100,000 years ago) the data would not be relevant to the causative phenomenon being observed today. The past reasons for climatic shifts are not as important as the current problems with increasing greenhouse gas levels.

    For those of you who insist on labeling the global warming scientific consensus as a "controversy" here is another example of a similar "controversy" that has been going on in the field of medicine for a while. While almost all scientists (and perhaps most of the folks here on TC) agree that HIV causes AIDS, there has been a tiny minority, including an eminent UC Berkeley professor (Peter Duesberg) who challenged the notion that HIV caused AIDS. While they admit that HIV virus existed, they felt that AIDS was caused by non-contagious factors such as malnutrition, drug abuse and so on. While the scientific community politely heard their alternate hyopthesis, in the end, the majority consensus moved on and made signficant contributions towards understanding the disease and developing drugs to control it. The dissident views did get some media attention, and of course there were the conspiracy theories that the drug companies were out to supress the minority attention. But in the end the health policies were driven by the science and not by politics or financial interests. Granted that AIDS has not been eradicated and is still a major problem in the developing world, but imagine if politicians decided to champion the minority dissenting viewpoint and instead questioned the scientific consensus and tried to block funding for drugs or vaccines against HIV until there was 100% consensus or "conclusive proof" of Koch's postulates 3 and 4 (i.e. you have to deliberately infect people with HIV and demonstrate that they get AIDS and that you can re-isolate HIV from such people). Since it would not be ethical to deliberately infect somebody with HIV, scientists would never have "conclusive proof" that HIV caused AIDS. If these doubters controlled the government and funding, then the problem would still continue to be "studied" or more data gathered while many thousands of people would continue to die of AIDS.

    In the case of global climate here are some of the facts:
    1. Increasing levels of greenhouse gases cause warming in a closed system such as the global climate system.
    2. There are several factors contributing to the global climate system (which seems to have been relatively stable over the past 10,000 years) and one of the major factors includes the greenhouse gas levels.
    3. The greenhouse gas levels in our atmosphere are currently at the highest levels ever in the past 600,000 years.
    4. There has been a perceptible increase in global temperatures in the past hundred years which happens to coincide with increased global human activity (industrialization, deforestation etc.).
    5. Dramatic shifts in global climate have occured in the past history of the planet - sometimes in as little as a few hundred years (and yes, I know there is speculation that a little Ice Age could have occured in as little as 20 years). It is not clear as to which factors (and how much) contributed to these past climatic shifts.

    For those of you who challenge these facts, this would be akin to saying that either HIV does not exist or that AIDS is not a disease.
    For those who acknowledge these facts, but do not believe that there is a clear link between increasing levels of greenhouse gases as a result of human activity and increasing global temperatures, then it would the same as saying that there is no clear link between HIV and AIDS, and that AIDS could be caused by other non-contagious factors, and therefore do not advocate any preventive measures such as using cond0ms. And it would also be the equivalent of saying that AIDS is not really such a major epidemic problem and therefore we should not waste efforts on trying to prevent it, let alone trying to find a cure for it (and certainly this was the attitude among some of the Repugnicans early on, especially since this was seen as a "gay" disease).

    The science indicates that there is a strong possibility that we might be at the verge of triggering a global climatic change though there is active scientific debate as to how soon it will occur or how dramatic this shift might be. The question is whether we recognize that risk, and what are the possible solutions to either averting that change or minimizing the impact.

    The fact that there have been dramatic global climatic shifts in the past history of the earth (yes, the Arctic region was a sauna at one time) is besides the point. And just because we do not have 10,000 years of detailed climatic data does not mean that we cannot make scientifically reasonable assessment of the current state of affairs or risks. While it is prudent to act "conservatively" in the face of "doubt" about the speed or magnitude with which a climate shift may occur, the right-wing tactics seem to be focused on not just denying that there is a risk in the first place, but also on viciously attacking the facts or on overwhelmingly amplifying the voices of the minority scientific dissenters. Science will never provide us with 100% certainity - but ignoring scientific consensus is not conservatism but wilful stupidity.
    Last edited by chillig35; 10/03/2006 at 06:59 PM.
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  15. #915  
    In religion and politics, people's beliefs and convictions are in almost every case gotten at second hand, and without examination" --Mark Twain
    Science was not a big thing in Twain's time but it is true of science too. Faith and reason are both metaphors.
  16. #916  
    The HIV comparison is a red herring and not analogous to the discussion of global warming.
  17. #917  
    the number of handsets in the world contribute to Global warming.
  18. #918  
    Quote Originally Posted by hoovs View Post
    The HIV comparison is a red herring and not analogous to the discussion of global warming.
    the analogy is that a minority viewpoint should not distort a science-based policy, which has happened in the case of global warming. Politics and special interests are deliberately distorting the discussions.
    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."
  19. #919  
    Quote Originally Posted by hoovs View Post
    The HIV comparison is a red herring and not analogous to the discussion of global warming.
    The analogy was used to demonstrate that one's religious, political, and other pre-existing belief systems are likely to influence one's assessment of new evidence and acceptance of the conclusions to which that evidence might lead. I found the analogy useful.

    For most of us, many, not to say most, of our beliefs are received wisdom. For some, our willingness to accept new ideas is a function of how well they fit into our existing belief systems. For others, it is a function of how much we trust the source. For all of us, it is some combination of the two. Most of us believe that we are sceptical and that most others are all too credulous.

    However, one interesting finding of social science is that our collective judgment is usually superior to our individual judgment. (The replicable experiment is the "jar of jelly beans" in which the mean guess is closer to the real number than any of the individual guesses and that the agreement between the mean guess and the actual goes up with the number of guessers.) That is why some of us prefer democracy to the most sagacious and benign autocracy.
  20. #920  
    Quote Originally Posted by whmurray View Post
    Science was not a big thing in Twain's time but it is true of science too. Faith and reason are both metaphors
    ah! you say that with such conviction!
    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."

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