ZPE_Logo
  
Search        
  Create an account Home  ·  Topics  ·  Downloads  ·  Your Account  ·  Submit News  ·  Top 10  
Mission Statement

Modules
· Home
· Forum
· LATEST COMMENTS
· Special Sections
· SUPPORT ZPEnergy
· Advertising
· AvantGo
· Books
· Downloads
· Events
· Feedback
· Link to us
· Private Messages
· Search
· Stories Archive
· Submit News
· Surveys
· Top 10
· Topics
· Web Links
· Your Account

Who's Online
There are currently, 269 guest(s) and 0 member(s) that are online.

You are Anonymous user. You can register for free by clicking here

Events
  • (August 7, 2024 - August 11, 2024) 2024 ExtraOrdinary Technology Conference

  • Hot Links
    Aetherometry

    American Antigravity

    Closeminded Science

    EarthTech

    ECW E-Cat World

    Innoplaza

    Integrity Research Institute

    New Energy Movement

    New Energy Times

    Panacea-BOCAF

    RexResearch

    Science Hobbyist

    T. Bearden Mirror Site

    USPTO

    Want to Know

    Other Info-Sources
    NE News Sites
    AER_Network
    E-Cat World
    NexusNewsfeed ZPE
    NE Discussion Groups
    Energetic Forum
    EMediaPress
    Energy Science Forum
    Free_Energy FB Group
    The KeelyNet Blog
    OverUnity Research
    Sarfatti_Physics
    Tesla Science Foundation (FB)
    Vortex (old Interact)
    Magazine Sites
    Electrifying Times (FB)
    ExtraOrdinary Technology
    IE Magazine
    New Energy Times

    Interesting Links

    Click Here for the DISCLOSURE PROJECT
    SciTech Daily Review
    NEXUS Magazine

    Climate Model Proves Erroneous
    Posted on Monday, October 25, 2004 @ 04:46:36 GMT by rob

    Science bodebliss writes: Global Warming Bombshell

    A prime piece of evidence linking human activity to climate change turns out to be an artifact of poor mathematics. In the scientific and political debate over global warming, the latest wrong piece may be the "hockey stick", the famous plot (shown below), published by University of Massachusetts geoscientist Michael Mann and colleagues.

    This plot purports to show that we are now experiencing the warmest climate in a millennium, and that the earth, after remaining cool for centuries during the medieval era, suddenly began to heat up about 100 years ago--just at the time that the burning of coal and oil led to an increase in atmospheric levels of carbon dioxide.

    I talked about this at length in my December 2003 column. Unfortunately, discussion of this plot has been so polluted by political and activist frenzy that it is hard to dig into it to reach the science. My earlier column was largely a plea to let science proceed unmolested. Unfortunately, the very importance of the issue has made careful science difficult to pursue.

    But now a shock: Canadian scientists Stephen McIntyre and Ross McKitrick have uncovered a fundamental mathematical flaw in the computer program that was used to produce the hockey stick. In his original publications of the stick, Mann purported to use a standard method known as principal component analysis, or PCA, to find the dominant features in a set of more than 70 different climate records.

    But it wasn?t so. McIntyre and McKitrick obtained part of the program that Mann used, and they found serious problems. Not only does the program not do conventional PCA, but it handles data normalization in a way that can only be described as mistaken.

    Now comes the real shocker. This improper normalization procedure tends to emphasize any data that do have the hockey stick shape, and to suppress all data that do not. To demonstrate this effect, McIntyre and McKitrick created some meaningless test data that had, on average, no trends. This method of generating random data is called ?Monte Carlo? analysis, after the famous casino, and it is widely used in statistical analysis to test procedures. When McIntyre and McKitrick fed these random data into the Mann procedure, out popped a hockey stick shape!

    That discovery hit me like a bombshell, and I suspect it is having the same effect on many others. Suddenly the hockey stick, the poster-child of the global warming community, turns out to be an artifact of poor mathematics. How could it happen? What is going on? Let me digress into a short technical discussion of how this incredible error took place.

    In PCA and similar techniques, each of the (in this case, typically 70) different data sets have their averages subtracted (so they have a mean of zero), and then are multiplied by a number to make their average variation around that mean to be equal to one; in technical jargon, we say that each data set is normalized to zero mean and unit variance. In standard PCA, each data set is normalized over its complete data period; for key climate data sets that Mann used to create his hockey stick graph, this was the interval 1400-1980. But the computer program Mann used did not do that. Instead, it forced each data set to have zero mean for the time period 1902-1980, and to match the historical records for this interval. This is the time when the historical temperature is well known, so this procedure does guarantee the most accurate temperature scale. But it completely screws up PCA. PCA is mostly concerned with the data sets that have high variance, and the Mann normalization procedure tends to give very high variance to any data set with a hockey stick shape. (Such data sets have zero mean only over the 1902-1980 period, not over the longer 1400-1980 period.)

    The net result: the ?principal component? will have a hockey stick shape even if most of the data do not.
    McIntyre and McKitrick sent their detailed analysis to Nature magazine for publication, and it was extensively refereed. But their paper was finally rejected. In frustration, McIntyre and McKitrick put the entire record of their submission and the referee reports on a Web page for all to see. If you look, you?ll see that McIntyre and McKitrick have found numerous other problems with the Mann analysis. I emphasize the bug in their PCA program simply because it is so blatant and so easy to understand. Apparently, Mann and his colleagues never tested their program with the standard Monte Carlo approach, or they would have discovered the error themselves. Other and different criticisms of the hockey stick are emerging (see, for example, the paper by Hans von Storch and colleagues in the September 30 issue of Science).

    Some people may complain that McIntyre and McKitrick did not publish their results in a refereed journal. That is true--but not for lack of trying. Moreover, the paper was refereed--and even better, the referee reports are there for us to read. McIntyre and McKitrick?s only failure was in not convincing Nature that the paper was important enough to publish.

    How does this bombshell affect what we think about global warming?

    It certainly does not negate the threat of a long-term global temperature increase. In fact, McIntyre and McKitrick are careful to point out that it is hard to draw conclusions from these data, even with their corrections. Did medieval global warming take place? Last month the consensus was that it did not; now the correct answer is that nobody really knows. Uncovering errors in the Mann analysis doesn?t settle the debate; it just reopens it. We now know less about the history of climate, and its natural fluctuations over century-scale time frames, than we thought we knew.

    If you are concerned about global warming (as I am) and think that human-created carbon dioxide may contribute (as I do), then you still should agree that we are much better off having broken the hockey stick. Misinformation can do real harm, because it distorts predictions. Suppose, for example, that future measurements in the years 2005-2015 show a clear and distinct global cooling trend. (It could happen.) If we mistakenly took the hockey stick seriously--that is, if we believed that natural fluctuations in climate are small--then we might conclude (mistakenly) that the cooling could not be just a random fluctuation on top of a long-term warming trend, since according to the hockey stick, such fluctuations are negligible. And that might lead in turn to the mistaken conclusion that global warming predictions are a lot of hooey. If, on the other hand, we reject the hockey stick, and recognize that natural fluctuations can be large, then we will not be misled by a few years of random cooling.

    A phony hockey stick is more dangerous than a broken one--if we know it is broken. It is our responsibility as scientists to look at the data in an unbiased way, and draw whatever conclusions follow. When we discover a mistake, we admit it, learn from it, and perhaps discover once again the value of caution.

    http://www.technologyreview.com/articles/04/10/wo_muller101504.asp


     
    Login
    Nickname

    Password

    Security Code: Security Code
    Type Security Code

    Don't have an account yet? You can create one. As a registered user you have some advantages like theme manager, comments configuration and post comments with your name.

    Related Links
    · More about Science
    · News by rob


    Most read story about Science:
    100 miles on 4 ounces of water?


    Article Rating
    Average Score: 4.66
    Votes: 3


    Please take a second and vote for this article:

    Excellent
    Very Good
    Good
    Regular
    Bad


    Options

     Printer Friendly Printer Friendly


    "Climate Model Proves Erroneous" | Login/Create an Account | 4 comments | Search Discussion
    The comments are owned by the poster. We aren't responsible for their content.

    No Comments Allowed for Anonymous, please register

    Re: Climate Model Proves Erroneous (Score: 1)
    by kurt9 on Monday, October 25, 2004 @ 09:28:28 GMT
    (User Info | Send a Message) http://www.metatechnica.com
    I've always thought the man-induced global warming thing to be a total scam. I never believed in it. The global warming scar is simply the latest attempt by the anti-industrial Left to thwart our economic growth.

    It is also an attempt by a uncompetitive EU to try to limit America's economic growth.

    Global warming is just a scam, nothing more.



     

    All logos and trademarks in this site are property of their respective owner. The comments are property of their posters, all the rest © 2002-2016 by ZPEnergy. Disclaimer: No content, on or affiliated with ZPEnergy should be construed as or relied upon as investment advice. While every effort is made to ensure that the information contained on ZPEnergy is correct, the operators of ZPEnergy make no warranties as to its accuracy. In all respects visitors should seek independent verification and investment advice.
    Keywords: ZPE, ZPF, Zero Point Energy, Zero Point Fluctuations, ZPEnergy, New Energy Technology, Small Scale Implementation, Energy Storage Technology, Space-Energy, Space Energy, Natural Potential, Investors, Investing, Vacuum Energy, Electromagnetic, Over Unity, Overunity, Over-Unity, Free Energy, Free-Energy, Ether, Aether, Cold Fusion, Cold-Fusion, Fuel Cell, Quantum Mechanics, Van der Waals, Casimir, Advanced Physics, Vibrations, Advanced Energy Conversion, Rotational Magnetics, Vortex Mechanics, Rotational Electromagnetics, Earth Electromagnetics, Gyroscopes, Gyroscopic Effects

    PHP-Nuke Copyright © 2005 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.