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Re: Human vs. natural influences on the environment



Harold Brashears (brshears@whale.st.usm.edu) wrote:
: Leonard Evens <len@math.nwu.edu> wrote for all to see:

: >Harold Brashears wrote:

: [edited]

: >> I think I would place less plausibility on the higher end, based on my
: >> own observations of the global warming reports.  Every time a new or
: >> revised model is generated, I have observed a downward trend in the
: >> forcast.  This will probably not continue forever, but I am not yet
: >> convincewd we are through, either.
: >> 
: >> I will place much more confidence in our ability to forcast the
: >> climate in one hundred years when I observe that we can take data from
: >> 1920 to 1960 and predict correctly the climate in 1990.  This is a
: >> mere 30 years.
: >> 
: >
: >I am a bit mystefied by this comment.   Why use only the data from
: >1920 to 1960 and then try for 1990?

: The dates were picked at random to have two characteristics:

: 1. The data is reliable, ie., obtained with relatively modern
: instrumentation in a fairly consistent fashion.

: 2. That the date to be forecast be less than that of the report (100
: years).

: Frankly, I wanted to leave as long a baseline and as short a forecast
: period as seemed reasonable.  If you want a shorter baseline or a
: longer forecast period, please have at it.

: >   As Michael Tobis and others have
: >pointed out, you can prove anything you want by carefully selecting
: >which dates in the record you start and finish at.   

: No kidding.  You mean like using from 1900 to 1990 to prove that
: temperatures are rising due to CO2 increase from human sources, when
: the temperature increase occurred prior to 1940 - 1950, and the CO2
: increase after?

: >A more reasonable
: >thing to do is to look at the entire observational record from some
: >early base point and see how accurately the models can track it.  The
: >more data you try to match, the harder it is to get agreement by
: >tweaking parameters.  The point made by Santer and his colleagues in the
: >detection chapter (8) of Climate Change, 1995 is that this is now at the
: >level where we can say with confidence that human activities have
: >affected climate but the uncertainties are still too large to quantify
: >the human contribution.   

: With this part I agree.

: >They also add that this does not mean that the
: >human contribution is likely to be small.  It could be small but it
: >could just as well be large.   

: This was the point of my earlier post.  The historical record of these
: predictions shows a strong trend downward.  Betting my own money, I
: would bet the next such "authoritative" report will continue this
: trend.  Betting the public money, I am more flexible.  To date, I have
: seen no evidence that this trend will not continue.  My bet is with
: Nuremberg (that spelling does not look right?) at Scripps.  Maybe 1/2
: a degree over 100 hundred years.

: Actually, I think he is pessimistic.  I believe technology will leave
: this problem behind us, unless the neoLuddites continue to have a
: disproportionate voice in modern technology decisions by the
: government (ie., nuclear power generation).

: >It should also be added that Santer and
: >his co-athors look not only at the record of average global temperatures
: >but also at things like regional effects, vertical profiles of important
: >variables, etc.
: >
: >Mr. Brashears certainly has the right to use whatever criteria he wants
: >to judge the significance of the problem, but the rest of us have no
: >reason to share his beliefs.   

: Certainly not!  Did you think I claiming to be Earth First! or
: Greenpeace, that I would force others to accept my beliefs?  

: >If we have to choose between him and
: >Benjamin Santer, I think there is little doubt whom to pay more
: >attention to. 
:   
: And, were I alone, you would be correct.  However, I must admit to a
: certain disappointment in your line of argument here.  This is the
: first time I have seen you argue by appeal to authority.  I am sorry
: that you felt that was necessary to make your point, as I had thought
: you more inclined to argue by evidence and logic.  

: My mistake.   I won't repeat it.  You have my apologies for bothering
: you. 

: [deleted]

: Regards, Harold
: ----
: "We were the first to assert that the more complicated 
: the forms assumed by civilization, the more restricted 
: the freedom of the individual must become."
: 	---Benito Mussolini

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