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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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