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Re: fHuman vs. natural influences on the environment
In article <321FEA34.71F28DF7@math.nwu.edu>,
Leonard Evens <len@math.nwu.edu> wrote:
>charliew wrote:
>
>> Thanks for admitting the error. Incidentally, until the
last
>> 10 years or so, we couldn't measure 300 ppb. Even 1700
ppb
>> only corresponds to 1.7 ppm. No matter what greenhouse
>> effect you attribute to methane, unless you assume a
>> ridiculously high value for this effect, 1.7 ppm is not
going
>> to make any kind of measureable change to anything of
>> importance.
>
>Whether you think so or not, Methane is a significant
greenhouse gas.
>It is not a simple matter to determine its significance in
units
>equivalent to CO_2 because the effect is dependent to some
extent
>on the time scale. But according to the IPCC, the
contribution from
>methane to enhanced greenhouse warming is a significant
portion of the
>total. Since the people doing these calculations did so
subject to the
>criticism of peer review, and since there is little
controversy
>about that conclusion, I am afraid I am just going to take
their word
>over yours. If you think you can prove that methane can't
have any
>singificant effect, you should publish this in Science or
Nature,
>because it will come as a great surprise to atmospheric
chemists and
>radiation physicists who thought they understood the matter.
>
OK, Mr. Evens. How much effect does methane have relative to
water vapor and CO2? Since CO2 supposedly has a
concentration of 300-400 ppm, and water vapor has a
concentration of approximately 10,000 ppm, why is methane at
1.7 ppm such a threat?
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