[Prev][Next][Index][Thread]

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?



Follow-Ups: References: