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Re: Human vs. natural influences on the environment
In article <32073e01.247176594@nntp.st.usm.edu>,
Harold Brashears <brshears@whale.st.usm.edu> wrote:
>af329@james.freenet.hamilton.on.ca (Scott Nudds) wrote for all to see:
>
>>jwas@ix.netcom.com(jw) wrote:
>>: it just *might* turn out that climate is just approaching a
>>: situation where positive feedback was present - for a while;
>>
>> Warmer oceans can hold less CO2.
>
>Warmer oceans release more water, forming cloud cover, blockin some
>light, and incidently trapping some IR.
And it is very far from clear at present which of these processes will
be predominant. Your mere mention of a possible negative feedback
mechanism does not establish that it is sufficient to save anyones'
bacon. The cloud physics and oceanography people are working on it.
We should go to them for estimates (you and Scott both) and not play
rhetorical games unworthy of a high school debating team.
>
>> Melted tundra rots and moves more CO2 into the atmosphere.
>
>Why would it rot? Higher CO2 stimulates plant growth.
It would rot because it would be warmer for more of the year, as the
permafrost moves north. This could very well cause the enormous
resrves of sequestered carbon that have built up in boreal peatlands
over the past 5000 years or so to start degrading. The effect of high
C02 levels on the growth rates of <some> kinds of plant has nothing to
do with the case.
>
>> More forest fires, more CO2 released into the atmoshpere.
>
>Warmer oceans mean more water evaporated into the atmosphere,
>resulting in more rain.
Maybe. I thought all those oceanic clouds you're so confident of would
mainly drop their rain right back into the ocean. It matters where the
rain falls. The Indian ocean is gulf or Carpenteria are plenty warm,
and look at Australia.
The last run of data from 4 major GCMs (1992 runs, I think) that I
worked with predicted somewhat higher temperatures and reduced
preciptation in much of the western Canadian noreal forest. If my
statistical models relating climate conditions to fire probabliity are
any good (and they seem to be much better than any previously
published) this means that those forests will burn at much higher
rates than in the past millenium or so. To reiterate, it really
matters where the rain falls.
>It would appear that there are a host of feedback mecanisms, many of
>which you failed to mention. Is that because you did not know about
>them?
You seem to know about them, at least as strings of text that one
might type. Based on the few areas where I have some specialied
knowledge, it seems to me that you don't understand them very well.
The issues involved are much to grave to permit nay of us to rummage
through the literature looking for text-bytes that support are
favoured ideological position.
Say, Steinn, in case you're reading this, I have not had time to
look at the Prentice references you mentioned....
--
Steve Cumming "I could save the world
stevec@geog.ubc.ca if I could only get the parts."
Honni soit qui mal y pense.
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