"Mark Fergerson" wrote in message
news:7tILf.569$fL3.557@fed1read01...
Richard Henry wrote:


"Mark Fergerson" wrote in message
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Richard Henry wrote:


"Mark Fergerson" wrote in message
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Ken Smith wrote:

And you think that the amount of CO2 man has added will have no

effect.

"Trivial" effect, no sarcasm intended.

What degree of CO2 increase would you consider to be non-trivial?

Something on the order of what natural sources regularly (and
irregularly) produce. The irregular events I consider more worrisome as
the overall environment has a better chance of coping with relatively
slower changes; we ramp up our CO2 production over decades, the
biosphere adjusts to utilize it. A volcano blows off ten times as much
in one hour and there's no immediate place for it to go. Homeostasis (in
this case meaning staying on the "natural" attractor that determines our
climate) is a lot easier to maintain when the individual elements of the
system have adequate time to react to changes by sequestering excesses
of any resource, and Earth's biosphere has gotten very good at that.

Actually I worry less about rapid volcanic CO2 releases than things
like deep-ocean methane ice blowoffs. A seaquake releases a few cubic
kilometers of that in say an hour upwind of a populated coast and the
population is non-trivially screwed. This is not alarmist fantasy, it's
actually happened in large, deep inland lakes, killing every
air-breather for kilometers around. That was estimated to be from on the
order of a few cubic _meters_ of methane ice.

Are you talkinga about Lake Nyos in Cameroon? That lake burped off
carbon
dioxide (CO2, heavier than air) and methane hydrates will burp off
methane
(CH4, lighter than air).

No, I meant an event at the Black Sea (for which I cannot find a
link), and freshly-melted methane is heavier than air. The stuff has
been found all over the planet, from the British Columbia coast (Canada
is apparently thinking about mining it for energy), to the Gulfs of
Mexico and California, to the Black Sea. Evidently there's twice as much
carbon sequestered in the clathrates as in all the petroleum known to
exist!

Freshly-melted methane is heavier than air? I did not know that.

Don't forget the Edmund Fitzgerald; it is thought that it sank due to
a methane ice blowoff.

I did not know that either.