X-Message-Number: 22650
From: "Steve Harris" <>
References: <>
Subject: Re: CryoNet #22638 CO2phobia
Date: Sun, 5 Oct 2003 18:43:43 -0700

> Message #22638
> From: 
> Date: Sat, 4 Oct 2003 10:31:30 EDT
> Subject: CO2phobia
>
> >Summary: we've seen what an increase of 87 ppm did. We
can't
> really take another 170 ppm (twice that) without real
> problems.
>
> Let's not be parochial here. The planet had far more life
when the CO2 level
> was closer to 1% than the current 0.037%. In fact, it may
be the only way to
> stop an Ice Age. So you have to replace your poodle with a
Deinonychus, it's
> better than global ice sheets.



COMMENT



I'd like to see a cite for your factoid. The Earth during
the age of land plants and

dinosaurs (certainly Deinonychus) ran at CO2 levels around 3
to 6 times current

levels (1000-2000 ppm = 0.1 to 0.2%). During the rare ice
ages hundreds of millions of

years ago CO2  levels dropped, but that was probably effect
rather than cause, since

such times were rare, and the levels were far higher than
they are now. Thus, we may

not be able to prevent ice ages even by raising CO2s to
those levels, but we'll still end

up raising the global temps to the tropical temps typical of
the carboniferous era. That's not

a good thing. Here's MY cite:



http://www.nature.com/cgitaf/google_referrer.taf?article_pro
duct_code=NATURE&fulltext_filename=/nature/journal/v411/n683
5/full/411287a0_fs.html&_UserReference=C0A804ED46539721F8276
DE2030F3F80C04B. This is the web address for Nature 411,
287 - 290 (2001); doi:10.1038/35077041.



I've been able to find suggestions that CO2 might have been
as high as 0.6 % 1.5 billion years ago, but

life was mostly in the seas then, and in any case the sun
was a lot cooler, so that doesn't mean it would

work now.



Ice ages are probably environmentally benign, since the come
on and retreat at time scales of 10,000 years

or more, which time enough to let plants and whole
ecosystems migrate. But do that in 50 years, and temp

change from north to south generally outrun the plants, and
then you get mass extinction. Let's not go there, is

my message.




> >Time for wind power and pebble bed fission reactors,
>
> Can't argue with that. Some He-3/deuterium reactors would
be nice too, while
> we're discussing the alternate world where people are
numerate enough to know
> that coal power plants release 100 times the radioactivity
that even
> old-technology fission plants do.



COMMENT:



Indeed, though that doesn't count the radioactivity if waste
or that released in accidents and

meltdowns. Thus the need for pebble bed technology. The
problem with fusion reactions such as

you mention is that they cause even worse radioactive waste
problems (neutron activation), plus

the problem that the technology is three decades in the
future. And has been three decades in the

future for many decades now :).



Hydrogen was mentioned in another message, and I have to
second that, so long as it's understood

that hydrogen isn't an energy source, so much as a way to
transport energy from fossil fuels in a

way which allows us to remove and bury CO2 at fossil fuel
usage point, rather than releasing it into

the air at the energy usage point. In other words, there is
a way to get energy out of fossil fuels safely,

and that is to use the energy from carbon and petroleum
oxidation to (directly or indirectly)
split water into hydrogen and oxygen, use the hydrogen in a
hydrogen economy, and pump the

CO2 back down gas wells, where it eventually combines with
rock and doesn't get into the

atmosphere. That's been prohibitively expensive until
recently, but new ceramic filters which
can separate out H2 from CO2 in the water-gas from coal
gasification, may actually make

this technically feasible here shortly. And we have huge
energy reserves in coal, which are all

perfectly usable if we extract the energy in that manner for
a hydrogen economy, rather than

burning the coal directly.



Steve Harris

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