161 lines
7.4 KiB
Plaintext
161 lines
7.4 KiB
Plaintext
From fork-admin@xent.com Thu Sep 26 11:04:32 2002
|
|
Return-Path: <fork-admin@xent.com>
|
|
Delivered-To: yyyy@localhost.spamassassin.taint.org
|
|
Received: from localhost (jalapeno [127.0.0.1])
|
|
by jmason.org (Postfix) with ESMTP id 90BF116F03
|
|
for <jm@localhost>; Thu, 26 Sep 2002 11:04:30 +0100 (IST)
|
|
Received: from jalapeno [127.0.0.1]
|
|
by localhost with IMAP (fetchmail-5.9.0)
|
|
for jm@localhost (single-drop); Thu, 26 Sep 2002 11:04:30 +0100 (IST)
|
|
Received: from xent.com ([64.161.22.236]) by dogma.slashnull.org
|
|
(8.11.6/8.11.6) with ESMTP id g8PLFFC14432 for <jm@jmason.org>;
|
|
Wed, 25 Sep 2002 22:15:15 +0100
|
|
Received: from lair.xent.com (localhost [127.0.0.1]) by xent.com (Postfix)
|
|
with ESMTP id CB1062940E9; Wed, 25 Sep 2002 14:11:09 -0700 (PDT)
|
|
Delivered-To: fork@spamassassin.taint.org
|
|
Received: from cats.ucsc.edu (cats-mx2.ucsc.edu [128.114.129.35]) by
|
|
xent.com (Postfix) with ESMTP id BD72429409A for <fork@xent.com>;
|
|
Wed, 25 Sep 2002 14:10:49 -0700 (PDT)
|
|
Received: from Tycho (dhcp-55-196.cse.ucsc.edu [128.114.55.196]) by
|
|
cats.ucsc.edu (8.10.1/8.10.1) with SMTP id g8PHxFT27510 for
|
|
<fork@xent.com>; Wed, 25 Sep 2002 10:59:15 -0700 (PDT)
|
|
From: "Jim Whitehead" <ejw@cse.ucsc.edu>
|
|
To: <fork@spamassassin.taint.org>
|
|
Subject: RE: CO2 and climate (was RE: Goodbye Global Warming)
|
|
Message-Id: <AMEPKEBLDJJCCDEJHAMIKEDKFIAA.ejw@cse.ucsc.edu>
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset="iso-8859-1"
|
|
Content-Transfer-Encoding: 7bit
|
|
X-Priority: 3 (Normal)
|
|
X-Msmail-Priority: Normal
|
|
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0)
|
|
In-Reply-To: <1032885762.24435.78.camel@avalon>
|
|
Importance: Normal
|
|
X-Mimeole: Produced By Microsoft MimeOLE V5.50.4133.2400
|
|
X-Ucsc-Cats-Mailscanner: Found to be clean
|
|
Sender: fork-admin@xent.com
|
|
Errors-To: fork-admin@xent.com
|
|
X-Beenthere: fork@spamassassin.taint.org
|
|
X-Mailman-Version: 2.0.11
|
|
Precedence: bulk
|
|
List-Help: <mailto:fork-request@xent.com?subject=help>
|
|
List-Post: <mailto:fork@spamassassin.taint.org>
|
|
List-Subscribe: <http://xent.com/mailman/listinfo/fork>, <mailto:fork-request@xent.com?subject=subscribe>
|
|
List-Id: Friends of Rohit Khare <fork.xent.com>
|
|
List-Unsubscribe: <http://xent.com/mailman/listinfo/fork>,
|
|
<mailto:fork-request@xent.com?subject=unsubscribe>
|
|
List-Archive: <http://xent.com/pipermail/fork/>
|
|
Date: Wed, 25 Sep 2002 10:56:41 -0700
|
|
|
|
OK, let's bring some data into the discussion:
|
|
http://www.grida.no/climate/vital/02.htm
|
|
(A graph, derived from Vostok ice core samples, of CO2 and temperature
|
|
fluctuations over the past 400k years).
|
|
|
|
> Recent high-resolution studies of historical CO2 concentrations and
|
|
> temperatures over hundreds of thousands of years have shown a modest
|
|
> correlation between the two. In a number of cases, CO2 level increases
|
|
> are not in phase with temperature increases and actually trail the
|
|
> increase in temperature by a short time i.e. increases in temperature
|
|
> preceded increases in CO2 concentrations. The more studies that are done
|
|
> of the geological record, the more it seems that CO2 concentrations are
|
|
> correlated with temperature increases, but are not significantly
|
|
> causative.
|
|
|
|
Based on the Vostok data, you are right, there is a very strong correlation
|
|
between temperature and CO2 concentrations, but it doesn't always appear to
|
|
be causal.
|
|
|
|
> With respect to absolute CO2 concentrations, it is also important to
|
|
> point out that our best data to date suggests that they follow a fairly
|
|
> regular cycle with a period of about 100,000 years.
|
|
|
|
Also correct -- the peak of each cycle is at about 290-300 ppm CO2.
|
|
|
|
> As it
|
|
> happens, current CO2 concentrations are within 10% of other previous
|
|
> cyclical concentration peaks for which we have good data.
|
|
|
|
Not correct. Mauna Loa data <http://www.grida.no/climate/vital/06.htm> and
|
|
<http://cdiac.ornl.gov/ftp/ndp001/maunaloa.co2> show that the current CO2
|
|
concentrations are at 370ppm, 18% *greater* than the *highest* recorded
|
|
value from the past 400k years. Furthermore, CO2 concentrations are growing
|
|
at 15ppm every 10 years, much faster than any recorded increase in the
|
|
Vostok data (though perhaps the Vostok data isn't capable of such fine
|
|
resolution).
|
|
|
|
> In other words, we may be adding to the CO2 levels,
|
|
|
|
No, we are *definitely* adding to CO2 levels. Look at the following chart:
|
|
http://www.grida.no/climate/vital/07.htm
|
|
(Shows CO2 concentrations since 1870, the "historical record").
|
|
|
|
Not only is the CO2 increase over 130 years unprecedented in the Vostok
|
|
record, it is clear that the rate of change is *increasing*, not decreasing.
|
|
There is no other compelling explanation for this increase, except for
|
|
anthropogenic input. You're really out on the fringe if you're debating
|
|
this -- even global warming skeptics generally concede this point.
|
|
|
|
> but it looks a lot like we
|
|
> would be building a molehill on top of a mountain in the historical
|
|
> record. At the very least, there is nothing anomalous about current CO2
|
|
> concentrations.
|
|
|
|
Wrong again. Current CO2 levels are currently unprecedented over the past
|
|
400k years, unless there is some mechanism that allows CO2 levels to quickly
|
|
spike, and then return back to "normal" background levels (and hence the
|
|
spike might not show up in the ice cores).
|
|
|
|
Still, by around 2075-2100 we will have reached 500 ppm CO2, a level that
|
|
even you would have a hard time arguing away.
|
|
|
|
> Also, CO2 levels interact with the biosphere in a manner that ultimately
|
|
> affects temperature. Again, the interaction is not entirely
|
|
> predictable, but this is believed to be one of the regulating negative
|
|
> feedback systems mentioned above.
|
|
|
|
Yes, clouds and oceans are a big unknown. Still, we know ocean water has a
|
|
finite capacity to store CO2, and if the world temperature doesn't increase,
|
|
but we all have Seattle-like weather all the time, the effects would be
|
|
enormous.
|
|
|
|
> Last, as greenhouse gases go, CO2 isn't particularly potent, although it
|
|
> makes up for it in volume in some cases. Gases such as water and
|
|
> methane have a far greater impact as greenhouse gases on a per molecule
|
|
> basis. Water vapor may actually be the key greenhouse gas, something
|
|
> that CO2 only indirectly effects through its interaction with the
|
|
> biosphere.
|
|
|
|
Correct.
|
|
|
|
Data on relative contributions of greenhouse gasses:
|
|
http://www.grida.no/climate/vital/05.htm
|
|
|
|
Note that methane concentrations now are *much* higher than pre-industrial
|
|
levels (many cows farting, and rice paddies outgassing), and methane is also
|
|
a contributor in the formation of atmospheric water vapor. Another clearly
|
|
anthropogenic increase in a greenhouse gas. I'm in favor of reductions in
|
|
methane levels as well.
|
|
|
|
Data on water vapor here:
|
|
http://www.agu.org/sci_soc/mockler.html
|
|
|
|
> CO2 was an easy mark for early environmentalism, but all the recent
|
|
> studies and data I've seen gives me the impression that it is largely a
|
|
> passenger on the climate ride rather than the driver.
|
|
|
|
I tend to think that holistic, and techical approaches would work best in
|
|
reducing global warming. I favor an energy policy that has a mix of solar,
|
|
wind and nuclear, with all carbon-based combustion using renewable sources
|
|
of C-H bonds. Aggressive pursuit of carbon sink strategies also makes sense
|
|
(burying trees deep underground, for example). Approaches that involve
|
|
reductions in lifestyle to a "sustainable" level are unrealistic --
|
|
Americans just won't do it (you'd be surprised at the number of climate
|
|
change researchers driving SUVs). But, as California showed during last
|
|
year's energy crisis, shifts in patterns of consumption are possible, and
|
|
improved efficiency is an easy sell.
|
|
|
|
- Jim
|
|
|
|
|