On 7 May, 12:25, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote:
> > Gavin Schmidt at
> > RChttp://www.realclimate.org/index.php/archives/2006/06/geo-engineering...
> > "Think of the climate as a small boat on a rather choppy ocean.
>
> What in terms of world climate is equivalent to the boat being turned
> over? It sounds pretty apocalyptic.
>
> With the example given by Gavin we know exactly what catastrophe will
> happen, if somebody starts jumping up and down, and we also know that
> it is hard to exactly counteract by somebody else jumping up and down,
>
> I don't see this for the climate system. What catastrophe is
> supposedly made more likely by two equivalent and opposite forcings,
> because they don't exactly off-set?
>
> It is entirely possible that such an unknown effect from the two
> opposite forcings would cause / contribute to apocalypse, but
> likewise, it might prevent / attenuate it.
>
> That depends entirely on what constitutes "apocalypse".
The implication appears to be that, under conditions of imbalance, the
inertial moment will be reached and exceeded; there comes a point
beyond which the possibility of avoiding capsize is zero. But this is
simply an analogy for the 'tipping point' idea of dangerous climate
change. There is a big difference, though, between the points of
balance of a dinghy and a small yacht' one is inherently unstable( the
ballast in a dinghy is the person sailing it, and the point of balance
is relatively high up), the other inherently stable (relatively). if
the climate is a boat, surely it is more like a yacht than a dinghy?
I read Gavin's point as being that reducing an artificially-generated
instability by introducing an equal and opposite force which is also
an instability may be a bad idea. What would be better would be to
remove the original source of the problem; get the idiot to sit down,
as it were.
The yacht analogy might be an interesting one to pursue, in some ways.
The system is, relatively speaking, quite stable. The combination of
forces applied to it in the process of sailing make use of the
stability to generate motion without serious risk of capsize. But
yachts do capsize, and sometimes sink, or spring leaks. Sometimes,
they are also sailed badly. We, the 'helmsman', are responsible for
sailing the yacht, trimming the sails, and responding to changes in
the forces acting on our boat in such a way as to maintain safety,
whilst also making progress through the water. Most accidents at sea
are consequence of either equipment failure (in the case of experts),
or poor handling of the vessel.
Now; our boat is in the ocean, making way, and a message comes through
the radio that conditions are changing for the worse up ahead; we
should anticipate the possibility of a storm. What do we do? We cannot
just 'give up'. Do we change direction, avoiding the storm risk, do we
adjust the sails and turn the motor on, maintaining progress but
adapting to expected problems? Or do we carry on, regardless, trusting
that our boat is tough enough and we know what we are doing, or that
the storm isn't going to be too bad, or is likely to miss us? Only a
total idiot would add more sails, throw his lifejacket overboard, and
head straight for the centre of the storm.
Adaptation: keep going but adjust to the forces; Mitigation: change
direction, minimising the risk of having to face the storm. Current
policy... ?
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