[geeks] More on global warming
patrick at zill.net
Fri Dec 21 19:40:27 CST 2007
On Dec 21, 2007, at 7:52 PM, Phil Stracchino wrote:
> Patrick Giagnocavo wrote:
>> On Dec 21, 2007, at 3:52 PM, Dr Robert Pasken wrote:
>>> spend more time learning about the science and less time reading
>>> paid for by lobbiest for the oil/gas industry. T
>> Actually the best way is to look at it mathematically and ask:
>> "is it possible with our current level of knowledge about the various
>> physical systems that make up climate, and the computing power
>> available, to end up with an accurate climate model" ?
>> A moment or two's reflection on the difficulty of modeling only the
>> Gulf Stream that flows from the Gulf of Mexico to Newfoundland, will
>> show that all climate change models must be inherently flawed.
> No model or simulation is perfect, practically by definition. So that
> rationale allows dismissal of anything based on any model.
> However, I venture to posit that merely the fact that TeVeS is
> leaving room for our model of gravity to be flawed, does not mean one
> can blithely step off a cliff and not expect to hit the bottom.
Actually you have this line of argument completely backwards.
The model of gravity that we all use in our daily lives, does in
fact, work, for most common cases.
We have a mostly-accurate model of gravity's effects, and are aware
of the limitations as things get either very very large (things as
big as the Sun or larger) or very very small.
> If I'm in a car careening towards a wall, and someone sitting in the
> passenger seat says "My model indicates we're going to hit that
> wall if
> you don't brake within the next thirty seconds, but I'm not taking
> debris or aerodynamic drag into account", I'm not going to keep my
> on the gas merely because the model is flawed.
And yet the very reason that you would brake would be precisely that
you do, in fact, understand that road debris and aerodynamic drag
would affect the final result very little.
It is not at all clear that we understand the impact of CO2 and
methane, etc.; or the impact of the Gulf Stream and what would happen
if it moved 100 miles east (on average, it does move around a bit
year to year) of where it usually is.
Let me ask you this: is it better to spend $100:
reducing my CO2 emissions
reducing methane output (eat less meat, more veggies = less cows grown)
reducing my nitrous oxide output (also considered bad for the
There is no way that you could answer that question, given the data
and models we have now.
> In general, when a model predicts a probable risk, it's far better to
> take precautions and develop a plan to deal with it, only to find
> it was
> a false alarm, than to dismiss the problem as an artifact of the
> and then ten years later be told "Hey, guess what, we've now confirmed
> our projections, but it's too late to do anything now."
The models are themselves unreliable, that is the issue being discussed.
patrick at zill.net
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