RE: [asa] Freeman Dyson on Climate Change

It often happens that one may base the physics of a process on sound physical models; however, in order to solve such basic equations, one often makes all sorts of approximations. Therefore, one is never sure what the sources of the resulting solutions are, whether they are in the basic physics or in the approximations themselves. This is the case when using the Navier-Stokes equations. Freeman Dyson is an outstanding physicist.

Moorad

________________________________

From: asa-owner@lists.calvin.edu on behalf of PvM
Sent: Mon 4/16/2007 10:19 PM
To: wdwllace@sympatico.ca
Cc: asa@calvin.edu; Glenn Morton
Subject: Re: [asa] Freeman Dyson on Climate Change

That just pure nonsense. They are hardly unreliable. In fact they are
based on Navier Stokes equations, which are the basic equation of
motion. Yes there are some parameters that require some tuning because
they capture small scale effects not adequately captured by the grid.

This is such nonsense, who is this Dyson that he can get away with
such nonsense?

On 4/16/07, Dave Wallace <wdwllace@sympatico.ca> wrote:
> From an Interview with Dyson reproduced on UnC
> http://www.uncommondescent.com/intelligent-design/interview-with-freeman-dyson/#more-2258
>
> <quote>
> Concerning the climate models, I know enough of the details to be sure
> that they are unreliable. They are full of fudge factors that are fitted
> to the existing climate, so the models more or less agree with the
> observed data. But there is no reason to believe that the same fudge
> factors would give the right behavior in a world with different
> chemistry, for example in a world with increased CO2 in the atmosphere.
> </quote> Dyson
>
> Essentially he is talking about curve fitting by adjusting the fudge
> factors which is an issue I raised a while back. This is the kind of
> reason that I am in favor of actions that address smog, peak fossil fuel
> and greenhouse gases, at least as a strong initial priority.
>
> For example few people will deny that smog is caused by burning fossil
> fuel. Even if Glenn is wrong by a few decades in terms of peak oil,
> fossil fuel is limited especially considering the increasing demand from
> China and India. Pushing intercity trucks and short haul air flights to
> use rail, seems to be a big win for all three concerns at least north of
> the 49th parallel but I would assume in the US as well. Heating and
> insulation in houses is also another similar win, especially wrt older
> or poorly built houses. When the temperature goes to -30F with a high
> of -20F, I feel cold spots very readily in our house even though we have
> been making improvements over the years.
>
> From
> http://www.railcan.ca/documents/publications/2006_10_24_DOH_Sustainable_en.pdf
> <quote>
> Per passenger or tonne, rail generates only one-fifth
> the greenhouse gas emissions of trucking, one-quarter
> the emissions of urban automobiles, and one-third the
> emissions of inter-city automobiles or planes in densely
> populated corridors.
> In Canada, approximately one-quarter of national greenhouse
> gas (GHG) emissions are from the transportation
> sector. Transport emissions actually rose 30 per cent between
> 1990 and 2004 to 190 megatonnes, the most recent
> data available across all transport modes, with more than
> half of the increase a result of road freight.
> </quote>
>
> (A tonne is a metric ton, 2200lbs appx.)
>
> Of course the models could be wrong the other way and be underestimating
> the impact of CO2 and eventually positive feedbacks could kick in like
> melting of the permafrost or the icecaps.
>
> Dave W
>
>
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Received on Tue Apr 17 08:53:40 2007